ACI Committee 376

ACI Committee 376

Agenda for Webinars on November 30, December 2 and 16, 2010

Chair: Charles Hanskat

November 30, 2010

1. Test Connectivity and Establish Mode of Operation:

The objective is to test whether all participants are able to fully use webinar features. For those with computer systems (e.g., firewalls, etc.) that are incompatible with the available webinar technology, develop an

alternative method for participating (e.g., teleconference call with items being discussed e-mailed during the teleconference). The ultimate goal is that by the end of this webinar ALL Voting Members can flawlessly participate in the following two

webinars in December. 2. Attendance & Quorum in December

Identify number of members that plan to attend December Webinars. 3. Defining Strategy and Sequence of Balloting

Identify two categories: o Category A - Public Comments that need to be addressed now (e.g., comments related to safety issues, comments

identifying clear errors, etc.), versus o Category F - For Future Action: Public Comments that will be addressed in the next (1st) revision of the Code. (Note: at this

point in time, after the Code has been reviewed and approved by TAC, we should not change the Code version that TAC has already reviewed.)

4. Balloting

If time and availability of quorum permit, start balloting items addressed during the Pittsburgh meeting.

December 2, 2010 1. Balloting

Ballot Category A items already handled (i.e., responses developed) during the committee meeting in Pittsburgh (unanimously agreed on; no quorum available for a ballot).

December 16, 2010 1. Balloting

Continue balloting Category A Public Comments with already developed responses. Start developing responses and ballot remaining Category A comments.

Document: “Code Requirements for Design and Construction of Concrete Structures for the Containment of Refrigerated Liquefied Gases (ACI 376) and Commentary” Public Discussion Period: March 1, 2010 – April 17, 2010 Includes Pittsburgh Comments – November 11, 2010

ACI to Chair Apr 20 Draft

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Col 8 Committee Response

USER NOTE This is an update of the original downloaded from ACI website; see April 20, 2010 Jesse Bournay email to NKO. Changes include:

1. Verification of page and line numbers shown in new columns 5‐6.

2. Comments 713‐720 are new.

3. Clarifications are shown in bold purple italics, double underlined with turquoise highlight.

4. Column 8, "Committee Response," is comment of reviewer intended as a starting point for committee discussion.

APPROVED W.01

OCTOBER 4, 2010 WEBINAR – APPROVED by quorum vote.

1. Hoang, Kim for Chevron Team Gen Gen Gen Gen No reference is provided in the document regarding seismic base isolation as an acceptable option for concrete tanks

2010.10.04 Webinar response: Editorial

2. Hoang, Kim for Chevron Team Gen Gen Gen Gen It is recommended using both customary and SI units in parenthesis – similar to ASCE 7‐05, AISC 360‐05, IBC 2006, and other current standards and codes. This code is likely to be referred to, specified, and used overseas for various LNG projects, and therefore it should be easily applicable to overseas locations. Using both units will make it current, and will help avoiding potential mistakes and confusion if conversion is needed.

2010.10.04 Webinar response: Editorial. ACI publishes metric and inch‐pound versions

4. Nahlawi, Khaled Gen Gen 6 41 Please, create an index for this standard. 2010.10.04 Webinar response: Response 4, 7: Current ACI policy does not produce indexes for its new documents.

5. Matrix Service (Hoptay) 1 13 2 1 This document should include the keywords “containment (double, full, primary)” since this document was created to fulfill a request by

2010.10.04 Webinar response:



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NFPA 59A to define the basis for concrete containment as discussed in the Introduction.

Editorial

7. Hoang, Kim for Chevron Team 6 41 6 41 Index is still not completed. 2010.10.04 Webinar response: Response 4, 7: See response 4.

9. CB&I 7 4 7 4 Editorial: Change wording from “ … construction of concrete and prestressed concrete structures…” to “ … construction of reinforced concrete and prestressed concrete structures…”

2010.10.04 Webinar response: Agree.

10. American Petroleum Institute Refrigerated Tank Task Group

7 5 7 5 R4.8 Suggest perhaps revising the ‐270F limit to ‐325 degrees F (for liquid oxygen). We note that there are concrete tanks storing liquid oxygen. Also note that future API stds are making ‐325F the limit.

2010.10.04 Webinar response: Agree to change to ‐325 Response to 10, and T.Ballard suggestion for improvement.

12. CB&I 7 10 7 10 Editorial: Change wording from “Typically, concrete and prestressed concrete structures…” to “Typically, reinforced concrete and prestressed concrete structures…”

2010.10.04 Webinar response: Agree

16. Blanchard, J. for NFPA 59A Task Group

9 14 9 14 The QA section leaves too much to the contractor. More specific requirements to be contained in the QA and QC program need to be defined. Also, there should be a defined criteria for the experience of the inspectors.

2010.10.04 Webinar response: Should conform to the project documents. Code is not specific but says that you need a plan.

17. Matrix Service (Hoptay) 9 20 7 18 Delete the last sentence beginning on line 18. The seismic design loadings and acceptance criteria based on this document assume accepted definitions of primary and secondary containments. Since the membrane tank configuration does not fit the definition of either type of containment, reference to using portions of this code is not appropriate.

2010.10.04 Webinar response: Disagree



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20. ACI 376 (Hoptay) 10 22 8JH[8]

22 Editorial: “In the this system, the….” 2010.10.04 Webinar response: Agree

22. Matrix Service (Vater) 12 7 12 7 “The location of all permanent materials shall be traceable to the source documents…” What is intended to be the extent to which this requirement is to be enforced? For example, does the reinforcing steel location need to be traceable to the certificate of conformance? Additional definition needs to be provided in the code section to eliminate interpretation of traceability.

2010.10.04 Webinar response: No Change. The extent to which traceability should be enforced is the responsibility of the owner and should be included in the project specifications not in the Code.

23. CB&I 12 8 12 8 Editorial: Change fci to f’ci. 2010.10.04 Webinar response: Agree. Editorial

24. ACI 376 (Hoptay) 14 10 & 21

11‐14JH[same

]

all Editorial: All chapter references should be checked. Chapter 1 is the introduction and does not contain these variables.

2010.10.04 Webinar response: Agree. Response 21 and 24

27. CB&I 16 12 16 6 Use “holding” instead of “keeping”? 2010.10.04 Webinar response: Agree

30. CB&I 17 14 17 7 Warmup is first, then purge out of service 2010.10.04 Webinar response: Change definition to “the process of the purging and warm‐up of the tank so it can be taken out of service. Response 30 and 37

31. Matrix Service (Oberman) 17 15 15 9 Suggest the following revision to the definition of boil‐off: “ boil‐off – process of evaporation to remove heat from the refrigerated liquid”

2010.10.04 Webinar response: Disagree. Leave as is.



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32. CB&I 17 16 17 9 Add “maximum” before the word “pressure”. 2010.10.04 Webinar

response: Disagree. Leave as is. Agree

33. Matrix Service (Hoptay) Reference to boat/vessel

impact??

17 22 15 16 Does this definition only apply to LNG tankers, or should the more generic term RLG be used?

2010.10.04 Webinar response: Agree. Change LNG to RLG Agree. Change LNG to RLG

34. ACI 376 (Hoptay) 18 6 15JH[same

]

23 Editorial: Calculated crack width is not defined in section 7.1.1.8 should be section 8.1.1.8.

2010.10.04 Webinar response: Has been corrected. Correct reference is 8.1.1.8 This is item 2 in April 1, 2009 email to ACI. Also see response 25.

35. CB&I 18 14 18 7 Suggest some definition or boundaries for “limited damage” 2010.10.04 Webinar response: Disagree

36. Matrix Service (Hoptay) 18 18 16 12 R1.1 states “This code is not applicable to the design of membrane tanks” as such membrane tanks should not be included in the definition of primary containment. Suggest the following revision; “containment, primary – part of a single double or full containment tank that contains liquid during normal operation. (See also containment)”

2010.10.04 Webinar response: Agree. Change to ““containment, primary – part of a single, double or full containment or membrane tank that contains liquid during normal operation. (See also containment)” Agree

37. Matrix Service (Oberman) 19 14 17 7 Suggest the following revision to the definition of decommissioning: 2010.10.04 Webinar



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“decommissioning – the process of purging the tank out of service, and the subsequent warm‐up and introduction of air.”

response: Disagree Response 30 and 37


19 15 19 9‐10 2.2.1 The definition of “liner” seems too narrow. Why only on the inside of a wall? Also in referring only to outer tank it excludes primary container liners which are referenced in 6.2.3.

2010.10.04 Webinar response: Change to: “liner – metallic or other barrier systems on either side of a primary or secondary containment structure impervious to liquid, vapor, and water vapor.” Response 38, 39, 42

39. Widianto 19 15‐16 19 9‐10 The definition needs to be modified because: a. ACI 376 discusses liner on both inner and outer tank b. Liners can also possibly be installed on the outside of outer tank Perhaps, the following definition can be used: Liner ‐ metallic plate installed against the concrete tank, impervious to product vapor and water vapor.

2010.10.04 Webinar response: See response 38. Response 38, 39, 42

40. CB&I 20 10 20 3 The definition states “(see settlement, long‐term)”, but there is no definition for “settlement, long‐term”. Add definition for settlement.

2010.10.04 Webinar response: Editorial: delete line 3 on page 20 Settlement, long term; occurs after the inflection point in the log time‐void curve when the curve becomes a straight line Editorial: delete line 10 on page 22


6 Editorial: Revise back to definition that was sent to TAC: “ An instrument for measuring angles of slope, tilt, or inclination of an




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] object with respect to gravity” Agree

42. Matrix Service (Hoptay) 21 15 19 9‐10 A liner does not only include plate that is installed against the inside surface of the concrete but can also be integral with the concrete such as a free standing wall liner or roof liner. Definition should be revised to include this option; “metallic plate installed against or integral with the inside of the concrete outer tank…”

2010.10.04 Webinar response: See response 38. Response 38, 39, 42

714. new

Hoang, Kim for Chevron Team 264 1 264263

14

Comment added in Chevron response "2E_Chevron verify_2010 04 20 ‐376 Public Comments Compiled to Chair ‐ Update 5‐14‐10.doc" received May 24, 2010

Section B.5.1.3 Global seismic analysis of the GBS is very complicated. Dynamic analysis using response spectrum method should not be allowed except for preliminary calculations. The detailed global analysis must include soil‐structure interaction effects. GBS base slab and wall flexibility should be modeled.


716 new

Pawski, R. J.B. April 1, 2010 email

168 15 Change reference 4.1.5.9 to 6.6.5.9 at end of line 15. This is not addressed elsewhere; see email item 18 response.

2010.10.04 Webinar response: Agree ADD GH CHANGES

717 new

Pawski, R.

121 22 Delete superscript at end of sentence: "… (refer to ACI 349, Appendix C, Eq. (C.7)6.14)."


718 new


222 22 Change reference R10.5.9 to R12.5.9. This is not addressed elsewhere; see email item 21 response.


719 new


277 18 Change reference R3.1.5.10 to R6.6.5.10. This is not addressed elsewhere; see email item 23 response.


720 new


283 21 Change reference C.7.3 and C.7.4 to C.3.3 and C.3.4. This is not addressed elsewhere; see email item 24 response.




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721 new


108 1‐8 The 8.1.1.8 on page 59108 is missing, and it appears two paragraphs are reversed; see TAC review PDF page 129 line 17 to page 130 line 3, and Response 411 that clarifies R6.1.1.7 should be 6.1.1.8 (now 8.1.1.8). To fix the two paragraphs on Page 59108 after 8.1.1.7 should read as follows: quote 8.1.1.8— The cracking analysis shall be based on a Finite Element Method that (1) uses recognized or codified constitutive models for the stress strain behavior of concrete, and (2) incorporates tension‐stiffening effects. When calculating calculated crack widths the tension stiffening term shall not be deducted from the calculation where tension stiffening is explicitly included in the analysis. Additionally the calculated crack widths shall be calculated as characteristic and not mean calculated crack widths. Unless otherwise specified, the concrete constitutive mode from European Code shall be used for determining calculated crack widths.

unquote


722 new

Hoff, G.. 2010.09.26 review comments

28 15 New: Make the following corrections to Section 2.3: 1..CPT cone penetration test, Chapter 8 10 2..DLE ductility level earthquake, 3, 5, Appendix B 3..MCE maximum considered earthquake, Chapter 3 5 4..NFPA National Fire Protection Association NFPA, 4, 5, 6, 10,

Appendix B 5..NSR notch sensitivity ratio, Chapter 3 4 6..OBE operating basis earthquake, Chapters 4, 5, 6, 7, 8, 9, 10,

Appendix B 7..PCPT piezometric cone penetration test, Chapter 9 10 8..QRA quality risk analysis, Chapter 4 5 9..SLE strength level earthquake, 2, 3, 5 Appendix B 10..SSE safe shutdown earthquake, Chapters 4, 5, 6, 7, 8, 9, 10,

Appendix B 11..SSEaft SSE aftershock, Chapters 4, 5, 6, 7, 8 12..SSI soil‐structure interaction, Chapter 7 8




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13..TCP thermal corner protection, Chapter 5 6 14..ULS ultimate limit state, Chapter 6 7

DISCUSS W.01

OCTOBER 4, 2010 WEBINAR – DISCUSS IN PITTSBURGH.

3. Krstulovic, Neven Gen Gen Gen Gen The Code needs to add marking provisions to identify standards by

which the inner and the outer containers were designed (e.g., name plates similar to what is defined in API 620).

Discuss in Pittsburgh to develop appropriate wording. 2010.10.04 Webinar response: Agree NK #20 (Gap analysis #) Pittsburgh response: Copy plate text from API 620 as a starting point. If the inner tank is concrete, special plate from ACI 376 is required. If the outer tank is concrete, special plate from ACI 376 is required. Garrison and Hoptay will propose text that will be balloted.

6. Krstulovic, Neven 2 9 2 9 Add the following text to the Introduction section to clarify background and to be consistent with issues covered in Introduction sections of other ACI Code documents:

Discuss in Pittsburgh the appropriate location for added text.



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The code and commentary includes excerpts from ACI 318‐** and ACI 350‐** that are pertinent to ACI 376. The commentary discusses some of the considerations of committee ACI 376 in developing “Code Requirements for Design and Construction of Concrete Structures for the Containment of Refrigerated Liquefied Gases (RLG) (ACI 376‐**),” hereinafter called the Code. Emphasis is given to the explanation of provisions that may be unfamiliar to users of the standard. Comments on specific provisions are made under the corresponding chapter and section numbers of the code and commentary. This commentary is not intended to provide a complete historical background concerning the development of the Code, nor is it intended to provide a detailed summary of the studies and research data reviewed by the committee in formulating the provisions of the code. However, references to some of the research data are provided for those who wish to study the background material in depth. “Code Requirements for “Design and Construction of Concrete Structures for the Containment of Refrigerated Liquefied Gases (RLG)” may be used as a part of a legally adopted code and, as such, must differ in form and substance from documents that provide detailed specifications, recommended practice, complete design procedures, or design aids. Requirements more stringent than the Code provisions may be desirable for unusual structures. This Code and this commentary cannot replace sound engineering knowledge, experience, and judgment. A code for design and construction states the minimum requirements necessary to provide for public health and safety. ACI 376 is based on this principle. For any structure, the Owner and the Engineer may require the quality of materials and construction to be higher than the minimum requirements necessary to provide serviceability and to protect the public as stated in the Code. Lower standards, however, are not permitted. ACI 376 has no legal status unless it is adopted by regulatory bodies.

2010.10.04 Webinar response: NK #6 (Gap analysis #) Pittsburgh response: Hoff will put this comment in the introduction and the comment remains editorial.



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Where the Code has not been adopted, it may serve as a reference to good practice. The Code provides a means of establishing minimum standards for acceptance of design and construction by a legally appointed official or his designated representatives. The Code and commentary are not intended for use in settling disputes between the Owner, Engineer, contractor, or their agents, subcontractors, material suppliers, or testing agencies. Therefore, the Code cannot define the contract responsibility of each of the parties in usual construction. General references requiring compliance with ACI 376 in the job specifications should be avoided, since the contractor is rarely in a position to accept responsibility for design details or construction requirements that depend on a detailed knowledge of the design. Generally, the drawings, specifications, and contract documents should contain all of the necessary requirements to ensure compliance with the Code. In part, this can be accomplished by reference to specific code sections in the job specifications. Other ACI publications, such as ACI 301, “Specifications for Structural Concrete,” are written specifically for use as contract documents for construction.

8. CB&I 7 2 7 2 Does this code apply to the foundation slabs/pile caps for double steel tanks? Assuming it does not, clearly state this in section 1.1.

2010.10.04 Webinar Discuss in Pittsburgh Section 1.1 explicitly says that the Code is for concrete structures and the incorporation of comments as to what it does not include is generally not appropriate. ADD: Notwithstanding, the principals listed herein may be applicable to double‐steel tanks on concrete foundations subject to the approval of ???? (Decide who in Pittsburgh)



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Pittsburgh response: Use the word 'owner'

11. CB&I 7 6 ‐ 8 7 6 ‐ 8 1.1.1: Add statement that only material selection criteria are included for the Thermal Corner Protection (TCP) of a secondary tank in this specification. The design parameters, analysis methods, acceptance criteria (stress or strain limits), detailing and construction requirements for are not included in this document.

2010.10.04 Webinar response: Agree but the statement should be in the commentary Section R1.1.1 Pittsburgh comment: Agreed it remains editorial and Hoff will address comment.


8 4‐14 8 4‐14 R1.1.1 ‐ These lines with its very specific list of considerations for a liner look very out of place in this basic scope section at the front of the document. Typo?

2010.10.04 Webinar Discuss in Pittsburgh as to where to put it Response to 13, 14, 15, 18, 19: Pittsburgh comment: Agreed it remains editorial and Hoff will address comment.


8 4 8 4 Liner design information is out of place in a scope commentary section. 2010.10.04 Webinar Discuss in Pittsburgh as to where to put it Response to 13, 14, 15, 18, 19: Pittsburgh comment: Agreed it remains editorial and Hoff will address comment.



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15. CB&I 8 4 8 4 This should be a new section. Define the purpose of the liner, and state if this is for a secondary containment liner. Define “extra gas pressures”. Define the fire resistance. Does this apply to “internal fire” per 5.1.14” Define resistance to blast and impact for an internal liner. Is this meant to apply to “internal explosion” per 5.1.14 only (since perforation of concrete is intended to be prohibited for external explosion impact forces)? Define term “sacrificial liner”: For example: A sacrificial liner is defined as steel plates in contact with the outer containment slab, wall and roof of a full containment structure that is gas tight in operation only, but unable to provide either gas or liquid containment when subjected to low product temperatures (as in the case of an inner tank leak) due to its brittleness at low temperature.

2010.10.04 Webinar Discuss in Pittsburgh as to where to put it Response to 13, 14, 15, 18, 19: Pittsburgh comment: Agreed it remains editorial and Hoff will address comment.

18. Hoang, Kim for Chevron Team 10 1 8 4 ‐ 14 R1.1.1 ‐ the paragraph about the design of the liner seems to be too detailed and out of context for this part of the code.

2010.10.04 Webinar Discuss in Pittsburgh as to where to put it Response to 13, 14, 15, 18, 19 Pittsburgh comment: Agreed it remains editorial and Hoff will address comment.

19. ACI 376 (Hoptay) 10 4‐14 10JH[8]

4‐14 Editorial: This portion of the commentary is not related to the code section. These lines need to be relocated to the appropriate Code section.

2010.10.04 Webinar Discuss in Pittsburgh as to where to put it Response to 13, 14, 15, 18, 19:



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Pittsburgh comment: Agreed it remains editorial and Hoff will address comment.

21. CB&I 11 15 11 15 Section 2.1 Notation – Review and revise all chapter references accordingly. REVISED REFERENCES: 1..Delete ac = coefficient of thermal contraction/ expansion, Chapter 6 2..Change B = blast, Chapters 4, 6 5, 7 3..Change c = specific heat, Chapter 7 6 4..Delete C = cool‐down, Chapter 6 5..Change C = penetration coefficient, Chapter 7 8 6..Change D d = projectile diameter, Chapter 7 8 7..Change D = tank diameter, Chapter 9 10 8..Change D = dead loads, or related internal moments and forces,

Chapters 4, 6 5,7 9..Change E = environmental load, Chapter 6 7 10..Change Ec = modulus of elasticity of concrete, Chapters 1, 7 2,6 11..Change Eo = operating basis earthquake (OBE), Chapters 4, 6

2,5,6,7,8,10,Appendix B (same as OBE below) 12..Change ES = safe shutdown earthquake (SSE) product (service),

Chapters 4, 6 2,5,6,7,8,10,Appendix B (same as SSE below) 13..Change fc′ = specified compressive strength of concrete, Chapters

5, 7, Appendix B 6,8,Appendix C 14..Change fci = specified compressive strength of concrete at time of

initial prestress, Chapter 5 6 15..Delete fct′ = specified tensile strength of concrete, Chapter 6 16..Change F = loads due to weight and pressure of fluids with well‐

defined densities and controllable maximum heights, or related internal moments and forces, Chapters 4, 6 5,7

17..Change Fs = foundation settlement, Chapter 4 5 18..Change Ft = maximum hydrostatic load due to test water, Chapter

4 5

2010.10.04 Webinar Discuss in Pittsburgh Response 21 and 24

Revisions are in column to the left for readability. Pittsburgh comment: Debbie provided additional comment to Hoff. Unanimously agreed it remains editorial and Hoff will address comment.



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19..Change Fv = vertical earth pressure, Chapter 4 5 20..Change g = gravitational constant, Chapter 1 6 21..Delete h = concrete thickness, Chapter 7 22..Change hd = minimum dome thickness to resist buckling, Chapter 7

8 23..Change H = heat radiation from adjacent fire, Chapters 4, 6 5,7 24..Change k = intrinsic coefficient of permeability, Chapter 1 and 7 6 25..Change K=coefficient of hydraulic conductivity, Chapter 1 6 26..Change L = live load (primarily snow; also: temporary equipment,

roof live load), Chapters 4, 6, 7 5,7 27..Change Lcn = live load effects resulting from construction activities,

Chapter 6 7 28..Change Lcm = live load effects resulting from commissioning

activities, Chapter 6 7 29..Change mp = projectile mass, lb, Chapter 6 8 30..Change Mi = missile impact, Chapters 4, 6 5,7 31..Change Ni(Si) = number of cycles to failure of a constant stress

reversal, Si, Appendix B C 32..Change Pd = internal pressure (service), Chapter 4 5 33..Change Pe = accidental internal overpressure (applies to full‐

containment outer wall and domed roof), Chapter 4 5 34..Change Pf = final prestressing (at service load), Chapters 4, 6 5,7 35..Change Pi = initial prestressing (at transfer), Chapters 4, 6 5,7 36..Delete Pp = piping load, Chapter 4 37..Change Pt = internal pressure (test), Chapter 4 5 38..Change Pu = factored axial force; to be taken as positive for

compression and negative for tension, Chapter 7 8 39..Change Pv = accidental vacuum pressure (applies to full‐

containment outer wall only), Chapter 4 5 40..Change rd = nominal radius of curvature of the dome, Chapter 7 11 41..Change rimp= average radius of curvature of dome in an

imperfection region, Chapter 7 8 42..Change R = roof loads (appurtenances and suspended ceiling),

Chapter 4 5 43..Change R = force reduction factor, Chapter 7 8



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44..Change R = tank radius, Chapter 10 11 45..Change T = cumulative effect of temperature, creep, shrinkage and

differential settlement, Chapters 4, 65,7 46..Change Tc = loads associated with the creep of concrete, Chapter

67 47..Change Tds = loads associated with differential settlement, Chapter

67 48..Change Te = temperature and temperature differential due to

sudden cooling, Chapters 4, 65,7 49..Change To = temperature and temperature differential at service

loads, Chapter 4 5 50..Change To = internal moments and forces caused by temperature

and moisture distributions within concrete structure as a result of commissioning, normal operating, or

decommissioning conditions, Chapter 67 51..Change Ts = loads associated with shrinkage of concrete, Chapter

67 52..Change v = projectile speed, Chapter 7 8 53.. Change w = concrete density, Chapter 7 8 54..Change W = wind, Chapters 4, 65,7 55..Change Qa = pile safe design load, Chapters 1, 9 2, 10 56..Change Qr = ultimate capacity of single piles, Chapter 9 10 57..Change ßc = buckling strength reduction factor due to creep,

material nonlinearity, and cracking of concrete, Chapter 7 8 58..Change ßimp = buckling strength reduction factor due to

imperfections, Chapter 7 8 59..Change ρ = density of fluid, Chapter 1 6 60..Change φ = strength reduction factor, Chapters 1, 6, 7 7, 8 61..Change qu = ultimate bearing capacity, Chapter 9 10 62..Change μ = Poisson’s ratio, or dynamic viscosity of fluid, Chapters 1, 7 Chapter 6

25. Krstulovic, Neven 15 22‐23 15 22‐23 To provide clear guidance on the method for calculating crack widths, add the following text:

Discuss in Pittsburgh any conflict between Oct 4 Webinar and Gap Analysis.



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“calculated crack width—crack width calculated using a concrete constitutive model defined in 87.1.1.8. The Eurocode 2 is recommended for determining calculated crack widths, in which case the calculated crack widths are characteristic and not mean calculated crack widths.

2010.10.04 Webinar response: Agreed to leave it as is and correct reference to 8.1.1.8. NK #4 (Gap analysis #) Correct reference is 8.1.1.8, and not 7.1.1.8. See item 2 in 2010.04.01response to 2010.03.31 J.B. email. Pittsburgh Comment: Agree. For future action. Changes to be provided by Hjoreset.

26. CB&I 16 7 16 1 The “process of testing” is precommissioning, not commissioning. From Oct 4 Webinar: Add a pre‐commissioning definition at Pittsburgh meeting. 2010.10.04 Webinar response: Change to: “the start‐up processes such as purging and cool‐down.” Disagree – discuss. Pittsburgh comment: Present definition is sufficient and it was decided that no new definition is needed.



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Unanimously agreed it remains editorial and no change is needed.

28. CB&I 17 8 17 1 Suggest a differentiation between “low temperature” and “cryogenic, with low temp being down to ‐60°F

Discuss in Pittsburgh where the new definition for "low temperature" is to be added. Note that it isn't needed if it doesn't occur in the text. 2010.10.04 Webinar response: Agree. Add new definition as given. Response 28, 29. Agree. Add a new definition as follows: low temperatures — temperatures below freezing to ‐ 60o F. Change cryogenic to read “being or related to very low temperatures from –60o F. down to –325 °F in the production, storage, and handling of refrigerated liquefied gas.” Pittsburgh comment: Unanimously proposed to leave document as is and definition of "low temperature" will be balloted as new business.

29. CB&I 17 10 17 3 Differentiate “low temperature reinforcement” 2010.10.04 Webinar response: Same as response 28.



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Response 28, 29. See response 28. Pittsburgh comment: Unanimously proposed to leave document as is and definition of "low temperature" will be balloted as new business.

713. new

Hoang, Kim for Chevron Team 255 17 255 17 Comment added in Chevron response "2E_Chevron verify_2010 04 20 ‐376 Public Comments Compiled to Chair ‐ Update 5‐14‐10.doc" received May 24, 2010

Section B.3.1.2.1 defines SSE as 4975 return period. This is not consistent with NFPA59A and criteria for onshore tanks.

2010.10.04 Webinar Discuss in Pittsburgh Pittsburgh comment: Response spectrum is site specific. Therefore, there is no inconsistency between Chapter 5 (2475 years) and Appendix B (4975 years).

715. new

Hoang, Kim for Chevron Team 265 4 265 4 Comment added in Chevron response "2E_Chevron verify_2010 04 20 ‐376 Public Comments Compiled to Chair ‐ Update 5‐14‐10.doc" received May 24, 2010

Section B.5.1.8—“If time‐history analysis is used, at least three sets of ground motion time histories shall be applied” Which set of results shall be used? Maximum or average response?

2010.10.04 Webinar Discuss in Pittsburgh Pittsburgh comment: Editorial. For future action.

GROUP 1.01 RESPONSES

Group 1: EDITORIAL – technical changes such as spelling, syntax, punctuation, references, and minor wording changes.

49. CB&I 25 13 25 4 Editorial: Remove quote marks ate end of sentence. Agree 59. CB&I 33 18 33 5 3.1: The standard Number for “General Rules and Rules for Buildings” Agree



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is EN 1992‐1‐1. Change “BS EN 1992‐1” to “BS EN 1992‐1‐1”. 66. Matrix Service (Hoptay) 38 7 37 20 Reference to section 4.14.3 relates only to roof plate. This reference

needs to be corrected. Agree reference is incorrect. Correct reference is 4.13.2. See 2010.04.01 response to item 3 in 2010.03.31 J.B. email.

78. CB&I 42 20 42 20 Section reference 4.7.2 should be 4.7.1. Response 78, 84 Agree


]

20 Editorial: Is section reference correct? This reference is to this section not another section as the wording implies. Should reference be 4.7.1?

Response 78, 84 See response 78


]

13 Editorial: Incorrect reference, Section 4.8.3.1(a) does not exist. Correct reference may be 4.7.2(a).

Agree reference is incorrect. Correct reference is 4.7.2(a). See 2010.04.01 response to item 4 in 2010.03.31 J.B. email.

82. Hoang, Kim for Chevron Team 43 2 43

2 It is recommended using consistency in writing units. For example, Page 43, line 2 has lb/in2, and line 14 has psi for “pounds per square inch”.

Agree. ACI Editing will standardize this.

86. CB&I 44 1 44 1 Editorial: Remove “_” after the word “bars”. agree 130. American Petroleum Institute

Refrigerated Tank Task Group 55 8 55 14 Reference should be to Chapter 4. agree


70 10 70 10 6.2.15 4.7.2 instead of 4.8.3. Response 194, 195. Agree; correct reference in line 10 is 4.7.2 and not 4.8.3. See item 5 in April 1, 2009 email to ACI.

195. CB&I 70 10 70 10 6.2.15.d): Cross reference is incorrect. Section 4.8.3 does not exist. Should reference be 4.7.2?

Response 194, 195. See response 194

197. CB&I 71 10 71 10 Editorial: 6.3.1: There is no section 6.3.22. The last sub‐section of the Section 6.3 is 6.3.17. Change wording “Sections 6.3.2 through 6.3.22” to “Sections 6.3.2 through 6.3.17”.

Agree; correct reference in line 10 is 6.3.17 and not 6.3.22. See item 6 in April 1, 2009 email to ACI.

219. American Petroleum Institute 73 21 73 21 6.3.16.1 It’s not clear, but it seems that probably the reference should Editorial: Agreed. Change



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Refrigerated Tank Task Group be to 6.9 rather than 6.8. reference 6.8 to reference 6.9 – Metal Components This used to be § 4.3.18 which referenced § 7.6.1 – Metal Components


]

7 Editorial: “ shall be provided in to accommodate liquid” Editorial: Agreed. Remove “in”

259. CB&I 91 20 91 20 Para 7.2.8: change section reference “5.10” to “5.1.10”. Response 259, 292. Editorial. Agreed. Change 5.10 to 5.1.10 at ALL of the following locations:

• Page 91, line 20, • Page 98, line 1, • Page 98, line 6,

There is no §5.10. §5.1.110 covers General Live Loads. Also, items 8, 11, 12 in April 1, 2009 email to ACI.


]

6 Editorial: Section 5.10 should be Section 5.1.10 Response 259, 292. Editorial. Agreed. There is no §5.10. §5.1.110 covers General Live Loads. Also, See item 8 response in April 1, 2009 email to ACI.

261. CB&I 92 7 92 7 Para 7.2.9 change to “Table 7.2” Editorial. Agreed. Change Table 6.2 to Table 7.2 as in the rest if the chapter. Also, see item 9 in April 1, 2009 email to ACI.

273. CB&I 96 4 96 4 Para R7.3.3 change to “..Table 7.3” Editorial. Agreed. Change Table 6.3 to Table 7.3 as in



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the rest if the chapter. Also, See item 10 response in April 1, 2009 email to ACI.

280. CB&I 99 22 99 22 Para 7.3.13 change to “… Table 7.3.” Editorial. Agreed. Change Table 6.3 to Table 7.3 as in the rest if the chapter. Also, See item 13 response in April 1, 2009 email to ACI.

388. CB&I 121 12 121 12 8.4.12: change “4.1.14” to “5.1.14”. Agree; line 12 should read "… of Section 4.1.14 5.1.14 …" See item 14 in April 1, 2009 email to ACI.


]

18 Editorial: “critical piping and or equipment.” Corrected in 4‐20 download

445. CB&I 142 7 142 7 Editorial: Update references. Shouldn’t reference to section 3.13 instead be to 4.15? (Note 4.15 contains no requirements, but redirects the reader to section 6.8.)

Agree; line 7 should read "… of Section 3.13 4.15 …" See item 16 in April 1, 2009 email to ACI. Discuss whether to reference 6.8 directly.


]

6 Editorial: section reference should be 9.7.5(b). Agree; line 6 should read "… described in 8.7.2(b) 9.7.5(b) …" See item 15 in April 1, 2009 email to ACI.

480. CB&I 154 15 154 15 Editorial: Para. R10.3.2.4 Change to “defined in Table 5.1 ….” Agree; line 15 should read "… in Table 5.2 5.1 …" See item 17 in April 1, 2009 email to ACI.

484. ACI 376 (Hoptay) 156 22 143 1 Editorial: Table title should refer to RLG not LNG. Agree.



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JH[same]

487. Matrix Service (Hoptay) 158 TopFig.

144 TopFig.

Delete the waterstop or state that waterstop is optional as it is not always required.

Agree. Change made. See 2‐column version dated 2010.03.01.

488. Matrix Service (Hoptay) 158 Bot.Fig.

144 Bot.Fig.

Delete “Note” since Figure 4.4 is not included. Reinforcing percentage varies depending on service conditions. Also remove reference to “sump”.

Agree. Change made. See 2‐column version dated 2010.03.01.


158 14 158 14 Requirement is not clear. Is it 1 in 300 with a maximum of 3/8 in.? If it is a maximum of 3/8 in in 300 feet, it may be too conservative.

Response 489, 490, 530. Agree that "3/8 in." should be deleted.

490. CB&I 158 14 158 14 Para 10.3.5.2 – delete 3/8 in. so that the line reads: “…a maximum of 1/300;”.

Response 489, 490, 530. Agree that "3/8 in." should be deleted.


]

14 Editorial: delete “of 3/8 in.” Response 489, 490, 530. Agree that "3/8 in." should be deleted.


]

8 Editorial: Should be 1.2. Agree; correct reference in line 8 is 1.2 and not 1.3. See item 19 in April 1, 2009 email to ACI.

546. Legatos, Nicholas A. 183 4 183 4 Sec. 11.2.3.1.4: Insert a comma after “sliding base” Agree – change made. Also included in Gap Analysis, but unnumbered.

566. CB&I 192 14 192 14 The reference to ACI 350/350R implies this section refers to chemicals that are listed as harmful to tendons. This section R18.6.2 in ACI 350/350R discusses sheathing for unbonded tendons thus appears to be the wrong reference. Update reference accordingly.

Change references on line 14 as follows: R18.16.2 R18,18.2 , and 18.18.2.1 18,18.1 .

572. CB&I 195 13 195 13 Editorial: The word “determining” is misspelled. Agree – change made. 584. CB&I 199 10 199 10 Editorial: The word “to” is repeated twice. Agree – change made. 711. Conlon, John F. 276 4 276 4 Cannot locate “reference B.8” Agree; change line 4 to

read: "… in Ref. B.8" ISO 19903." See item 22 in April 1, 2009 email to ACI.



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Group 2: EDITORIAL – wording changes that clarify meaning, or improve understanding. Also corrections to errors in Public Comment version from Final to TAC document.

51. CB&I 28 8 27 22 Editorial: Add the word “tensile” before the word “stress”. Agree 52. Hoang, Kim for Chevron Team 29 3 28 17 CPT – shall be Cone penetration test. Response 52, 53: agree 53. ACI 376 (Hoptay) 31 3 28

JH[same]

17 Editorial: cone penetration test Response 52, 53: agree


]

3 Editorial: Reference to Section 11.4.5 is not required since it refers to grout and not post‐tensioning ducts.

Agree. Also review reference to 11.4.4 for same reason.

123. Matrix Service (Hoptay) 53 2 51 17 Remove inner stair and add to f) since it is an appurtenance. agree 245. ACI 376 (Hoptay) 83 20 JH[78] 13 Editorial: ASTM reference is incorrect – Delete

REFERENCES IN 376 TO TAC TO BE ADDED TO COMMENTARY 2.30 Rostasy, F. S., and Wiedemann, G., “Stress, Deformation and Thermal Strains of Concrete at Cryogenic Conditions, Proceedings, 1st International Conference on Cryogenic Concrete, Newcastle, 1981. 2.38 Krstulovic‐Opara, N., “Performance of Reinforced and Prestressed Concretes in Cryogenic Environments,” Mindess Symposium; Concrete: Bridging Materials and Structures, ConMat05, Third International Conference on Construction Materials – Performance, Innovations and Structural Applications, Vancouver, Canada, 2005. 2.41 CRD‐C 39‐81, “Test Method for Coefficient of Linear Thermal Expansion of Concrete,” U.S. Army Corps of Engineers, Available from the National Institute of Building Science, United Facilities Guide Specifications (UFGS), Specifications Library. Whole Building Design

Discuss Editorial: Agreed – delete (see version sent back to TAC). Response to TAC 208 was: "The commentary has been revised to include references to: 2.30, 2.38, and 2.41, which contains the requested information." REFERENCES FROM 376

to TAC in the PUBLIC COMMENT VERSION. {Shown to left for brevity



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Guide (WBDG), Washington, DC, (http://www.wbdg.org). 2.42 ASTM D4611‐86, “Standard Test Method for Specific Heat of Rock and Soild,” ASTM Book of Standards, V. 04:08, ASTM International, West Conshohocken, PA, 2004, 4 pp. OTHERS THAT COULD BE ADDED from 376 to TAC 2.40 Krstulovic‐Opara, N., “Liquefied Natural Gas Storage: Material Behavior of Concrete at Cryogenic Temperatures,” ACI Materials Journal, V. 104, No. 3, May‐June 2007, pp. 297‐ 306. 2.43 Hirth, H. C., Jr., “Thermal Properties of Concrete at Extreme Temperatures,” PhD dissertation, University of California at Berkeley, 1982.

PC 245 is ti DELETE this.

246. ACI 376 (Hoptay) 85 10 JH[80] 1 Editorial: The phrase “realistic assessment” has been removed from the code section and replaced with “most probable” revise commentary.

Editorial: Agreed. In § R6.6.5.4 change “realistic assessment” to “most probable”.


]

18 Editorial: “The 1.2 load factor for dead load for OBE loading…..” Editorial. Agreed. Insert “for dead load”.


]

1 Editorial: “The 1.0 load factor for dead load for SSE, explosion…..” Editorial. Agreed. Insert “for dead load”.

275. Hoang, Kim for Chevron Team 99 3 99 3 Section R7.3.10.2 It is recommended including some examples of “other” environmental load effects.

Editorial. Agreed. Suggest to add an example such as: “Other environmental load effect (e.g., solar radiation, snow, rain, etc.).....”

276. CB&I 99 4‐7 99 4‐7 Para R7.3.10.2: Define what is “other environmental loads”. “Other environmental loads” per ACI 350 Eq‐9‐3 are snow and rain (S and R).

Editorial: Agreed. See response to comment 275

278. Hoang, Kim for Chevron Team 99 11 99 11 “…two levels of earthquake: …” This section shall include three levels of earthquake: OBE, SSE, and SSEAFT

Editorial: Sounds correct. Accept? DISCUSS This is for secondary



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container. Should similar change be made to R7.2.11, primary container??


]

5 Editorial: Add wording “depending on which is constructed first or if the containers are constructed in parallel.”

Editorial: Agreed. Add “depending on which is constructed first or if both containers are constructed in parallel.”

282. Matrix Service (Hoptay) 100 14, 16 93 14, 16 “as per load reduction factors (LRF) industry practice” was not part of the original committee text. These are load factors not load reduction factors, suggest maintaining original text. 376 TO TAC IS AS FOLLOWS: R5.2.11 – Seismic loads (Eo, Es) Following current LNG tank practices, this Code uses two levels of earthquake: OBE and SSE. For the OBE condition, a load factor of 1.3 should be used. For the SSE condition, a load factor of 1.0 should be used. R5.3.11 – Seismic loads (Eo, Es) Following current LNG tank practices, this Code uses two levels of earthquake: OBE and SSE. For the OBE condition, a load factor of 1.3 should be used. For the SSE condition, a load factor of 1.0 should be used. For the spill + SSEaft condition, a load factor of 1.0 should be used, as per ACI 350,5.1 Eq. (9‐5). Response to TAC 424 appears to be only comment to touch on this, and it was to add the following sentence to various code sections, including 5.3.1.1: “The load factors shall be in accordance with in Table 5.3.”

Editorial. Agreed. Remove: “As per load reduction factors (LRF) industry practice for…” This text was not in editing version 7 (12/12/08). It appears in the final response to TAC. To left for brevity is 376

to TAC. ROLF / GEORGE: This text was added in the final response to TAC we sent. Do you have anything on the history of this change?

289. Matrix Service (Hoptay) 104 1 96 9 The load factor cannot be reduced for vapor or gas, wording only applies to vacuum. Suggest the following change: “The 1.0 load factor applied to should be applied to the design gas or vapor pressure during a spill or spill + SSE aft loading. Vacuum loading during these loadings is not a credible loading due to the vapor generation during a spill so the load factor is reduced to 0.0.”

Editorial: Agreed. Change to: “In the case of positive pressure from vapor or gas, or vacuum, occurring during the spill and the spill +



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SSEaft event, the 1.0 load factor should be used. Due to vapor generation during a spill, negative pressure from vacuum is not a credible event during for the spill and the spill + SSEaft event. Therefore, the load factor should be reduced to 0.0 because the generation of vapor during a spill event for vacuum loading is not a credible event.


149 11 149 11 Reference should read Chapter 20 of ASCE 7‐05. Agree; lines 11‐12 should read "… Chapter 11 20, "Site Classification Procedure for Seismic Design Criteria”, of ASCE/SEI 7." Revision year however is not needed because it is provided in Chapter 3 (page 32 line 9).


151 20 151 20 10.2.3.2 Wording is confusing. Suggest instead of text up through parentheses say “For site classes C, D, and E a soil‐structure interaction analysis …”

Agree that proposed wording is an improvement.

512. CB&I 165 17 165 17 Para. 10.4.6.3 change to “predicted tank foundation deflections with allowable pile deflections and by ….

Agree – change made.

513. CB&I 165 19 165 19 Para 10.4.6.4 change to “Tank foundation deflections …” Agree – change made. 519. CB&I 169 7,8 169 7,8 Para R10.6.1.4 – Make this a separate sub‐paragraph. It has nothing to

do with drainage issues that the rest of the paragraph is addressing. Agree. Incorporate text into paragraph discussing air gap on page 170 lines 3‐5. See also comment 558.

531. Matrix Service (Hoptay) 174 12 158 15 Suggest replacing “footing” with the more generic “foundation”. Agree.



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176 19 176 19 Recommend “Field weld splices…” in lieu of Field splices. Agree.

535. CB&I 176 9,10 176 9,10 Paragraph 10.9.1 – replace with “…..be performed as directed by the project specifications.”

Agree.

547. CB&I 183 15‐16 183 15‐16 Tolerances for temporary construction access openings should be subject to the minimum tolerances set forth herein or as specified by the Engineer. ½in seems too restrictive. Consider allowing 1in.

Agree that 1" is more reasonable tolerance for location and dimensions in elevation.

548. CB&I 183 22 183 22 Editorial: Delete the word “are” following the word “tolerances”. Agree – change made. 567. CB&I 193 21‐22 193 21‐22 Incomplete sentence. That is, “800 psi is achieved”? Agree – change made. 569. CB&I 194 13 194 13 Revise reference to ACI350 section 18.20.1.

Committee note ‐ This comment is understood to be referring to replace the phrase "ACI 318‐89 section 18,18.1" with "ACI 350 section 18.20.1."

Agree since the intent is to reference 350 where possible.

573. CB&I 195 15 195 15 Editorial: This sentence should read, “...be considered early in the design.”

Agree – change made.

663. Matrix Service (Hoptay) 242 4 216 3 For RLG tanks the annular space may not be filled with perlite. Suggest deleting perlite and just refer to the annular space.

Response 607, 663. Agree. Delete the word "Perlite" in line 3.

607. CB&I 216 3 216 3 12.4.3 – refers to the annular ‘Perlite’ space. Since perlite insulation may not be used on all refrigerated storage options, suggest just referring to the “annular space” and remove reference to insulation type.

Response 607, 663. Agree – see response 663.


]

9 Editorial: Suggested rewording: “The provisions of this Chapter 12.2 section apply for hydrostatic testing, commonly called….”

Agree.

659. Matrix Service (Hoptay) 239 22 214 3 The test pressure could be air or nitrogen. Suggested rewording: “An air test pressure of 1.25 times….”

Agree. Revise as suggested.

660. Matrix Service (Hoptay) 240 1 214 5 Suggested rewording: “The test pressure to the vapor space design pressure shall then be reduced to the tank design pressure and inspection …..”



]

10 Editorial: “with alarm settings to guard against pressure/vacuum conditions to prevent excess pressure or vacuum conditions.


666. Matrix Service (Hoptay) 242 10 216 8, 10 For RLG tanks the annular space may not be filled with perlite. Suggest Agree that this should be



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deleting perlite and just refer to the annular space. Adjust wording in R12.4.4 as well.

changed to annular space. Delete the word "Perlite" in lines 8 and 10.

670. Kuebitz, Karl 243 1 243 1 Fig (a) and (b) Replace “(or strands)” with “or strands.” Parentheses are not needed.

Agree. Parentheses will be removed.


]

11 Editorial: “apply when when the…” Agree


]

19 Editorial: replace LNG with RLG. Agree


]


678. Matrix Service (Hoptay) 246 1 219 6 Remove reference to metal inner tank. When cooling down a metal tank the through thickness gradients in is not a concern as indicated in this sentence.

Agree. Delete " and metal" from end of line 6 on page 219.


]


680. Legatos, Nicholas A. 247 1 247 1 Fig, A.10 is missing the legend that goes with the numerical markings. Attached is a complete figure including the legend [PDF File LNG*].

Missing legend has been corrected.

690. Matrix Service (Oberman) 250 1‐3 223 21 Why are requirements related to LNG and not RLG? Revise for RLG. Committee note ‐ This comment is understood to be referring to section title: "12.7 – LNG tank fill methods."

Agree that this should be changed to RLG. Editorial, also, change line 22 to read: "The provisions of this Chapter 12.7 section shall apply when …"

691. ACI 376 (Hoptay) 250 13,14 223JH[same

]

7, 8 Editorial: replace LNG with RLG. Agree


16, 21, 23

Editorial: replace methane with product gas? Agree



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] 698. ACI 376 (Hoptay) 255 9 227

JH[same]

10 Editorial: replace methane with product gas? Agree

699. ACI 376 (Hoptay) 255 4,13, &17

227JH[same

]

8, 17, 20

Editorial: replace LNG with RLG. Agree


]

5, 21 Editorial: replace LNG with RLG. Agree


]


693. Conlon, John F. 251 18 251 18 Replace ‘National Regulatory’ with Cognizant Regulatory’ Body. Agree that "National Regulatory" should be changed. To be consistent with similar wording throughout the document change line 18 to read: "b) The approval from National Regulatory regulatory agencies and Owner’s requirements."

696. Conlon, John F. 254 3 254 3 The correct spelling is ‘Morison’s. Agree


Group 3: Gap Analysis – items approved at Chicago meetings by ballot.

99. Krstulovic, Neven 46 13 46 13 4.9.2 Since this particular section applies to both internal and external strand‐prestressing systems, Introduce the following change: “4.9.2 – The strand for internal circumferential prestressing systems…”

Response 99, 100: Agree with 100. NK #11 (Gap analysis #‐‐) Introduce the following change (D.J., Pawski,



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Ballard, Howe, NKO, Domas, Hoff, Garrison, Hoptay (100%))

100. Legatos, Nicholas A. 46 13 46 13 Sec. 4.9.2 – “The strand for internal circumferential prestressing systems…”

Response 99, 100: Agree with recommended change.

103. Krstulovic, Neven 47 4‐5 47 4‐5 1. The reference to ACI 350, App. G, is enough. 2. If there was a need to single out an ASTM Standard in this section, it should be the most‐commonly used ASTM A821, not A421. Therefore, introduce the following change: “4.9.3 – Steel for wire‐wound prestressing shall comply with the provisions of ASTM A421 and ACI 350, Appendix G, for...”

Response 103, 104: Agree with 104. NK #12 (Gap analysis #) Introduce the following change (D.J., Pawski, Ballard, Howe, NKO, Domas, Hoff, Garrison, Hoptay supported (100%))

104. Legatos, Nicholas A. 47 4‐5 47 4‐5 Sec. 4.9.3 – “Steel for wire‐wound prestressing shall comply with the provisions of ASTM A421 and ACI 350, Appendix G, for...”

Response 103, 104: Agree with recommended change.

173. Krstulovic, Neven 67 12 67 12 R6.1 Both ACI 372R and ACI 373R apply here. Therefore, introduce the following change: “Applicable recommendations reported in ACI 372R and ACI 373R should be followed for…”

NK #13 (Gap analysis #‐‐) D.J., Pawski, Ballard, Howe, NKO, Domas, Hoff, Garrison, Hoptay supported (100%)

174. Legatos, Nicholas A. 67 12 67 12 Sec. R6.1, Line 12: “Applicable recommendations reported in ACI 372R and ACI 373R should be followed for…”

Accepted ‐ see 174 for response.

175. Krstulovic, Neven 67 13 67 13 R6.1 To clarify meaning, introduce the following change: “…installation of prestressed concrete tanks.”

NK #14 (Gap analysis #‐‐) D.J., Pawski, Ballard, Howe, NKO, Domas, Hoff, Garrison, Hoptay supported (100%)

176. Legatos, Nicholas A. 67 13 67 13 Sec. R6.1, Line 13: “…installation of prestressed concrete tanks“ Accepted ‐ see 175 for response.

211. Krstulovic, Neven 73 3 73 3 R6.3.11 Both ACI 372R and ACI 373R apply here. Therefore, introduce the following change:

NK #15 (Gap analysis #‐‐) D.J., Pawski, Ballard, Howe,



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“R6.3.11 ‐ See ACI 372R and ACI 373R for further information” NKO, Domas, Hoff, Garrison, Hoptay Meier supported (100%)

212. Legatos, Nicholas A. 73 3 73 3 Sec. R6.3.11 ‐ “See ACI 373R for further information Accepted ‐ see 211 for response.

224. Krstulovic, Neven 75 12‐13 75 12‐13 R6.5.1 To clarify meaning, introduce the following change to line 12: “…an elevated tank is used, the bearing capacity of piers supporting the tank base exposed to thermal radiation should also be checked.”

NK #16 (Gap analysis #‐‐) D.J., Pawski, Ballard, Howe, NKO, Domas, Hoff, Garrison, Hoptay, Meier supported (100%)

225. Legatos, Nicholas A. 75 12‐13 75 12‐13 Sec. R6.5.1, Line 12: “…an elevated tank is used, the bearing capacity of piers supporting the tank base exposed to thermal radiation should also be checked.”

Accepted ‐ see 224 for response.

541. Krstulovic, Neven 179 4 179 416‐17

Chapter 11 The ACI 117, Specifications for Tolerances for Concrete Construction and Materials, currently is not based on as‐built data. While some of the tolerances could be less restrictive, due to the lack of data on selecting less conservative values, presented existing values should be kept as‐is. However, Code text should be updated as shown below: “Unless otherwise specified in the project documents: 1) Tolerances shall be in accordance with ACI 117, and 2) Additional requirements listed in Sections 11.2.1 to 11.2.8 shall also

be satisfied.”

NK #2 (Gap analysis #15, rank #2) (3/20/2010 – Berner, Hoff, Hjorteset, Domas, NKO, Ballard, Hoptay, Brannan, Pawski Correct reference in line 17 is "Sections 11.2.1 to 11.2.5." See item 20 in April 1, 2009 email to ACI.



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Group 4: Gap Analysis – items resolved at Chicago meetings without ballot. REQUIRES COMMITTEE DISCUSSION.

134. Krstulovic, Neven

56 6 56 6 5.1.12 To more clearly indicate how would a designer use the information provided regarding a probabilistic approach add following text to Commentary: “As per ASCE 7, extreme ‐ value statistical analysis procedures should be used in evaluating data available in the vicinity of the site.”

NK #1 (Gap analysis #)

167. Krstulovic, Neven 65 1 65 1 Table 5.1 To provide a clear explanation on how would Table 3.1 be used, introduce the following text to Commentary: for 5.2.2: “Table 5.1 is a load combination matrix. As an example, in Table 5.1 each column lists loads that occur during a stage or event of the structure’s life cycle, such as:

Operations: Load combination = DL + PS + (Liquid + vapor) pressure + Normal thermal and moisture + shrinkage + creep + LL + Settlement + environmental (wind, snow, etc).

Note that normal thermal load is the gradient between the inner and outer faces of a concrete wall. For tank cooling, this would be replaced by the transient cooldown thermal and moisture conditions.

Abnormal: DL + PS + (liquid + vapor) pressure + shrinkage + creep + LL + Settlement + + Normal thermal and moisture + seismic Or + Spill thermal and moisture Or + fire thermal and moisture

Load factors are defined in section 5.2.”

NK #3 (Gap analysis #17, rank #3)

179. Krstulovic, Neven 68 1 68 1 6.2.3 The minimum residual average compressive stress within the compressive zone of 145 lb/in2 has been defined on the Commentary Side. To be consistent with 6.3.3 (b) where the stress limit is provided on the Commentary side, move the stress definition from the Commentary R6.2.3 to the Code 6.2.3 side.

NK #19 (Gap analysis #‐‐)



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6.2.3—Unless a leak‐tight membrane/liner has been used, minimum requirements for liquid tightness in the concrete wall and in the concrete base shall be:

a) Under empty and operation load conditions, the net resultant force in a section shall be compression; and

b) Under empty, operation load, and operation load plus OBE conditions, a compressive zone of either 50% of the section thickness or 8 in., whichever is greater, shall be maintained.

c) Unless liquid tightness under given conditions is proven using other methods, a minimum residual average compressive stress within the compressive zone of 145 lb/in.2 should be maintained in both the vertical and the circumferential directions.

R6.2.3—The liquid tightness requirements are applicable for the empty, operation, and OBE conditions.

Unless liquid tightness under given conditions is proven using other methods, a minimum residual average compressive stress within the compressive zone of 145 lb/in.2 should be maintained in both the vertical and the circumferential directions.

187. Krstulovic, Neven 69 12 69 12 6.2.9 to 6.2.14 And 6.3.12, new 6.3.13 Maximum service level concrete compression and tension stresses for primary and secondary containments are not clear, and should aligned with those in ACI 350. Revise 6.2.9 – 6.2.13 and 6.3.12 ‐ as follows: 6.2.9—Under normal conditions stresses in concrete at service loads (based on uncracked section properties, and after allowance for all prestress losses) the maximum concrete compressive stresses shall not exceed: a) Extreme fiber stress in compression 0.45 fc′ due to prestress plus sustained load ……………0.45 fc′; and b) Extreme fiber stress in compression 0.6 fc′ due to prestress plus total load ….. 0.6 fc′ c) Extreme fiber stress in tension in precompressed tensile zone....................6 (f’c)^1/2

NK #21 (Gap analysis #)



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6.2.10—Under abnormal OBE conditions, the concrete stress stresses in concrete (based on uncracked section properties, and after allowance for all prestress losses) due to prestress plus total load shall not exceed. the linear elastic region of the stress‐strain curve defined in 6.2.11. a) Extreme fiber stress in compression due to prestress plus total load …..…0.85 fc′; b) Extreme fiber stress in tension in precompressed tensile zone....................7.5 (f’c)^1/2 6.2.11—Unless the limiting elastic concrete stress is determined using other methods, a concrete stress level of 0.85fc´ shall be used as the limiting stress level of the linear elastic stress‐strain region. {RENUMBER AS REQUIRED!!!} 6.2.12—The effects of restrained deformation shall be considered. 6.2.13—Concrete and steel coefficients of thermal expansion at cryogenic over the range of operational temperatures shall be used. 6.3.12— Under normal conditions stresses in concrete at service loads (based on uncracked section properties, and after allowance for all prestress losses) the maximum concrete compressive stresses shall not exceed: a) Extreme fiber stress in compression 0.45 fc′ due to prestress plus sustained load ……………0.45 fc′; and b) Extreme fiber stress in compression 0.6 fc′ due to prestress plus total load ….. 0.6 fc′ c) Extreme fiber stress in tension in precompressed tensile zone....................6 (f’c)^1/2 6.3.13—Under OBE conditions, stresses in concrete (based on uncracked section properties, and after allowance for all prestress losses) shall not exceed.



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a) Extreme fiber stress in compression due to prestress plus total load …..…0.85 fc′; b) Extreme fiber stress in tension in precompressed tensile zone....................7.5 (f’c)^1/2

189. Krstulovic, Neven 69 20 169 20 R10.6.2.1 The value in the commentary R10.6.2.1 (paragraph 2) of 40 °F is inconsistent with the value of 32 °F provided on the Code side. Reconcile text as shown below:

“Controlling the position of the 32 40 °F isotherm prevents freezing the soil below the tank that can cause frost heave forces on the base of the tank. Frost heave may be avoided by trace heating the base slab or elevating the base slab, allowing heat input to the foundation through natural air convection.”

NK #5 (Gap analysis #21, rank 6)

328. Krstulovic, Neven 110 13 110 13 8.1.3.1.2 The use of R factors in design of RLG tanks is should not be permitted by this Code. Nonlinear analysis should use best estimates of loads and material properties. Change text as follows: 8.1.3.1.2 ‐ Selected methods shall be approved by the Engineer. If the design of an RLG tank is based on linear analysis, the response modification factor (R) shall be taken as 1.0, that is, no reduction in seismic forces are permitted. Results of nonlinear dynamic or nonlinear static (pushover) analyses may be used provided the peak strains in concrete and steel do not exceed the limiting values prescribed in this Code. Nonlinear analysis shall be carried out with true best estimates of demand (load) and strength without any load reduction or material safety factors. All responses (for example, plastic yielding, base uplifting, base sliding) should shall be explicitly calculated in the nonlinear analysis.

NK #24 (Gap analysis #1)

329. Ballard, Thomas A. 110 13‐18 110 13‐18 The use of R factors in design of RLG tanks should not be permitted by this Code. Nonlinear analysis should use best estimates of loads and material properties. (8.1.3.1.2 and R8.1.3.1.2)

To ballot – see 328 response

330. Krstulovic, Neven 110 14 110 14 R8.1.3.1.2 Change text as follows: R8.1.3.1.2 ‐ Both Linear and nonlinear analysis can be used to determine the seismic forces. In general, the design of a RLG tank

NK #25 (Gap analysis #2)



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should be based on a linear analysis with a force reduction factor R = 1. Historically, linear analysis is used in the case of low seismic regions and/or OBE case, while nonlinear analysis is used in regions with higher seismicity and/or SSE case. Results of nonlinear dynamic or nonlinear static (pushover) analyses may be used provided the peak strains in concrete and steel do not exceed the limiting values prescribed in this Code. Nonlinear analysis should be carried out with true estimates of demand (load) and strength without any load reduction or material safety factors. All responses (for example, plastic yielding, base uplifting, base sliding) should be explicitly calculated in the nonlinear analysis

331. CB&I 110 15‐16 110 15‐16 Para R8.1.3.1.2 delete sentence “In general, the … R=1.” This is a general comment that may cause confusion.


336. Krstulovic, Neven 111 5 111 5 8.1.3.1.3 Soil structure interaction effects should always be considered in the design of RLG tanks. With the provision to vary soil properties by +100% and ‐50%, the variation of response due to SSI (see 8.1.2.1) is adequately considered in the response calculations. SSI could and should reduce high frequency response significantly and will most likely amplify low frequency response, therefore, placing a maximum limit on the response reduction is not rational. Change text as follows: 8.1.3.1.3 – The reduction of responses due to soil‐structure interaction (SSI) effects shall be permitted, but limited to a maximum reduction of 50% for SSE analysis and 40% for SSEaft and OBE analyses.

NK #26 (Gap analysis #3) Response to 337

337. Ballard, Thomas A. 111 5‐7 111 5‐7 Soil structure interaction effects should always be considered in the design of RLG tanks. With the provision to vary soil properties by +100% and ‐50%, the variation of response due to soil properties (see 8.1.2.1) is adequately considered in the response calculations. SSI could and should reduce high frequency response and will most likely amplify low frequency response, therefore, placing a maximum limit on the response reduction is not rational. (8.1.3.1.3)


340. Krstulovic, Neven 111 10 111 10 8.1.3.2.1 The last sentence of the commentary should be on the Code side.

NK #27 (Gap analysis #4) Response to 338 and 339



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Change text as follows: 8.1.3.2.1 – The response spectrum or time history analysis method shall be used for calculating the seismic responses of the tank‐fluid‐foundation system. The time histories shall meet the amplitude, frequency, and duration requirements for the site for OBE, SSE and SSEaft events.

338. Ballard, Thomas A. 111 10‐16 111 10‐16 The last sentence of the commentary, “The time histories should meet the amplitude, frequency, and duration requirements for the site for OBE, SSE and SSEaft events”, should be on the Code side. (8.1.3.2.1 and R8.1.3.2.1)


339. Hoang, Kim for Chevron Team 111 10 111 10 8.1.3.2.1 “The response spectrum or time history analysis method shall be used for calculating the seismic responses of the tank‐fluid‐foundation system.” Comment 1: Response spectrum method should not be used for complicated SSI analysis (for example for pile foundations). If used at all the results from response spectrum method should be calibrated with time history analysis. Comment 2: This section does not state that when performing SSI analysis both inertial and kinematic SSI effects can be considered.


341. Krstulovic, Neven 111 12 111 12 R8.1.3.2.1 Change text as follows: R8.1.3.2.1 – The modal superposition method is used for response spectrum analysis. For time history analysis, the modal superposition or direct integration method can be used for calculating the seismic responses (MCEER 2001; Malhotra 1995 and Veletsos 1998). The time histories should meet the amplitude, frequency, and duration requirements for the site for OBE, SSE and SSEaft events.


346. Krstulovic, Neven 112 4 112 4 R8.1.3.3.1 This commentary restricts the seismic analysis to stick models. 3‐D finite element models with potential based fluid modeling should also be permitted. Details and demands on details can often be better characterized using 3‐D modeling, for example, tie‐down straps, uplift and impact of the tank edges, distribution of ring wall and insulation stresses, etc. Change text as follows: R8.1.3.3.1 – Where stick models are used as the basis for seismic analysis, The member axial, bending and shear stiffness……


345. Ballard, Thomas A. 112 4‐12 112 4‐12 This commentary restricts the seismic analysis to stick models. 3‐D See Response 346



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finite element models with potential based fluid modeling should also be permitted. Details and demands on details can often be better characterized using 3‐D modeling, for example, tie‐down straps, uplift and impact of the tank edges, distribution of ring wall and insulation stresses, etc. (R8.1.3.3.1)

446. Krstulovic, Neven 143 1 143 1 Table 9.1 To clarify whether there is a limit on the thickness to which these minimums apply (e.g., in ACI 373 that limits it to a 24 inch thick section), add text as listed below: 1) Add the following footnote to Table 9.1

“FOOTNOTE: Gross concrete area for calculating minimum reinforcement shall be based on the smaller of actual member thickness or 24 in.”

2) and adjust 9.2.2.1 as shown below:

9.2.2.1—Minimum reinforcement ratio of nonprestressed reinforcement used for control of cracking due shrinkage and ambient temperature stresses shall comply with Table 9.1. Gross concrete area for calculating minimum reinforcement shall be based on the smaller of actual member thickness or 24 in. Reinforcement shall comply with Section 4.8 when minimum nonprestressed reinforcement is considered effective at service temperatures below 0 oF.

3) Also change “LNG” in the table title to “RLG.” 4) In R9.2.2.1, paragraph 2 – change reference from Table 8.1 to Table 9.1


518. Krstulovic, Neven 168 9 168 9 R10.6.1.2 – Cathodic protection does not have to be isolated, but the design should account for all metals and be electrically bonded to the system. Most often the metal parts referenced here are bonded to the main plant grounding system. There is no way to provide cathodic protection without isolation of the parts to be protected and there is no way to account for all metals and be electrically bonded to the system.

NK #23 (Gap analysis #20, rank 23) D.J., Pawski, Ballard, Howe, NKO, Domas, Hoff, Garrison, Hoptay, Meier supported (100%) STEVE to pursue this



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551. Krstulovic, Neven 186 1‐16 186 1‐16 R11.3.3.2 The details in lines 2 through 16 ‐ though important – do not

belong in this document but are best left to the “practice‐specific” reference standards. Therefore, introduce the following change: “Application of shotcrete is material and workmanship sensitive, and should comply with the requirements of ACI 350 and ACI 372R. , and tThe following is included for information and guidance:


552. Legatos, Nicholas A. 186 1‐16 186 1‐16 Sec. R11.3.3.2, Lines 1 & 2: “Application of shotcrete is material and workmanship sensitive, and the following is included for information and guidance. should comply with the requirements of ACI 350 and ACI 372R Delete lines 3 through 16

Similar to response 551. Discuss deleting lines 3‐16.

553. Kuebitz, Karl 186 16 186 16 Add “(d) Nozzles may be mounted on power driven machinery enabling the nozzle to travel parallel to the exterior surface and spray at a uniform linear or bi‐directional speed. Automated shotcrete has been used on most externally prestressed tanks over 20 million gallons in capacity.”

Include with response 552.

549. Krstulovic, Neven 185 8 185 8 11.3.1 Strength is only one factor desired in shotcrete. A very high cement content is desired to establish and maintain high alkalinity for corrosion protection of the prestressed reinforcement. Such additional pieces of the information are useful to a designer. Therefore, add following text to Commentary:

R9.3.1 – Proportioning shotcrete Wire coating material is typically made using one part Portland cement and not more than three parts fine aggregate by weight. Body coating material is typically made using one part Portland cement and not more than four parts fine aggregate by weight.

NK #8 (Gap analysis #24, rank 13) Due to renumbering, correct section number is R11.3.1

550. Kuebitz, Karl 185 12 185 before10

Add “R11.3.1 – Polypropylene fibers conforming to C1116 are commonly used in the shotcrete mix to help mitigate shrinkage cracking.”


561. Krstulovic, Neven 190 4 190 4 11.4.4.2 There should be a requirement for a full scale vertical tendon grout test. While this is more difficult than the horizontal test, the vertical test would confirm that (a) bleed requirements are met at the




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10

tendon top, and (b) the means and methods for the vertical tendon grouting are satisfactory. Therefore, add to the commentary side “and vertical”, as shown below: R11.4.4.2—Full‐scale grouting tests, using a mock‐up, should be performed on the horizontal and vertical tendons to specifically demonstrate the suitability of the selection of tendon, grout and distribution of vent tubes and selection of pumping equipment. After the grouting trials the tendon should be cut transversely and inspected at selected locations before commencement of grouting operations on the structure. The grouting trials should ensure the following; …….

562. Widianto 191 5 172 19 There is a conflict between Section Q.8.4.2 of API 620 and Section 10.7.2 of ACI 376 related to the minimum number of survey points. Section Q.8.4.2 of API 620 requires at least 4 points whereas Section 10.7.2.1 of ACI 376 requires at least 8 points and Section 10.7.2.2 indicates that the spacing < 33ft.



Group 5: RESPONSES REQUIRING COMMITTEE DISCUSSION.

75. Reiterman, Roy 42 1‐3 42 1‐3 Its conjecture to say that steel reinforced concrete is not affective below 0 degrees. That’s new to me and I have been in this industry for over 50 years.

Response 75, 76. No action is required. The Code does not state that ordinary reinforcement is not effective below 0oF. NOTE ‐ Committee may want to consider a lesser value than 0oF. See Comments #28 and #76.


42 4, 15 42 4, 15 4.7.2 0°F should change to ‐4°F(‐20°C) to conform to other international codes.

Response 75, 76. See response 75



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42 17 42 17 4.7.2 It is indicated that this section applies to components exposed to “cryogenic conditions”. The section heading would imply this means below 0F. But that would be an unconventional use of the term. “Cryogenic” is generally understood to refer much colder temperatures. Page 19 defines cryogenic as “very low temperatures down to ‐270F. So this section becomes hard to interpret.

Needs Committee discussion. See Comment #28.

43. Matrix Service (Oberman) 21 17 19 11 Suggest the following revision to the definition of liquefied gas: liquefied gas (gas, liquefied) – a substance that exists in a gaseous state at room temperature and atmospheric pressure standard pressure and temperature (STP) that has been converted to a liquid by cooling and increasing pressure a liquefaction process.”

Agree

47. Matrix Service (Oberman) 23 11 21 2 Suggest the following revision to the definition of refrigerated liquefied gases: “refrigerated liquefied gases (RLG) ‐ matter a substance that occurs exists in a gaseous state at standard temperature and pressure (STP) and that has been liquefied by a refrigeration process.”

Agree

48. Matrix Service (Oberman)

24 14 21 3 Add the following definition after this line: “standard temperature and pressure – A temperature of 60 F and a pressure of 14.7 psia.”

Agree

45. CB&I 23 2 22 15‐16 Change “outer tank” to “outer tank corner joint” 46. CB&I 23 8 22 22‐23 “vapor barrier” and “product vapor barrier” are not always equivalent 50. CB&I

27 8 26 22 Definition unclear. Reword: “a method of member proportioning

based on ensuring that the design strength (nominal strength x strength reduction factor, ф) is larger than the required strength (service load x load factor).

44. Matrix Service (Pullinger)

22 3 19 19 The Load Combination Table 5.1 defines only normal and abnormal loads in the table but the definition for accidental loads includes some that are listed under abnormal loads. Categorization of the loads should be consistent.


37 15, 22 37 15, 22 4.1.1 Licensed design professional not defined. Engineer is defined (on p18, line 17).

Response 63, 64

64. Matrix Service (Hoptay) 37 37 37 15 Unclear, suggest the following revision: “Testing of materials used in concrete construction shall conform to the applicable building codes and shall be approved by the licensed design professional.”

Response 63, 64

67. Matrix Service (Hoptay) 38 9 37 22 The two year requirement contradicts section R1.2.3.1 which indicates that owner keep the records for the life of the structure.

Discuss Change as follows: “…shall be preserved by the licensed design professional



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or Owner for at least 2 years after completion of the work. through the life of the facility or as required by regulatory agencies.”

68. Reiterman, Roy 40 20‐21 40 20‐21 It’s misleading to discuss fiber reinforced concrete in the same vain as steel reinforced concrete – not the same. My unbiased field experience does not show that fiber concrete improves the structural strength of concrete.

With response 68 to 73. No action is required. The Code only permits the use of fibers but does not require that it be used.

69. Reiterman, Roy 40 22‐23 40 22‐23 Inaccurate to state fibers improve “certain” properties. A flag should be considered so that people don’t believe fibers can be substituted for steel reinforcing.

With response 68 to 73. No action is required. 50‐years of research and documentation by ACI 544 support this statement. The Code does require that fibers replaced ordinary reinforcing bars.

70. Reiterman, Roy 41 1‐3 41 1‐3 Delete compressive ductility, tensile strength and ductility and shear strength and ductility – these structural amenities can only be handled by with steel reinforcing.

With response 68 to 73. No action is required. The Commenter is not informed on these issues.

71. Reiterman, Roy 41 4 41 4 Toughness, crack control – but only in the plastic shrinkage stages. Not the drying shrinkage (longer shrinkage stage).

With response 68 to 73. No action is required. Supporting information exists in ACI 544 documents.

72. Reiterman, Roy 41 5 41 5 I would not say fiber concrete can control fatigue. I am familiar with auto plans that require heavy steel reinforced beam and slab cross sections around press machinery to handle vibrations and fatigue stresses.

With response 68 to 73. No action is required. Supporting information exists in ACI 544 documents.

73. Reiterman, Roy 41 8‐10 41 8‐10 Delete section 4.6.2. Fibers improve resistance to spalling in fires. It’s speculation and also needs to be approved and put into an ACI Standard. I am not aware of any text.

With response 68 to 73. No action is required. Supporting information exists in ACI 544 documents



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and in the references in this Code.

74. Kuebitz, Karl 41 17 41 17 Add “Polypropylene fibers are commonly added to shotcrete of wire or strand‐ wrapped prestressed concrete structures.”

85. Reiterman, Roy 43 22 43 22 States that when limited stresses are exceeded, the non‐prestressed reinforcing should not be considered. What kind of statement is that? Engineers design structures with safety or load factors to account for possible overloads. The statement does not belong in an ACI standard document. I am at a loss to believe that engineers can design fiber structures with safety and load factors when it’s not known where fibers are in the concrete, let alone a required length and volume measurement throughout a structure, and then to design fibers to do what steel reinforcing intends – to provide structural strength to support dead, live and seismic loads – and yet to handle overloads (they are called safety factors). I believe that the preliminary 376 text has been prepared by those that believe fibers are the chosen reinforcement and steel reinforcement is only discussed as an alternate. ACI does not go down this road. It is a professional engineering organization with ethics and a strong background in structural engineering.

Discuss. No action required. Comment offers no solution.

101. Kuebitz, Karl 46 16 46 16 Add the sentence, “When galvanized wire or strand is used for prestressed reinforcement, the wire or strand should have a zinc coating of 0.85 oz./ft 2 (260 g/m2) of uncoated wire surface, except for wire that is stressed by die drawing. If die drawing is used, the coating can be reduced to 0.50 oz./ft 2 (150 g/m2) of wire surface after stressing. The coated wire or strand should meet the minimum elongation requirements of ASTM A 421 or ASTM A 416. The coating should meet the requirements for Table 4, Class A coating, specified in ASTM A 586.”

Response 101, 102:

102. Kuebitz, Karl 47 1 47 1 Add, “Galvanized wire and strand for prestressing is commonly used on externally wire and strand wrapped structures for improved corrosion protection of the primary reinforcement.”

Response 101, 102:

105. Kuebitz, Karl 47 5 47 5 Replace “other wire‐wound systems” with “electronically controlled mechanical prestressing systems”

200. American Petroleum Institute 71 15 71 15 6.3.3 This implies that the required compression zone in a concrete Editorial: This is issue of



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Refrigerated Tank Task Group secondary container is only required if there is no leak‐tight membrane/liner. But it is common to design a liner that is not expected to remain leak‐tight in the event of liquid filling the annular space. In that arrangement it is important that concrete compression zones are maintained to ensure concrete liquid tightness even though a liner is provided. Such a liner is leak‐tight, but only during normal operation.

interpretation. Leave as is. § 6.3.3 states that unless a leak‐tight membrane / liner is used, a minimum ‐ compression‐zone requirement must be satisfied. Hence, if a liner is not leak‐tight, as is the case with a “wallpaper” liner under spill conditions, the minimum ‐ compression‐zone requirement must be satisfied.

201. CB&I 71 19 71 19 6.3.3.b): Remove the word “residual”. The word “residual” is not required and may be confusing.

Editorial comment. Agreed

202. CB&I 71 21‐22 71 21‐22 6.3.4: Define the method for crack width calculation at cryogenic temperature.

Use same as at room temperature. Note that Code already specifies that room temperature values be used in the design when selecting the elastic modulus and the concrete strength (see § 6.6.5.5 and 6.6.5.6, respectively). Recommendations for crack width calculations are provided in §8.1.1.7 (page 108, line 1). VERIFY

203. CB&I 72 4‐6 72 4‐6 R6.3.4: Provide more guidance on required time‐history analysis. Specify/recommend minimum number of product levels to be considered for such transient analysis. Otherwise, analysis becomes

Defining specific product levels would be too prescriptive. It should be



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too subjective and amount of work may be infinite. the responsibility of the design engineer to identify governing conditions for a particular temperature history. Leave as is.

204. Matrix Service (Hoptay) 72 9 69 3 Why does the primary tank need to only “retain its containment capability” for an SSE event? This is inconsistent with the design of the secondary containment under spill conditions which is required to remain liquid tight. The requirements of 6.2.6 specify a larger minimum compression zone for primary containers than for secondary containers. R6.1d refers to the maximum resulting stresses and refers to NFPA 59A which limits the rebar stress to yield and the prestressing steel to 94% of yield. Both requirements are consistent with a container remaining leak tight under the SSE loading. Suggest requiring the primary container be designed to be liquid tight for all loadings including a SSE loading.

This is NFPA 59A requirement. NFPA 59A section 7.2.2.5‐D requires that there is no loss of containment capability for the primary container during and after an SSE. Considered and discussed at length during document development balloting.

205. Hoang, Kim for Chevron Team 72 11 72 11 6.3.6 “The secondary concrete containment shall be designed for the SSEaft event while containing the total volume of spilled product.” Comment: This is a good requirement but not consistent with NFPA59A. See above comment.

T0 DISCUSS

206. CB&I 72 15‐16 72 15‐16 6.3.8: a) Cross reference is incorrect. Section 4.8.3 does not exist. Should reference be 4.7.2? b) Re‐phrase for clarity: Instead of “… at service temperature down to 0°F…” suggest

a) Editorial. Change 4.8.3 to 4.7.1 (4.7.1—Deformed reinforcement at service temperatures down to 0 °F) Note: NOT 4.7.2 which is for temp. below 0 F.) Also, See item 7 response in April 1, 2009 email to ACI. b) Not agreed. Section



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“… exposed to temperature of 0°F or lower during normal service conditions…”

6.3.8 relates to service temperatures DOWN TO 0F. CB&I’s suggestion changes it to 0F or LOWER. Section 6.3.9 refers to that case.


72 16 72 16 6.3.8 Suggest delete “at service temperatures down to 0F” for consistency with section 4.8.2 since 4.8.2 seems to be addressed to all temperatures.

Editorial?? – see comm. 206‐a and the response.


72 22 72 22 6.3.10 “withstand” should be described more specifically. Editorial?? – Change to “should not fail”.

209. CB&I 73 1‐2 73 1‐2 6.3.11: a) Remove the words “Under design loading”. This only causes confusion and does not add value. b) Define whether specified limit of 0.55f’ci applies to the average compressive stresses or extreme fiber compressive stresses

a) Editorial. Agreed. b) Editorial: This is a question of terminology. Leave as is. R6.3.11 refers to ACI 373R for further information. ACI 373R states: 3.3.3.2 Maximum initial prestress—The circumferential compressive stress in the core wall and buttresses produced by the unfactored initial prestress force should not exceed 0.55f’ci for concrete. This stress should be determined based on the net core wall area, after deducting for openings, duct areas and recesses.



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c) Revise wording “at transfer of maximum prestress” to “at or after transfer (before time dependent prestress losses)”

Current requirement is self explanatory. It implies that no compressive stress can EXCEED the limit anywhere in the section. Hence, it does NOT refer to an AVERAGE stress value, but the MAXIMUM value. Editorial. Leave as is or else copy text from ACI 318: “Stresses in concrete immediately after prestress transfer (before time‐dependent prestress losses) shall not exceed …..”


73 1 73 2 6.3.11 This value is 0.6fci by ACI318. Editorial: Leave as is. Commentary R6.3.11 clearly refers to ACI 373R for further information, not ACI 318. ACI 373R states: 3.3.3.2 Maximum initial prestress—The circumferential compressive stress in the core wall and buttresses produced by the unfactored initial prestress force should not exceed 0.55f’ci for concrete. This stress should be determined based on the net core wall area, after deducting for openings, duct areas and recesses.



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213. CB&I 73 4 73 4 6.3.12: Change the wording from currently shown to: “Under normal conditions, the maximum concrete extreme fiber compression stresses at service loads (after allowance for all prestress losses) shall not exceed:”

Inserting “extreme fiber” Editorial. Not persuasive. Leave as is. Current requirement for “maximum concrete compression” is self explanatory. It implies that no compressive stress can EXCEED the limit anywhere in the section. Hence, it does NOT refer to an AVERAGE stress value, but the MAXIMUM value. Inserting “at service loads” Requirement references tow specific cases: (a) prestress plus sustained load, and (b) prestress plus total load. Adding “at service loads” will change the intent of this paragraph.


73 9 73 9 6.3.14 Indirectly in EN14620, (via EN1992) crack limit is indicated as 0.2mm(=0.008in) for prestressed members. Consider whether major international codes like ACI and EN should be consistent. Also crack width limit requirement for foundation piles may be different and should be addressed also.

Discussed at length during document balloting. Consider before future editions.

215. CB&I 73 9‐10 73 9‐10 6.3.14: a) Do crack widths need to be checked for all “normal situations”. Typically crack width criteria does not have to be satisfied for transient loads such as wind (environmental load). Based on this, replace “normal design loading” with “construction and operating loading conditions”.

a)Editorial: Discussed at length during document balloting. Crack limits need to be considered for all normal loading conditions. Leave as is. Crack limits in concrete also



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Also: b) Define a method for crack width calculations or provide a cross reference to the other Sections of the Code, which defines the method c) Contradicts to ACI350 §10.6.4, which gives an indirect method for limiting crack width. ACI350 method is based on a smaller allowable crack width. Does the tank need to comply with ACI350 §10.6.4 or not? d) Inconsistent with 6.3.17.2 and 6.8.2.f) for non‐metallic liner Both 6.3.17.2 and 6.8.2.f) requires non‐metallic vapor barrier to be intact and fully functional after OBE i.e. be able to bridge cracks. This section should therefore also state that crack widths shall also be calculated for the OBE case where non‐metallic vapor barriers are used. (see also comments on §6.8.2)

– indirectly – limit how far is a section pre‐cracked and what strains have been locally reached in steel. b) Editorial: Defined in the Analysis chapter. Leave as is. This Chapter defines minimum performance requirements, i.e., in this case crack width limit. How to calculate crack width is defined in the Analysis chapter §8.1.1.7 (page 108, line 1). c) Editorial: Discussed at length during document balloting. Consider before future editions. d) This issue was discussed at length by the Committee. It would be very difficult to define and verify crack opening velocities and crack limits during a seismic event. Instead section 6.3.17.2 (page 74, lines 6‐8) defines corresponding performance requirement



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as: “During an OBE event the vapor barrier can experience elongation strain rates induced by crack opening velocities. The vapor barrier should remain functional after an OBE event.” It is therefore left to the designer to verify that a given vapor barrier type satisfies this performance requirement.

216. CB&I 73 11‐13 73 11‐13 6.3.15: Add a §R6.3.15 with some discussion on this subject to explain better the intent of this paragraph.

ANY SUGGESTIONS for text? If there are no suggestions and since no justification or proposed text were provided, consider for future editions.


73 14 73 14 6.3.16 Add “under normal service conditions” after the sentence. OK? Editorial?

218. Matrix Service (Hoptay) 73 16 Suggest adding the following to be consistent with NFPA 59A requirements: actual mix proportions over the range of operational temperatures unless prior data on this property is available.

ASK JOE AGAIN FOR LOCATION

221. Matrix Service (Hoptay) 74 1 70 10?? Why if nonprestressed reinforcement is ductile at cryogenic temperature are the stresses limited to low stress design? Editorial paragraph 4.8.3 does not cover reinforcing steel, should be 4.7.2.

See explanation in § R4.7.2 Editorial: Change reference to 4.7.2 instead of 4.8.3. There is no § 4.8.3. Furthermore, in editing version 7 (12/12/08) this was section 4.2.15‐d , which referenced § 2.8.2. ‐ Deformed reinforcement at



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service temperatures down to 0 °F. NOTE THAT IT SHOULD HAVE BEEN “2.8.3 – Deformed reinforcement at service temperatures below 0 °F” Hence, current reference should be § 4.7.2 “4.7.2—Deformed reinforcement at service temperatures below 0 °F”

222. CB&I 74 6‐8 74 6‐8 6.3.17.2: a) Does it mean that after any seismic event exceeding an OBE level (even slightly) a non‐metallic liner is allowed to loose its vapor and moisture containment capabilities?

Editorial. Not persuasive. Leave as is. NFPA 59A (§ 7.2.2.2) states that: “The LNG container and its impounding system shall be designed for the following two levels of seismic ground motion: (1) The safe shutdown earthquake (SSE) …., (2) The operating basis earthquake (ORE) …” Hence, the design deals with conditions AT OBE and AT SSE. The design does not consider cases BEWTEEN OBE and SSE. ACI 376 design requirements follow the same approach.

223. CB&I 74 11‐13 74 11‐13 6.4:



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a) Either add other transient and accidental loads such as wind, blast, external fire, etc. to the list of transient loads or just state “Ultimate strength design shall be used for transient conditions.” and explain what transient conditions are in the Commentaries. Add §R6.4. b) Either define a method for crack width calculations or provide a cross reference to the other Section of the Code, which defines the method. c) Does crack width need to be controlled for seismic conditions when non‐metallic liner is used?

a) Editorial: Leave as is. Listed loads are only given as an example and not as a comprehensive list of all transient loads. Therefore no need to change. TO DISCUSS: Can examples be left on the Code side or must they be moved to the Commentary Side? b) Editorial: Leave as is. Chapter 6 only provides performance requirements and not methods of analysis, which are provided in Chapter 8. More specifically, recommendations for crack width calculations are provided in §8.1.1.7 (page 108, line 1). c) This issue was discussed at length by the Committee. It would be very difficult to define and verify crack opening velocities and crack limits during a seismic event. Instead section 6.3.17.2 (page 74, lines 6‐8) defines corresponding performance requirement



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d) Do crack widths need to be checked for all “normal situations”. Typically crack width criteria does not have to be satisfied for transient loads such as wind (environmental load). Based on this, replace “normal design loading” with “construction and operating loading conditions”.

as: “During an OBE event the vapor barrier can experience elongation strain rates induced by crack opening velocities. The vapor barrier should remain functional after an OBE event.” It is therefore left to the designer to verify that a given vapor barrier type satisfies this performance requirement. d) Editorial: Leave as is. The paragraph clearly states that the crack limit (=SLS condition) must be satisfied for ALL normal loading conditions, except for transient loads. For transient loads ULS design shall be used instead of verifying that the crack width limit has not be exceeded, i.e. SLS design is not used in this case.

226. Matrix Service (Hoptay) 75 14 Other than the spill load case, do these requirements apply to other load combinations such as Spill + SSE aft? Suggest adding a paragraph that addresses which load combinations need to comply with this requirement.

ASK JOE AGAIN FOR LOCATION

227. Matrix Service (Pullinger) 75 16 71 17 Is the 3.5” minimum depth of compression measured from the outside surface or does it exclude the cover? Suggest stating how the compression zone is to be measured for the secondary container.

Editorial: Since concrete remains in elastic compression throughout its



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life, cover concrete contributes to section capacity. As in any other RC and PSC design, concrete cover is included, i.e., the compression zone depth is measured from the outside concrete surface.


75, 85 17, 1 75, 85

17, 1 6.6 & 6.7 Concrete quality and properties belong in Section 4, Materials

ROLF: How did these end up in the Performance section? I checked with one of our last drafts (7) and it was not in here? If there are no specific reason I would say: Editorial. Agreed.

231. CB&I 77‐79 ALL 77‐79

ALL 6.6.5.1‐6.6.5.3: These sections should provide to the designer clear instructions what to use instead of a wish list of what needs to be considered.

1) To support normal construction schedule concrete design typically must be completed before mix trials are finalized and moisture content of concrete and/or other mix‐specific properties such as thermal conductivity,. coefficient of thermal contraction can possibly be determined. The Code should specify the most realistic values to be used for the design prior all necessary testing is complete and values confirmed. Otherwise, sections 6.6.5.1‐6.6.5.3 have no practical meaning.

2) Concrete moisture content changes with time and ambient conditions. Temperature dependent properties will change as well. Is it an intent of the Code to run a moisture monitoring program for the lifetime of the tank?

See comment 228 above – this text seems to belong to the materials chapter

229. CB&I 75 21‐22 75 21‐22 6.6.1: Does this section intend to state that 4000psi concrete is acceptable for the prestressed secondary containment which usually does not contain liquid? Create a list that specifically states required

Editorial: Do not change Code text. Current text is sufficiently generic and



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minimum concrete strengths: Primary Slab: 5000psi Primary Wall: 5000psi Secondary Slab: 4000psi Secondary Wall: 5000psi Secondary Roof:4000psi

clear that no additional tables are needed.

230. ACI 376 (Hoptay) 76 21 JH[72] 15 Editorial: Section 4.7 and 4.8 Editorial. Agreed in principle. However, the reference should be § 4.7.1 ‐ Deformed reinforcement at service temperatures down to 0 °F. Section 6.3.8 references § 4.8.2, which does not exist. In editing version 7 (12/12/08) this was section 4.3.9, which referenced § 2.8.2. ‐ Deformed reinforcement at service temperatures down to 0 °F. Hence, current reference is § 4.7.1.

232. Hoang, Kim for Chevron Team 77 2 77 3 The sentence ends with “…refer to.” It should be appropriately completed.

Editorial: Agreed. Cite references that in the editing version 7 (12/12/08) were 2.2 – 2.40 In editing version 7 (12/12/08) this section was “R2.1.5 See References 2.2 to 2.40 for information on the cryogenic behavior of..” ROLF: This was removed from our response to TAC. Can we still put it back?



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243. Matrix Service (Hoptay) 82 6 77 1 6.6.5 Wording from previous versions of the document has been

removed. Suggest including the following wording from Version to TAC:” The behavior of concrete at cryogenic temperature shall be considered included in the in the determination of the performance and integrity of the structure.”

Editorial. Agreed. See response to comment 232

233. Conlon, John F. 77 3 77 3 in R6.6.5; is there a x‐ref. missing Editorial. See 232. 234. Matrix Service (Hoptay) 77 5 Why if nonprestressed reinforcement is ductile at cryogenic

temperature are the stresses limited to low stress design? See explanation in § R4.7.2 ASK JOE AGAIN FOR LOCATION

235. Matrix Service (Hoptay) 77 8 What are the minimum acceptance criteria for these loadings? ASK JOE AGAIN FOR LOCATION

236. ACI 376 (Hoptay) 78 14 JH[73] 20 Editorial: Sections 4.8 and 4.13 Editorial: Agreed. Same as comment 219: Change reference 6.8 to reference 6.9 – Metal Components In editing version 7 (12/12/08) this was § 4.3.18 which referenced § 7.6.1 – Metal Components. Note that this is not section 4.8 which refers to plate steel used as reinforcement, or section QUESTION for future consideration – in the balloted document we referenced what is currently paragraph 6.9 – Metal Components. Consider why we did not reference 4.13 – Metal Liners

237. Matrix Service (Hoptay) 79 3 74 6 This should be R6.3.17.2 Editorial: Agreed. Add



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R6.3.17.2 at the beginning if the line. In editing version 7 (12/12/08) this was § R4.3.22, which was commentary to § 4.3.22, Now § 4.3.22 is § 6.3.17.2.

238. Matrix Service (Hoptay) 79 21 74 22 The first sentence of R6.5.1 repeats the code requirements. Consider deleting.

Editorial: Disagree. Text is the same as the balloted version (see final response to TAC). Leave as is.

239. Matrix Service (Hoptay) 80 1 75 1‐3 Suggest adding statement explaining why cellulosic fires are different from hydrocarbons fires and provide an example of what “certain precautions” are to be considered.

§ R5.5.1 presents know behavior observed in the field. Not sure if the science behind the behavior is known. Provide an explanation if there is one.

244. ACI 376 (Hoptay) 83 8 JH[78] 2 Editorial: First paragraph text is incorrect. Should have text from previous version: “The design of concrete members shall consider include thermal deformations over the appropriate temperature and moisture range.”

Editorial: Leave as is. This text was removed in the final response to TAC (see corresponding file): “The design of concrete members shall consider thermal deformations over the appropriate temperature and moisture ranges.”

240. Hoang, Kim for Chevron Team 80 9 80 9 Section 6.6.5.5 “Elastic Modulus” – usage of a term such as “elastic modulus” is not appropriate as it does not have a physical meaning, even though it is used typically in engineering slang. The official term is “Modulus of Elasticity”, and is the correct term that should be used throughout the document.

Editorial: Can use both. ACI 116R ‐ Cement and Concrete Terminology defines elastic modulus as: “elastic modulus—see modulus of elasticity



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(preferred term).” 242. Hoang, Kim for Chevron Team 81 4 81 4 “elastic modulus” – see comment to Section 6.6.5.5 above. Editorial: Leave as is. See

response to comment 240. 241. Hoang, Kim for Chevron Team 80 12 80 12 “… normal production range, …” : This term is not widely used, and is

recommended to be substituted with “normal weight”, “lightweight” and “heavyweight” concrete in compliance with other documents such as ACI‐318‐08 and ACI 350‐06 for consistency.

Editorial: Sounds reasonable. Consider adopting proposed

257. Matrix Service (Hoptay) 88 18 83 2‐3 How is it conservative to obtain the intrinsic permeability from dried samples if the measured permeability is less and the permeability limit is not to be exceeded?

As moisture in concrete freezes, pores are closed and permeability decreases. This is the reason why concrete permeability at cryogenic temperatures should be lower than at room temperatures (i.e., concrete Impermeability INCREASES with cryogenic temperatures). Therefore, if moisture content is not known, measuring permeability of dry samples will provide conservative values.

254. CB&I 87 2‐5 87 2‐5 6.9.3: What is the meaning of this paragraph? Reference to Table 7.1 does not make sense. Place a “.” after the word “conditions” and remove words “by using the appropriate reduction factor as shown in Table 7.1.”

Editorial: Agreed. Reference to Table 7.1 was added in the final submission to TAC. It was not in the editing version 7 (12/12/08). ROLF/GEORGE: do you have any history on why was additional text added at the end of the sentence?

264. Matrix Service (Hoptay) 93 5 87 2 This code section permits higher stress levels if the material always exhibits ductile behavior. 1.) What minimum requirements are

DISCUSS • Probably this should be



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required to establish that the material is ductile? 2.) Allowable stresses are based on the strength of the material not its ductile behavior. Why does the code allow higher stresses in this case?

viewed as a special case that needs to be justified to the Owner. Since both (1) we do not want to be prescriptive, and (2) we want to allow for future developments, we can not be more specific than this.

• Perhaps we can add something on “must be demonstrated and approved by …???....”

265. Matrix Service (Hoptay) 93 6 87 5 “by using the appropriate reduction factor as shown in Table 7.1” was not part of the committee document. The strength factors are not related to the allowable stresses referred to in this section and should not be added to this section.

Agreed. See response to comment 254.

255. CB&I 87 12 87 12 Para 7.1, Table 7.1 ‐ ACI Code 350 or 318 do not address what strength reduction factors shall be used under accidental/emergency events such as SSE and spill. European (BS‐EN) Code recommends different factors for normal and accidental cases. Per EN1992‐1‐1 Section 2.4.2.4, the material strength reduction factors for reinforcing steel are 1.15 (persistent & transient) and 1.0 (accidental), a 15% increase in capacity for accidental cases. For concrete the material strength reduction factors are 1.5 (persistent & transient) and 1.2 (accidental), a 25% increase in capacity for accidental cases. Thus the Table 7.1 strength reduction factors can be increased in a similar manner for the accidental/emergency cases:

Considered and discussed at length during document development balloting. Revisit this issue before the next Code edition



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Stress TypeNormal Emergency

Tension controlled sections* 0.90 1.00Compression controlled sections** - with spiral reinforcement 0.70 0.90 - with other reinforcement 0.65 0.80Shear and torsion** 0.75 0.90Bearing on concrete** 0.65 0.80Post-tensioned anchorage** 0.85 1.00Flexure without axial load where strand embedment is less than the development length** 0.75 0.90Strut-and-tie models** 0.75 0.90* 15% increase in φ factor (reinforcing).** 25% increase in φ factor (concrete).

Strength Reduction Factor, φ

256. CB&I 88 16‐17 88 16‐17 It is industry practice to use load factor of 1.0 for dead loads under SSE

and other emergency conditions. ACI 350 does not apply since SSE seismic and other emergency events are not addressed. A load factor of 1.0 should be used for dead load when applied to emergency conditions.


258. CB&I 89 14‐22 89 14‐22 7.2.2.2 and R7.2.2.2: This information should be in the analysis section, not the load factor section since these requirements are met using proper analysis models, not varying load factors.

Editorial: Not persuasive. Leave as is. This section deals with load factors presented in Table 7.2. The table defines load factors for various time depended effects, such as creep and shrinkage, with load factors varying between 1.0 and 1.2. Therefore, time depended effects and related issues are covered in §7.2.2.2 and §R7.2.2.2.

260. CB&I 92 2,3 92 2,3 Para R7.2.8: ACI 350 specifies a live load load factor of 1.0 when live load acts in combination with earthquake, see ACI 350 equation (9‐5). Therefore, wording should be changed to “… under normal loading and OBE loads conditions use load factors of 1.6 and 1.0, respectively”.




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Check with ACI 350

263. Hoang, Kim for Chevron Team 93 3 93 3 Section R7.2.10.2 It is recommended including some examples of “other” environmental load effects.

Editorial. Agreed. Suggest to add an example such as: “Other environmental load effect (e.g., solar radiation, snow, rain, etc.).....”

266. CB&I 93 7 93 7 Define what is “other environmental loads”. “Other environmental loads” per ACI 350 Eq‐9‐3 are snow and rain (S and R).

Editorial. Agreed. See response to comment 263.

267. CB&I 93 14 93 14 R7.2.11 Seismic Loads “As per load reduction factors (LRF) industry practice for the OBE condition, a load factor of 1.3 should be used.” Industry practice for seismic design is based on one level of load. This code requires performance based design using three levels of load to handle the potential for a load exceeding the design load basis. Load factors should not be applied to performance based design loads. Any actual load in excess of the defined OBE load basis must then meet the SSE performance criteria. The OBE load factor should be 1.0


268. CB&I 93 14, 15 93 14, 15 Para R7.2.11: Per comment Error! Reference source not found., OBE load factor should be 1.0.


269. CB&I 94 21‐23 94 21‐23 Para. R7.3.1 Per comment Error! Reference source not found., A minimum load factor of 1.0 can be used for dead load when in conjunction with emergency loads.


272. CB&I 95 5‐7 95 5‐7 Para 7.3.1: It is industry practice to use load factor of 1.0 for dead loads under SSE and other emergency conditions. ACI 350 does not apply since SSE seismic and other emergency events are not addressed. A load factor of 1.0 should be used for dead load when applied to emergency conditions


274. CB&I 98 6‐8 98 6‐8 R7.3.8: ACI 350 specifies a live load load factor of 1.0 when live load acts in combination with earthquake, see ACI 350 equation (9‐5). Therefore, wording should be changed to “… under normal loading and

Discussed at length during document balloting. Consider before future



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OBE loads conditions use load factors of 1.6 and 1.0, respectively”. editions. 277. CB&I 99 10 99 10 R7.3.11 Seismic Loads

Same comment for R7.2.11 above. Discussed at length during document balloting. Consider before future editions.

279. CB&I 99 12 99 12 Para R7.3.11 Per comment Error! Reference source not found., OBE load factor should be 1.0.


283. CB&I 101 1 101 1 Table 7.2 Load Factors for OBE Seismic OBE load factors should be 1.0

Discussed at length during document balloting. Consider before future editions

284. CB&I 101 1 101 1 Additional column could be added to make clear the requirements of R7.2.1 and R.7.2.3 (when to use DL factor of 1.2 and when to use 1.4) for these fundamental design cases.

Editorial: R7.2.1 and R7.2.3 provide verbal explanation on which load factor to use. Lave as is. Consider comment for the future edition

285. ACI 376 (Hoptay) 102 7&10 JH[94 95]

211

Editorial: To be consistent with previous paragraphs place the discussion of OBE factors before the SSE factors.

Editorial. Leave as is? SSEaft is a lower level eq. than OBE. Note that SSE is already listed after OBE, as suggested in this comment.

286. CB&I 103 1 103 1 Table 7.3 Load Factors for OBE Seismic OBE load factors should be 1.0


287. CB&I 103 1 103 1 Table 7.3 “PRODUCT PRESSURE: Liquid” LF of “1.2” should be added for “testing and commissioning” and for “operation” for the design of the base slab. Thermally induced tank cooling and filling load factor for operation should be added (mainly used for slab and wall). It should be “1.2”.


288. Hoang, Kim for Chevron Team 104 1 104 1 Table 7.3, third line from bottom: Under Seismic Loads, there should be another line “SSEAFT”. Spill and SSE should not be combined as this is

Editorial: This is what is the intent of the table. Leave



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unlikely and would be a very conservative combination. The combination should be Spill and SSEAFT as specified in Section 6.3.6.

as is? SSEaft case is only relevant if spill already occurred. “SPILL+SSEaft” indicates that SSEaft earthquake occurs after a spill, i.e., it occurs after the outer container has been filled with LNG. This is what is stated in 6.3.6: “6.3.3 ‐ The secondary concrete containment shall be designed for the SSEaft event while containing the total volume of spilled product.”


105 4 105 22 R8.1.1 Delete rollover. This only applies to LNG terminals and there is a requirement for measuring density and mixing to prevent this. Prevention is absolutely essential as rollover releases an enormous and dangerous vapor cloud.



105 19‐20 105 19‐20 R8.1.1 Annual average ambient temperature is enough for the construction stage (it may be the initial temperature profile).

Editorial: Because of the significant of excessive ambient temperatures that can occur in many places around the World (e.g., Sakhalin, Qatar, etc.), using average annual ambient temperature is non conservative. Leave as is.

293. Matrix Service (Pullinger) 106 10 5556

15‐231‐8

Some general live loads defined in Section 5.1.10 (such as the weight of fluid n pipes and vessels) should be combined with the OBE loading if these are present during normal operation.

Editorial: Load combination tables define MINIMAL load combinations. The designer can add others depending on his/her engineering judgment. Leave as is and consider for the future



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edition. 294. CB&I 106 15‐17 106 15‐17 8.1.1.2: Too open ended.

Give a clear definition of what transient conditions must be considered in the analysis for both loading per 5.1.15 and 5.1.16, i.e. clearly define the minimum scope of analysis. Otherwise, due to ambiguity, required amount of work is subjective and may be endless.

Editorial? This goes back to the fundamental issue of the performance‐based code vs. a prescriptive code. Details should be worked out by the designer using sound engineering judgment?


106 20 106 20 8.1.1.3 Annual average ambient temperature is enough for the construction stage (it may be the initial temperature profile).

Editorial: Because of the significant of excessive ambient temperatures that can occur in many places around the World (e.g., Sakhalin, Qatar, etc.), using average annual ambient temperature is non conservative. Leave as is.

296. CB&I 107 4‐6 107 4‐6 8.1.1.4: Too open ended. Give a clear definition of minimum requirements for temp time‐history and transient analysis. Otherwise, required amount of work is subjective and may be endless.

Editorial? This goes back to the fundamental issue of the performance‐based code vs. a prescriptive code. Details should be worked out by the designer using sound engineering judgment?


107 5 107 5 “the entire temperature time history” should be described more specifically.

Editorial: “Entire” = “complete” time history experienced throughout the life of the structure. Leave as is.

478. Matrix Service (Hoptay) 154 4 140 11 Circumferential embedment plates are provided with anchorage that prevents the embedment plate from shrinking away from the concrete surface. The embedded plate does provide an effective liquid barrier

Disagree, unless there evidence that a particular detail is in fact liquid tight.



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and is the typical configuration. This portion of the commentary should be deleted or rewritten.

Hydrotesting of an embedment with heavy weldments in mid 1980's resulted in substantial leakage around the embedment.

498. CB&I 160 22, 23 160 22, 23 R10.4.2.1 ‐‐ Add “Where possible, …” before “Pile blow…”. It is not always possible to record the blow counts electronically. replace ‘fabrication” with “installation”.

"ASCE – 1997" should probably be "ASCE 20‐96 Standard Guidelines for the Design and Installation of Pile Foundations."

501. Matrix Service (Gianni) 161 12 148 1 Are Standard Penetration Tests not permitted by this section as part of the subsurface investigation? Committee note ‐ This comment is understood to be referring to section "10.2.2—Number, location, and depth of boreholes and cone penetration tests" on page 148 line 1.

SPT testing is common in US practice, and should be included.


169 22 169 22 R10.6.2.1 Although this is part of the commentary, the foundation should be protected from the 32oF isotherm, as noted in the provision paragraph, not 40oF.

Response 520, 556. Agree.

556. Matrix Service (Hoptay) 188 1 169 22 Revise 40F to 32F to be consistent with 10.6.2.1. Response 520, 556. Agree.

558. Matrix Service (Hoptay) 189 5 171 3 The 6 ft high space is not typical for pile supported tanks, and pile spacing may need to be closer than six feet. These values should be removed from the commentary. Also the air space required is dependent on in some part to the stored product.

Response 521, 522, 558. Agree. Numerous LNG tanks have been built with 24" nominal air space without any known detrimental affects.


171 3,4 171 3,4 R10.6.2.1 We suggest that 376 should say that 6’ high is recommended “if lateral load conditions permit”.

Response 521, 522, 558. See response 558.

522. CB&I 171 3,4 171 3,4 Para. R10.6.2.1 remove the whole sentence “Normally, to meet .. 6 ft high and 6 ft wide..”. The designers will determine the access limitations based upon the owner’s specifications and specified codes.

Response 521, 522, 558. See response 558.

537. CB&I 176 19,20 176 19,20 Para 10.9.2.5 – Need to allow use of ASME welding as well. Disagree in that the appropriate welding code



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for structural sections is AWS D1.1. It permits qualification of welders and procedures in accordance with ASME so the "need" is addressed; see section 4 of D1.1 that references AWS B2.1, both of which discuss acceptability welders and procedures by "other codes and standards."

539. Matrix Service (Gianni) 178 7 160162

4??1??

Given the critical nature of these structures and the strict performance criteria and severe loadings should not pile load tests be mandatory and a minimum number of tests required? Committee note ‐ This comment is understood to be referring to either: R10.4.2 starting on page 160 line 3, or R10.4.2.3 starting on page 162 line 1. RP comment: there is no code text in 10.4.2 and 10.4.2.3 for the accompanying the commentary. Suggest the following: For 10.4.2 add "Unless otherwise specified, ultimate capacity of single piles shall be determined by static or dynamic testing." For 10.4.2.3 add "Number and type of tests to be conducted shall be specified in the contract documents."

Response 539 and 540.

540. Matrix Service (Hoptay) 178 9 160 4?? If a load test is required, guidance for determining the load to which the pile is to be tested should be included in the commentary.


545. Matrix Service (Gianni) 182 17 Provide clarification of the concept. None of the concepts shown in Appendix A appear to show this concept. Committee note – Cannot find text being discussed. Is the reference possibly to 10.5 Ground Improvement on page 166 line 19?

No action required unless the paragraph can be identified.

564. Kuebitz, Karl 192 16‐18 192 16‐18 Delete paragraph. Epoxy grout in prestressing ducts is commonly and extensively used.




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Committee note – Cannot find the mentioned phrase. 570. CB&I 194 16‐17 194 16‐17 Is it the intent of the authors to allow broken strands or completely

failed tendons in a structure? What is the intent of this section? Committee note – Replace "tendon" on page 194 line 16 with "prestressing steel" to be consistent with ACI 318 and 350 wording.

Yes, the intent is to permit up to 2% of prestress loss due to broken or unusable strand or tendons. This is consistent with 1820.4 of both ACI 318‐05 and 350‐06. It is not uncommon to have individual strands break or be damaged during the stressing operation.

571. Matrix Service (Gianni) 195 10 What is intended by this requirement? Clarification should be added to the commentary. Committee note – Cannot find text being discussed.



210 2‐5 210 2‐5 12.2.7 Hydrotest water quality for stainless steel and aluminum tanks does not belong in ACI 376 since the ACI document is for concrete, not metallic tanks.

Response 595, 596. Include with response 650. Also see response 601. Pittsburgh comment: Agree. Editorial. Included in response 650 Also see Responses 596 and 601.


210 2‐5 210 2‐5 12.2.7e&f Delete – do not cover metal tanks, not part of the scope and will create conflicts with API 620.

Response 595, 596. Include with response 650. Also see response 601. Pittsburgh comment: Agree. Editorial. Included in response 650 Also see Responses 596 and



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601. 601. CB&I 211 5 211 5 12.2.8 – states that all internal components shall be 9% nickel or high

nickel alloy. However, if ACI 376 addresses storage of a broad range of refrigerated gases and will, therefore, not require these material in all cases and various grades of carbon steel will suffice, based on product temperature.

Response 597‐601, 651. Agree that scope of this section should be limited to discussing performance requirements for corrosion protection of metal components during hydrotest, and that there is no need to specify particular materials. Pittsburgh comment: Agree. For future action. Also see Responses 597‐601, 651. Agree that scope of this section should be limited to discussing performance requirements for corrosion protection of metal components during hydrotest, and that there is no need to specify particular materials.

597. CB&I 210 17 210 17 12.2.8 The corrosion protection requirements for steel components are very restrictive and appear to be pointed at a steel primary tank. It would be more appropriate to place this information within API620 and just reference that standard here. It is recognized that sea water is not addressed in API620 at this time.

Response 597‐601, 651. See response 601. Pittsburgh comment: Agree.



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It is also noted that protection of a Stainless steel pump column in a concrete tank may carry a higher level of corrosion risk than when placed within a primed steel tank.

For future action. See responses 597‐601, 651.


210, 211

18 210, 211

18 12.2.8 (a), (b), (c) and (e) all sound like they are addressing metal tanks which are outside scope of ACI 376. If they really are addressed to some bits of metal that are part of concrete containers, then the commentary should explain that.

Response 597‐601, 651. See response 601. Pittsburgh comment: Agree. For future action. See responses 597‐601, 651.

599. CB&I 211 2 211 2 12.2.8 – requires coating / priming of all weld seams after NDT. It is not clear what tank components are addressed in this; however, it has not been industry practice to coat inner tank seams and other containment embedments. Not sure if this requirement is necessary. or justified. Needs clarification and more appropriately placed in API 620 which addresses metal components more thoroughly.



211 4‐10 211 4‐10 12.2.8 Metallic internal pump columns are not appropriately within the scope of ACI 376. These are not in any way a part of a concrete container.


651. Matrix Service (Hoptay) 236 9 211 2,3 8,

The code should only require that the engineer determine if corrosion protection of metallic components is required and to define those

Response 597‐601, 651. See response 601.



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11, 12,17

requirements. Tanks have been successfully hydrotested with seawater without providing them with a coating.

Pittsburgh comment: Agree. For future action. See responses 597‐601, 651.

602. CB&I 212 16 212 16 12.2.9.2 – requires visual inspection of all tank surfaces after hydrotest within 24 hours. Note that all surfaces may not be accessible and the 24‐hour timeframe may not be possible.

Agree. Suggest omitting the time limit by changing line 16 to read: " 12.2.9.2—Within 24 hours after After hydrotesting …" Pittsburgh comment: Agree. Editorial. Omit the time limit by changing line 16 to read: " 12.2.9.2—Within 24 hours after After hydrotesting …"

654. Matrix Service (Hoptay) 238 7 212 18 Delete reference to metal tanks. “12.2.9.3 – For metal tanks , or metal components of concrete tanks.

Response 603, 654. Suggest changing line 18 to read : "12.2.9.3—For metal tanks, or metal components of concrete tanks, the The entire surface of …" The reason being that the provision is not dependent on whether the tank is constructed of metal or concrete. Pittsburgh comment:



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Agree. Editorial. Also see Response 603. Change as follows: 12.2.9.3—For metal tanks, or metal components of concrete tanks, the The entire surface of …" The reason being that the provision is not dependent on whether the tank is constructed of metal or concrete.


212 18‐21 212 18‐21 12.2.9.3 Delete. Does not belong in ACI 376 since the ACI document is for concrete, not metallic tanks.

Response 603, 654. See response 654 Pittsburgh comment: Agree. Editorial. . See response 654

604. CB&I 214 6 214 6 12.3.1.3 – requires leak inspection at all openings, penetrations and construction joints, but does not define the inspection method or acceptance criteria. Visual inspection?

Pittsburgh Comment: The method of inspection can vary and should be required in the QA project specifications.

613. ACI 376 (Hoptay) 217 17 194JH[]

13‐155

Editorial: commentary for this section is missing. Add commentary from committee version to TAC

No change required. Line 5 is simply a title for a two‐column format. The first commentary text is R11.4.8.1 (lines 13‐15). This agrees with response to TAC 617 (refer to file "attachment to NKO email 2009.11.12).



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614. ACI 376 (Hoptay) 217 22 194

JH[same]

11 Editorial: c) should be a separate section as in the committee version. Section 11.4.8 refers to both methods and then lists three.

Item c) as written agrees with response to TAC 617 (ref. file "attachment to NKO email 2009.11.12). To address the second comment regarding "both methods,", delete listing "c)" and keep the wording as a new paragraph.

615. ACI 376 (Hoptay) 217 22 JH[194] 11 Editorial: c) should be revised to included both pre‐tensioned elements and post‐tensioned elements per the committee version sent to TAC.

No change required. Accuracy of stressing for post‐tensioned systems is dealt with here, and that for external winding is covered in 11.5.1 on page 196.

617. Matrix Service (Hoptay) 220 8 196 16 The minimum specified cover in the completed structure is one inch. Why is this statement included in the code section? Committee note ‐ This comment is understood to be referring to the last sentence in 11.5. that discusses concrete cover over strand/wire anchoring clamps.

Agree – committee discuss.

622. CB&I 223 7 223 7 12.6.2 – Differential settlement needs to be monitored for exceedance of the design settlement basis. The design basis does not need to include monitoring. Recommend revised wording as follows: “The tilt and differential settlement of the LNG tank and external piping shall be monitored to confirm that settlement is within allowable limits.”

Agree. Change as suggested. Also, line 4 needs to be rewritten to delete the term "design basis." Pittsburgh comment: Agree. Editorial. Change as follows:



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12.6.1—The tank design basis shall provide equipment and instrumentation for the measurement and recording of translational and rotational movement of the inner vessel for use during and after cool‐down. 12.6.2—The tank design basis shall include LNG tank tilt settlement and differential settlement monitoring between of the LNG tank and external piping shall be monitored to confirm that settlement is within allowable limits.


]

16 Editorial: “Slipforming operations involves a large number of people on in a limited amount of …”

Agree. Change as suggested. Pittsburgh comment: Agree. Editorial. R11.6.2.3—Slipforming operations involve a large number of people on in a limited amount of space, working at different levels simultaneously.


224 20 224 20 12.8 There should be more discussion regarding safety and maintaining a safe environment for tank entry. Concrete may outgas following initially reached safe levels. Reentry may be dangerous.

Response 629 and 631. Comments 629 & 631 have identical wording. Proposed wording change



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in response 632 addresses this comment. Pittsburgh comment: Agree. Proposed wording change in response 632 addresses this comment. Also see response 631.

632. Matrix Service (Oberman) 227 23 203 10 Decommissioning also includes bringing the tank back to conditions where the tank can be entered. Suggested rewording: “Decommissioning” denotes the purging of the tank out of service, the subsequent warm‐up and the introduction of air.”

Agree – adopt suggested wording. Pittsburgh comment: Agree. Editorial. R12.1—Scope The term “Commissioning” is used in this Chapter to denote the tests (hydrostatic and pneumatic) that must be conducted before placing the tank into service; plus the start‐up procedures, such as purging into service and cool‐down. “Decommissioning” denotes the purging of the tank out of service, and the subsequent warm‐up and the introduction of air.

635. Matrix Service (Hoptay) 230 3 205 11 Any reinforcement tests should be completed and approved before concrete placement. Suggested revision: “Concrete and reinforcement tests are completed.”

Agree – committee discuss. Should it be: "Concrete acceptance tests …" or



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possibly "Concrete quality assurance tests. " that are to be completed before hydrotest? Pittsburgh comment: Agree. Editorial. 12.2.3.1—Hydrostatic testing shall not be performed before: a) Concrete materials have reached specified strength and age; b) Prestressing installation, grouting and, if specified, concrete protection is completed; c) Concrete quality assurance and reinforcement tests are completed; d) Inspection and testing of welded joints of metal liners, penetrations, and piping is completed; and e) Metal surfaces are coated or protected against corrosion from test water.

638. Matrix Service (Hoptay) 230 6 205 14 This item implies that all metal surfaces are protected in some manner. Unless test water is not potable metal surfaces typically do not need to be coated. Suggested revision: “If required, corrosion protection of metal surface is complete.”

Agree “corrosion protection of metal surfaces, if required, is complete.



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Pittsburgh comment: Agree. Editorial. 12.2.3.1—Hydrostatic testing shall not be performed before: a) Concrete materials have reached specified strength and age; b) Prestressing installation, grouting and, if specified, concrete protection is completed; c) Concrete and reinforcement tests are completed; d) Inspection and testing of welded joints of metal liners, penetrations, and piping is completed; and e) Metal surfaces are coated or protected against corrosion from test water. Corrosion protection of metal surfaces, if required, is complete.

640. Matrix Service (Hoptay) 230 17 206 1 This first paragraph discusses load conditions previously defined in Chapter 5. Recommend deleting this paragraph which is not relative to commissioning and begin R12.2.4.1 with the second paragraph.

Disagree. Leave as is. Hoptay concurred. Pittsburgh comment: Disagree. No action required.

645. Matrix Service (Hoptay) 231 13 209 9

This wording seems to apply to the inspection of a metal component not a concrete component. Suggest deleting or rewording.

Do not agree. Leave as is. Hoptay concurred.



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Committee note ‐ This comment is understood to be referring to section title: "12.2.6 – Anchorage."

Assuming the comment is referring to line 9 that discusses "tightening of individual anchors," some concrete tank designs being considered do use individual anchors that would require tightening; see C3T brochure for example. Pittsburgh comment: Disagree. No action required. Committee note - This comment is understood to be referring to "12.2.6 – Anchorage." Assuming the comment is referring to line 9 that discusses "tightening of individual anchors," some concrete tank designs being considered do use individual anchors that would require tightening; see C3T brochure for example.

646. Matrix Service (Hoptay) 232 1 209 16 This paragraph assumes that the tank will be hydrotested with seawater but this may not be the case. Suggested rewording: “If the primary container is to be tested with non‐potable water such as brackish water or seawater, all surfaces of the primary concrete tank exposed to seawater the test water shall be spray saturated to a saturated surface dry condition using fresh potable water immediately before the hydrotest.

See response 650. Pittsburgh comment: See response 650.



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650. Matrix Service (Hoptay) 235 2 209 17 This code should not provide guidance on metal tanks. Delete metal containers from this line.

Response 646, 650.Accept and change as shown below. Similar reasoning as response 654 that the provision is not dependent upon whether the tank is constructed of metal or concrete. Hoptay concurred. Therefore suggest changing line 17 to read : ".. seawater for hydrotesting of primary lined or unlined concrete or metal containers is permitted, …" Pittsburgh comment: Agree. Editorial. Also see Response 646 and 654. 12.2.7—Quality of test water The test water shall be clean, and may include suitable corrosion inhibitors. Use of clean seawater for hydrotesting of primary lined or unlined concrete or metal containers is permitted, but at a minimum the following criteria shall be met



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whether using potable, brackish, or seawater for the hydrotest:

682. Matrix Service (McGahey) 248 1 221 1 Pressure and temperature readings should also be recorded. Suggested rewording: “Pressure and temperature readings shall be recorded, monitored and controlled continuously to…”

Agree. Editorial 12.5.9—Pressure and temperature readings shall be recorded, monitored and controlled continuously to ensure that the limiting thermal gradients, acceptable to the future tank performance defined in Chapter 6, are not exceeded.

685. Matrix Service (McGahey) 248 22 221 20 Pressure value for these small pressures should be defined by inches of water. Suggested rewording: “shall be less than 5.0 inches of water (12.5 Mbar).

Agree. Editorial Also see response 694. 12.5.10—Maximum pressure differential between the annulus and inner tank shall be no more than 13 mbar 5.0 inches of water (12.5 Mbar) with the inner tank always at a higher pressure.

694. Matrix Service (McGahey) 252 2 224 11 Pressure value for these small pressures should be defined by inches of water. Suggested rewording: “shall be less than 5.0 inches of water (12.5 Mbar).

Agree. ‐ Editorial Response 685 and 694. See response 685.



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Group 6: Comments not yet addressed.

54. CB&I 32 8 31 18 3.1: Refer to sections of ACI350, which are integral part of this Code (similar to references to API620, NPFA 59A, etc…). For example a cross‐reference to section 3.8 of ACI350 will cover missed ASTM reference standards like C33, C595 etc…

Disagree. This is the reference section and all of ACI 350 is invoked. ACI 350.3 is a separate document which may have caused confusion. PITT 10/27


32 15‐19 32 2‐6 3.1 The list of portions of API 620 applied in ACI 376 is too short. Several topics in addition to those named are referenced to API 620 in various places in ACI 376. For example; Steel plate in composite action (4.8), allowable stresses and joint efficiencies (6.9.1), welding and testing of weldments (6.9.2), and weldment details (9.6.1).

Response 55, 56, 57 Agree in part. The main portions of the API 620 are referenced. The committee will consider the comment as new business for the next edition of this code. PITT 10/27


32 16 32 2‐6 3.1 I understand that ACI 376 must reference the 2008 version of API 620 since it is the currently published version. But note that a new version of 620 will be published soon and will fit with 376 much better. Perhaps an ACI 376 revised edition can follow fairly soon and update this reference.

Response 55, 56, 57 Agree. The latest version of API 620 will be referenced in the next version of the 376 code. PITT 10/27


32 17‐18 32 4‐5 3.1 API 620 App Q at 2008 does not address classification of nonstructural metal barriers. API is incorporating this into next edition.

Response 55, 56, 57 See response 56. PITT 10/27

58. CB&I 33 4‐7 32 14‐17 3.1: Similar to the way this code handles references to API620 or NFPA 59A refer to the exact sections of AWS, which are to be an integral part of this standard, instead of just stating that AWS requirements toward welder's qualification are set forth…

Agree in part. This is a clarification issue and the comment will be addressed as new business. PITT 10/27

60. CB&I 34 1‐6 34 1‐6 3.1: Same comment as for AWS. Similar to the way this code handles references to API620 or NFPA 59A refer to the exact sections of EN 14620‐3, which are to be an integral part of this standard, instead of just stating that EN requirements toward such and such are set forth…

See response 58. PITT 10/27



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61. CB&I 34 17‐20 34 17‐20 3.1: Same comment as for AWS and EN 14620. Refer to the exact sections of MNL‐116‐99, which are to be an integral part of this standard, instead of just stating that MNL‐116‐99 requirements toward precast piles dimensional tolerances are set forth

See response 58. PITT 10/27

62. Matrix Service (Hoptay) 36 4 34 13‐14 Should NFPA 59A reference the latest version 2009? See response 56. PITT 10/27


38 6 38 6 R4.1.1 (b) ACI 349 is the only standard listed as acceptable for material testing of metallic liners. ACI 349 is for nuclear safety‐related concrete structures. This seems like overkill for this application.

Disagree. ACI 349 has tests for metal liners. Consider using the new API 620 in the next edition of the 376 code. PITT 10/27

79. Reiterman, Roy 43 1 43 1 Has no max/min. allowable stresses for steel reinforcement and overlooks min. yield strengths for steel reinforcement which can be found in approved reinforcing standards (both ACI and ASTM). Also a reason to drop fiber strengths since there are none listed. What I do know about temperatures of reinforced concrete is that it is not placed outdoors below freezing temperatures or that heated blankets are used. I.e.: bridge decks when it’s anticipated that concrete will be exposed to temps below 32 degrees overnight.

Response 79, 80, 81 Disagree. The maximum reinforcing steel stresses for cold service were taken from NFPA 59A. The committee does not understand the reference to drop fiber strengths. The temperatures referred to in this section are service temperatures not placement temperatures. PITT 10/27

80. Reiterman, Roy 43 1 43 1 Today there are ASTM standards for A615 reinforcing with higher grades that 60 ksi. They go over 80 ksi in the latest standards. Also, ASTM A706 is higher strength – to over 78 ksi yield strength. Some other corrosion resistant reinforcing is over 100 ksi fy.

Response 79 Disagree. The allowable stresses in this section of the code are based on ductility at service temperature and not based on yield strength of material. PITT 10/27

81. Reiterman, Roy 43 1 43 1 I am not aware of ACI or ASTM that has BS standards. Suggest the text include other steel reinforcing standards, i.e. A775 & 934 are epoxy coated reinforcing standards. Also A767 is zinc coated (galvanized). A1035 low carbon, chromium reinforcing and A933 is vinyl coated.

Response 79 See response 80.



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A955 stainless reinforcing is noted in the text – a states reinforcing with not less than 60 ksi fy but the A955‐09 lists 40, 60, and 75 ksi. Why not list high strength reinforcing?


44 5 44 5 R4.7.2 The list of low temperature rebar seems quite dated. I’d be surprised if one can actually procure today either 25Mn 5 Cr 1 Ni or 9%Ni as rebar. On the other hand something that certainly should be on the list is rebar produced by the Tempcore process (see http://www.arcelormittal.com/sections/uploads/tx_abdownloads/files/TMCP_2004__01.pdf)

Response to 87 to 91 Agree in part. List appears to be incomplete. Defer 87 through 91 to Dale Berner. PITT 10/27


44 6 44 6 R.4.7.2 Krybar is a trade name of ArcelorMittal. Is only that brand permitted?

Response to 87 to 91 See response 87.


44 7 44 7 R4.7.2 Austenitic steels 25 Mn 5Cr 1Ni? Never heard of this. Typo? Response to 87 to 91 See response 87.


44 7 44 7 R.4.7.2 25Mn 5Cr 1Ni is named from Nippon Steel. Is only that one supplier permitted for this grade?



44 8 44 8 R.4.7.2 9% Ni steel is named from Nippon Kokan. Is only that one supplier permitted for this grade?



44 10 44 10 The reference to section 4.10.2 does not pertain to metal liners. It is unclear what actual section reference is intended.

Response to 92, 93 Agree. Reference should be section 4.8. Suggested wording below. 4.8—Plate steel composite with concrete Selection of plate steel used as reinforcement acting in composite action with concrete shall be based on the requirements of API 620, Appendix Q or R, as applicable for the design metal temperature corresponding to minimum service temperature at surface of the plate.



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R4.8—Plate steel composite with concrete Selection of plate material in API 620 Appendices Q and R depends on design metal temperature (DMT) as follows: Appendix Q is applicable to product temperatures to –270 °F; and Appendix R is applicable to product temperatures at +40 to –60 °F.

93. Conlon, John F. 44 10 44 10 is the cross‐reference to 4.10.2 correct? Response to 92, 93 See response to 92. PITT 10/27


45 2 45 2 There is no code requirement for section 4.8. R4.8 is commentary but it uses “shall”. Was it really intended to be commentary?

Response 94, 96, 97 See response to 92. PITT 10/27


45 4‐5 45 4‐5 R4.8 API 620 Tables R‐1 & R‐2 for primary components and Tables R‐3 and R‐4 for secondary components cover similar temperature ranges. These would include product temperature of LPG and of some ambient air conditions. So for an LPG tank, the temperature alone does not determine which table applies in the API 620 edition/addendum referenced. This implies that this section of ACI 376 leads to ambiguous requirements. Note that the planned next addendum of API 620 will resolve this ambiguity for such liners.

Disagree. Plate steel in composite action is a primary component. We will consider additional clarification in next edition. PITT 10/27

96. ACI 376 (Hoptay) 45 14 45JH[44]

210

Editorial: Is section reference correct? Should reference be 4.8? Response 94, 96, 97 See response to 92. PITT 10/27


]

2 Editorial: R4.8 should start on line 6 and the first sentence is section 4.8.

Response 94, 96, 97 See response to 92. PITT 10/27


11 Editorial: TAC had previously commented that a paragraph number can not just be a title and needs to have text associated with it. Section

Agree. Editorial. Renumber paragraphs. PITT 10/27



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] 4.9.1 should be moved to 4.9 and subsequent paragraphs renumbered. This occurs throughout the document.


48 8 48 8 It is hard to understand exactly the respective scopes of sections 4.9 and 4.13. 4.9 is said to be for plate steel used as reinforcement. Is 4.13 for liner plate that is NOT used for reinforcement? Is that the meaning of the term “non‐structural”? It would be clearer if the same terminology were used in both sections. Further the term “non‐structural” is used in 4.13.2 & 4.13.3 but not in 4.13.1, 4.13.4, 4.13.5, or 4.13.6. So is the scope of application limited to non‐structural components only for the sections where the term is used?

Response 106, 107: Agree in part. Consider additional clarification in future business. Consider possible breaking into “non‐structural metal components and metal liners ” PITT 10/27


48 10‐13 48 10‐13 4.13.1 & R4.13.1 It’s not clear to me what the subject of this section is. The commentary states that steel tanks are outside the scope of ACI 376. If the code provisions also pertain to these same tanks, then it should be deleted since there is no point in trying to state a mandatory requirement regarding something outside the scope of ACI 376. Further, why would such full thickness steel tanks be spoken of in a section on “Metal Liners”?

Response 106, 107: Agree in part. Editorial. Replace “Plate steel used solely for…” with “Steel plate liners used solely for…) in 4.13.1. PITT 10/27


48 16 48 16 API 620 upcoming revision will change terminology to “product temperature materials” and “atmospheric temperature materials” In the future ACI 376 should use the later terminology in its references to API 620.

Response 108, 111, 115: Agree. Consider in new business. PITT 10/27


48 16‐17 48 16‐17 4.13.2 This would permit a primary tank liner for LNG to be made of carbon steel (metal classified as secondary component in 620‐Q) no matter what stresses may exist including high tension stresses. That differs from industry practices that I am aware of.

Disagree. This provision allows for design of tanks similar to the successful tanks which have been operating for many years. The section does not permit high tensile stresses. API 620 Q.1.4.1 classifies primary components that would be stressed to a significant level and etc.. Consider adding a commentary section as new business. PITT 10/27



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48 20 48 20 4.13.4 “at least Group II ASTM A516” sounds too severe. Any material confirming the minimum design temperatures in Table R‐4 of API620 should be acceptable.

Disagree. Consider in new business. Review with new version of API 620. PITT 10/27


49 2, 5 49 2, 5 4.13.5 & 4.13.6 API 620 upcoming revision will change terminology to “product temperature materials” and “atmospheric temperature materials”

Response 108, 111, 115: See response 108. PITT 10/27


49 3 49 3 4.13.5 It is not clear what the “service temperatures” are for these vapor barrier plates. For the liner of an outer container of a full containment system, do the service temperatures address only those existing during normal operation or also the colder temperatures existing during a spill case?

Disagree. Service temperatures would be as defined by the function of the component being considered. PITT 10/27


49 4‐5 49 4‐5 4.13.6 This section tries to make its scope of applicability “primary components as defined in Appendix Q of API 620.” But Appendix Q at the edition/addendum referenced does not refer to liners at all so it is unclear how to apply this. Also, consider cases where cryogenic alloy materials (9Ni or stainless) could be required for a liner by the rules of ACI 376, in such a case you would not want the welding procedures to follow App R.

Agree. Revise 4.1.3.6 to read “Welding procedures shall comply with either of Appendix R or Appendix Q of API 620 for primary components.” Committee to discuss. PITT 10/27


49 9 49 9 R4.14 Note that API 625 section 9 will cover insulation in detail and will be appropriate for both steel and concrete containers. Suggest that in the future this section of 376 can be dropped.

Response 108, 111, 115: Agree. Will consider as new business. PITT 10/27

116. ACI 376 (Hoptay)

49 13 49JH[48]

6??8

Editorial: Previous approved versions this document had a commentary for metal liners including part of page 10 8 lines 4‐14. The commentary needs to include this information.

Agree. See response 13. Move lines 4‐13 of page 8 to new section 8.6. 8.6 Liner Design The liner must comply with the applicable performance requirements of Chapter 6 R8.6 Liner Design ‐ The design of the liner should



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consider: a) Service conditions; b) Potential thermal

shock; c) Extra gas

pressures; d) The need to bridge

cracks in the concrete;

e) Resistance to fire; f) Resistance to blast

and impact; g) Resistance to

earthquakes; h) Residual weld

stresses; and i) Concrete strain

due to shrinkage and pre‐stressing.

j) Liners, except for sacrificial liners, must be ductile at all design temperatures. Committee to review. PITT 10/27

117. Matrix Service (Hoptay)

50 4 50 4 Remove reference to roof plates in this paragraph since it is specifically

covered by paragraph 4.13.4 Agree. Revise wording as shown below: PITT 10/27 4.13.3—All roof plate material and nonstructural metallic barriers in the concrete wall 19 and the base slab shall



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be of carbon steel conforming to Table R‐4 of Appendix R of API 620.

118. Matrix Service (Hoptay) 50 4, 11 4849

181

Paragraphs 4.13.3.and 4.13.5 cover the same topic. These paragraphs should be combined.

Agree. Editorial. Revise as future business. PITT 10/27

119. ACI 376 (Hoptay) 50 19, 22 49JH[same

]

8, 10 Editorial: NFPA 59A‐2009 paragraph for insulation is 7.3.5. Disagree. NFPA 59A 2006 version is used in this code. PITT 10/27

120. Matrix Service (Hoptay) Is reference to page 51, lines

2‐6??

52 9‐13 51 2‐6 This was commentary related to the definition of “T” when variable definition was placed at the beginning of each chapter. These lines should be incorporated in the commentary, R5.1.5 Thermal and moisture gradient loading.

Agree. Move the following to the first paragraph of R5.1.5 R5.1.5 Temperature Thermal design loads include loads developed as the result of both transient and steady‐state thermal gradients due to differential time rate of cooling between the concrete wall, steel embedments, and wall liner. Attachment loads developed in the wall at the thermal corner protection location due to a steady state thermal gradient between the wall embedment and secondary bottom are included in this load category. PITT 10/27

121. CB&I Is reference to page 52 line

20??

52 13 52 20 R5.1.2: Define prestressing decommissioning force(s) that must be considered in the design of a primary or secondary containment concrete tank.

Agree. Consider adding clarification in future business. PITT 10/27



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52 19 52 19 Insulation pressure due to perlite will be an internal pressure for the outer containment for full containment tank system and should be considered.

Response 122, 124 Agree. Consider adding to load table, load description and clarification in future business. PITT 10/27


53 6 53 6 Insulation pressure due to perlite will be an external pressure for the inner containment for full containment tank system with a concrete inner tank and should be considered.

Response 122, 124 Agree. Consider adding to load table, load description and clarification in future business. PITT 10/27

125. Matrix Service (Pullinger) 53 6 51 21 Suggest revising to define the bottom insulation system: “2) Bottom insulation systems, including all components that comprise the system (leveling courses, plate and insulation).

Agree in part. Editorial. Revise to: “Bottom insulation systems”. PITT 10/27

126. Matrix Service (Pullinger) 53 16 52 8‐9 The containment may have ring beams at the top and bottom of the wall. Suggest revising as follows: “Vertical prestressing in the wall and the effect of circumferential prestressing force in the wall and in the top or bottom ring beams shall be considered”

Disagree. Leave as is. PITT 10/27

127. CB&I 53 18 54 1 R5.1.5: Define the necessary details of the moisture‐gradient loading needed for design to be provided in the project specifications and make this a mandatory requirement. If definition in the project specification is not mandatory, then indicate the ACI 376 acceptable method(s) for contractor to determine moisture‐gradient loading details. Add method or provide reference to other ACI requirement.

JH & MB. Committee to discuss moisture gradient loading. PITT 10/27

128. CB&I 54 11, 17 54 16, 23 5.1.7 and R5.1.7: Define decommissioning loads that must be considered in the design of a primary or secondary containment concrete tank.

Disagree. Code defines thermal loads during tank warm‐up as an example. PITT 10/27

129. Matrix Service (Hoptay) 54 19 53 8 Lateral earth pressure is not limited to only the walls. Suggest revising line 19: “acting on the walls structure shall be considered.”

Agree. Editorial. Change “walls” to “structure”. PITT 10/27

131. Hoang, Kim for Chevron Team 55 11 55 17 Section 5.1.10 General Live Loads (L), Line 19, Uniformly distributed roof load (R): It is recommended to specify the minimum design live load in this sub‐section, as opposed to Section 5.1.12 – Environmental

Agree in part. Editorial change for next edition as follows:



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loads. Rolf to consider. 5.1.10—General live loads (L) 16 General live loads to be considered include, but are not limited, to: a) Uniformly distributed roof load (R); – A minimum uniformly distributed loading of 25 lb/ft2 shall be used; R5.1.10—General live loads are loads that may change during the mode of operation being considered. Examples include: a) Uniformly distributed roof load (R); both API 650 (Paragraph 3.10.2.1) and BS EN 14620, Part 1 (Section 18 7.3.2.2.2) define a minimum roof live load of 25 lb/ft2. API 620 does not have a similar requirement b) The weight of temporary equipment that can be removed; … .

132. CB&I 56 5 56 11 5.1.11: Replace “applied to the tank as deformed loads. with “accounted for in the design.”

Agree in part. Revise to read: 5.1.11—Differential settlement Short‐ and long‐term differential settlement‐induced loading (Fs) shall be determined by



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analysis and applied to the tank as deformation loads. applied to the structure as imposed deformations. PITT 10/27

133. Conlon, John F.

56 6 56 6 reference to ASCE/ SEI 7 not appropriate for types of structures in Appendix B especially wave and current induced loads. Any guidance for simultaneously occurring environmental loads.

Agree. Consider adding clarification in next edition. PITT 10/27


56 7 56 13 5.1.12 a) ‐ 20 lb/ft2 is described in API620. It should be consistent. Response 135, 136 See response 131. JMH to review roof live load for current code load magnitude. PITT 10/27

136. Hoang, Kim for Chevron Team 56 7 56 13 Section 5.1.12 Environmental loads,– it is not clear what would be an “environmental load” that would create a uniform distributed load of 25 psf. This is obviously not a snow load, as it is discussed in the following sub‐section. If it is a minimum live load, it should be specified in Section 5.1.10. In addition, it is not clear what dictates the increase in the minimum distributed roof live load as compared with other standards that specify a minimum of 20 psf (API 650), and of 12 psf (ASCE 7‐05) roof live load.

Response 135, 136 See response 131. JMH to review roof live load for current code load magnitude. PITT 10/27


56 8 56 14‐19 5.1.12 b) & c) ‐ Detail description of the snow load and wind load are different from API620 section 5.4. They should be consistent.

See response 131. JMH to review roof live load for current code load magnitude. PITT 10/27


56 13 56 17 Refer to using a 3 Second Gust Disagree. ASCE 7 defines wind loading basis. PITT 10/27

139. Cormire, Don A. 57 11 57 18 Paragraph R5.1.12 – Environmental Loads makes note that “API‐650 (paragraph 3.10.2.1) defines a minimum roof live load of 25 lb/ft2. API‐620 does not have a similar requirement.” That was true in 2003 when the ACI‐376 committee began its work on this document. However, the API‐650 document was changed effective 2007 with the release of the 11th edition of that standard. Now the proper paragraph

See response 131. JMH to review roof live load for current code load magnitude. PITT 10/27



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references and design loads are given in “API‐650‐5.2.1.f Design Considerations – Loads – Minimum Roof Live Load (Lr): 20 lb/ft

2 on the horizontal projected area of the roof. The minimum roof live load may alternatively be determined in accordance with ASCE 7, but shall not be less than 15 psf.” Additionally, “API‐650‐5.10.2.1 Roofs – General – Loads: All roofs and supporting structures shall be designed for load combinations (a), (b), (c), (e), (f) and (g) of Appendix R.” [see Appendix R of API‐650 for those load combinations]. Nonetheless, 20 lb/ft2 is the new API‐650 acceptable minimum roof live load in lieu of 25 lb/ft2 given in earlier versions of the document, unless ASCE 7 is invoked which will allow for loadings down to 15 lb/ft2. Additionally, API‐620 was updated effective 2008 with the release of the 11th edition of that standard. See “API‐620‐5.4.1.e Loads – Individual Loads – Minimum roof live load (Lr): 20 lb/ft

2 on the horizontal projected area of the roof.” So, again 20 lb/ft2 is the new API‐620 acceptable minimum roof live load, vs. previously being silent on the subject.


57 15 57JH[55]

1514

Editorial: Reference to Chapter 5 should be Chapter 6. Agree. Editorial. Rolf to confirm. PITT 10/27

141. Matrix Service (Pullinger) 58 5 56 2 The weight of fluid in pipes is a well defined load and should be classified as a product load and removed from this paragraph.

Agree. Consider for new business. PITT 10/27

142. Hoang, Kim for Chevron Team 58 11 58 16 5.1.13 Defines the SSEaft = ½ SSE. This is a better definition than what has previously been assumed where the Aftershock is equal to the OBE. How will inconsistency with NFPA59A be dealt with? NFPA59A implies that the aftershock is equal to the OBE? In some areas the SSE<2OBE. This means that SSEaft < OBE. Is this ok or should the greater number control the size of the aftershock?

Yes, the committee defined SSEaft. As we understand it, NFPA 59A will address the inconsistency in their future revisions. PITT 10/27


59 16 59JH[57]

1614

Editorial: The subjects of the commentary do not follow the same sequence of subjects on the code side. Commentary paragraphs should be rearranged to be consistent with the code sequence.

Agree. Editorial. Consider sequencing and placement in next edition. In particular, lines 8‐16 more properly belong in R5.1.5. PITT 10/27

144. Matrix Service (Pullinger) 60 1 60 JH[57

]

116

Is this not already covered by (c) of this section? If not, clarification of e) may need to be added.

Agree. Editorial. Delete item “e)”. PITT 10/27

145. CB&I 60 10 60 14 5.1.14: Define internal explosion or impact (this seems like a non‐ Agree. Revise section as



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credible design loading condition). Define acceptance criteria and acceptable method(s) of design.

follows: 5.1.14—Explosion and impact (B, Mi) Both external and internal Both explosion and impact loadings shall be considered, if required by the project specification. PITT 10/27

146. Hoang, Kim for Chevron Team 60 13, 15 60 13, 15 Section 5.1.14 Explosion and impact (B, Mi) – It is recommended specifying a minimum “missile impact” or “impact of windborne object” to provide guidance to the Engineer.

Disagree. Project specification should state these loading values. PITT 10/27

147. CB&I 60 17 60 21 R5.1.14: Define acceptance criteria for scabbing. Disagree. Scabbing is defined in R8.4.12. PITT 10/27

148. CB&I 61 1 61 6 R5.1.15: Define the necessary details of the moisture‐gradient loading needed for design to be provided in the project specifications and make this a mandatory requirement. If definition in the project specification is not mandatory, then indicate the ACI 376 acceptable method(s) for contractor to determine moisture‐gradient loading details. Add method or provide reference to other ACI requirement.

See comment 127 & 161. Editorial. : PITT 10/27

149. CB&I 61 8, 9, 10, 11

61 13, 14,

15, 16

5.1.16 and R5.1.16: Define the requirements of NFPA 59A including, if applicable, acceptance criteria and acceptable method(s) of designing for internal fire effects.

Disagree. This chapter is about loads. Acceptance criteria should not be defined in Chapter 5, Design Loads. Design guidance is in 8.4.17. PITT 10/27

150. CB&I 61 12 61 17 5.1.16: Replace the word “Quality” with the word “Quantitative”. Agree. Editorial. PITT 10/27


]

11 Editorial: Redundant wording “ reduces the period of ground motion to reduce to as low as 700 years”

Agree. Editorial. PITT 10/27



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]

14 Editorial: remove parenthesis and negative signs. Agree. Editorial. PITT 10/27

153. Hoang, Kim for Chevron Team 62 4 62 9 d) External pressure: It is recommended providing guidance how to define this loading condition, and what would be the source of this pressure. In case this is to account for “negative pressure”, i.e. pressure resulting from vacuum effects inside the tank that would create a differential external pressure, then this should be clarified. In case the listed “external pressure” is meant to be something else, then the normal loading conditions shall include a vacuum condition as well.

Disagree. Consider adding clarification commentary as new business to suggest external loads can be due to vacuum, wind, perlite, and etc. PITT 10/27

154. CB&I 62 12 62 17 5.2.1.2 Abnormal Loads All potential abnormal loads are not listed. Add site specific abnormal loads as identified through project risk assessment.

Disagree. Ask Jeff Garrison to clarify comment. PITT 10/27

155. CB&I 62 17 62 22 5.2.1.2 Abnormal Loading: “All different cases of product spilling . . . including, but not limited to:” This requirement does not limit a dynamic rupture of the primary liquid container as not viable. Clarify that this is not a viable load condition. Product spilling cases not specifically listed should be handled by a general site specific load requirement.

Disagree. Code does not define all non‐credible loads. PITT 10/27

156. CB&I 62 23 63 5 5.2.1.2: Define the required design spill level in the outer tank when considering “Overfill of the inner tank”.

Disagree. Design spill is a function of the process design. PITT 10/27


63 4‐8 63 9‐13 Editorial: Recommend moving lines 4 to 8 to line 15 for clarity. Disagree. Wording acceptable as is. PITT 10/27

158. CB&I 63 10 63 15 R5.2.1.2 Code states: “Consideration should be given to extending the thermal corner protection to some nominal distance above the normal thermal corner protection if the potential for a full spill exists.” It is recognized that the design of the secondary containment requires consideration for containment of the entire primary container contents which would result in a full spill condition. What is the intent of the code statement? Consider removing.

Agree. Consider removing the second sentence of the second paragraph of R5.2.1.2 PITT 10/27

159. CB&I 63 11 63 16 R5.2.1.2: The phrase “if the potential for a full spill exists” should be deleted. Designing for a full spill is a requirement of 5.2.1.2 (line 16

Agree. See response 158. PITT 10/27



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and 17). 160. CB&I 63 11 63 16 R5.2.1.2: Define “normal thermal corner protection” in terms of

height. Agree. See response 158. PITT 10/27

161. Matrix Service (Hoptay) 63 21 61 6‐11 Typical secondary containments do not install systems to handle small spills. Suggest rewording the commentary as follow: “Small spills are typically spills whose resultant liquid levels are not above the top of the thermal corner protection. Therefore the concrete wall and foundation typically do not experience significant thermal gradients as a result of the spill. Large spills are spills whose resultant liquid levels are above the above the top of thermal corner protection. Therefore the concrete wall is subject to significant thermal gradients during both the transient and steady state phases.” Necessary details Definition of the moisture‐gradient loading needed required for design of the structure should be provided in the project specifications.

Agree. Use suggested wording. Small spills are typically spills whose resultant liquid levels are not above the top of the thermal corner protection. Therefore the concrete wall and foundation typically do not experience significant thermal gradients as a result of the spill. Large spills are spills whose resultant liquid levels are above the above the top of thermal corner protection. Therefore the concrete wall is subject to significant thermal gradients during both the transient and steady state phases.” Necessary details Definition of the moisture‐gradient loading needed required for design of the structure should be provided in the project specifications. PITT 10.27

162. CB&I 64 1, 7 64 6, 12 5.2.2: Define mandatory decommissioning loads. See comment 128. PITT 10/27



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163. Hjorteset, Kare 65 1 65 1 I propose deleting Table 5.1 on page 65, and adding two new tables for primary and secondary tanks SLS cases. The new SLS tables will mirror ULS tables except: ∙ Load factors above 1.0 will be reduced to 1.0. ∙ Columns for abnormal loading conditions except for OBE will be removed. ∙ Rows for SSE, Explosion and Impact, and Fire will be removed. ∙ Row for anchorages will be removed. ∙ Rows for Thermal and/or Moisture: Spill and Fire will be removed. The new SLS tables should be located before the ULS tables in the Code. References to Table 5.1 in page 64 line 13, and page 163 line 119 will need to be changed to reflect reference to new SLS tables.

164. CB&I 65 1 65 1 Table 5.1 1) internal gas pressure should be considered for abnormal

condition of external fire. 2) Thermal and/or moisture should be replaced with individual

lines for thermal, and moisture. 3) Thermally induced (product) loading should be included with

abnormal loads OBE, SSE and explosion (especially for single containment tanks).

4) Spill SSEaft Additional loading type row SSEAFT should be added.

165. Hoang, Kim for Chevron Team 65 1 65 1 Table 5.1, third line from bottom: Under Seismic Loads, there should be another line “SSEAFT”. Spill and SSE should not be combined as this is unlikely and would be a very conservative combination. The combination should be Spill and SSEAFT as specified in Section 6.3.6.

166. Matrix Service (Hoptay) 65 1 65 1 Table: In the first column, Seismic loads – Add a row for SSE aft under SSE and remove the X from that spill column. Place an X in the Spill + SSE aft column.


65 2 65 2 Note a is not very clear when you consider that single containment tank systems may be either single or double wall. We suggest instead “Note a: Will also apply to the primary tank of a single wall tank system.”



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169. CB&I 66 6 66 6 Editorial: 6.1: Section should state, “…minimum performance criteria defined in Section 6.2 through 6.5 and the…”

170. Matrix Service (Pullinger) 66 11 Suggest rewording or deleting second sentence since for secondary containment the potential for a full spill always exists. What is this sentence trying to indicate?

171. Matrix Service (Hoptay) 67 10 64 1 This paragraph begins a new topic. Suggest giving section a new paragraph number (5.2.3?). Also move last sentence as suggested in pervious comment.

172. Matrix Service (Hoptay) 67 11 64 2 Suggest moving to 5.2.2.a.1 to read as follows: “Construction related loading condition, including the sequence of construction and the post‐tensioning sequence.”


67 17 67 17 The material used for inner tank in the installed condition shall be demonstrated to be capable of being purged of natural gas during decommissioning. The natural gas remaining shall not be significant and shall not increase the combustibility of material. In order to meet this requirement, necessary inspection and testing requirements shall be included in this code.

178. CB&I 67 22 67 22 6.2.2: Why is it that the primary container is not required to remain liquid tight for the SSE loading condition? Is the intent of the Code that any earthquake exceeding OBE level follows by a product leak from the primary container? Steel inner tanks are typically designed to withstand the SSE load condition without leak.

180. Matrix Service (Hoptay) 68 1 65 2 What will apply to single containment tanks? Should note “a” read: “This table is also applicable to single containment tanks”?

181. CB&I 68 7 68 7 6.2.3.b): At the end of item b), add the words “in both the vertical and the circumferential directions”

182. CB&I 69 3‐4 69 3‐4 6.2.5: This section states that the primary container shall retain “containment capability” under SSE and SSEaft events. Is containment capability different from liquid tightness? §6.2.2 does not require that the inner tank remain “liquid tight” under SSE conditions while this paragraph requires “containment capability”. Is “liquid tightness" and “containment capability” the same or different. Please clarify in sections 6.2.2 and 6.2.3 and add definitions in section 2.2 as appropriate.


69 3 69 3 6.2.5 “containment capability” should be described more specifically.



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184. CB&I 69 10‐11 69 10‐11 6.2.8: a) Remove the words “Under design loading”. These words only cause confusion and do not add value. b) Define whether specified limit of 0.55f’ci applies to the average compressive stresses or extreme fiber compressive stresses. c) Revise wording “at transfer of maximum prestress” to “at or after transfer (before time dependent prestress losses)”


69 11 69 11 6.2.8 This value is 0.6fci by ACI318.

186. CB&I 69 12 69 12 6.2.9: Change the wording from currently shown to: “Under normal conditions, the maximum concrete extreme fiber compression stresses at service loads (after allowance for all prestress losses) shall not exceed:”

188. CB&I 69 16 69 16 6.2.10: Revise the wording “Under abnormal condition the concrete stresses…” be changed for clarity to “Under abnormal conditions the maximum extreme fiber concrete stresses in compression…”

190. CB&I 69 21 69 21 6.2.12: Define what restrained deformation should be considered and/or add §R6.2.12 with commentaries.


70 1‐2 70 1‐2 6.2.14 This section specifies that “the coefficient of the thermal contractions of the concrete shall be confirmed by the actual mix proportion over the range of the operational temperatures.” The actual mix design of the concrete is done after the type and source of the concrete raw materials are determined, which is typically after the completion of the design. Therefore, it is not practical to specify that the coefficient of the thermal contraction shall be confirmed by the actual mix design. The code should provide a practical guidance to determine the coefficient that should be used for the design

192. CB&I 70 1‐2 70 1‐2 6.2.14: Suggest that this section be modified to reflect the intent of NFPA 59A section 7.5.2.1. (B). This can be done by adding the words “unless prior test data on these properties are available.” At the end of the text in this section. Also, Provide references to the appropriate standards (or cross reference to other parts of this Code) defining testing methods and testing procedures for concrete coefficient of thermal expansion at all ranges of cryogenic temperature. Define a minimum number of temperatures within the required



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temperature range at which tests to be conducted. 193. American Petroleum Institute

Refrigerated Tank Task Group 70 1 70 1 6.2.14 It should be mentioned typical value of the coefficient of

thermal contraction rather than doing test.

196. Matrix Service (Hoptay) 71 8 68 ?? For wire wrapped tanks how is the uncracked zone to be measured? Does the zone include the shotcrete? Suggest adding a sentence to clarify.

198. Matrix Service (Hoptay) 71 13 68 10 This requirement of maintaining a minimum residual prestress level is a code requirement for secondary containment but is not a code requirement for primary containment. This seems inconsistent. Suggest moving this requirement from R6.2.3 and placing on the code side after 6.2.2.c.

199. CB&I 71 13‐14 71 13‐14 6.3.2: a) Re‐phrase for clarity: Change wording “based upon minimum depth of compression and precompression” to “as defined in section 6.3.3.” b) Re‐phrase to make clear that the same liquid tightness requirements at spill apply to the following parts of the tank: i. wall above the TCP potentially in contact with spilled liquid in

case a TCP system and a secondary bottom are provided ii. bottom slab and wall potentially in contact with spilled liquid in

case the TCP/secondary bottom are not provided.


85 10 85 10 6.8 Coating properties belong in Materials Editorial: Not persuasive. This chapter 6 presents minimum performance requirements. Section 6.8 defines requirements coatings must meet for various uses.

248. CB&I 85 16‐18 85 16‐18 6.8.2.a): Is a specified moisture permeability criteria for non‐metallic vapor barrier too liberal? Water vapor permeability allowed by this section for non‐metallic vapor barrier leads to approximately 22lb of water in 24 hrs for an average size LNG tank (80mø x 40m HT). Assuming that unfavorable temp‐humidity condition applies for 2.5mnth per year the annual moisture intake is 22*75=1650 lb/year or 49500 lb for 30 years average of tank service. Any moisture passing through the liner will be traveling toward colder



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surfaces, which may create a significant ice lenses under the perimeter of the inner tank damaging primary concrete or steel tank and insulation. Understand that these requirements are copied from EN 14620, but are they reasonable?

249. CB&I 86 3‐8 86 3‐8 6.8.2.f): a) Is it an intent of the Code that for any seismic event even slightly exceeding the OBE level that the non‐metallic vapor barrier can stop being functional? b) What is a “calculated design crack width” here? Is it a nominal crack width calculated using code methods or a maximum expected crack width? It needs to be defined. To guarantee impermeability it appears that the vapor barrier should be capable bridging the maximum expected crack width. c) Should a non‐metallic liner ability to withstand cracking at seismic be judged only by crack opening velocity or by both crack opening velocity and crack width? It appears that, similar to operating conditions, the liner should be able to span 1.2 times of the crack width expected at seismic to ensure that the vapor barrier remain functional. d) Provide a reference to the method to determine crack opening velocity. Either refer in the Code or add to the Commentaries (§R.6.8.2).

a)

250. Matrix Service (Hoptay) 86 5 Editorial: The entire commentary for this section has been deleted and only the first sentence applies which is new and was not accepted by the committee. Reinsert previous commentary and adjust location of added sentence as appropriate.

Editorial: Ask Joe for location and the old text he is referring to. ROLF: Do you have anything on these changes?

251. ACI 376 (Hoptay) 86 7‐14 JH[80] 19 Editorial: Replace with correct text see above comment. Editorial:



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Ask Joe for the old text he is referring to. ROLF: Do you have anything on these changes?


86 23 86 23 6.9.1 3.9.2 is clearly a bad reference. I think that R4.8 may be intended.

This is correct. Our original text, which was § 2.9.3, referenced § 2.9.2: “… design metal temperature determined in Section 2.9.2.” § 2.9.2 is now § R4.8. ROLF: TO BE RESOLVED: Should § R4.8. be on the code side, as it originally was? It is written in Code language (“shall”). Was it intentionally moved to Commentary or was this an error id editing?

253. CB&I 86 23 86 23 6.9.1: Typo. Section 3.9.2 does not exist. See response to comment 252.

262. Matrix Service (Hoptay) 92 23 86 23 Reference to Section 3.9.2 is incorrect. What is the correct reference? Editorial. See response to comment 252.

298. CB&I 107 7‐10 107 7‐10 R8.1.1.4: See the comment Error! Reference source not found.. 299. CB&I 107 11‐14

17‐18 107 11‐14

17‐18 8.1.1.5 & 8.1.1.6: Wind velocity for roof does not have the same limitations as wind velocity for wall. It may lead to conditions when temperature increase due to solar for the wall is much higher than for the roof. Does it make sense? Suggest in 8.1.1.5 instead of 5% lower velocity limit for solar radiation use a wind velocity averaged over occurrence percentile either for the summer or annually and apply same wind velocity (with allowance for



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height adjustment) to both roof and wall. 300. American Petroleum Institute

Refrigerated Tank Task Group 107 11,

17, 19, 5

107 11, 17,

19, 5

8.1.1.5, R8.1.1.5, 8.1.1.6 ‐ All subsections within 8.1.1 should specify which loading condition is applicable. E.G. Do this in 8.1.1.5, 8.1.1.6, 8.1.1.7 and 8.1.1.11 as is done already in 8.1.1.2, 8.1.1.3, and 8.1.1.4. Otherwise the reader can think that 13 ft/sec is appropriate as a max wind load when we think ACI 376 intends it for thermal analyses.

301. Cormire, Don A. 107 11

107 14 107 14 Paragraph 8.1.1.5 gives coincident wind speed no greater than 13ft/sec for the outside vertical tank surface of the secondary container. This is a little less than 9 miles/hour design loading. This seems contrary to the wind loadings specified for the main tank system given in 5.1.12 – Environmental loads where the Wind loading (W) shall be determined in accordance with ASCE 7. For reference, the API standards use 120 mph winds to be able to withstand hurricane force winds on the gulf coast, or 3‐sec gust design wind speed from ASCE 7, or 3‐sec gust design wind speed specified by the Purchaser. In my local region it would be purchaser specified as 90 mph. Why is the ACI‐376 committee specifying ASCE 7 wind loading for the primary tank system, yet allowing only 9 mph wind design loading for the secondary container? This seems non‐conservative to me. Especially in light of wind loading which must needs impact the secondary (outside) walls of the tank system before coming in contact with the inner walls, if at all. It would seem that the secondary containment walls would need to be designed to the same stringent (high wind) speeds as the inner primary container.

302. Hoang, Kim for Chevron Team 107 14, 15 & 18

107 14, 15 & 18

“13 ft/second”: Wind speed is defined in ASCE 7‐05 in mph (mile per hour), or m/s (meters per second). It is recommended using consistent units to avoid confusion and potential mistakes during conversion.


107‐108

19 107‐108

19 8.1.1.7 The type of requirement in this section, which is non‐linear analysis of the concrete, should be limited for only spill condition.


107 19‐22 107 19‐22 8.1.1.7 Repeat of lines 5 to 8 from Page 106.

305. Hoang, Kim for Chevron Team 107

19‐22 107108

19‐221‐8

Section 8.1.1.7 It is recommended including direction to what loading conditions shall be considered when calculating crack widths.

306. CB&I 107 & 108

19‐22&

1‐8

107 &

108

19‐22&

1‐8

8.1.1.7: This section is very unclear and difficult to read. It should be completely re‐written. Remove pseudo‐scientific wording and define clearly the requirements.



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a) Line 20, p. 107: ”: cracking & tension stiffening are not material modifications – they are stiffness modification. Suggest replace “…material stress‐strain relationship…” with “…section stiffness…” b) Lines 1‐2, p. 108 b. Define required Code c. What is “concrete constitutive model”? Is it EN 1992‐1‐1 concrete stress‐strain relationship? Which one? It allows two different ones… Or crack width calc method?

d. How does this European Code crack width calc method correlate with ACI350 Section 10.6.4?? Should ACI350 be followed?

e. How much credibility European Codes have with US building officials?

c) Line 3, page 108: clearly define a purpose of mandatory FEA? ‐ Is it to obtain internal forces? ‐ Or to determine crack width directly from a non‐linear FEA taking into account concrete/steel stress‐strain behavior? The later one is impractical for the amount of load combinations and design section requiring investigation. The results will be software‐dependent and would not correlate to any codified methods of crack width calcs. c) Lines 7‐8, p. 108: Define characteristic and mean crack width in the definition section 2.2.1. Consider re‐writing this. It should be divided in two sections. i. The first one should address internal force redistribution due to

section stiffness modification via cracking. i. The second one should address crack width calculations method

and requirements. 307. American Petroleum Institute

Refrigerated Tank Task Group 108 1 108 1 8.1.1.7 “The reference to ‘European Code’ should be restated as ‘EN

1992‐1‐1’ The reference in section 3 of ACI 376 should also be to EN1992‐1‐1”.

308. CB&I 108 1 108 1 The term “European Code” should not be used change to EN1992‐1

309. Hoang, Kim for Chevron Team 108 1 108 1 “…European Code…”: It is recommended more specific reference to the relevant European code section, such as “EN 1992‐1‐1: General rules,



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and rules for buildings”, or “EN 1992‐3: Liquid retaining and containing structures”. Also, It is recommended including the reference in Chapter 3 of this document.


108 8 108 8 “8.1.1.8” is missing.


108 9 108 9 R8.1.1.8 “The reference to ‘Eurocode 2’ should be restated as ‘EN 1992‐1‐1”


108 9 108 9 R8.1.1.8 “calculated calculated crack widths” is typo?

313. CB&I 108 9 108 9 The term Eurocode 2 should not be used. Change to EN1998‐2 314. ACI 376 (Hoptay) 108 20 108

JH[same]

20 Editorial: Section 8.1.1.9 should be 8.1.1.8; Section 8.1.1.10 should be 8.1.1.9; and Section 8.1.1.11 should be 8.1.1.10.

315. CB&I 108 20‐23 108 20‐23 8.1.1.9: There are other ways to justify the design besides 3D FEA. Why 3D FEA is mandatory? Suggest the following modifications to this clause: iii. Add at the end of the first sentence “…, unless justified by

alternate methods.” iv. Remove from the second sentence “… and potential failure to

attain the performance level of this standard.”


109 5

109 1 8.1.1.10 The type of requirement in this section, which is non‐linear analysis of the concrete, should be limited for only spill condition.

317. CB&I 109 5‐7 109 5‐7 8.1.1.11: The requirements for transient temperature profile shall be better defined, otherwise this is an open ended list. Ambiguity should be taken out. Does code require that crack widths (serviceability requirements) be checked for transient conditions? Crack widths are not typically checked for transient and temporary conditions.

318. CB&I 109 13‐19

109 13‐19

Para R8.1.2.1 Delete whole section of R8.1.2.1 or replace the whole section with “The determination of the material property values shall be determined by the Foundation Engineer based upon the soil investigation report.” The term Foundation Engineer describes an experienced competent Engineer who possesses a specific mix of talents that encompass both



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geotechnical and structural issues. NEHRP recommended provisions for soil‐structure interaction includes the procedure for the determination of soil/pile stiffness and are acceptable worldwide. ASCE 7 referenced NEHRP in their seismic criteria and soil‐structure procedure.


109 19 109 19 R8.1.2.1 Regarding the sensitivity analysis for soil properties, the variation range is 50 % to 150％ in ASCE‐07. It should be consistent.

320. CB&I 109 20‐21 109 20‐21 Para. 8.1.2.2 Replace to “The range of soil stiffness shall be determined by the Foundation Engineer based upon the variability of the soil provided as described in the geotechnical investigation.” This section could be combined with Section R8.1.2.1.

321. Matrix Service (Hoptay) 110 Table 101 Table In the first column under seismic loads, add a row under SSE and insert SSE aft.


110 1 110 1 8.1.2.3 “Non‐linear soil properties and/or non‐linear pile stiffness” isn’t always required for static and dynamic analysis. Add “if necessary” or “in case linear analysis result is not within acceptable criteria”.

323. CB&I 110 4 110 4 Pare 8.1.2.4 change to “Foundation Engineer.” This can be deleted, it is the same as Section 8.1.2.2 recommended above

324. CB&I 110 10 110 10 8.1.3.1.1: Delete “foundation system” from this line 325. Hoang, Kim for Chevron Team 110 10 110 10 8.1.3.1.1 “The seismic analyses of the RLG tank foundation system

shall be performed for the OBE, SSE, and SSEaft events. The effect of tank wall flexibility shall be considered in these analyses.” Comment: Detailed analysis has shown that considering foundation flexibility is also important and can affect analysis results especially in the vertical and rocking modes. Assuming the foundation to be rigid may be unconservative in some cases.


110 11 110 11 8.1.3.1.1 “SSEaft” should be read as “SSEaft plus spill”.


110 13 110 13 8.1.3.1.2 This paragraph leaves all up to the Engineer. R8.1.3.1.2 Limitations are placed in the commentary section. There should be more limitations on how OBE and SSE performance criteria is achieved. Linear analysis R values and non‐linear analysis requirements should be included as provisions and the criteria should be consistent with the specified damping level and load factors.

332. CB&I 111 3‐4 111 3‐4 Delete “Guidance for selecting…1995.” There are several methods of modeling and the method should be left up to the competent



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Engineer. 333. American Petroleum Institute

Refrigerated Tank Task Group 111 5 111 5 8.1.3.1.3 “Consider suggestion that limitations in reductions of

response should be terms of damping (20%) for SSE & SSE aft, and 15% for OBE.

334. CB&I 111 5 111 5 8.1.3.1.3 Reduction of responses due to soil structure interaction. The limits placed should be based on the damping due to SSI. A change in period should not be part of the reduction limit.

335. Hoang, Kim for Chevron Team 111 5 111 5 8.1.3.1.3 “The reduction of responses due to soil‐structure interaction (SSI) effects shall be permitted, but limited to a maximum reduction of 50% for SSE analysis and 40% for SSEaft and OBE analyses.” Comment: This implies that a fixed base analysis will be required to compare with the SSI effects. Is this the case? Why limit SSI reductions if a detailed analysis is performed that is approved by the owner. Additionally what do those limits apply to? Accelerations, displacements, response spectra, forces?


111 17 111 17 8.1.3.2.2 API620 and API650 do not require the response spectra or time histories for the vertical ground motion. Vertical response could be calculated by simply factored horizontal seismic coefficient.

343. Matrix Service (Hoptay) 112 Table 103 Table In the first column under seismic loads, add a row under SSE and insert SSE aft.

344. Ballard, Thomas A. 112 1 112 1 Section 8.1and 8.2 should include provisions for seismic isolation, time history selection, time history analysis and ground motion selection when performing time history analysis.

347. Hoang, Kim for Chevron Team 112 15 113 4 R8.1.3.3.2 “….For a complex dynamic soil‐pile‐tank foundation interaction problem, the seismic response may be determined based on the finite element seismic analysis method (U.S. NRC 1973).” Comment: The NRC reference provided: U.S. NRC, 1973, “Regulatory Guide 1.61—Damping Values for Seismic Design of Nuclear Power Plants,” U.S. Nuclear Regulatory Commission, Washington, DC, 12 pp. This reference does not seem to be the correct reference as implied in the text.

348. CB&I 112 16 112 16 Para R8.1.3.3.2 Recommend replacing “MCEER 2001 and ASCE/SEI 7‐05” with “NEHRP Recommended Provisions”. See comment 318.

349. CB&I 112 17 112 17 Delete the last sentence. Foundation Engineer as described in comment Error! Reference source not found. has the capability of determining the foundation impedances based upon the data from the



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soil investigation report. 350. CB&I 113 3‐6 113 3‐6 Delete the sentences from “A simple and practical approach … method

(U.S. NRC 1973).” There are several methods available and we leave this to the Foundation Engineer.

351. Matrix Service (Hoptay) 113 13 105 16 The second and third paragraphs are in the wrong section of the commentary remove and renumber as follows: second paragraph should be R8.1.1.2; the current R8.1.1.2 should become the second paragraph. The third paragraph should be R8.1.1.6 (see below).

352. Matrix Service (Hoptay) 113 19 105 22 Roll‐over is not a viable case since for those products where it is a potential condition the tanks are instrumented and piped to control roll‐over. Suggest rewording: “…resulting from vapor generation during roll‐over and spill events should be taken into account.”


113 23 113 23 R8.1.3.4.2 Table 8.1 is correct, not table 7.1.

354. CB&I 113 23 113 23 R8.1.3.4.2: a) Wrong reference. ACI209 is guide on creep and shrinkage. If the intent was to refer to ACI SP‐209 – correct the reference and identify which page (pages) define damping b) Correct typo. Ref table shall be 8.1

355. CB&I 114 1 114 1 8.1.3.4.3: Typo in reference. Should be Table 8.1.


114 4 114 4 Table 8.1 Structural dampings shown in this table are different from value in API620 App. L, which is 5% for impulsive mode.

357. CB&I 114 6 114 6 8.1.3.4.4: Provide damping values for impulsive liquid or provide appropriate reference.


114 12 114 12 8.1.3.4.5 The foundation damping is limited within 10% for OBE and 20% for SSE in API620. They should be consistent.

359. Hoang, Kim for Chevron Team 114 12 114 12 8.1.3.4.5 “The foundation damping for any vibration mode shall not exceed 25% of critical.” Comment: The damping limit should only apply to analysis techniques using modal or composite damping, If a detailed SSI analysis is performed using frequency domain approach As presented in your reference Lysmer et al (1981) a damping limit should not be imposed. Note that updated NRC guidelines do not impose such arbitrary limits for analysis of nuclear plants.

360. Jacobs, Wesley 114 12‐20 114 12‐20 The provisions in 8.1.3.4.5 and 8.1.3.4.6 do not, at least specifically, address the case of a seismically isolated tank, that is, a tank supported on seismic isolator bearings. Several tanks have recently been



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constructed (by CBI) using the FPS system bearings, namely the LNG storage tanks constructed in Peru and Chile. I have copied below several comments and suggestions for specification or ACI standard provisions from a report that I prepared in 2007. Damping: For seismically isolated tanks (base isolated foundation) utilizing friction pendulum type bearings, total system damping shall not exceed; OBE ‐ 25%, SSE ‐ 20% (Total system damping includes material structural damping and SSI damping. The maximum system damping is in addition to the effective damping due to the longer structural period due to lateral deflection of the isolator bearings.) Explanation: This damping limitation requirement specified in 8.1.3.4.6 is applicable to tanks on flexible foundations, eg., Soil Structure Interaction damping, but not to tanks supported on seismic isolator bearings. For seismically isolated tank structures/foundations, the damping is inversely proportional to lateral displacement. Since the greatest displacement will occur during a postulated SSE event, SSE damping will be less than OBE damping. Note that there are two friction pendulum bearing suppliers, so we can use a lower case description.


114 14

114 19 8.1.3.4.6 The foundation damping is limited within 10% for OBE and 20% for SSE in API620. They should be consistent.

362. Hoang, Kim for Chevron Team 114 19 114 19 Section 8.1.3.4.6 The system damping for any vibration modes shall not exceed 15% for OBE and SSEaft, and 20% for SSE. Comment: Same as above comment

363. Matrix Service (Hoptay) 115 5 107 11 This section should be relocated after all paragraphs dealing with the thermal analysis. Current 8.1.1.5 should be 8.1.1.4; current 8.1.1.6 should be 8.1.1.5; current 8.1.1.4 should be 8.1.1.6; and current R8.1.1.4 should be R8.1.1.5.


115 9 115 9 8.1.3.4.8 The “(1‐0.3‐0.3) is not consistent with other published standards such as ASCE7 and API 650/620.

365. CB&I 115 13‐14 115 13‐14 8.1.3.4.10: Why acceleration at the top of the wall but not the appropriate roof acceleration. Suggest the following wording: “For design of suspended deck, steel roof and other equipment supported at



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the roof the maximum seismic acceleration response of the roof at the appropriate radiuses shall be required”

366. CB&I 115 16 115 16 8.2 or 8.3: The code does not address a primary tank slab. It addresses only the foundation design which implies a secondary containment slab or a pile cap. Any special design requirements for the primary tank concrete slab?

367. Matrix Service (Pullinger) 115 22 107 17?? Is it the intent if the committee to have the coincident wind speed requirements be the same for the cylinder and the roof? Currently the roof specifies the speed differently than the cylinder. If they are to be different then it is recommended that the basis be given in the commentary, other wise consider combining 8.1.1.5 and 8.1.1.6.


]

1 Editorial: “constitutive mode model.”


]

9 Editorial: “calculated calculated crack widths.”

370. ACI 376 (Hoptay) 116 7 JH[108] 3 Editorial: Line 7‐12 should be the first paragraph of R8.1.1.7: the second paragraph should consist of lines 5,6 & 15. Lines 16‐23 should form the second and third paragraphs or R8.1.1.7

371. CB&I 116 107

20‐211‐3

116107

20‐211‐3

8.1.1.3 & R81.1.3: Clearly define the temperature requirements for minimum and maximum temperature requirements. R8.1.1.3 says 95% and 5% percentile temperatures. Percentile of what???

- absolute min/max? - average seasonal min/max, i.e. 3months min/max? - 10 days min/max? - 5 days min/max?

372. CB&I 117 2 117 2 8.3: General: Section R8.3 correctly distinguishes structural foundation slabs and slabs contacting with cold liquid. Requirements, similar to the wall requirements outlined in Section 8.4.9, should be added to Section 8.3 to specifically address foundation slab contacting cold liquid.

373. CB&I 117 14‐19 117 14‐19 Para 8.3.3.1: This does not match the requirement in Table 9.1 (page 143). Suggest removing this section and relying only on Table 9.1 for reinforcement ratios.



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117 20 117 20 8.3.3.2 if pile will be applied, about 100mm pile top will be penetrated to slab. So, 5 in. seems to be small. 6 in would be suitable.

375. Hoang, Kim for Chevron Team 117 23 117 23 “No. 4” seems to be redundant. 376. CB&I 118 5‐7 118 5‐7 Para R8.3.5 Replace the whole section to “The anchorage to concrete

shall be designed per Appendix D of ACI 318.

377. CB&I 118 8‐11 118 8‐11 Para 8.3.6 and Para R8.3.6 delete the sections. Anchorage design is covered. Ductility and brittle failures are already addressed in Appendix D of ACI 318 Code.

378. CB&I 118 15 118 15 8.3.8: Remove “When a monolithic wall to foundation joint is incorporated in the design” The presence of the wall will affect the slab analysis for differential settlements included edge differential around circumference even for the sliding or pinned joints. The effects will be smaller than for the monolithic joints but it may have an impact on the design w/ other joint besides monolithic …

379. Matrix Service (Pullinger) 119 3 Recommend stating that the composite structure shall be analyzed for all seismic loadings with the primary container both full and empty.

380. Widianto 119 7‐9 110 14‐16 Please consider moving the following statement to the main body: “The design of a RLG tank should be based on a linear analysis with a force reduction factor R = 1”.

381. Matrix Service (Pullinger) 119 20 Recommend committee add a definition of the basis for which the reduction is to be compared against (i.e. elastic fixed base analysis. Commentary should also provide the basis for the limits on the reduction.

382. CB&I 119 12, 13 119 12, 13 8.4.4: Semantics: Suggest in Line 12: “Service Loads alone” change to “Normal Loads alone” Suggest in Line 13: “Service Loads” change to “Normal Loads”

383. Matrix Service (Pullinger) 120 13 111 18 Recommended that the committee provide guidance on obtaining the time histories as that would match the design spectra. Also the minimum number of time histories to be evaluated.

384. Matrix Service (Hoptay) 120 15 111 19 Section 10.7.5 does not define how the ground motions are determined.

385. Matrix Service (Hoptay) 121 5 112 8 Recommend that stick models be deleted since it is a finite element model and is therefore unnecessary suggested rewording: “…to construct the detailed finite element or stick models of the tank‐fluid‐



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foundation system.” 386. American Petroleum Institute

Refrigerated Tank Task Group 121 8 121 8 8.4.10 This section is not necessary. Vertical pre‐stress is provided to

prevent deformation of wall‐to‐slab due to horizontal pre‐stress.


121 12 121 12 8.4 Revise to “If an impact load is specified….” Impact load is not automatic or mandatory. Revise 4.1.4 to 5.1.4

389. CB&I 123 8‐9 123 8‐9 8.4.15: Editorial: Pressure load applied to the wall below the TCP embedment shall always be included regardless of a spill level. Suggest the following re‐wording: “Pressure load applied to the wall below the TCP embedment due to spilled liquid and, if applicable, internal pressure shall be included in the design of the wall for spill.”

390. Matrix Service (Pullinger) 123 12 Recommend that the vertical mode of vibration (breathing) also be discussed in the section.

391. Matrix Service (Hoptay) 123 15 114 10 Recommended revision: “The convective (sloshing) mode that exhibits a very long period of vibration is considered as decoupled mode from the finite element tank‐foundation model impulsive mode.

392. CB&I 124 12 124 12 8.5.2.b): Change wording: “missile” to “projectile” 393. CB&I 124 16 124 16 R8.5.2: What section of ACI318 addresses dome buckling? Could not

find anything in ACI318 except a few references to papers and IASS recommendations. Same references are in ACI350. Why is it necessary to refer to ACI318? Just refer to the actual papers containing the calc method…

394. Matrix Service (Pullinger) 124 16 115 7 All modes, not just the impulsive and convective modes need to be considered. Recommended revision: “The impulsive, and convective and all other significant modal responses shall be combined by the SRSS (square root sum of the squares) method. The total horizontal and vertical loads responses shall be combined by the (1‐0.3‐0.3) rule for the 3 orthogonal directions.”


125 11 125 11 8.5.4 In case that not consider composite member, is there any limit of distance between studs?

396. Matrix Service (Hoptay) 125 16 116 2 The commentary is discussing types of loads and therefore to be consistent with the nomenclature in Chapter 5 revise to the following: “..both during service conditions normal and abnormal load conditions.

397. Matrix Service (Hoptay) 125 19 116 5 The design of the container is not based on the behavior at service conditions but the requirements of Chapter 6. Suggested revision: “Design of prestressed concrete containers shall be based on both



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strength requirements and on behavior at service conditions serviceability requirements at all load stages that will be critical during throughout construction and the life of the structure. from the time prestressing is first applied .”

398. Matrix Service (Hoptay) 125 19 116 7 To be consistent with the proposed rewording of 8.2.1.2, suggested revision: “While the design is primarily based on the strength method, a number of loading conditions and serviceability performance criteria (particularly those associated with extreme event abnormal loading loads) lend themselves to the allowable stress design method are also required to comply with serviceability limits.”

399. CB&I 126 17 126 17 Reference should be made to ACI 350 Chapter 7 “Details of Reinforcement”, not ACI 350 Ch 9.

400. CB&I 127 11 127 11 R9.2.2.1: Should line refer to table 9.1, not 8.1? 401. Matrix Service (Hoptay) 127 16 143 1 The minimum steel required for a slab in contact with RLG is 0.006 and

is based on ACI 373R. This is inconsistent with Table9.1 of this code which only requires 0.005. Suggest changing the Table to be consistent with Section 8.3.3.1.

402. Matrix Service (Pullinger) 128 1 117 20 .” If the slab is reinforced in both directions with larger bars than # 6 bars the requirement may not be able to be met for both layers. Suggest changing the wording as follows: “The upper mat layer of reinforcement shall be located in the top 3.0 in. of the slab.


]

23 Editorial: delete No.4 since it is redundant.

404. Matrix Service (Hoptay) 128 10 118 3 To insure that the inner tank can if required develop an inelastic response as discussed in R8.3.5 it is suggested that the pull out capacity of the anchor be designed for the yield strength of the anchor. Suggest the following rewording: “When seismic loads dictate that anchors are required to resist the inner tank seismic overturning loads, the pull out strength of the slab or pile cap shall be designed to resist the yield strength of the anchors loads.”

405. Matrix Service (Hoptay) 130 4 119 10 What is the purpose of this section? If it is to define the load combinations, suggest rewording as follows: “8.4.4 The prestressed concrete wall shall be analyzed for the loads and load combinations defined in Chapter 5.”



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]

15 Editorial: Delete “Criteria” and replace with “Requirements” that is the actual title for the chapter.

407. Matrix Service (Hoptay) 130 15 119 18 Consideration was to evaluate having the capacity to place more strands within a duct by having fewer strands in the anchor than the anchor has capacity. Suggest revising the wording: “Consideration should be given to including space within the selected anchorage so that additional strands could be installed to compensate for the loss of prestressing force should a duct become blocked.”

408. Krstulovic, Neven 131 9 131 9 9.4.1.2 To point out that 1" of non prestressed shotcrete cover over the outer layer of wires might not be always sufficient given the corrosive environment these structures could be subjected to, add following text to Commentary: “However, for added durability, cover greater than 1 in. might be considered.”

409. Kuebitz, Karl 131 18 131 18 Delete the sentence beginning with “Moreover…” and add the sentence, “However, additional cover may be specified.”

410. Matrix Service (Hoptay) 132 3 121 1 The distribution of the circumferential tendons is non‐uniform not nonlinear. Suggest revising to read “ Non‐uniform distribution of circumferential tendons.”

411. Matrix Service (Pullinger) 132 9 121 6 Seismic loads also develop vertical bending moments in the wall add point “h.) Seismic loads (OBE, SSE, SSE aft). Remove “;and” from f.)

412. Matrix Service (Hoptay) 133 8 122 3 The variable, “d” in the formula is not defined in Chapter 2, but the variable “D” is defined as the diameter of the Projectile Diameter. Change formula to be consistent.


]

5 Editorial: should be Section 6.3.4.

415. Hoang, Kim for Chevron Team 134 19 134 19 “a durable permanent cover”: It is recommended providing definition and some commentary for what is considered a durable permanent cover.

416. Matrix Service (Pullinger) 134 19 123 8 Does below the liner means below the embedment for the TCP? Suggest wording be changed as follows: “8.4.15 – Pressure loads applied to the wall along the thermal corner protection (TCP) liner shall be included in the design of the wall for both the maximum spill depth



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and for any intermediate spill depth. The pressure may be reduced by the portion of the load resisted be the TCP liner if applicable.”


135 8‐11 135 8‐11 9.5.4.1 The total prohibition of all shell/bottom penetrations on double and full containment differs from what is proposed in API 625 where such penetrations are allowed in a few cases. R9.5.4.1 seems to recognize that the outright prohibition applies to LNG (consistent with NFPA59A) but what about other products? I recommend bringing ACI 376 into conformance with the proposed API 625 and in due course this section might eventually just become a reference to API 625.

418. Hoang, Kim for Chevron Team 135 14 135 14 “…single‐containment concrete tanks, …”: It seems the author meant “…single‐containment concrete tank bund walls, …”.


]

20 Editorial: change bi to bimp in formula.

420. Widianto 137 1‐2 137 1‐2 Chapter 10 is about Foundations and I could not find any test requirements for liners in Chapter 10.


137 1 137 1 9.6.2 Reference to Chapter 10 (which is foundations) makes no sense. It’s not clear what was intended, maybe Chapter 12 on Commissioning.

422. CB&I 137 3‐4 137 3‐4 R.9.6.2: “A metal liner acts as an impervious barrier in direct contact with, and usually bonded to, the concrete.” Recommend changing to more definitive wording: Metal liners shall be attached to the concrete wall. Headed weld studs are usually used, but other structural connections are acceptable. For full containment tanks with concrete roofs, the steel roof liner is usually bonded to the concrete roof with headed weld studs and forms a composite structural element, but this is not mandatory. Steel liners placed on the foundation slab are usually never bonded to the slab, except perhaps at the perimeter. Whenever liners are connected to the concrete, design precautions shall be taken to accommodate differential strains.

423. CB&I 137 6 137 6 R9.6.2: recommend separating the functions and design considerations of liners by type of liner: 1) steel liner liquid and gas tight at product temperature, 2) steel liner gas tight only at temperature above product temperature, 3) non‐metallic liners, 4) membranes.



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424. CB&I 137 12 137 12 R.9.6.2.c: Define “extra” gas pressure. 425. CB&I 137 13 137 13 R.9.6.2.d This seems like a requirement for a coating or a non‐metallic

liner. The subject of 9.6 metallic components. Shouldn’t the crack bridging design requirement be in section 9.8?

426. Hoang, Kim for Chevron Team 137 14‐16 137 14‐16 It is recommended including direction to how exactly should the design of the liners consider resistance to abnormal conditions such as fire, blast and impact, and earthquakes. Also, It is recommended including acceptance criteria. For example, resistance to fire is typically provided by concrete, and the acceptable condition for the liner may be specifying a certain maximum temperature not to be exceeded after specified fire duration.


137 18 137 18 R9.6.2 (i) ‐ The meaning of the term “sacrificial liner” should not be left for readers to figure out. The meaning should be spelled out.

428. CB&I 137 18 137 18 R9.6.2.i: Create new subclause, “j” to separate the loading considerations from the material selection considerations? Define “sacrificial” liner.


137 19 137 19 R9.6.2 (i) line 19 add “except if the liner remains in compression due to prestressing” Reason‐carbon steel liners are use in LNG service and don’t fail.


137 20‐21 137 20‐21 Don’t understand “A membrane is an impervious barrier separated from the concrete by insulation.” Are you trying to cover membrane tanks, where this would apply? These were excluded from the scope.

431. CB&I 138 10‐17 138 10‐17 Suggest including anchorage of the steel liner embedments in the list of metal components covered by this section, and adding what the embedment requirements are for sacrificial liners.


138 11‐14 138 11‐14 R9.7.1 Liners are not named in the scope of this section, but could be construed to be included as an “other item supported directly by concrete”. This important component should not be left unclear. It should be stated to be included or excluded.


]

3 Editorial: Section 4.8 should be 4.7.


139 8‐9 139 8‐9 9.7.4(c) Delete “15 degrees warmer than the LODMAT” as this criteria is for steel shells warmed by the liquid they contain.

435. Matrix Service (Hoptay) 139 12 127 11 Editorial: Table 8.1 should be Table 9.1.



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436. CB&I 140 11‐13 140 11‐13 If circumferential embedments are not to be relied on as an “effective liquid barrier” between the concrete containment and the “metal corner protection”, then state what is considered an effective liquid barrier and specify its use. Note that 6.3.4 states that “Calculated crack widths shall be considered at TCP embedment when cracking would result in liquid product migrating behind the TCP and compromising its effectiveness.” This is not a clear specification requirement either. IF the circumferential embedments are not to be relied on as an “effective liquid barrier”, then calculation of crack widths at the circumferential embed should be mandatory, and the acceptance criteria should be stated.

437. CB&I 141 1 141 1 9.8.2 (Concrete roof, 9.8.4) is a subset of 9.8.2 secondary outer container. Add section to identify need for liner or coating on foundation slab.

438. CB&I 141 11, 12 141 11, 12 R9.8.4. The statement that concrete may be built up in layers is unclear. It is assumed to mean that layers be allowed to harden and gain strength prior to placing subsequent layer. This would require suitable preparation and detailing of the construction joint between concrete layers. Requirements for the construction joint should be included accordingly. Also, it is recommended that the alternative to provide air pressure support of the roof liner to completely or partially offset the fresh concrete load be recognized as an alternative.

439. CB&I 141 13‐16 141 13‐16 Editorial: Update references. Should reference to sections 4.10 and 4.11 instead be to section 4.13 (Metallic Liners) and 4.15 (Coatings)?

440. Widianto 141 14‐16 141 14‐16 The minimum thickness of plate in API 620 is 3/16 in. I understand that there are any other liners that can be used (other than plate liners per API 620). However, currently Section 4.13.1 indicates that plate steel used solely for primary or secondary containment of RLG shall conform to the requirements of API 620.


141 15‐16 141 15‐16 9.8.5 Clearly 4.10 and 4.11 are incorrect references. Perhaps 6.9 and 6.8 respectively are intended.


141 18‐20 141 18‐20 R9.8.5 See comment on 9.6.2(i) above. Liner requirements in too many places, suggest condensing.

443. CB&I 142 4 142 4 9.8.6: Should this section be called “Internal Coatings” to distinguish it from external coatings or paint systems that might be used for



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different reasons? 444. CB&I 142 6 142 6 R9.8.6: Shouldn’t vapor be better defined as “product vapor” and liquid

be defined as “product liquid”?

447. CB&I 144 1 144 1 Fig. R9.1Title should read: Recommendation for increased reinforcing percentage parallel to construction joints” not “… parallel to bonded joints” unless bonding is a requirement. If bonding is a requirement, then specifications for bonding compound should be added and the requirement “concrete ‘bonded’ at joint” should be added to the wall/floor joint. If bonding is not a requirement then the requirement for bonding should be removed from the sketch “joint in floor slab”.

448. CB&I 144 1 144 1 Fig. R9.1Joint in floor slab indicates the use of a waterstop which is not typical in RLG storage tanks. If a waterstop is a requirement, then the specifications for the waterstop should be added to the specification. If a waterstop is not required, it should be deleted from the sketch.

449. Matrix Service (Hoptay) 144 12 131 16 Delete last sentence. The 1 inch of cover is supported by ACI 350, ACI272R and AWWA D110 which is more compelling than the last sentence. The last sentence belongs in the proposed report and not part of the code.


145 16 145 16 Article conflict (“a the structural engineer”) in 1st sentence – Editorial

451. CB&I 145 16 145 16 10.1.1 – change to “…designed by a Foundation Designer …”. The term Foundation Designer represents a specific mix of talents that encompass both geotechnical and structural issues.

452. Matrix Service (Hoptay) 146 5 133 9 The last sentence should be more forceful, suggest the following: “ Field quality control should plays an important rope in validating the construction at joints where liquid tightness is a concern.”

453. CB&I 146 16 146 16 R10.2.1 – change to “…water table are some of the …”. Too restrictive – other information is just as important.

454. CB&I 146 22 146 22 10.2.1.1 Change all following “Structural Engineer” term to “Foundation Designer”

455. CB&I 147 7 147 7 10.2.1.1 Change to “may typically include…” 456. CB&I 147 16 147 16 Change to “prediction of lateral pile load – deflection behavior should

be furnished.”

457. CB&I 147 19‐22 147 19‐22 R10.2.2 – delete paragraph – it is not needed – a competent foundation engineer will know what a borehole is.

458. American Petroleum Institute 148 6 148 6 10.2.2.1 According to this section, total boring hole number will be



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Refrigerated Tank Task Group calculated as 4 + 5 = 9, if base slab diameter is 80m and its area 5026m2 (54100 ft^2). It seems more than usual, which is only 5 locations.

459. Matrix Service (Hoptay) 148 6 135 2 The metallic cover does not need to be continuous over the product height but only over the height of the insulation. Suggested rewording: “Metallic shall be continuous over the product height of the insulation to be protected or and anchored to the concrete wall in a manner that prevents product from leaking behind the metallic cover.”

460. CB&I 148 7 148 7 Para 10.2.2.1 – change to “…tank footprint or at the tank perimeter for each additional…”.

461. CB&I 148 8‐15 148 8‐15 R10.2.2.1 ‐‐ delete paragraph – it is not needed – a competent foundation engineer will know what a CPT is.

462. CB&I 149 3‐6 149 3‐6 Para 10.2.2.6This paragraph essentially defines the intent of Para 10.2.2.3. Combine the two paragraphs.

464. CB&I 150 12 150

149 127

Para R10.2.2.6 this is a commentary, change to “Consideration may be given …”

465. CB&I 150‐151

16‐23, 1‐14

150‐151

16‐23, 1‐14

Para R10.2.2.7 – This statement is purely an opinion and should not be included. Other factors contribute to the choice for additional investigation points. Delete the whole section of R10.2.2.7


]

11 Editorial: Delete and since list continues.

467. Matrix Service (Hoptay) 151 9 137 20 Liner in this code has been used to indicate metallic components that are in contact with the concrete and that are separated from the concrete by insulation. Since this code does not cover membrane tanks this distinction is not required.

468. Matrix Service (Hoptay) 151 13 138 1 Liners that are sacrificial under cryogenic temperatures do not need to be cryogenic grade material. Suggested rewording: “Liners which are required for liquid tightness or structural reinforcement during thermal loadings will require material suitable for the design temperatures unless precompression of the steel is ensured for all design cases.”

470. CB&I 152 10 152 10 Para R10.2.3.4 – The performance criteria should be spelled out or summarized here in case the location of the requirement changes location in the next edition of NFPA 59A.

Discussion Note: reference to NFPA 59A is to 2006 edition. See page 34 line 10 of Chapter 3 – Referenced



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Standards. 471. American Petroleum Institute

Refrigerated Tank Task Group 152 12 152 12 10.3 Should add mention of “modulus of subgrade reaction” for

shallow foundations. Additionally, information should be provided in the geotechnical report about usage of friction between the base slab and soil to provide additional lateral resistance.

472. Matrix Service (Hoptay) 152 19 139 3 A thermal analysis that predicts the temperature of a concrete anchor above the liquid level will always be warmer than the product temperature. Reword “The warmer of product temperature or The temperature determined in accordance with Chapter 6 8 where metal …..”

473. Matrix Service (Hoptay) 152 22 139 6 The design metal temperature should be the colder of the two criteria. Suggested rewording: “For metal components on the exterior of concrete containments the design metal temperature shall be the colder of the temperature determined from analysis in accordance with Chapter 8 and the lowest 1‐day mean ambient temperature” The 15 F increase in temperature is not applicable and is deleted since it does not meet the requirements of API 620 where this provision originated.


153 9 153 9 Should reference be PIP STE03020? Please clarify. Response 474, 475. PIP STE03020 is titled Guidelines for Tank Foundation Designs.

475. CB&I 153 19‐22 153 19‐229‐10

Para R10.3.1 – There are several methods for design of ringwalls. PIP 2005c is one way – not the only way. Listing just one is too specific. The method should be left up to the competent Foundation Designer.

Response 474, 475.

476. CB&I 153 20 153 20 R10.3.2.1 Remove sentence “The approach defined in Duncan ..purpose.” There are several methods how to perform this and we should leave this to the Foundation Designer.


154 9‐ 18 154 9‐ 18 10.3.2.4 I don’t understand how the CODE can mandate that allowable bearing pressures must conform to Table 10.1, and then the COMMENTARY says that the safety factors in Table 10.1 can be reduced. Doesn’t the code side need to address permitted variations from Table 10.1?

481. Matrix Service (Hoptay) 155 15 141 16 What performance requirements are thin metal liners required to meet? Should section 4.11.be section 6.8?

Reference to 4.10 and 4.11 should be ___ and ___.

482. American Petroleum Institute 156 13 156 13 10.3.4 It is better to express these safety factors in a table like table



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Refrigerated Tank Task Group 10.1 and 10.2 483. CB&I 156 15 156 15 Para. 10.3.4. Change to “The minimum factor of safety against sliding

due to service level loads (unfactored loads) shall not be less than 1.5 for wind and OBE, and 1.0 for SSE loading cases.”

485. CB&I 157 3, 4 157 3, 4 Para. R10.3.4 change to “The maximum ultimate coefficient of friction should be tan 30 degree unless testing validates a higher value. The maximum allowable frictional resistance under wind lateral load is equal to 0.40 with a safety factor of 1.5. The coefficient of friction should consider the materials underlying the tank bottom.”

Response 485, 524.


157 9 157 9 Recommend adding the word “foundation base slabs”.

491. CB&I 159 5,6 159 5,6 Para 10.4.1.1 – Replace this sentence with “The selection and design of the deep foundation system shall be conducted by the Foundation Designer in close cooperation with the Geotechnical Engineer and the Structural Engineer. “

492. CB&I 160 3 160 3 Para R10.4.2 – Replace with “Many types of piles can be utilized.” Driven and CIP piles are not the only types.

Response 492, 493, 494, 495.

493. CB&I 160 5 160 5 Para R10.4.2 – Delete “Such a program is most effectively conducted shortly after the geotechnical investigation.” The pile test program can be done at any time prior to start of production piles. Linking it to the geotechnical investigation is not needed.

Response 492, 493, 494, 495.

494. CB&I 160 6 160 6 Para R10.4.2 – Add “Where possible, …” before “All piles…”. It is not always possible to wire all test piles. Use “may” instead of “should”

Response 492, 493, 494, 495.


160 7 160 7 Electronic monitoring is not clear. Does the code mean a dynamic analysis program?

Response 492, 493, 494, 495.


160 16 160 16 Should the dimensional tolerances for Steel H‐Piles be governed by AISC?

Response 497, 499.


160 22‐23 160 22‐23 Blow counts should be performed by the best method possible. If you have multiple rigs operating (which is the case for most piles), it may be impossible to get the right count electronically if it is done by the sound.

Response 497, 499.

499. CB&I 161 1‐3 161 1‐3 R10.4.2.1 – Reference to the FHWA course is too specific. Leave the requirements to the project specifications as stated in line 23.


161 11 161 11 Reference numbers are not clear.

502. Matrix Service (Gianni) 161 22 147 14 R10.2.1.2 should be written in mandatory language and moved over to



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the code side. These design parameters should not optional. The uplift capacity of the piles should also be provided by the Geotechnical Engineer.

503. CB&I 162 1‐7 162 1‐7 R10.4.2.3 – Rewrite to address all types of piles. The existing words address only driven piles.

504. CB&I 163 4,5 163 4,5 R10.4.3.2 replace with “…piles may be determined by a test performed in accordance with ASTM D3689, dynamic test, osterberg cell and others.”


163 12 163 12 10.4.4.1c) This section is not required because settlement can be evaluated by b).

506. CB&I 164 16 164 16 R10.4.5.3 replaced “AISC 2005” with “ASCE 7‐05”. ASCE 7 considers the soil, test results, and steel allowables.

507. CB&I 164 17,18 164 17,18 R10.4.5.3 change to “Ultimate strength for concrete piles … with ACI 350 or ACI 318”

508. CB&I 164 22, 23 164 22, 23 Para R10.4.6 – Either delete or Replace second sentence with “The design of the pile and/or pile group should be based on a determination of the lateral deflection of the pile head and distribution of resulting moment and shear along the pile shaft using a method of analysis that takes into account such issues as pile‐soil interaction, load duration, load repetition, structural restraint at the pile head and the effect of pile group action.” The pile design is performed by the Foundation Engineer.

Response 508, 509, 510.

509. CB&I 165 2 165 2 Para R10.4.6 – Delete reference to PIP 2005a. Too specific. Response 508, 509, 510. 510. CB&I 165 6‐9 165 6‐9 Para R10.4.6 – Delete all of this paragraph. Should not reference

commercial programs. There are other methods that can be used. The last sentence is out of context and not needed.

Response 508, 509, 510.

511. CB&I 165 13 165 13 Para. R10.4.6.1 delete “by the Geotechnical Engineer”. The appropriate people will review the test results.

514. ACI 376 (Hoptay) 166 23 JH[152] 2 Editorial: Section reference should be 8.1.3. Committee note – Cannot find text being discussed.

515. CB&I 168 11‐15 168 11‐15 Para 10.6.1.3 Consider deleting this section. ACI 350 covers the requirement for mix design already.

Response 515, 516 are same.

516. CB&I 168 16‐19 168 16‐19 Para R10.6.1.3 Consider deleting this section. ACI 350 covers the requirement for mix design already.

Response 515, 516 are same.

517. Matrix Service (Gianni) 168 1 153 1 ?? Provide clarification of “Transition zones”.



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Committee note ‐ This comment is understood to be referring to the term "transitional zones" on page 153 line 1.

523. Matrix Service (Hoptay) 171 11 156 10 ?? Does the foundation design permit the partial uplifting of the foundation during overturning loadings such as seismic loadings?

524. Matrix Service (Gianni) 172 20 156157

144

The 0.40 coefficient of friction has an inherent factor of safety which is nominally 1.5. Does the minimum factor of safety recognize this or is it intended to place an additional factor of safety on the sliding resistance?

Response 485, 524.


173 14 173 14 10.7.3 “the foundation” should include “foundation and pile”. Include with response 565.

526. CB&I 174 3‐8 174 3‐8 Para. 10.7.5 and R10.7.5 – Delete these paragraphs. Seismic monitoring is usually an owner requirement. While perhaps a good idea, it is not appropriate to include this requirement in a concrete design code.

Response 526, 527, 528.


174 3 174 3 10.7.5 Multiple seismometers should not be required on all tanks. One seismometer is normally enough to record the seismic event. Refer to API625 section 7.5.3.

Response 526, 527, 528.

528. Hoang, Kim for Chevron Team 174 3 174 3 Section 10.7.5 Seismic monitoring “The seismic response of the RLG tank shall be monitored by triaxial accelerometers mounted at the foundation and the roof of the tank. A third accelerometer shall be located at a free‐field site at a distance of at least two tank diameters away from the tank and other major structures.” Comment: This is a very good requirement. However current NFPA59A does not have such a requirement. Will the NFPA59A include this in the future?

Response 526, 527, 528.

529. CB&I 174 10 174 10 10.8 Monitoring Frequency This Code is for design and construction. It is not intended for operation. All operation monitoring requirements are not appropriate for this Code. A requirement to have the ability to monitor is appropriate and monitoring prior to commissioning is appropriate.


175, 176

18‐23, 1‐

4

175, 176

18‐23, 1‐4

10.8.4 & 10.8.5 Recommend deleting these sections. Basis is that these are on‐going MAINTINANCE INSTRUCTIONS indicated for the owner to follow after tank is in service. Seems out of proper scope of the code.

533. CB&I 176 12 176 12 Para. 10.9.2.1 Replace “precise” with “actual” Include with response 536.



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536. CB&I 176 12,16 176 12,16 Paragraph 10.9.2.1 – Adding total traceability is a new requirement –

especially for loads of concrete and lots of rebar. Adds significant cost. This normally an owner requirement if desired. This is too strict for many instances.

538. CB&I 177 16 177 16 Para 10.9.3.4 – When lots of activity is going on , it may be very difficult to get this data to the owner in one day. Too tight of a time line. Time is needed for the contractor and sub‐contractor to review the data first. This is normally an owner requirement. Perhaps one can say “… in a timely manner.”

542. CB&I 180 3 180 3 Verify statement, “These tolerances are typically in line with established LNG/LPG practice.” What is the value of this statement? Consider removing.

543. CB&I 181 13 181 1314

Maximum tank wall radius tolerance at top of wall is too restrictive. Allow maximum of 1.25 in.

544. CB&I 181 15 181 1512

Maximum tank wall radius tolerance at base of wall is too restrictive. Allow maximum of 2.0 in.

554. Kuebitz, Karl 186 23 186 23 Add “the exterior of tank may be wrapped in plastic to maintain moisture in the shotcrete”.

555. Kuebitz, Karl 187 20 187 20 Replace “the normal method used” with “one way”. 557. Kuebitz, Karl 188 2 188 2 Add “Automated shotcrete with the nozzle traveling parallel to the

surface at a known linear or bi‐directional speed ensures uniform coverage and thickness over the entire exterior surface.”

559. Widianto 190 19‐23 172 11‐15 Do we need to specify the required minimum holding time during hydrotest for settlement readings? For example, we need to keep at least 24 hours at full hydrotest level. Settlement readings should be taken when the water reaches the full hydrotest level and after 24 hour holding period. This is probably more important in clay‐type soil where the settlement can occur after a longer period than that in sandy soil.

560. Widianto 190 19‐20 172 11‐12 Section R10.7.1 Settlement measurement should also be taken prior to hydrotesting to obtain baseline data


563. Krstulovic, Neven 191 6 191 6 11.4.4.3 (c) What is the source of the acceptable bleed limits listed in the section? Replace 11.4.4.3 ‐ (f) with:



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“A grout bleed test shall be performed for horizontal and vertical tendon grout. Grout bleeding shall be determined per the Wick Induced Bleed as described in the PTI guide Specification, “Specification for Grouting of Post‐Tensioned Structures”. When tested by the Wick‐induced method average bleeding for 3 test series shall not exceed 0.30% of the initial volume of grout after 3 hours kept at rest.”

565. Matrix Service (Hoptay) 192 9 173 15 This is not consistent with R10.7.1 which indicates that the inclinometers should be considered when the predicted settlement values approach the limiting settlement values. Suggest requiring inclinometers when the predicted settlement exceeds ½ of the code limits and not only soil types A and B.

568. Matrix Service (Hoptay) 194 11 175 4?? During hydrotest the readings should also be taken with approximately the same liquid level in the tank.

574. Matrix Service (Hoptay) 196 2 176 12 The precise location of each load of concrete in the structure is not practical and should not be required.

575. Matrix Service (Hoptay) 196 5 176 14 The location of each lot of reinforcing within the structure is also not practical and should not be required.

576. Matrix Service (Hoptay) 196 8 176 17 What type of mill certificate is required? Mill test reports or certificates of conformance?

577. Kuebitz, Karl 196 11 196197

11 Add, “Through the use of continuous electronic force measurement and correction a more stringent force tolerance is achievable.”

Response 577‐583.

578. Kuebitz, Karl 197 2‐6 197 2‐6 Move second sentence beginning with “At…” to commentary and replace “one stress reading” with “four stress readings”.

Response 577‐583.

579. Kuebitz, Karl 197 9‐11 197 9‐11 Move paragraph to commentary. Response 577‐583. 580. Kuebitz, Karl 197 7 197 7 After “written,” add “or continuous electronically generated”. Response 577‐583. 581. Kuebitz, Karl 197 12 197 12 Replace, “the” with “field die‐drawn”. Response 577‐583. 582. Kuebitz, Karl 197 14 197 14 After “reinforcement,” add “without deflecting the wire or strand.” Response 577‐583. 583. Kuebitz, Karl 197 14 197 14 Add, “Continuous electronic reading should be made along the full

length of the wire or strand. Continuous electronic force readings are usually performed in conjunction with mechanical prestressing methods.”

Response 577‐583.

586. Matrix Service (McGahey) 200 17 180 4 How many places and at what location are these tolerances to be checked in the base slab?

587. Matrix Service (McGahey) 202 16 182 5 Definition of the minimum number of intermediate heights to be checked should be established. Recommend a minimum of



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approximately every 10 ft of height. 588. American Petroleum Institute

Refrigerated Tank Task Group 203 8 203 8 R12.1 Revise – commissioning in all the other industry standards refers

to purging, cooldown and product introduction. Hydrostatic and pneumatic testing are just that – tests. NFPA 59A also lists them under tests.

Term commissioning is used throughout this document to denote hydrostatic and pneumatic testing as well as all other procedures necessary for placing the tank in service. Leave as is. Consider as new business. See Comment 26 with the same response.


205 14 205 14 12.2.3.1(e) “or protected against corrosion” is quite vague. Disagree. This paragraph does not define the type of corrosion protection to be used, It defines timing of hydrostatic testing which cannot be executed before corrosion protection has been applied. See also response 638


205 21‐22 205 21‐22 12.2.4.1 I believe that the ACI 376 code should mandate the minimum hydrotest levels that are given in the R12.2.4.1 commentary. This should not be made a contractual matter. This is a serious deviation from accepted industry practices for RLG tanks. Regardless of the quality of the concrete container design and construction, the supporting soils are always a matter of significant uncertainty.

Agree. Add to 12.2.4.1. “The test load shall not be less than 1.25 times the product weight.”

591. CB&I 205 21 205 21 Hydrostatic testing12.2.4.1 “The contract documents must define the test loads that were considered in the design.” This would allow the contract documents to allow no hydrostatic load test. There MUST be a load test and this code must define the minimum test level for the primary liquid container. It also must define is the secondary liquid container requires a load test.

See response to 590



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Paragraph R12.2.4.1 discusses test liquid heights but is not clear at all on what should be the basis.

592. CB&I 206 18 206 18 12.2.4.4 – requires visual inspection of all surfaces prior to hydrotest. Note, all surfaces may not be accessible. Considering defining pertinent surface that require visual inspection.

Agree. Change text to: “Before hydrotesting, all accessible surfaces to be wetted shall be…”

593. CB&I 207 1 207 1 12.2.4.6 – requires spray‐saturated surfaces. Note that fill rate may limit the ability to maintain saturated‐surface‐dry condition prior to test water fill level reaching all surfaces.

Leave for new business.

594. CB&I 209 15 209 15 12.2.7 Quality of test water This section allows brackish and sea water for testing. While sea water may be an acceptable water source, does following this code’s requirements assure that the structure will maintain its structural integrity during service? For this section it appears more appropriate to place the language in a commentary paragraph.

The committee believes that, if properly executed following 376 test water requirements, hydrotesting will not jeopardize structural integrity of the tank. Also see responses 595, 596, 601, 650.


214 7 214 7 12.3.2 Consider making Pressure and vacuum relief testing simply refer to API620.

To be considered in new business.


215 7‐9 215 7‐9 12.3.4 Metallic internal pump columns are not appropriately within the scope of ACI 376. These are not in any way a part of a concrete container.

Disagree.

608. CB&I 216 5 216 5 R12.4.3 The reference should be “before the dew point temperature . . . “

Disagree: However, Remove the first phrase “Before the temperature reaches the freezing point of water, “

609. CB&I 216 14 216 14 R12.4.5 Dew point temps API 625 provides dew points. Suggest that API625 be referenced as a better source than a paper.

Disagree



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610. CB&I 217 1 217 1 12.4.8 This paragraph discussed the use of “liquid nitrogen as a prelude to cool‐down.” Use of liquid nitrogen for cool‐down is not the standard method of cool‐down and may damage a tank designed for LPG or other similar gasses. There is no paragraph covering warm product gas purge following the nitrogen purge and prior to introduction of product liquid which is the norm. Introduction of product liquid directly into a pure nitrogen environment can cause sub‐cooling below the design temperature due to the lack of a product partial pressure.

Agree Change to read “Alternatively, purging into only LNG service”. Include with response 684 Also correct error in R12.4.8 by changing 32oF to 14oF. Address the last paragraph of this comment as new business.


217, 228

1 217, 228

1 Replace LNG with RLG – ACI 376 is for many products. Agree. This is addressed in response 684, 685, 690‐691, 695‐699, 701‐702.


217 13 217 13 R12.5 Imposing ACI 376 (concrete code) on the cooldown of metal primary tanks is inappropriate.*

Response 612, 674. Agree. Change text to: “Except for cool‐down rates, these provisions also apply



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to tanks where the inner container is metal. Cool‐down rates for metal inner tanks are tank‐specific and should be referenced in the contact documents”


219, 220

16, 8 219, 220

16, 8 R12.5.7 & 8: The cooldown rates and maximum permitted temperature differentials seem to be taken from metal tank criteria and might be unconservative for thick concrete walls and rigid wall to floor joints. Suggest you talk to N. Legatos but inform him your walls are much thicker that his experience.

R12.5.7 covers inner steel tanks. The text should read as shown below: R12.5.7—For steel inner tanks A typical overall cool‐down rate is approximately 5.4 oF to 9.0 oF per hour or as stated in the contract documents. For steel inner tanks A typical maximum permitted temperature difference between any two adjacent RTDs (or thermocouples) is 54 oF and is 90 oF between any non‐adjacent RTDs (or thermocouples) except as limited by the recommendations of R12.5.8. Two adjacent RTDs (or thermocouples) are defined as RTDs (or thermocouples) (a) on the same surface located next to each other, or (b) at the same elevation but on opposite faces of the wall.



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Since this Code does not deal specifically with steel tanks, both this commentary and the corresponding code paragraph 12.5.7 should be removed (note that 12.5.8 repeats what 12.5.7 states). 12.5.9 and R12.5.8 are related to inner concrete tanks and should be left as is. Response covers both 679 and 616. See response 679.


221 4‐18 221 4‐18 Section R12.5.9 provides detail flow rate, duration and cooling rate. However, the cooling rate is in conflict with the previous section R12.5.7. The flow rate 353 ft3/hr (= 10m3/hr) is a typical flow rate for steel tanks. This flow rate is not realistic for concrete tanks.

Agree. This needs to be made generic for RLG or deleted. NOTE: The objective is to control temperature gradients. Prescribing it in terms of product rates does not provide a generic solutions since it is a function of the product type (different latent heats of vaporization) and the tank size. R12.5.9—For approximately the first three hours of the cool‐down, pressure and



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temperature readings should be made as often as possible on a continuous basis. The maximum time interval between readings should not exceed 15 minutes. During the first third of the cool‐down period 12 hours, the rate of RLG LNG flow should be kept below approximately 353 ft3/hr. After 12 hours, the rate of LNG flow may be increased in increments while monitoring the temperature decrease to avoid excessive thermal gradients. A rate of increase at each 3‐ to 12‐hour interval of approximately 1.32 gal/minute has been successfully used before. This value might be subject to variation depending on the temperature or pressure readings. The estimated maximum flow during the cool‐down operation should be approximately 2300 ft3/hour. This flow range



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is only a guideline. The actual flow rate should be governed by the temperature gradient guidelines provided in R12.5.8 rate of temperature drop between approximately 1.08 °F/hour – 2.27 °F/hour, subject to the aforementioned recommendations. If the allowable rate of temperature change is not within the allowable limits, RLG LNG flow should be reduced or stopped until appropriate action is taken to ensure that the cool‐down rate is under control.

Include with response 684 to rewrite for RLG.


221 13 221 13 R.12.5.9 A cool‐down rate is provided but it is placed in the commentary. Cool‐down can cause undetectable cracking in the concrete that goes beyond the assumed design basis. Limits should be placed in the provisions paragraph.

Include with response 684 to rewrite for RLG. See response to 618.

620. CB&I 223 4 223 4 12.6.1 Why is transitional and rotational movement monitoring needed?

Response 620, 621. Jeff Garrison will check 49CFR. Recommend deletion if not required by CFR or make specific to LNG. Generic for



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RLG is NOT to have these devices. PITT 10/25

621. CB&I 223 4 223 4 12.6.1 – requires provision of equipment to measure movement of inner tank shell (including rotational movement) during and after cooldown. This has not been a required practice for metal tanks previously and is considered unnecessary.

Response 620, 621. Same issue as 620. PITT10/25

623. American Petroleum Institute

Refrigerated Tank Task Group 223 16 223 16 12.6.5 Revise “design professional” or define. Engineer is defined. Agree. Change to

“Engineer”. PITT 10/25 Straw vote OK.

624. CB&I 223 21 223 21 A structural design standard should not instruct an owner how to operate his tank. All provisions and comments in this section should be restricted to instruments that are necessary to maintain the tank design basis. Suggest that this section refer to API625.

Agreed in part. This section needs to be reviewed to make it generic for RLG. • George to check FIP. • Tom Howe will check

with process engineers. PITT 10/25


224 1 224 1 12 7.1 Revise to “…top and bottom fill nozzles for terminal LNG tanks shall be required.” No need for bottom fill at LNG base plants or for other products.

Response 626, 627. Address in response to 624. PITT 10/25


224 1 224 1 12.7.1 Other methods such as recirculation may be used to avoid stratification. Also, tank stratification is not normally a problem for “pure products” such as Propylene, Ammonia and Ethylene. The requirement for top and bottom fill nozzles appears too restrictive..

Address in response to 624. PITT 10/25


224 20 224 20 12.8 The decommissioning section is outside the scope described in 1.1 (“design and construction…”) It seems like it ought to be in an appendix or separate document.

Disagree. Decommissioning considerations should be part of the design. PITT 10/25

630. CB&I 224 20 224 20 This section makes many references to LNG and Methane. This Code applies to many more gasses than Methane and this section should reflect that.

Agree. This is addressed in response 684, 685, 690‐691, 695‐699, 701‐702. VERIFY THAT CONTEXT HAS NOT CHNAGED

631. CB&I 224 20 224 20 There should be more discussion regarding safety and maintaining a safe environment for tank entry.




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Concrete may outgas following initially reaching safe levels. Reentry may be dangerous.

See response 629 Committee agrees with response 629. PITT 10/25

634. Matrix Service (Hoptay) 229 4 204 13 The requirement for hydrotesting the secondary containment needs to be more definitive in the code section. Suggested rewording: “Hydrotesting of the secondary containment is not customary required. R12.2.1 If specified in the contract documents that the secondary containment is to be hydrotested but the provisions of Chapter 12.2 are also applicable. for testing the secondary containment when it is required.

Agreed. Use commentor’s suggested wording. PITT 10/25 Straw vote yes.


Refrigerated Tank Task Group 230‐240

5 230‐240

5 Appendix A Consider deleting these figures since these integrated concept figures more properly fit in the scope of API 625. Instead refer to API 625 (which contains better quality color figures) for the storage concept figures and in ACI 376 concentrate on the distinctives and details of concrete containers.

637. CB&I 230 5 230 5 Tank configurations This standard should reference API625 for tank configurations. Any configurations not shown in API625 can be added there. Definitions for single, double and full containment are much more complete in API625


Refrigerated Tank Task Group 230 7 230 7 A.1 & A.2 Appendix A appears to be presented as code rather than

commentary. It should be commentary (i.e. RA.1, and RA.2) and be introduced as “examples” or “some variants” of the storage concepts. We don’t want such illustrations to preclude other possible variations. “Examples” is what they are called in EN 1473 from which the figures were adapted.

641. Legatos, Nicholas A. 231‐240

1 231‐240

1 Fig. A.1(a) and A.1(b) are mislabeled and in fact incorrect. For example, they are both titled “Single‐containment tank system” while actually showing a single‐containment on one side of the tank cross section and a full‐containment on the other. Fig. A.2(a) through A.3(b) are correct but insufficiently titled. This is because, although the titles are accurate, they do not clearly identify the difference between A.2(a) & A.2(b) on one hand and A.3(a) &



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A.3(b) on the other (metal primary container in the former pair vs. concrete primary container in the latter). Moreover, the whole grouping of the figures is inconsistent, with some of them paired up on one page and others occupying single pages. Attached is a set of correct figures, titled and arranged in a more logical method. [PDF Files LNG 1, LNG2, LNG 3, LNG4, and LNG5]. These are updated versions of the figures prepared by the writer for the original draft of the ACI 376 document. These figures are also available in AutoCAD format.

642. Krstulovic, Neven 231‐240

1 231‐240

1 Fig. A.1(a) through A.5(b) Modify the figures to clarify the intent. Show the OUTSIDE container made of steel in both side (a) and (b) of Figure A.1. Change legend to state: “Outer tank shall typically be made of steel”



231‐240

1 231‐240

1 Appendix A Section 6.2 ‐ specifies requirements for primary container, and sections 6.2.3 and 6.2.6 makes reference to concrete base. However, Appendix A does not provide any example that includes “concrete base” used as part of the primary container. Looking at the figures, it appears that steel plate is on top of base insulation.


231 1‐3 231 1‐3 Fig A.1(a) and (b) right half It does not make sense to show three concrete walls (two are full height) in a single containment tank system. That’s never been built and would never make sense to build. Who would build an outer full height concrete wall that contains the vapor that would not be designed to hold spilled liquid?


232, 240

1, 1 232, 240

1, 1 Figure A.1(b) and A.5(b) The right half section of Single Containment example A.1(b) appears to be more stringent (3 concrete walls) than Full Containment example A.5(b) (2 concrete walls).


232, 235, 236, 239, 240, 243

1 232, 235, 236, 239, 240, 243

1 Figures A.1(b), A.3(a), A.3(b), A.5(a), and A.5(b) These figures show concrete wall as primary container and the bottom annular insulation under the concrete primary container is “Bottom rigid insulation”. In Figure A.7(a) it shows “BALSA BLOCK FOOTING with RADIAL SHEAR BARS”.



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This annular insulation is essential to support all the loads from the concrete primary container including dead weight, seismic loads, etc. Annular insulation system for conventional LNG tanks (9%Ni tanks) consists of concrete ring beam and foamglass insulation as shown in Figure A.6(c). However, due to the fact that the total weight of the concrete primary container wall is estimated to be more than 10 times heavier than that of a 9%Ni primary container shell, it is not possible to use foamglass. Typically, materials that have higher strength will have higher density and higher thermal conductivity. Therefore, it may be a challenge to select a material that has enough compressive strength (with a certain safety factor) and low thermal conductivity to prevent frost heave at the same time.

649. Matrix Service (McGahey) 232 20 207 18 Reviewing ACI 228.2R it is not clear which NDE test would be used to check for liquid tightness. As discussed in R12.2.5.2 each test has its strengths. Committee should provide direction as to which test or tests need to be performed to verify leak tightness.

Revise by adding “and as approved by Owner.” To the end of 12.2.5.1 (b)(2) on line 18 pg 207. PITT 10/25

652. Matrix Service (Hoptay) 237 13 212 5 Previously it is stated that the hydrotest shall not exceed 30 days but in this section the hydrotest may be extended to consolidate the soil. Given the critical nature of these tanks and the unpredictable behavior of soil this code should not suggest that consolidation of the soil could be accomplished by the hydrotest. Suggest deleting this paragraph.

Revise by removing the phrase “to consolidate the soil.” Suggest: “In some instances the hydrotest water will be maintained in the tank for an extended period of time. In these instances, the engineer should make special provisions.” PITT 10/25

653. Matrix Service (McGahey) 237 21 212 13 The code needs to address Microbiologically Induced Corrosion (MIC) as a potential source of corrosion and steps to take to mitigate risk from MIC.

Suggest revising sentence starting on line 13 page 210 to read, “ Use of non‐potable water as the liquid for hydro test in RLG tanks poses a unique set of



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challenges ,including microbiologically induced corrosion.(MIC) “ PITT 10/25

655. Matrix Service (Hoptay) 238 15 213 1 The 250 ppm is less strict than the quality of the water required in 12.2.7 (e) which is 50 ppm and is also the requirement of API 620 App. Q.

Suggest deleting sentence starting on line 1 page 213 12.2.9.5 should then read. “The washing shall be performed with a high‐pressure (> 2500 psi) spray . The tank shall be dried immediately after washing.“ PITT 10/25

656. Matrix Service (McGahey) 238 19 213 5 It is assumed that this requirement is for concrete tanks only. Provide commentary describing what is trying to be removed and what an inspection after brush scrubbing should look for.

Suggest deleting 12.2.9.6 page 213. OR Change it so it is only for concrete when seawater is used ‐‐ If this can not be confirmed, leave it to be only for concrete and revisit it as a part of New business

657. Matrix Service (Hoptay) 239 2 213 7 The engineer should be notified before the settlement limits are exceeded. Suggested rewording: “When settlement monitoring determines that the measured settlements exceeds 75% of the predefined predicted values the Engineer shall be notified immediately.”

Agree use commentor’s suggested wording. PITT 10/25

658. Matrix Service (Hoptay) 239 5 213 10 R12.2.10 is covered in Section 10.7.1, suggest removing from this section. Committee note – Combine this with comment 560.

Agree that R12.2.10 does not belong here. However it does not appear to be covered by 10.7.1 and related sections. Suggest moving from here and incorporating into appropriate sections in Ch.



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10. Propose moving to R 10.8.2. Mike to verify where to put it.


242 1 242 1 Fig. A.6 (b) Revise perlite (yellow) to not extend horizontally past extension of inner tank shell. Overhang is dangerous. Perlite in LNG requires filters for removal. See Fig. A‐7(a)

664. Matrix Service (McGahey) 242 5 216 4 There should not be any standing water at the start of the purging or the tank. This should be required before the start of the purging procedure. Also is the 8% limit conservative for all RLG? Recommend defining the limit in generic terms as a property of the gas.

Agree that standing water should be removed before start of purging. (Paragraph 12.2.9.5 specifies that after the hydrotest “the tank shall be dried immediately after washing”). Change text to: 12.4.3—Both the inner tank and the annular Perlite space shall be purged to a final oxygen level of 8% or less by volume, and dried so that all standing water is removed. Oxygen limit response 664, 667, and 671. Jo to develop corresponding text that will include all other RLG..

665. Matrix Service (Oberman) 242 7 216 5 What temperature is being referred to in this section and how does the commentary relate to the code section?

See response 608 R12.4.3—Before the temperature reaches the freezing point of water, prolonged and excessive drying should be avoided as



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residual moisture enhances compressive and tensile strength.

667. Matrix Service (McGahey) 242 15 216 11 Refer to previous comment on oxygen limit. Response 664, 667, and 671. See response 664


243 1 243 1 Figure A.7(a) A layer of Teflon/Fiberglass sheet is laid under both the inner wall and outer wall. This may reduce the friction factor to accommodate the thermal movement of the wall. However, this will also affect the sliding resistance against the horizontal seismic acceleration, which is required in section 6.2.5 and 10.3.4.

669. Hoang, Kim for Chevron Team 243 1 243 1 (a) Detail at roof: The detail clearly shows steel framing supporting the roof. This steel framing, combined with the concrete overlay creates a composite section, and there is no guidance or reference in this code for how to design the composite section. ANSI/AISC 360‐05 Specification for Structural Steel Buildings, Chapter I, provides specifications for design of composite members, and therefore it should be included within the referenced standards in Chapter 3 of this document.

671. Matrix Service (McGahey) 243 2 216 19 Refer to previous comment on oxygen limit. Response 664, 667, and 671. See response 664

672. Matrix Service (Hoptay) 243 4 216 21 The purge of the tank may need to be held for an extended period if the remainder of the facility is not complete.

• Matrix: not always feasible?

• Possible reason – concrete tanks – in which case we do not want to dry the tank for too long (Note ONLY to NKO ‐ before locking concrete moisture at freezing temp).

• Possible solution: change “immediately” to “as soon as practical.” Move to



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Commentary & add explanation that we want to avoid excessive drying of concrete, which stops once concrete moisture freezes

12.4.7—If the entire purging operation is to be accomplished with warm nitrogen, advanced preparations shall be made to begin cool‐down immediately after the oxygen and dew point target values are reached.

674. Matrix Service (Hoptay) 244 1 217 11 If the commissioning section covers only concrete tanks why is this sentence included here?

Response to 612 resolves this issue.

677. Matrix Service (Hoptay) 245 19 219 4 A cooldown ring may not be required for all RLG. Warmer products do not require cooldown rings.

Proposed change: 12.5.5—A cool‐down spray ring line shall be provided under the suspended deck and equipped with spray nozzles so that cooling down of the tank can be controlled effectively.

679. Matrix Service (McGahey) 246 14 219 16 Are these typical rates for a concrete primary container? These are typical rates experienced for steel inner tanks.

See Response to 616. (This question has been addressed previously. Check with correspondence or contact Nick Legatos.)


]

17‐21 Editorial: It appears that this is a repeat of 12.5.8. Delete 12.5.8.2. Agreed. Remove lines 17 to 21 on page 220, because they are a repeat of lines 3 – 7 on the same page.



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MOVE TO EDITORIAL 683. ACI 376 (Hoptay) 248 8,9,1

7 221

JH[same]

7, 8, 16, 21

Editorial: replace LNG with RLG. See response to 618. Response 683, 684, 686. 688. See response 684. 12.5.11—The fill bottom unloading line shall not be opened once until RLG LNG has begun to accumulate in the tank. Wording change to be consistent with RLG and response 684

684. Matrix Service (Oberman) 248 8‐16 221 4‐18 This data is for an LNG tank and possibly for a steel inner tank and specific cooldown ring. Since this code covers all RLG then specific values such as these could be misleading without a frame of reference. Guidelines for determining the flow and cooldown rate should be given not specifics.

See response to 618. Response 683, 684, 686. 688; also 618, 619. Pg. 221 lines 4‐18 & pg. 222 lines 1‐22 are specific to LNG. Agree that this should be rewritten to address RLG.

686. Matrix Service (Oberman) 249 3‐22 222 1‐22 Why are requirements related to LNG and not RLG? Revise for RLG. Response 683, 684, 686. 688. See response 684. R12.5.11—(Remove the following text because 12.5.11 states that you need to wait until RLG has begun to accumulate in the tank.) When the average bottom slab temperature is approximately–238 °F and the thermal gradient in the concrete has begun to



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stabilize, the flow of LNG through the unloading line to bottom of tank may begin. The tank should not be filled from the bottom unloading line yet. When the average bottom slab temperature is approximately the stored product temperature –256 °F and liquid LNG is detected by the tank gauging system, RLG LNG will have begun to accumulate in the tank. At this time the bottom filling line may be opened and the flow through the cool‐down line may be stopped. At this point, before continuing unloading, the emergency shutdown valve should be opened and tested. 12.5.12—The cool‐down shall be considered complete when the warmest point on the inside face of the wall is at least ‐250 °F and the thermal gradients are within the specified limits, and a minimum amount of product as specified in



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contract documents, has accumulated. R12.5.12— (CHECK Author of this paragraph to verify that the quasi‐complete concept is no longer required and can be removed. The ‐250F requirement in the definition of completed cool down was deleted to make the paragraphs more generic for RLG.) The cool‐down can be considered complete if the warmest point on the inside face of the structure is at least ‐250 °F. If, despite extended spraying, this condition is not reached, the structure can be considered as cooled quasi‐complete. If the cool‐down of the structure is complete (so that the warmest point is at least ‐250 °F), it can then be filled at specified maximum filling rate of 70,630 ft3/hr, unless the rate of filling is limited by geotechnical other considerations (for example by geotechnical or process design considerations)., need for



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slow‐rate loading of foundations, as may be specified in Chapter 12.6). The tank should be initially filled with LNG from the bottom fill line to a height of 10 ft. If the cool‐down of the structure is only quasi‐ complete (that is, some point will remain warmer than –250 °F) the rate of bottom filling should be such as to satisfy the criteria outlined in R10.5.9. In this case, readings should be taken at intervals not longer than 1 hour.

687. Conlon, John F. 249 3‐7 249 3‐7 Appendix B Scope—the status and relevance of ACI 357 (Fixed Offshore Concrete Structures) to the scope of this draft is not addressed. It needs to be. In line 6, suggest changing ‘350’ to ‘357’ as a good start to fix the omission.


]

2, 5 , 6, 18

Editorial: replace LNG with RLG.

Response 683, 684, 686. 688. See response 684.

689. Hoang, Kim for Chevron Team 249 1 249 1 Text in red is what is contained in Chevron response "2E_Chevron verify_2010 04 20 ‐376 Public Comments Compiled to Chair ‐ Update 5‐14‐10.doc" received May 24, 2010

a. Sliding of GBS is not addressed. Do safety factors in Section

10.3.4 against sliding also apply to GBS? In moderate to high seismic zones it may be difficult to design for no sliding for the



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SSE. b. Does this appendix apply to all types of tanks, SPB,

membrane? If so some specific requirements to membrane tanks are necessary

c. Sliding of GBS is not addressed. Do safety factors in Section 10.3.4 against sliding also apply to GBS? In moderate to high seismic zones it may be difficult to design for no sliding for the SSE.

d. Does this appendix apply to all types of tanks, SPB, membrane? If so some specific requirements to membrane tanks are necessary.

e. Section B.3.1.2.1 defines SSE as 4975 return period. This is not consistent with NFPA59A and criteria for onshore tanks.

f. Section B.5.1.3 Global seismic analysis of the GBS is very complicated. Dynamic analysis using response spectrum method should not be allowed except for preliminary calculations. The detailed global analysis must include soil‐structure interaction effects. GBS base slab and wall flexibility should be modeled.

g. Section B.5.1.8—“If time‐history analysis is used, at least three sets of ground motion time histories shall be applied” Which set of results shall be used? Maximum or average response?

692. Matrix Service (Oberman) 251 4 223 18 This visual inspection may only identify large voids in the insulation since the thermal mass of the concrete secondary container may mask the cold spot unlike a steel outer tank. It may be necessary to perform a thermal scan of the wall if this inspection is to be meaningful. If voids are determined to be present how will the voids be filled? Committee note ‐ This comment is understood to be referring to section title: "12.6.6—The tank shall be inspected for cold spots where insulation may have formed air pockets in the vertical side walls."

Add Commentary: R12.6.6 – Due to large thermal mass of the concrete outer wall (as compared to a steel tank wall) visual detection of cold spots might not be possible. Therefore, use of other methods, such as thermal imagining, might be necessary.


255 13, 14 255 13, 14 Appendix B provides design criteria for offshore units (concrete GBS or floating hulls) and refers to the requirements of NFPA 59A. It is not appropriate for B.3.1.2.1 to make reference to NFPA 59A (7.3.2), since



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this is for land based field erected containers 703. Conlon, John F. 257 7 257 13 suggest that: mooring loads should be categorized as ‘live loads’. 704. Conlon, John F. 257 7 257 13 e) mooring loads for vessels moored to the structure; and for a floating

RLG structure, temporary and permanent anchor line loads maintaining the structure onsite.

705. Conlon, John F. 258 2 258 2 Suggest in item (d) mention be made of liquid sloshing in floating structure.

706. Conlon, John F. 259 8‐11 259 8‐11 The application of B.3.4.2 is unclear. Presumably the mentioned probability values are ‘per annum’.

707. Conlon, John F. 262 2 262 2 Delete wording after ‘…containment.’ 708. Conlon, John F. 271 7 271 7 In B.8.4.3, suggest that mention be made of ‘air gap’ to avoid overhead

obstructions

709. Conlon, John F. 272 15‐17 272 15‐17 In B.8.5 Moorings, possible confusion in terminology. Text refers to tow arrangements (tow lines and fittings) not moorings. The subject of permanent moorings of a floating terminal structure was not found in the draft standard.

710. Conlon, John F. 274 16 274 16 In B.9—‘Decommissioning’ here implies removal of the structure. Earlier in section 12.8, decommissioning addressed purging out of service and warm‐up. The latter is appropriate; the former may not be. See also ‘Weaknesses’ below, item 3.


280 17 280 17 Appendix C provides guidance on fatigue résistance. It is noted in section C1 that it focuses principally on offshore facility, however same requirements also applies to onshore facilities. While fatigue resistance criteria furnished for off‐shore facility appears to be a good guidance, this is not required for on‐shore facility.

Please provide your input on the document in each area below: Strengths: Thomas A. Ballard: The entire Code is well written and covers a considerable amount of experience from the oil and tank manufacturing industry. John F. Conlon: This standard is needed to facilitate the use of concrete structures for LNG (RLG) containment. It is my understanding from this draft that the primary interfaces between the LNG (RLG) and the concrete will be metal liners or specialized coatings. Weaknesses:



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Thomas A. Ballard: Seismic isolation and other seismic analysis provisions. John F. Conlon: 1) As indicated by my specific comments above, my main interest is with offshore structures {bottom founded (GBS) and moored‐floating}; while the work expended to create Appendix B is commendable, I believe the design of a GBS OFFSHORE structure should follow ACI 357R, and not this standard. More specifically this means: the specification of load categories, the defining recurrence periods for environmentally induced loads, the averaging period for wind loads, and Load Combinations and the Load Factors should be as specified in Subsection 4.4 of ACI 357R. The use of this draft standard for these considerations will not be correct. For example, typically the dominant design environmentally induced load for an offshore structure are hydrodynamic loads from wave and current (based on 100 year return period per Appendix B and ACI 357R). The hydrodynamic loads will be ‘Environmental Loads: other’ in the Load Factor tables in Section 7 of the ACI 376 draft; thus a Load Factor of 1.6/ 0.5 is specified. Per ACI 357R, the Load Factor for wave induced storm loading is 1.3. As can be seen, this will make a large difference in design requirements for the structure and its foundation or moorings. 2) The design of a floating structure may have other ramifications that are not addressed by either draft ACI 376 or ACI 357R. In general, the type of structure for floating offshore LNG storage will probably be more ‘ship‐like’ and not cylindrical. More specifically the design criteria will also need to be more ship‐like, where there will be the need to give consideration to global ( ‘hull‐girder’ strength) and local strength considerations. In maritime countries, the local authorities will have experience with LNG tank vessels, and it might be expected that numerous local and international technical regulations dealing with such vessels will be applied to offshore storage structures. This has already happened with offshore oil storage where Marine Pollution and other IMO Regulations are imposed by regulatory bodies (e.g. Coast Guards) on offshore hydrocarbon storage structures, even though the structure is not a trading vessel. 3) Mention is made in Appendix B (B.9) of structural removal. It may be appropriate to require in design –a study to assess the feasibility of platform removal and the need to build into the structure special features that will facilitate removal; (such as under foundation slab water jet outlets to break soil adhesion). However, is structural removal typically considered in the scope of ACI design and construction standards? Cognizant regulatory bodies will most likely have project specific requirements about structural siting, navigation hazards, platform removal, etc. So, for such considerations it may be more appropriate just to mention that, “the rules and regulations of all cognizant regulatory bodies are to be identified and considered in the design, construction, inspection, maintenance and repair of the platform.” Roy Reiterman: It’s obvious the text is biased toward fiber concrete and states that steel reinforced structures are an alternate. Suggestions for improvement: Thomas A. Ballard: Much more guidance should be provided for use of time history analysis since details such as isolation are becoming important to design of RNG tanks in high seismic regions. The Code should include a section on seismic isolation, time history selection, response spectrum matching and number of ground motions to be considered. It would also be useful to discuss design of RLG below LNG temperatures, such as liquid nitrogen and liquid oxygen tanks. John F. Conlon: 1) Perhaps brief mention can be made about expected functions, subsystems and other considerations that will affect the design. For example: Is it expected that personnel will be quartered on the offshore structure? Can transport / supply and maintenance vessels be expected to berth and moor to the platform? Will there be helicopter facilities? What needs to be said about loading and unloading arrangements from the offshore terminal? Are there structural design implications concerning equipment to gasify/ re‐gasify?



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2) In the draft, reference is made to other ACI documents. In some cases the subject being referred to is of fundamental importance such as Load Case and Load Factors. To the greatest extent possible, fundamentally important topics should be included in the standard itself. Personally, I do have the latest version of ACI 350, which appears to be necessary to apply 376. 3) In Appendix B, will any mention be made of: corrosion protection criteria; sea floor scour and scour protection; and structural inspections? Blanchard, J. for NFPA 59A Task Group: Provide more provisions to limit design and construction variation. There is too much definition in the commentary section. If it is important, set minimum requirements in the provision paragraphs and then place background and preferred direction in the commentary. Roy Reiterman: None. I do not believe that the text is accurate. Overall opinion: Thomas A. Ballard: This is a well written Code and should be very useful for designing RLG tanks. John F. Conlon: The draft is a very worthwhile document that fulfills important needs concerning the subject of RLG containment. Hopefully suggested improvements and corrections will be made to the standard before it is issued. The status of ACI 357R is called into question because of Appendix B. ACI needs to clarify the status of ACI 357R. Appendix B is not a suitable replacement for ACI 357R. Similarly the status of ACI 357.2R for concrete barges and its relationship to Appendix B of ACI 376 needs to be addressed by ACI. Karl Kuebitz: This document is very clear and professional. Thank you to all of the contributors. Blanchard, J. for NFPA 59A Task Group: As chairman (speaking for myself – not the NFPA 59A committee) of the NFPA 59A task group assigned to review this ACI document for general content, and duplication & conflict with the NFPA 59A document, I can state that the ACI376 document provides much needed definition / regulation of concrete liquefied gas storage structures. The ACI 376 document should allow NFPA 59A to reference the document to add the same depth of regulation as provided for steel tanks. While there are many minor refinements which can be addressed in the revision process for the standard, the content and depth of coverage provide what the committee was looking for from ACI. The task group review process was based on a draft version provided by ACI in February 2009. As such the comments above are limited to what the task group identified except for comments which are no longer applicable due to final changes made by ACI376. Comments are mainly directed to eliminate conflict between standards. A critical detailed review for design content was not made except to verify current NFPA59A provisions were satisfied. I would like to thank ACI for completing this effort in time to incorporate it into NFPA 59A during the current revision cycle. Roy Reiterman: I am disillusioned to think that this text could be an ACI document.

ACI Committee 376

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Transcript of ACI Committee 376