7 3814 AX SG 000002 IS05 Structural Steel Specification

STRUCTURAL DESIGN SPECIFICATION

FOR

STEEL & R.C. STRUCTURES

Document Identification Code

3814-AX-SG-000002

Sheet 1/34 Issue 05 Client: CDEEE - Corporación Dominicana de Empresas Eléctricas Estatales

Plant: 2x360 MW Coal-Fired Power Plant Location: Punta Catalina, Baní República Dominicana

This document is CDEEE‟s property, and cannot be used by others for any purpose, without prior written consent


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05 05.Mar.2015 FINAL ISSUE - revised where marked V.Manerba A.Guarino M.Martoglio

04 03.Feb.2015 FINAL ISSUE V.Manerba A.Guarino M.Martoglio

03 10.Nov.2014 FINAL ISSUE (revised where marked ) V.Manerba A.Guarino M.Martoglio

02 23.Jul.2014 FINAL ISSUE (revised where marked ) V.Manerba A.Guarino M.Martoglio

01 14.Apr.2014 FOR COMMENTS V. Manerba A. Guarino M. Martoglio

Issue Date Reason for Issue – Revision Description Prepared Checked Approved

OWNER DOCUMENT CLASSIFICATION CODE

IN – INTERNAL ISSUANCE

FI – FOR INFORMATION ONLY

FA – FOR OWNER‟S REVIEW AND APPROVAL

X

FC – FOR CONSTRUCTION OR FOR PURCHASE

FR – FOR RECORDS

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CONTENTS

1 SCOPE ................................................................................................................................ 4

2 CODES, STANDARDS AND SPECIFICATIONS ................................................................ 4

2.1 LOCAL REGULATIONS ............................................................................................................. 4 2.2 PROJECT SPECIFICATION AND DRAWINGS ................................................................................ 4 2.3 INTERNATIONAL CODES .......................................................................................................... 5 2.4 TECNIMONT‟S STANDARDS ..................................................................................................... 6

3 DESIGN REQUIREMENTS ................................................................................................. 7

3.1 LANGUAGE ............................................................................................................................ 7 3.2 SITE CONDITIONS................................................................................................................... 7 3.3 SOIL MECHANICS AND GEOTECHNICAL CONDITIONS ................................................................ 7

4 DESIGN LOADS ................................................................................................................. 7

4.1 DEAD LOADS (DL) .................................................................................................................. 8 4.2 LIVE LOADS (LL) .................................................................................................................... 9 4.3 EQUIPMENT LOADS (EE, ET, EO) ......................................................................................... 10 4.4 THERMAL LOADS.................................................................................................................. 11 4.5 WIND LOAD (WL) ................................................................................................................. 12 4.6 EARTHQUAKE (EL)............................................................................................................... 12 4.7 TEST LOAD (TEL) ................................................................................................................ 12 4.8 FLUID LOAD (FL) .................................................................................................................. 12 4.9 EARTH LOAD (HL) ................................................................................................................ 12 4.10 IMPACT LOAD (IL) ................................................................................................................ 12 4.11 LOADS FROM VIBRATION (VL) ............................................................................................... 13 4.12 CONSTRUCTION LOAD (CL) .................................................................................................. 13 4.13 LOADS DUE TO PULLING TUBE BUNDLES ................................................................................ 14 4.14 ELEVATORS ......................................................................................................................... 14 4.15 FORKLIFT ............................................................................................................................ 14 4.16 PAVING, TRENCH COVERS, CULVERTS AND BRIDGE LOADS (VEHICLE LOADS) ........................... 14 4.17 PIPE RACK MINIMUM LOADS ................................................................................................. 15

5 LOADS COMBINATIONS ................................................................................................. 15

5.1 BASINS ............................................................................................................................... 16 5.2 COMBINING NOMINAL LOADS USING ALLOWABLE STRESS DESIGN ......................... 16 5.3 COMBINING FACTORED LOADS USING STRENGTH DESIGN ...................................... 17

6 SERVICEABILITY ............................................................................................................. 19

6.1 CRACK LIMITATIONS ............................................................................................................ 19 6.2 ALLOWABLE DEFLECTIONS ................................................................................................... 20 6.3 ALLOWABLE DRIFT LIMITS .................................................................................................... 21

7 MATERIALS ...................................................................................................................... 21

7.1 CONCRETE .......................................................................................................................... 21


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7.2 REINFORCING STEEL ............................................................................................................ 22 7.3 REINFORCEMENT COVER ...................................................................................................... 22 7.4 MAXIMUM AND MINIMUM REINFORCEMENT SPACING .............................................................. 22 7.5 MINIMUM REINFORCEMENT .................................................................................................. 22 7.6 ANCHOR BOLTS ................................................................................................................... 23 7.7 JOINTS ................................................................................................................................ 23 7.8 GROUTING .......................................................................................................................... 23 7.9 METAL DECKING .................................................................................................................. 23 7.10 GRATING ............................................................................................................................. 24 7.11 STRUCTURAL STEEL MEMBERS AND CONNECTIONS ................................................................ 24

8 FOUNDATION DESIGN .................................................................................................... 25

8.1 STABILITY ........................................................................................................................... 25 8.2 BUOYANCY .......................................................................................................................... 26 8.3 FOUNDATION SUPPORTING HEAVY VIBRATING EQUIPMENT ...................................................... 26


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1 SCOPE

This specification contains the general criteria and methods of calculation to be applied for the design of CONCRETE and STEEL structures for the 2x360 MW Coal-Fired Power Plant, PUNTA CATALINA, BANI, in DOMINICAN REPUBLIC.

2 CODES, STANDARDS AND SPECIFICATIONS

Design, materials, erection works and test shall be made in accordance with the latest edition of the following Codes, Standards and Specifications. In case of conflict amongst them, the most stringent requirement shall be applied and the following order of precedence shall be considered:

1st Local Regulations 2nd Project Specification and drawings 3rd International Codes 4th Tecnimont standards

2.1 Local regulations

R-001 Reglamento sismico R-028 Reglamento acero M-009 Especificaciones generals

2.2 Project specification and drawings

3814-YZ-SG-000001 Design basis and site conditions

3814-AX-SG-000003 Seismic load calculation procedure

3814-AX-SG-000004 Wind load calculation procedure

3814-AI-SG-000002 Project specification for anchor bolts

3814-AI-SG-000003 Project specification for embedded plates

3814-AA-DC-000002 STD details for Anchor Bolts

3814-AA-DC-000003 General note for RC Structures

3814-AI-SG-000001 General Specification for Steel Works

3814-AA-SG-000001 General specification for concrete works

3814-VW-SG-000001 Coating specification and systems

3814-AI-DU-000001 STD for steel work general notes & materials

3814-AI-DU-000002 STD for steel work, stair, grating and chequered plates

3814-AI-DU-000003 STD details for ladders


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3814-AI-DU-000004 STD for steel work details for stairs

2.3 International codes

The work shall comply with all Codes and Standards mentioned in this specification. The latest revision of Codes and Standards shall be used. American Concrete Institute (ACI) ACI 224R-01 Control of Cracking in Concrete Structures; ACI 301/301R Specifications for Structural Concrete for Buildings; ACI 318/318R Building Code Requirements for Reinforced Concrete and Commentary with

supplements; ACI 350/350R Code requirements for Environmental Engineering Concrete Structures &

commentary; ACI 530/530R Building Code Requirements for Masonry Structures. ACI 351.4R Foundations for Dynamic Equipment American Society of Civil Engineers (ASCE) ASCE 7-05 Minimum Design Loads for Buildings and Other Structures; ASCE Anchorage Design for Petrochemical Facilities; ASCE Guidelines for the Seismic Evaluation and Design of petrochemical facilities; ASCE Wind Loads Anchor Bolt Design for Petrochemical Industries. American Institute of Steel Construction (AISC) AISC 360-05 Specification for Structural Steel Buildings (LRFD Method); AISC 341-05 Seismic Provisions for Structural Steel Buildings; AISC 358-05 Prequalified Connections for Special and Intermediate Steel Moment Frames for

Seismic Applications; AISC 303-05 Code of Standard Practice for Steel Buildings and Bridges; American Society For Testing And Materials (ASTM) ASTM A36 Carbon Structural Steel ASTM A1064 Standard Specification for Carbon-Steel Wire and Welded Wire Reinforcement,

Plain and Deformed, for Concrete ASTM A307 Carbon Steel Bolts and Studs, 60,000 psi Tensile Strength ASTM A325 Structural Bolts, Steel, Heat Treated, 120/105 ksi Minimum Tensile Strength ASTM A490 Structural Bolts, Alloy Steel, Heat-Treated, 150 ksi Minimum Tensile Strength ASTM A615 Deformed and Plain Billet Steel Bars for Concrete Reinforcement ASTM A992 Standard Specification for structural steel shapes ASTM F1554 Standard Specification for Anchor Bolts, Steel, 36, 55 and 105-ksi Yield Strength ASTM C90 Specification for Load-Bearing Concrete Masonry Units ASTM C270 Specification for Mortar for Unit Masonry American Welding Society (AWS) AWS D1.1/ D1.1M Structural Welding Code – Steel

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AWS D1.3/ D1.3M Structural Welding Code – Steel Sheet AWS D14.1/D14.1M Specification for Welding of Industrial and Mill Cranes and Other Material

Handling Equipment

Steel Deck Institute (SDI) Design Manual for Composite Decks, Form Decks and Roof Decks – No. 31

Steel Joist Institute (SJI) Standard Specifications and Load Tables for Steel Joists and Joist Girders Tecnimont‟s Standards Reference Literature S. Prakash & V.K.Pury - Foundations for machines: analysis and design. Wiley and son, 1988; J.E. Bowles - Foundation analysis and design. Mc Graw-Hill 1996; PIP STC01015 - Structural Design Criteria; PIP REIE 686 - Recommended Practices for Machinery Installation and Installation Design DIN: 4024 (Part - 1), 1988: Machine foundations – Flexible structures that support machines with

rotating elements”

2.4 Tecnimont’s Standards

TM902.14 Loads on pipe rack TM902.1 Rotary Machines – Data required to foundation designer TM902.2 Rotary machines TM902.3 Vibrating machines TM902.4 Reciprocating machines TM902.5 Vibrations caused by machines TM902.11 Bridge Cranes TM903.8 Foundation on piles TM903.10 Anchor Bolts TM903.16 Sleepers TM 905.4 Grouting, leveling and anchoring TM914.3 Checkered and buckle plates TM 914.4 Gratings TM914.5 Detail of pedestrian grating bearing TM914.10 Gangways and Gangways supports TM914.13 Checkered or buckle Plates for manholes TM914.14 Checkered or buckle Plates for light duct covering TM922.1 Heavy-duty precast concrete covering slabs TM922.2 Light-duty precast concrete covering slabs TM904.40 R.c. basins – Design criteria – Details


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3 DESIGN REQUIREMENTS

3.1 Language

All design documentation will be in English.

3.2 Site conditions

Design of foundations, steel and concrete structures shall be carried out on the base of the site general data applicable to the project such as:

Basic wind speed;

Seismic zone;

Design thermal loads due to temperature variation;

Site data shall be in accordance with 3814-YZ-SG-000001 “Design basis and site conditions”.

3.3 Soil Mechanics and Geotechnical Conditions

Design of foundations, structures, earthworks and other concrete works shall be carried out in accordance with the prescriptions included in the final soil report related to:

Foundations level;

Allowable bearing capacity of soil related to settlements, dimensions and depth of foundations;

Piles vertical and horizontal bearing capacity;

Expected settlements (short term and long term);

Specific weight of soil (dry and wet);

Cohesion and friction angle ();

Elastic modulus E;

Dynamic modulus G;

Westergaard modulus;

Poisson coefficient;

Water table elevation (min. and max);

Permeability;

Soil chemical characteristics;

Shear velocities of each stratum.

4 DESIGN LOADS

In general, different design conditions have to be considered for the design of buildings and structures:

- erection/construction; - test condition; - operating;


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The following loads shall be considered in the design of the plant:

- Dead Load (DL) - Live Load (LL) - Equipment Erection Load (EE) - Equipment Test Load (ET) - Equipment Operating Load (EO) - Thermal Loads (ThL, TeL, TaL, FrL) - Wind Load (WL) - Earthquake Load (EL) - Impact Load (IL) - Vibration Load (VL) - Fluid Load (FL) - Earth Load (HL) - Construction Load - Loads due to pulling tube bundles - Elevators - Forklift - Moving Loads (Vehicle Loads) - Load Pipe Rack Minimum Loads

4.1 Dead loads (DL)

Dead load is the self weight of structures and the weight of all materials permanently fastened thereto or supported thereby, such as pipes, insulations and walkways, weight of empty equipments and vessels. The following density of materials shall be considered as dead load:

- reinforced concrete: c = 25.0 kN/m3

- lean concrete: lc = 23.0 kN/m3

- structural steel: s = 78.5 kN/m3

- soil: soil =18.5 kN/m3

Use the following uniformly distributed dead loads in addition to the self-weight of the structure:

Structural element Loading kN/m2

Steel platform framing and flooring 1.0

On process structure floors & roof

where applicable to cover weight of

small piping and other miscellaneous

permanent loads 1.0


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On compressor building operating floors

to cover piping and miscellaneous loads 1.5

On floors in office buildings to

cover movable and future partitions 1.0

On roof members of offices,

laboratories, to cover lighting fixtures,

suspended ceiling, air conditioning ducting

and small piping loads 0.40

On roof members or elevated floors of control

and switchgear buildings in designated areas to

account for cable trays and cable dead loads 1.0

Pipe loads on racks: 40% of the loads indicated

in TM902.14 0.8

All pipes larger than 12" in diameter shall be considered as concentrated loads at their point of support.

High pressure pipes and fitting of all sizes shall be adequately considered.

The dead load for all the secondary steel element, grating, handrail and etc. is estimated equal to qsec,St = 0.75 kN/m2

4.2 Live loads (LL)

Live loads shall be the maximum loads expected by the intended use or occupancy and consists of the following movable loads:

persons, portable machinery, tools and, for buildings furniture, business machines and active materials

materials temporarily stored during maintenance such as exchanger parts, pipes and fittings, valves

materials normally stored during operation such as tools, maintenance equipment, catalysts and chemicals

passing or staying vehicles, trucks and operating machines

Live loads shall be uniformly distributed over the horizontal projection of the specified areas. They shall be arranged in such a way as to produce the maximum actions both at the supports and in the span. They have the following minimum values: distributed live loads on floors:

Structural element Loading kN/m2


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Offices 3.0

Control Room, change rooms,

compressor building and laboratory 5.0

Mechanical equipment areas 10.0

Substations, Electrical equipment battery rooms 10.0

Operating floors in process structures 5.0

Stairs (or moving concentrate load 4.5 kN) 5.0

Ladders moving concentrate load 2.5 kN

Roofs areas for maintenance only 0.75

Purlin on roof (local check) 1.0

Roof used as platform around apparatus 2.5

Cable trays in racks (each tray level) 1.0

Checkered Plate or Grating (All Locations) 5.0

Walkway, platforms (1200mm wide or less) 3.0

Warehouse and Storage areas: to be determined considering

the intended use of the area, but never less than 7.5

Handrails: 0.75 kN/m linear load or concentrate 1 kN in all directions

Pipe loads on racks: 60% of the loads indicated

in TM902.14 1.2

In areas of a lesser amount of piping 0.7

Roving non accumulating point load applied to mid-span of beams to account for disproportionate concentration of hanging loads: based on rational analysis of hanging loads, but not less than (2,000 lb) 9.07kN

All content of pipes larger than 12" in diameter shall be considered as concentrated loads at their point of support.

For the STG top floor, for maintenance, shall be considered as minimum 28.73kN/m2

Uniform and concentrated loads do not occur simultaneously. Concentrated loads shall be placed upon a space of 1' x 1' (300 mm x 300 mm).

4.3 Equipment Loads (EE, ET, EO)

Equipment erection (EE) This load includes the weight of equipment. It is to be considered as a dead load.

Equipment test (ET)

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Equipment test load is the weight of the equipment plus the weight of water necessary to perform the hydraulic test. In static calculation the weight of water shall be considered as a live load.

Equipment operation (EO) This load includes the weight of equipment (including platforms and ladders attached to the equipment), solids e/o liquids normally inside the equipment, connected pipes. In static calculation this load shall be considered as a dead load.

4.4 Thermal loads

Thermal loads are those forces caused by temperature variations. The following three different types of thermal loads shall be considered in design of structures and foundations:

ThT = Loads due to the variation of ambient temperature. Loads caused by the variation of ambient temperature. It shall be limited by adopting expansion joints at proper distance. A

minimum differential temperature T = ± 15°C shall be considered; it shall not be combined with other instantaneous loads such as wind, earthquake or impact.

Steel structures have to be designed with expansion joints at a maximum distance of 200 ft (60m), in which case the thermal load need not be included in the structural design. For Reinforced Concrete regular structures, the maximum spacing between expansion joints shall be 165 ft (50m) if temperature differences and the influence of expansion shrinkage and creep are not considered in the design. The spacing can be increased if temperature differences and the influence of expansion shrinkage and creep shall be accounted for in the design.

TeL = Loads caused by the thermal expansion of vessel & exchangers. This load shall be combined with other instantaneous loads such as wind or earthquake.

TaL = Pipe anchor & guide forces. This load shall be combined with other instantaneous loads such as wind or earthquake.

FrL = Friction load caused by thermal expansion (hot/cold lines sliding across the pipe rack or supports). In order to take into account friction forces due to thermal expansion/contraction of equipment, the following static friction coefficient “f” shall be used, in absence of any input from equipment supplier.

- stainless steel on teflon 0.10

- steel on steel 0.30

- steel on concrete 0.45

- on pipe racks loaded with more than 4 pipes, a friction coefficient of 0.1 (applied to total pipe weight) should be used in the design of support beams.


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Estimated pipe friction loads shall not be combined with wind or seismic loads on pipe racks and their foundations. Only anchor and guide loads, excluding their friction component, shall be considered with wind and seismic loads. Pipe anchorage forces from stress analysis shall be dealt in the same way as friction forces in the load combinations.

4.5 Wind load (WL)

Site conditions are described in document 3814-YZ-SG-000001 Design basis and site conditions. For wind load calculation procedure refers to specification n. 3814-AX-SG-000004.

4.6 Earthquake (EL)

Site conditions are described in document 3814-YZ-SG-000001 Design basis and site conditions. For Seismic load calculation procedure refers to specification n.3814-AX-SG-000003.

4.7 Test load (TEL)

Test load is the weight of water inside the equipments during their hydro-test. During the test, wind has to be considered 25% of its nominal load. For each test condition, only one equipment at a time need be considered full of water, unless otherwise requested by other disciplines.

4.8 Fluid load (FL)

Fluid loads are those forces due to weight and pressure of fluids (1)

4.9 Earth load (HL)

Earth loads are those loads due to soil pressure against structure, retaining walls and foundations.

4.10 Impact load (IL)

An impact load shall be defined as an equivalent static load that conservatively approximates the dynamic effect of reciprocating machinery, rotating machinery, or a moving load. Impact and hoist loads shall be considered to be live loads. Impact loads shall be per SEI/ASCE 7, and as shown in paragraphs a) through d). The crane live load shall be the rated capacity of the crane. Design loads for the runway beams, including connections and support brackets, of moving bridge cranes and monorail cranes shall

1 Dead load of vessels plus fluid load is sometime named as operating load.


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include the maximum wheel loads of the crane and the vertical impact, lateral, and longitudinal forces induced by the moving crane.

Note: Impact factors shall be in accordance with SEI/ASCE 7 – crane load, or vendor provided criteria.

a) Crane beams, support brackets and connections shall be designed for impact load. Impact factors shall be as listed below or in vendor provided criteria, whichever is greater: - To account for impact, the maximum vertical wheel load shall be increased as follows:

- Gantry and bridge crane supports 25% - Monorail supports and under-hung cranes 25% - Davits, jib cranes 25%

- Transverse impact shall be as follows: - Craneway 20% of the lifted load, hoist and trolley. The lateral force shall be assumed to

act horizontally at the traction surface of the runway beam, in either direction perpendicular to the beam, and shall be distributed with due regard to the lateral stiffness of the runway beam and supporting structure.

- Davits 20% of the lifted loads - Longitudinal impact load shall be as follows:

- Craneways 10% of the maximum wheel load applied at the top of the runway - Monorails 10% of the lifted load, hoist and trolley - Davits 10% of the lifted load

b) Lifting lugs or pad eyes and internal members (included both end connections) framing into the joint where the lifting lug or pad eye is located shall be designed for 100% impact. c) All other structural members transmitting lifting forces shall be designed for 15% impact.

Allowable stresses shall not be increased when combining impact with dead load.

4.11 Loads from vibration (VL)

These are the loads resulting from rotating & reciprocating equipment, vibration and resonance. Apply these loads for the design of compressors and pumps foundations in accordance with TM 902.1 to 902.5.

4.12 Construction load (CL)

Construction loads are temporary forces due to the erection of structures or equipment. In case of multi-storey reinforced concrete buildings, the phase of construction has to be carefully analyzed and the relevant temporary loads on the supporting floors, like scaffolding and propping, have to be accounted. In certain cases, structural steel members and vertical bracing are temporarily removed to allow for the installation of equipment. In this case, the actual structural steel configuration needs to be checked for the construction condition.


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4.13 Loads due to pulling tube bundles

When the local truck machine is not available to extract bundles, on exchanger saddles the bundle pulling force shall be assumed as 100% of bundle weight for bundles weighing less than 22 kN, 22kN for bundles with a weight between 22 and 44 kN., and 50% of bundle weight for bundles weighing over 44 kN. The pulling force is assumed to be resisted by exchanger fixed saddle pier. Bundles over 100 kN require special analysis.

4.14 Elevators

All elevator loads shall be increased by 100% for impact and the structural supports shall be designed within the limits of deflection prescribed by the elevator‟s vendor.

4.15 Forklift

Where Forklift is to be foreseen it shall be accounted as a live load. A concentrated load of 60 kN to be distributed on two squares with 20 cm side, 1.2m from each other. This load shall also be amplified with the impact factor of 1.4. Concentrated loads do not occur simultaneously with uniform live loads.

4.16 Paving, trench covers, culverts and bridge loads (Vehicle Loads)

Concrete paving and trench covers in roadways and paved areas subject to truck traffic shall be designed for 150kN axle load (HS20-44 truck load); contact area of wheel on paving or cover shall be 320mmx320 mm. Concrete paving and trench covers in other areas with vehicular access shall be designed for a minimum of 60kN wheel concentrated load (2). Wheel contact area on paving shall be 250mmx250mm. Trench covers in unpaved areas with no vehicular access shall be designed for a uniform loading of 5.6 kN/m2 (3). Special load requirements for specific duties, including construction requirements shall be considered separately. In line pumps with motor drives not exceeding 55kW may be supported on concrete pedestals directly on the pavement. The pump vendor shall supply a base flange for bolting to the pedestal. Chemical bolts shall be maximized.

2 See TM 922.1

3 See TM 922.2


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4.17 Pipe Rack Minimum Loads

Loads on pipe racks shall be as per “TM 902.14: Loads on pipe rack”, unless other load information‟s from stress/piping department are available.

5 LOADS COMBINATIONS

Allowable Stress Design method will be used for displacement checks, and foundation geotechnical & stability checks. The load combinations will be according to the ASCE 7-05. Strength Design Method will be used for the design of reinforced concrete structures reinforced concrete foundations and steel structures. The load combinations will be according to the ACI 318-08 and AISC 360-05 (LRFD Method). The loads shown in the following table shall be considered to determine the critical loading condition for the design of the structural elements (columns, beams, slabs, bracings, anchor bolts, foundations) and to check the stability of the structure. When inclusion of fluid loads or live loads results in a less critical loading condition, these loads shall be excluded. However safety of persons and structures shall be assured during all transient phases of construction. Erection 1. Dead loads of structure less: fireproofing (except when the fireproofing is installed at shop) and piping. 2. Equipment load 3. Temporary loads and forces caused by erection 4. Wind load or Earthquake load whichever is greater If construction is known to occur during hurricane season and a basic wind speed of 149mph (240km/h) is used in determining Wp, then temporary wind bracing must be provided. Test 1. Dead loads of structure plus fireproofing 2. Equipment load 3. Dead load of piping plus insulation 4. Live load from platforms and walkways 5. Wind load (50% of wind pressure) Operation 1. Dead loads of structure plus fireproofing 2. Equipment load 3. Dead load of piping plus insulation 4. Live load from platforms and walkways 5. Thermal loads 6. Impact loads 7. Wind load or Earthquake Load (whichever is grater) Maintenance


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1. Dead loads of structure plus fireproofing 2. Equipment load (EE) 3. Live load from platforms and walkways 4. Maintenance load 5. Wind load (1/3 of maximum wind load)

5.1 Basins

Basins shall be designed in accordance with requirement and prescriptions included in ACI 350-06. The loads shown in the following table shall be considered to determine the critical loading condition for the design of the structural elements (i.e. design of reinforcement, cracking check etc.) and to check the stability of the structure. When inclusion of earth passive pressure results in a less critical loading condition, this load shall be excluded.

Construction Dead loads of structure Earth load Construction Loads Earthquake load

Operation Dead loads of structure Equipment load Live load from platforms and walkways Thermal loads Earth load Earthquake Load

5.2 COMBINING NOMINAL LOADS USING ALLOWABLE STRESS DESIGN

The loading combinations shown in the following table shall be considered to determine displacement checks, and foundation geotechnical & stability checks of the pipe racks and the process structures:

Erection DL+EE+ThL

DL+EEWLX

DL+EEWLZ

DL+EE 0.7(ELX0.3ELZ)

DL+EE 0.7(0.3ELXELZ)

0.9DL+0.9EEWLX

0.9DL+0.9EEWLZ

0.9DL+0.9EE 0.7(ELX0.3ELZ)

0.9DL+0.9EE 0.7(0.3ELXELZ)

Test


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DL+ET+0.5LL

DL+ET0.25WLX

DL+ET0.25WLZ

DL+ET0.75(0.5WLX+0.5LL)

DL+ET0.75(0.5WLZ+0.5LL)

0.9DL+0.9ET0.5WLX

0.9DL+0.9ET0.5WLZ

Operation DL+EO+LL+ThL+TaS+FrL

DL+EO+TLSWLX

DL+EO+TLSWLZ

DL+EO+TLS 0.7(ELX0.3ELZ)

DL+EO+TLS0.7(0.3ELX ELZ)

DL+EO+TLS0.75WLX+0.75LL

DL+EO+TLS0.75WLZ+0.75LL

DL+EO+TLS0.75*0.7(ELX+0.3 ELZ)+0.75LL

DL+EO+TLS0.75*0.7(0.3ELXELZ)+0.75LL

0.9DL+0.9EO+0.9TLSWLX

0.9DL+0.9EO+0.9TLSWLZ

0.9DL+0.9EO+0.9TLS 0.7(ELX0.3 ELZ)

0.9DL+0.9EO+0.9TLS 0.7(0.3ELXELZ)

5.3 COMBINING FACTORED LOADS USING STRENGTH DESIGN

The loading combinations shown in the following table shall be considered to determine the critical loading condition for the design of the structural elements:

Erection 1.4DL+1.4EE 1.2DL+1.2EE+1.2ThL 1.2DL+1.2EE±1.6WLX 1.2DL+1.2EE±1.6WLZ 1.2DL+1.2EE±(ELX±0.3ELZ) 1.2DL+1.2EE±(0.3ELX±ELZ) 0.9DL+0.9EE±1.6WLX 0.9DL+0.9EE±1.6WLZ 0.9DL+0.9EE±(ELX±0.3ELZ) 0.9DL+0.9EE±(0.3ELX±ELZ) TEST 1.4DL+1.4ET 1.2DL+1.2ET+1.6(0.5LL) 1.2DL+1.2ET±0.65WLX+0.5LL


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1.2DL+1.2ET±0.65WLZ+0.5LL 0.9DL+0.9ET±0.65WLX 0.9DL+0.9ET±0.65WLZ OPERATION 1.4DL+1.4EO 1.2DL+1.2EO+1.2ThL+1.2TaL+1.2FrL+1.6LL+1.6IL 1.2DL+1.2EO+1.2 TaL ±1.6WLX+ f1LL 1.2DL+1.2EO+1.2TaL±1.6WLZ+ f1LL 1.2DL+1.2EO+1.2TaL±(ELX±0.3ELZ)+f1LL 1.2DL+1.2EO+1.2TaL±(0.3ELX±ELZ)+f1LL 0.9DL+0.9EO+0.9TaL±1.6WLX 0.9DL+0.9EO+0.9TaL±1.6WLZ 0.9DL+0.9EO+0.9TaL±(ELX±0.3ELZ) 0.9DL+0.9EO+0.9TaL±(0.3ELX±ELZ)

Where: WLX = wind load in 1st principal direction; WLZ = wind load in 2nd principal direction; ELX = Earthquake load in 1st principal direction; ELZ = Earthquake load in 2nd principal direction. f1 = 0.5 if L<100 psf (4.8 kN/m²); If L>100 psf or areas occupied as places of public assembly then f1 = 1.0 Use of a 1/3 stress increase for allowable stress load combinations involving wind loads should not be used.

According to "PIP STC0101015" and to "ASCE Guidelines for seismic evaluation and design of petrochemical facilities", since the dead loads of non-building structures are known to a higher degree of accuracy than are the corresponding dead loads of buildings, the dead load factor used for the seismic uplift in the loadings combinations for displacement checks and foundation checks will be taken as 0.9 instead of 0.6. The seismic load on the structure, E, is made up of two components: Eh, horizontal seismic effect,

calculated from the base shear and amplified by redundancy factor , and Ev, vertical seismic effect, calculated from a percentage of the design spectral response acceleration parameter, SDS, time the effective seismic weight of the structure. Response effect due to vertical components of ground motion are not required to be calculated where SDS is ≤ 0.125. Vice versa the vertical earthquake forces are to be considered explicitly in the design or analysis of the structure:

E = Eh ± Ev = QE ± 0.2 SDS DL


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QE = Effect of the horizontal earthquake ground motions

6 SERVICEABILITY

6.1 Crack Limitations

Crack limitation to RCC structures shall be as per ACI 224R-01, Reasonable “average” crack widths per Table 4.1 of ACI 224R-01:

Exposure condition Crack width

in mm

Dry air or protective membrane 0.016 0.41

Humidity, moist air, soil 0.012 0.30

Deicing chemicals 0.007 0.18

Seawater and seawater spray, wetting and drying 0.006 0.15

Water-retaining structures 0.004 0.10

The prescription of ACI 318 section 10.6.4 shall be carefully applied with service loads to limit the crack width.

For water retaining structures, maximum tensile stress in reinforcement at service loads, due to water pressure shall be limited to:

for normal environmental exposure:

for severe environmental exposure:

Where: fs, max = tensile stress in reinforcement at service loads (Mpa) (not less than 120Mpa) s = center-to-center spacing of deformed bars (mm) db = nominal diameter of bar (mm) β = 1.25 if thickness of member > 400 mm β = 1.35 if thickness of member < 400 mm


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6.2 Allowable deflections

Design deflections of structural steel members (DL+LL) shall not exceed the following values:

For steel structures:

Purlins and roof girders L/200

Floor beams without equipment L/300

Floor beams supporting equipment

- Operating state L/400

- Hydraulic test L/250

Pipe rack beams L/300

Girders and joists under masonry walls L/500

Cantilevers L/250

Grating: more stringent between resistance at 5 kPa, maximum vertical deflection L/200 but not more than 5mm.

Crane Supports

- Vertical deflection of support runway girders shall not exceed the following limits when loaded with the maximum wheel load(s), without impact: Monorails and Under-Running CMAA Class A, B, and C Cranes L/450

Top-running CMAA Class A, B, and C Cranes L/600

Top-running CMAA Class D Cranes L/800

Under-running CMAA Class E and F Cranes L/1000

- Vertical deflection of jib crane support beams shall not exceed L/225 (where L = the maximum distance from the support column to load location along the length of the jib beam when loaded with the maximum lifted plus hoist load(s), without impact. - Lateral deflection of support runway girders for cranes with lateral moving trolleys shall not exceed L/400 when loaded with a total crane lateral force not less than 20 percent of the sum of the weights of the lifted load (without impact) and the crane trolley. The lateral force shall be distributed to each runway girder with due regard for the lateral stiffness of the runway girders and the structure supporting the runway girders. - Building frame lateral deflection at runway beam level from unfactored crane loads or from the unfactored 1-in-10-yr wind load:

H/100 (pendant–operated crane for CMAA class „A‟, „B‟, „C‟ & „D‟)

H/240 (cab–operated crane for CMAA class „A‟, „B‟ & „C‟)

Where L=theoretical span of beam (for cantilever it‟s twice the projection of beam length)


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6.3 Allowable Drift Limits

Maximum horizontal displacements of steel frame structures, in accordance with ASCE7-05, AISC-Steel Design Guide 3, 2nd edition / serviceability design considerations for steel buildings, and process industry practice PIP STC01015, shall not exceed the following values:

Allowable drift limits for pipe racks shall not exceed H/150 (where H = pipe rack height) for 50 yr wind.

Allowable wind drift limits for process structures and personnel access platforms shall not exceed H/200 (where H = structure height) for 50 yr wind.

Allowable wind drift limits for buildings shall not exceed H/400 for 10 yr wind.

Allowable drift limits for buildings with bridge cranes (pendant–operated crane for CMAA class „A‟, „B‟, „C‟ & „D‟) shall not exceed H/150, for crane lateral load OR 10 yr wind.

Allowable drift limits for buildings with bridge cranes (cab–operated crane for CMAA class „A‟, „B‟ & „C‟) shall not exceed H/240, for crane lateral load OR 10 yr wind.

Allowable seismic drift limits shall be in accordance with ASCE/SEI 7.

For concrete structures: See ACI 318, chapter 9.

7 MATERIALS

7.1 Concrete

Material quality for reinforced concrete shall be in accordance with ACI 318/318R "Building Code , Concrete design for liquid-containing structures shall also be designed in accordance with ACI 350/350R Requirements for reinforced concrete". Reinforcement details not shown on standard drawings shall be carried out in accordance with the requirements of ACI SP-66 "ACI Detailing Manual". Concrete shall have the Minimum Cylinder Strength listed below:

Mix A: Screed, lean concrete, duct banks 2500 psi (17.5 N/mm2)

Mix B: Foundations, structures, chimney, paving,

pipe sleepers, pits slabs, walls, slabs on grade; 5000 psi (35 N/mm2)

Mix C: Water retaining structures, exposed to wastewater 5000 psi (35 N/mm2)

Mix D: Marine concrete and precast seawater structures 5802 psi (40 N/mm2)

(As per letter CTPC-CDEEE-0294-14)

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7.2 Reinforcing steel

Deformed reinforcing steel bars shall conform to ASTM A615/A615M, Grade 60, with specified yield strength fy=60000 psi (414 N/mm2). Fusion-bonded epoxy coated steel reinforcement (FBECR), of the same steel material as above, shall be used, below and above ground, for all structures in contact with sea water. FBECR shall be conforming to ASTM A775/A775M or ASTM A934/A934M grade 60. Coating thickness shall be between 180 and 300 µm. Welded wire fabric shall conform to ASTM A1064 for plain fabric and to ASTM A497 for deformed fabric with specified yield strength fy=65000 psi (450 N/mm2). Bar diameters shall be as per dwg. n. 3814-AA-DC-000003 General notes for RC structures.

7.3 Reinforcement cover

The minimum concrete cover shall be as per dwg. n. 3814-AA-DC-000003 General notes for RC structures.

7.4 Maximum and Minimum Reinforcement Spacing

Minimum distance between individual reinforcing bars shall be in accordance with ACI 318. Maximum center to center spacing of individual reinforcing bars shall be as follows:

- Not more than 6 in (150 mm) for main bars in beams.

- Not more than 10 in (250 mm) for bars perpendicular to main bars in slabs, minimum shrinkage and temperature reinforcing in slabs, and bars in walls.

- Not more than 7 in (180 mm) for longitudinal bars in columns

- Not more than 12 in (300 mm) for stirrups in beams.

- Not more than 16 in (400 mm) for any other bars not mentioned above.

In walls and floors with a thickness of 10 in (250 mm) or more, reinforcing bars shall be placed on both sides, over the full section. In footings and foundations with a thickness of 10 in (250 mm) or more, reinforcing bars shall be placed on both the top and bottom, over the full section.

7.5 Minimum Reinforcement

The minimum reinforcement for flexural members shall be in accordance with ACI 318 Chapter 10.5 but shall not be less than 0.0035 of the gross concrete area.

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7.6 Anchor Bolts

The design requirements for anchors in concrete used to transmit structural loads by means of tension, shear, or a combination of tension and shear shall be in accordance with ACI 318-08 Appendix D and “3814-AI-SG-000001 General Specification for Steel Works”. Shear-keys shall be provided under columns which transfer important shear loads (such as braced frames, shelters with bridge-crane and pipe rack braced bays). Shear-key consists of steel profile welded under column base plate. Shear can be transferred to foundation by friction for minor structures, such as walkways, shelters without bridge-crane, pipe-racks, etc. In these cases the effective compressed area shall be calculated based on actual vertical load and moment. If the effective shear load exceeds the maximum shear transferred by friction, shear-key shall be foreseen.

7.7 Joints

Expansion joints, contraction joints, and construction joints shall be detailed in accordance with ACI 301, ACI 302.1R, and ACI 504R. For detail see specification 3814-AASG-000001.

7.8 Grouting

Grouting shall be in accordance to “3814-AA-SG-000001 General specification for concrete works”.

7.9 Metal Decking

Metal deck shall be designed in accordance with Design Manual for Composite Decks, Form Decks and Roof Decks – No. 31. When roof or floor metal decking is used as a diaphragm to carry lateral forces, both the metal deck and the deck attachments to the structural frame shall be designed to transfer the lateral forces in accordance with the requirements of SDI. In areas where steel deck is used as form for concrete slab, and in order for the steel decking to provide lateral bracing to the top flange of beams in a corrosive environments, shear connectors shall be installed on the top flange at positions providing the desired unbraced length (say at spacing = lc or lu). The connectors function is to engage the slab providing a positive lateral brace point at the beam flange. Connector strength shall provide a shear strength equal to or greater than 2% of the compression strength of the compression element being braced (the beam). In a corrosive environment, the decking can corrode away negating the assumption of bracing of the compression flange by the decking. In areas where corrosion of the deck is not a concern, deck can be tack welded to the beams.

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Light equipment and pipe supports with a concentrated load less than 10kN or a distributed load under 2.5 kN/m2 may be supported directly on the deck.

7.10 Grating

Grating shall be in accordance to “3814-AI-SG-000001 General Specification for Steel Works”

7.11 Structural steel members and connections

Steel structures shall be designed in agreement with “Specification for Structural steel Buildings” ANSI/AISC 360-05, “Seismic Provision for Structural Steel Buildings” ANSI/AISC 341-05 and “AISC 358-10 Prequalified Connections for Special and Intermediate Steel Moment Frames for Seismic Applications”; Seismic prevision for structural steel buildings shall govern the design, fabrication and erection of structural steel members and connections in the seismic force resisting system (SFRS).

Materials shall be in accordance to “3814-AI-SG-000001 General Specification for Steel Works”

Compression flanges of floor beams, not supporting equipment, may be considered braced by decking (concrete or floor plate) if positively connected thereto.

Grating shall not be considered as lateral bracing for support beams;

All column base plates shall be designed with a minimum of four anchor bolts. Posts (which weigh less than 300 lb [136 kg]) are distinguished from columns and are excluded from the four anchor bolt requirement.

Slip-critical-type connections shall be used in connections subject to vibration or repeated stress reversal. Slip-critical (friction-type) connections shall also be used for crane girders and crane girder supports connections. Connections, Joints and Fasteners: Connections, joints and fasteners that are part of the seismic load resisting system (SLRS) shall comply with the AISC Specification Chapter J, and with the additional requirements in this section. Connections in the SLRS shall be configured such that a ductile limit state in either the connection or in the connected member controls the design. Requirements for bolted joints:

All bolts must be high strength

Bolted joints may be designed as bearing type connections, but must be constructed as slip critical

o bolts must be pretensioned o faying surfaces must satisfy Class A surface requirements


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Holes: standard size or short-slots perpendicular to load (exception: oversize holes are permitted for diagonal brace connections, but the connection must be designed as slip-critical and the oversize hole is permitted in one ply only)

Nominal bearing strength at bolt holes cannot exceed 2.4 d t Fu

Bolts and welds shall not be designed to share force in a joint, or the same force component in a connection.

8 FOUNDATION DESIGN

Soil bearing foundations shall be designed to conform to the final soil report and to the following minimum safety factor requirements under the most critical loading conditions.

Stability checks shall be performed for non-piled structures.

Friction coefficient between soil and concrete foundation may be taken as tan(2/3*).

Over excavation below the specified level shall be filled with mass concrete.

Backfilling shall be as indicated in final soil investigation report.

8.1 Stability

The stability of the structure shall be checked for the non-factored load combinations.

A. Stability against overturning, defined as the ratio of stabilizing moment to overturning moment:

o Square or rectangular footings, about the longer side:

F.S. = 1.5 for erection F.S. = 1.7 for operation and test

o Octagonal or round footings, about side of octagon:

F.S. = 1.7 for erection F.S. = 1.9 for operation and test

The above safety factors provide for a minimum area of footing under compression of 50% for erection and 67% for operation and test.

For chimneys, stacks and other similar construction area of footing compression shall be 80%.

B. The factor of safety against uplift shall be calculated as the minimum downward column load plus weight of foundation divided by the total uplift force. Factor of safety against uplift shall be not less than 1.5 for operating plus wind or earthquake and not less than 1.2 for erection plus wind. The resistance to uplift due to cohesion or friction shall normally be ignored.

C. Factor of safety against sliding for retaining walls and similar structures shall be 1.5 minimum.


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8.2 Buoyancy

The effect of buoyancy shall be considered only when ground water level is expected above the bottom of the foundation or basin. If ground water level changes with season, maximum compression (bearing stress) on soil shall be calculated with the water level at the lowest point; tensions with the water table at the highest point. Factor of safety against buoyancy shall be 1.2 for operation (without live loads) and 1.1 for erection.

8.3 Foundation supporting heavy vibrating equipment

Reciprocating Machinery: Heavy machinery with reciprocating masses as the major moving parts. This machinery should be supported directly on a rigid foundation at grade. Rotary Machinery: heavy machinery with rotating masses as the major moving parts. This machinery should be supported on a rigid foundation at grade or on an elevated structure. It is considered as heavy vibrant machine any reciprocating or rotating (such as compressing, pumps, turbines, etc.) equipment with a projected total area in plant greater than 2,5 m2 or with a gross weight greater than 25 kN. It is considered as light vibrant machine any reciprocating or rotating (such as compressing, pumps, turbines, etc.) equipment with a projected total area in plant less than 2,5 m2 or with a gross weight small than 25 kN. Dynamic analysis is not required for foundations of limited power machineries [less than 150 kW (200horsepower) for alternative machine and less than 370 Kw (500 horsepower) for rotating machine]. For foundation with power less than above specified, or if are not indicated dynamic forces, the design can be done according to static method (as shown in next points).

A. General Recommendations for Design

1. Foundation design shall be as follows:

a. Foundation shall consist of clean simple lines.

b. Pockets where vapours could accumulate shall not be permitted.

c. In the absence of a detailed dynamic analysis (i.e. for small machinery or limited power only) the foundation weight shall be at least three times the weight of the rotating machinery and five times the weight of the reciprocating machinery.

d. For both types of foundations, the height of support above grade shall be kept as low as possible.

e. Beams and columns of tabletop foundations shall be of uniform rectangular shape, except haunches beams are permitted.


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f. The foundation shall be designed so that the centroid of mass of machine and foundation systems coincides with the centroid of the base contact area. In any case, horizontal eccentricity shall not exceed 5% of the corresponding base dimension.

g. For both types of foundations, the thickness of the foundation slab shall not be generally less than 0.6 + L/30 [m] where L is the longest horizontal dimension of the foundation slab. Moreover the minimum depth of foundation below ground level shall not be less than 500 mm and, for alternative machine, not less than thk / 2;

h. The allowable soil-bearing or allowable pile capacity for foundations for equipment designed for dynamic loads shall be a maximum of half of the normal allowable for static loads.

2. Design of Drilled Shafts:

a. Minimum vertical reinforcement shall be 0.50% of the pier gross area or as required to resist axial loads and bending moments.

b. The minimum clear spacing of vertical bars shall not be less than three times the maximum coarse aggregate size nor less than three times the bar diameter.

c. Reinforcing steel shall allow a minimum of 3 inches (75 mm) of concrete cover on piers without casing and 4 inches (100 mm) of concrete cover on piers in which the casing will be withdrawn.

3. For tabletop construction, the sizing of structure and foundation shall usually conform to the following:

a. Beams and slabs shall have spans as short as possible.

b. The minimum depth of beams shall be 1/4 of the clear span between faces of columns (disregarding any haunches).

c. The minimum width of beams shall be 1/5 of the clear span between faces of columns (disregarding any haunches) or equal to the width of the smaller column, whichever is less.

d. Columns shall be dimensioned to carry at least 6 times the vertical load from beams or slab.

e. All columns shall have approximately the same ratios of direct load to cross-sectional area.

f. The combined centre of gravity of machine and structure shall coincide with the centre of resistance of all columns. For this purpose, only that portion of the structure that is above the foundation slab shall be considered.

g. The weight of the foundation slab shall not be less than the combined weight of the structure and machine. Only that portion of the structure that is above the mid-height of columns shall be considered to contribute to the weight of the structure.


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h. The weight of the machine shall include the weights of Turbine, Gear Box, Motor, sole plates and frame, and any other parts supported by the upper slab and beams.

4. Cantilevered construction in the form of overhanging brackets or free-standing columns shall be avoided where possible. If cantilevered elements must be used the length to depth ratio shall be less than or equal to unit.

5. All parts of machine supports shall be independent from adjacent foundations and buildings to prevent transmission of vibration. Concrete floor slabs adjacent to the machine foundation shall be spaced a minimum of 25 mm from the foundation. The space between the two structural elements shall be filled with a flexible joint filler and sealer.

6. High strength, cement based non-shrinking grout shall be utilized for machines and drivers. Epoxy, non-shrinking grout shall be utilized only when required by Vendors or by contract.

7. The geometric layout of the structure shall be basically symmetrical with reference to the vertical plane passing through the rotational axis of the machine.

8. Axes of columns and transverse frame beams shall lie in the same vertical plane perpendicular to the rotational axis of the machine.

9. Foundations for low speed machines shall be low and wide to provide a foundation machine system with a high natural frequency.

10. Groups of reciprocating machinery foundations can be tied together with a common foundation slab whenever practical.

11. Pulsation bottles shall have their supports integrated with the compressor foundation.

12. All reinforcing shall be according to the American Concrete Institute Code, ACI 318, unless as noted below, and as per OWNER requirements and/or local Codes, whichever is more stringent.

a. Minimum vertical reinforcement in columns shall be 0.5 percent of the gross concrete area.

b. Ties in columns shall be of 10mm dia. bars minimum. They shall be spaced at 16 longitudinal bar diameters, but not more than 300 mm apart.

c. Minimum top and bottom reinforcement in beams shall be each 0.25 percent of the gross concrete area.

d. Side rebars in beams shall be for each side a minimum of 0.10 percent of gross concrete area.

They shall not be spaced at more than 350 mm apart.

e. At least one 10 mm dia. bar shall be used on each side of beams having a depth of 300 mm or more.

f. Stirrups in beams shall be of 8 mm dia. bars min. and they shall not be spaced more than 300 mm.

g. Open type stirrups shall not be used in beams.


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h. Minimum top and bottom steel in mats shall be each 0.125 percent of gross concrete area each way.

i. Minimum skin reinforcement: 16mm bar diameter every 300mm (both direction).

l. Minimum internal/volume reinforcement: 16 mm bar diameter every 600mm (tri-axial directions).

m. Minimum total reinforcement: 50kg/mc.

n. Adequate pocket reinforcement around anchor bolts of machine.

13. Rectangular Block Foundations:

a. The required reinforcing steel necessary to resist the internal forces and moments is relatively small in the majority of block foundations because of their massive size. Therefore, the minimum quantity of steel will likely be controlled by the amount of steel necessary to meet temperature and shrinkage requirements. Although ACI 318 does not specifically address the required steel in a block foundation, the requirement of 0.18% of the cross-sectional area of the concrete may be used as guidance for the amount of temperature reinforcing steel in a foundation using grade 60 reinforcing. In the event that a foundation size greater than 1.20 meters (48 inches) thick is required for stability, rigidity, or damping, the minimum reinforcing steel may be as suggested in ACI 207.2R, Effect of Restraint, Volume Change, and Reinforcement on Cracking of Massive Concrete, with a suggested minimum reinforcement of 22.2-millimeter (#7) bars at 30 centimeters (12 inches) on center.

b. Block foundations for reciprocating machines (compressors, and so forth) should have a minimum of 50 percent of the block thickness embedded in the soil, unless otherwise specified by the equipment user. Note: It is desirable to have at least 50 percent of the total depth of the foundation embedded in the soil to increase the lateral restraint and the damping ratios for all modes of vibration.


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Typical rectangular Block Foundations Detail (ref. PIP REIE 686)


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Typical anchor Bolt Detail for Rectangular Block Foundations (ref. PIP REIE 686)

B. Static Condition

1. For rotary machinery static design shall include loads due to the weight of the machinery, auxiliary equipment, other applied loads and the following:

a. 50 percent of the dead weight of the machine and base plate considered as vertical impact.

b. Lateral forces representing 25% of the weight of each machine, including its base plate, applied normal to its shaft at a point midway between the end bearings.

c. Longitudinal forces representing 25% of the weight of each machine, including its base plate, applied along the shaft axis.


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d. The total lateral and total longitudinal forces per Section b and c above, shall not be considered to act concurrently.

2. For reciprocating machinery static design shall include all loads due to the weight of the machinery, auxiliary equipment, piping and the following:

a. Unbalanced forces, couples and moments obtained from the machine manufacturer.

b. Individual piston forces

C. Dynamic Condition

1. Dynamic design for all type of foundations shall be as follows:

a. Generally, as far as practicable, the natural frequencies of any component part as well as those of the whole supporting foundation or structure shall be clear of the following existing frequencies of machinery, in order of importance, to avoid resonance:

At operating speed range, clear by ± 30%.

b. In particular for reciprocating machinery, which generates vibrating forces at low operating frequencies, the operating frequencies may lie close to the natural frequencies of the foundations (ratios of natural frequencies to operating frequencies in the range of 0.8 to 1.2). In this case, the magnitude of vibration amplitudes becomes the controlling criterion.

c. Amplitude shall be determined through dynamic analysis by using exciting dynamic forces from data supplied by manufacturer.

For rotating machinery in the absence of specific manufacturer's recommendations, the dynamic forces shall be calculated as follows:

K = L Q 2.5

where:

Q = balance quality grade (6.3mm/sec)

= velocity (rad/sec) of the machine in operation

L = rotor weight

K = dynamic exciting force

2. The single amplitude of vibration of the foundation in any direction at any point in the foundation mat or machine supporting block shall be such that it will fall below the zone "troublesome to persons" for the specific exciting frequency, as given in figure 1. Where second-order unbalanced forces are present, total amplitude to be considered at the primary frequency shall be the sum of the primary and the secondary amplitudes.

Moreover it shall be demonstrated that the vibration amplitudes are lower than the allowable ones given by the Machine Vendor.


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In any case the following requirement shall be respected:

For reciprocating machine:

1) 0.05 mm (peak to peak) for machines with power < 150 CB (112 kW)

2) 0.10 mm (peak to peak) for machines with power > 150 CB (112 kW)

For Rotating machine:

The amplitude will be determined using the dynamic forces of each rotor given by manufacturer or, if missing, calculated as follows:

Fd= 0,001 x rotor weight x (speed of rotor (r.p.m)/1000) 1.5 SI units

The total amplitude peak to peak of the structure supporting machine or foundation shall be in any direction not higher than:

Rotor Speed (r.p.m) Total admissible amplitude (mm) < 999 0,023 1000-1149 0,020 1150-1299 0,018 1300-1499 0,015 > 1500 0,013

3. Foundations for equipment composed of machines having different speeds shall be designed for all potential combinations of vibration frequencies.

D. Dynamic Elastic Modules

Dynamic Elastic Modulus of (E') of concrete, to be uses for dynamic analysis will be calculated

as per following formula:

E´= 6500 xs (fć) ½; where both Eánd fć are expressed in N/mm²

Or as per following table (DIN 1045):

f'c E' (N/mm2) 25 30.000

30 32.000 35 34.000 45 37.000 55 39.000

Note: values higher than f'c=35 N/mm2 will only be considered for prefabricated concrete.


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Figure 1 General limits of displacement amplitude for a particular frequency of vibration (from Richart, 1962)

General limits of displacement amplitude for a particular frequency of vibration (from Richart, 1962).

7 3814 AX SG 000002 IS05 Structural Steel Specification

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