GEOTECHNICAL ENGINEERING INVESTIGATION PROPOSED HADLEY FRUIT ORCHARDS … · 2018. 8. 27. · ph:...

www.mooretwining.comPH: 559.268.7021FX: 559.268.71262527 Fresno StreetFresno, CA 93721

GEOTECHNICAL ENGINEERING INVESTIGATION

PROPOSED HADLEY FRUIT ORCHARDS AND FUTURE BUILDING

NORTH OF RUBY’S DINER RESTAURANT

SOUTHWEST CORNER OF MORONGO TRAIL

(A.K.A. THUNDER ROAD) AND AGAVE ROAD

CABAZON, CALIFORNIA

Project Number: E88904.01-01

For:

Morongo Band of Mission Indians949 South Hope Street

Los Angeles, CA 90015

May 28, 2015

BID SET 06/19/15

www.mooretwining.comPH: 559.268.7021FX: 559.268.71262527 Fresno StreetFresno, CA 93721

May 28, 2015 E88904.01-01

Morongo Band of Mission Indians12700 Pumarra RoadBanning, CA 92220

Attention: Mr. Roger Meyer

Subject: Geotechnical Engineering InvestigationProposed Hadley Fruit Orchard and Future BuildingNorth of Ruby’s Diner RestaurantSouthwest Corner of Morongo Trail (a.k.a. Thunder Road) and Agave RoadCabazon, California

Dear Mr. Meyer:

We are pleased to submit this geotechnical engineering investigation report prepared for theproposed Hadley Fruit Orchard and a future building to be located at the southwest corner ofMorongo Trail (also known as Thunder Road) and Agave Road in Cabazon, California.

The contents of this report include the purpose of the investigation, scope of services, backgroundinformation, investigative procedures, our findings, evaluation, conclusions, and recommendations.It is recommended that those portions of the plans and specifications that pertain to earthwork,pavements, and foundations be reviewed by Moore Twining Associates, Inc. (Moore Twining) todetermine if they are consistent with our recommendations. This service is not a part of this currentcontractual agreement, however, the client should provide these documents for our review prior totheir issuance for construction bidding purposes.

In addition, it is recommended that Moore Twining be retained to provide inspection and testingservices for the excavation, earthwork, pavement, and foundation phases of construction. Theseservices are necessary to determine if the subsurface conditions are consistent with those used in theanalyses and formulation of recommendations for this investigation, and if the construction complieswith our recommendations. These services are not, however, part of this current contractualagreement. A representative with our firm will contact you in the near future regarding theseservices.

BID SET 06/19/15

BID SET 06/19/15

E88904.01-01TABLE OF CONTENTS

Page

1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2.0 PURPOSE AND SCOPE OF INVESTIGATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.2 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

3.0 BACKGROUND INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.1 Site History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.2 Previous Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43.3 Site Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53.4 Anticipated Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4.0 INVESTIGATIVE PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74.1 Field Exploration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4.1.1 Site Reconnaissance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74.1.2 Drilling Test Borings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74.1.3 Soil Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

4.2 Laboratory Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

5.0 FINDINGS AND RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85.1 Surface Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85.2 Soil Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95.3 Soil Engineering Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95.4 Groundwater Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

6.0 EVALUATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116.1 Existing Surface and Subsurface Improvements . . . . . . . . . . . . . . . . . . . . . . . . . 116.2 Processing of Onsite Soils with Gravel, Cobbles and Boulders for Use as

Engineered Fill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116.3 Existing and Proposed Graded Slopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126.4 Expansive Soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136.5 Static Settlement and Bearing Capacity of Shallow Foundations . . . . . . . . . . . . 136.6 Seismic Ground Rupture and Design Parameters . . . . . . . . . . . . . . . . . . . . . . . . 136.7 Liquefaction and Seismic Settlement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146.8 Asphaltic Concrete (AC) Pavements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146.9 Portland Cement Concrete (PCC) Pavements . . . . . . . . . . . . . . . . . . . . . . . . . . . 156.10 Soil Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156.11 Sulfate Attack of Concrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

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E88904.01-01TABLE OF CONTENTS

Page

7.0 CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

8.0 RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1888.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1888.2 Site Grading and Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198.3 Manufactured Slope Gradients, Setbacks, Grading, Drainage, Protection

and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2188.4 Site Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228.5 Engineered Fill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258.6 Conventional Shallow Spread Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288.7 Interior Slabs-on-Grade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318.8 Exterior Slabs-on-Grade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348.9 Asphaltic Concrete (AC) Pavements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358.10 Portland Cement Concrete (PCC) Pavements . . . . . . . . . . . . . . . . . . . . . . . . . . .378.11 Slopes and Temporary Excavations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398.12 Utility Trenches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408.13 Corrosion Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

9.0 DESIGN CONSULTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

10.0 CONSTRUCTION MONITORING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

11.0 NOTIFICATION AND LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

APPENDICES

APPENDIX A - Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

Drawing No. 1 - Site Location MapDrawing No. 2 - Test Boring Location Map

APPENDIX B - Logs of Borings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

APPENDIX C - Results of Laboratory Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

BID SET 06/19/15

GEOTECHNICAL ENGINEERING INVESTIGATION

PROPOSED HADLEY FRUIT ORCHARDS AND FUTURE BUILDING

NORTH OF RUBY’S DINER RESTAURANT

SOUTHWEST CORNER OF MORONGO TRAIL

(A.K.A. THUNDER ROAD) AND AGAVE ROAD

CABAZON, CALIFORNIA

Project Number: E88904.01-01

1.0 INTRODUCTION

This report presents the results of a geotechnical engineering investigation for two (2) buildings tobe located at the southwest corner of Morongo Trail (also known as Thunder Road) and Agave Roadin Cabazon, California. Moore Twining Associates, Inc. (Moore Twining) was authorized by theMorongo Band of Mission Indians to perform this geotechnical engineering investigation.

The contents of this report include the purpose of the investigation and the scope of servicesprovided. The site history, previous studies, site description, and anticipated construction arediscussed. In addition, a description of the investigative procedures used and the subsequent findingsobtained are presented. Finally, the report provides an evaluation of the findings, generalconclusions, and related recommendations. The report appendices contain the drawings (AppendixA), the logs of borings (Appendix B), and the results of laboratory tests (Appendix C).

The Geotechnical Engineering Division of Moore Twining, headquartered in Fresno, California,performed the investigation.

2.0 PURPOSE AND SCOPE OF INVESTIGATION

2.1 Purpose: The purpose of the investigation was to conduct a field exploration and alaboratory testing program, evaluate the data collected during the field and laboratory portions of theinvestigation, and provide the following:

2.1.1 Evaluation of the near surface soils within the zone of influence of theproposed foundations, exterior slabs-on-grade, and pavements with regard tothe anticipated foundation and traffic loads;

2.1.2 Recommendations for 2013 California Building Code seismic coefficientsand earthquake spectral response acceleration values;

BID SET 06/19/15

Proposed Hadley Fruit Orchards and Future Building E88904.01-01North of Ruby’s Diner RestaurantSWC of Thunder Road and Agave Road, Cabazon, CaliforniaMay 28, 2015 Page No. 2

2.1.3 Geotechnical parameters for use in design of foundations and slabs-on-grade,(e.g., soil bearing capacity and settlement);

2.1.4 Recommendations for site preparation including placement, moistureconditioning, and compaction of engineered fill soils;

2.1.5 Recommendations for the design and construction of new asphaltic concrete(AC) and Portland cement concrete (PCC) pavements;

2.1.6 Recommendations for temporary excavations and trench backfill; and

2.1.7 Conclusions regarding soil corrosion potential.

This report is provided specifically for the two (2) buildings referenced in the AnticipatedConstruction section of this report. This investigation did not include a geologic/seismic hazardsevaluation, flood plain investigation, compaction tests, environmental investigation, environmentalaudit nor was any investigation conducted outside the “limit of work” shown on the project gradingplans. This report did not include an assessment or recommendations for the proposed slopes outsidethe “limit of work” shown on the project grading plans.

2.2 Scope: Our revised proposal, dated April 1, 2015, outlined the scope of our services.The actions undertaken during the investigation are summarized as follows.

2.2.1 The Site Improvement Plans (8 Sheets) for Hadley Fruit Orchards, preparedby Kimley-Horn and Associates, Inc., dated March 13, 2015, were reviewedto gain an understanding of the proposed grading for the project.

2.2.2 A report entitled, “Geotechnical Engineering Investigation, Two (2) ProposedBuildings, West of Morongo Casino Resort & Spa, Southwest Corner ofTumbleweed and Agave Roads, Cabazon, California,” prepared by MooreTwining, Project No. E88901.01-01, dated July 17, 2013, was reviewed.

A report entitled, “Geotechnical Engineering Investigation, Proposed In-N-Out Burger Restaurant, West of Morongo Casino Resort & Spa, NorthwestCorner of Seminole Drive and Eagle Pass Road, Cabazon, California,”prepared by Moore Twining, Project No. E88902.02-01, dated August 6,2013, was reviewed.

A report entitled, “Geotechnical Engineering Investigation, Proposed TacoBell and Starbucks Buildings, Morongo Travel Center, Northeast Corner ofSeminole Drive and Morongo Trail (a.k.a. Thunder Road), Cabazon,California,”prepared by Moore Twining, Project No. E88903.01-01, datedJune 25, 2014, was reviewed.

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2.2.3 A visual site reconnaissance and subsurface exploration were conducted.

2.2.4 Satellite images of the site between the years 1996 and 2014 from onlinesources, were reviewed.

2.2.5 Laboratory tests were conducted to determine selected physical andengineering properties of the subsurface soils.

2.2.6 Mr. Jason Marechal (Kimley-Horn) and Mr. Ross Kriso (Morongo Band ofMission Indians) were consulted during the investigation.

2.2.7 The data obtained from the investigation were evaluated to develop anunderstanding of the subsurface soil conditions and engineering properties ofthe subsurface soils.

2.2.8 This report was prepared to present the purpose and scope, backgroundinformation, field exploration procedures, findings, evaluation, conclusions,and recommendations.

3.0 BACKGROUND INFORMATION

The site history, previous studies, existing site features, and the anticipated construction aresummarized in the following subsections.

3.1 Site History: Based on our review of aerial satellite images of the site, the siteappears undeveloped in a 1996 image. The 2002 image of the site shows the area south of the siteas being developed with the current improvements (Ruby’s Diner Restaurant) and the area east ofthe site as being developed with the current improvements (Morongo Travel Center with car wash,gas dispensers and fast food restaurant. The 2003 and 2004 images of the site are similar to the 2002image of the site, and the Morongo Casino Resort & Spa is shown as being constructed east of theMorongo Travel Center. The 2005, 2006, 2009, 2011 and 2012 images of the site show the site asit appeared at the time of our field observations: a graded lot covered by gravel and with slopes andvegetation existing around the southern perimeter and vegetation around the southeastern perimeterof the site. The 2013 and 2014 images of the site also show the site as it appeared at the time of ourfield observations, and the In-N-Out restaurant building is shown as being constructed in thesoutheast portion of the Morongo Travel Center.

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3.2 Previous Studies: Various reports prepared by Moore Twining for areas of sitedevelopment located directly east of the subject site were reviewed as noted below.

Moore Twining conducted a geotechnical engineering investigation for two proposed buildings tobe located east of the subject site, between the developed Morongo Travel Center and the MorongoCasino (Project No. E88901.01-01, dated July 17, 2013). Six (6) borings were drilled to depths of20½ to 37½ feet BSG. The soils encountered generally consisted of silty sands with gravel andvarying amounts of cobbles and boulders overlying interbedded layers of poorly graded sands withsilt and gravel, silty gravel with sand, and poorly graded gravel with silt and sand extending to themaximum depth explored, about 37½ feet BSG. The two (2) proposed buildings were recommendedto be supported on shallow foundations supported on engineered fill soils. The foundations wererecommended to be designed for a net allowable bearing pressure of 3,000 pounds per square footfor dead-plus-live loads. Static foundation settlements of 1 inch total and ½ inch differential in 40feet were estimated.

Moore Twining also conducted a geotechnical engineering investigation for the proposed In-N-Outrestaurant located southeast of the subject site, between the developed Morongo Travel Center andthe Morongo Casino (Project No. E88902.02-01, dated August 6, 2013). Seven (7) test borings weredrilled at the site to depths ranging from about 16 to 21½ feet BSG. The soils encountered generallyconsisted of silty sands with gravel and varying amounts of cobbles and boulders and poorly gradedsands with silt and gravel which were underlain at varying depths by silty gravel with sand andvarying amounts of cobbles and boulders that extended to the maximum depth explored, about 21½feet BSG. The proposed In-N-Out building was recommended to be supported on shallowfoundations supported on engineered fill soils. The foundations were recommended to be designedfor a net allowable bearing pressure of 3,000 pounds per square foot for dead-plus-live loads. Staticfoundation settlements of 1 inch total and ½ inch differential in 40 feet were estimated.

Moore Twining also conducted a geotechnical engineering investigation for the proposed Taco Belland Starbucks buildings to be located in the southwestern portion of the Morongo Travel Centerwhich is located directly east of the subject site. Four (4) test borings were drilled at the site todepths ranging from about 7 to 17¾ feet below site grades (BSG). The soils encountered generallyconsisted of silty sands with gravel, overlying interbedded layers of silty gravel with sand extendingto the maximum depth explored in these borings, about 15 feet BSG, as noted in borings B-1 throughB-3. However, the soils encountered in boring B-4 directly below the asphaltic concrete pavementsconsisted of poorly graded gravel with silt and sand overlying poorly graded sand with silt and gravelextending to the maximum depth explored, about 17 ¾ feet BSG. The proposed Taco Bell andStarbucks buildings were recommended to be supported on shallow foundations supported onengineered fill soils. The foundations were recommended to be designed for a net allowable bearingpressure of 3,000 pounds per square foot for dead-plus-live loads. Static foundation settlements of1 inch total and ½ inch differential in 40 feet were estimated.

No other previous geotechnical engineering, geological, compaction reports, or environmentalstudies conducted for this site were provided for review during this investigation. If available, thesereports should be provided for review and consideration for this project.

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3.3 Site Description: The project site is located at the southwest corner of MorongoTrail (also known as Thunder Road) and Agave Road in Cabazon, California. The proposed HadleyFruit Orchard building and future building are to be located directly north of the existing Ruby’sDiner restaurant. A site location map is presented on Drawing No. 1 in Appendix A, and a boringlocation map that shows the general locations of the proposed buildings relative to theaforementioned streets is presented on Drawing No. 2 in Appendix A. The site was bound to thenorth by vacant land, to the southeast by Morongo Trail (also known as Thunder Road), to the southby Ruber’s Diner restaurant, and to the west by an existing Hadley Fruit Orchards store.

At the time of our investigation, the subject site was generally covered by silty sand and gravel.Agave Road crosses the northern portion of the site in an east-west orientation. The southeasternportion of the site, adjacent to Morongo Trail (also known as Thunder Road), is overlain by a thinlayer of gravel and a row of palm trees. A strip of grass lawn exists between the palm trees andThunder Road.

A south-descending graded slope, with an inclination as steep as about 3 Horizontal to 1 Vertical(3H:1V) and approximately 8 feet in height, exists within the northern property boundary, just northof Agave Road. This slope was noted to be generally covered by weeds.

The ground surface in the area where the building pads and parking and drive areas are plannedgently slopes in a southerly to southwesterly direction and is covered by silty sand and gravel.

A south-descending graded slope, with a maximum height of about 10 feet and an inclination ofabout 3H:1V was located south of the southern property boundary. The eastern portion of this slope(southern portion of the site) is covered by vegetation and includes two trees. A chain link fence wasnoted at the top of a portion of the slope, and a gas line was marked out in the middle of the slope.The western portion of this slope is mostly barren of vegetation, and the gas line was marked ascontinuing across the western portion of the slope. A concrete swale and stairway exists in thecentral portion of this slope in the southern portion of the site.

An approximately 20-foot long concrete masonry unit (CMU) wall is located within thesouthwestern portion of the site. A 5-foot deep excavated area exists directly north of the wall andthe excavated area was noted as being surrounded by gravel and cobbles. The wall is notched at thetop to allow for storm water to flow over the wall and into a concrete lined swale.

In addition to the gas line noted near the southern property boundary, underground water andelectrical utilities exist near the southeastern boundary adjacent to Thunder Road.

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3.4 Anticipated Construction: It is our understanding the project will includeconstruction of two (2) buildings that will be located north of the existing Ruby’s Diner restaurantand northwest of the existing Morongo Travel Center in Cabazon, California. Agave Road will beremoved where it crosses through the northern portion of the site to make room for the proposedconstruction. It is our understanding the project will include construction of a 14,000 square-footbuilding in the western portion of the site (proposed Hadley Fruit Orchards), and we understand thata similar sized future pad is also planned about 200 feet east of the proposed 14,000 square-footbuilding. It appears that a drive-through canopy may be planned for the proposed future pad.

The site slopes down in a southerly to southwesterly direction and ranges in elevation from about1,987 feet above mean sea level (AMSL) to about 2,009 feet AMSL. Based on our review of theGrading Plans, the proposed 14,000 square-foot building will have a pad elevation of 1,993.35 feetAMSL. Based on our review of the existing elevations shown on the Grading Plans, grading for theproposed 14,000 square-foot building will include up to 3 feet of cut in the northeastern portion ofthe building pad and up to 5 feet of fill in the southwestern portion of the building pad to achieve thedesign pad grade. The future pad to be located about 200 feet east of the proposed 14,000 squarefoot building will have a pad elevation of 1,993.30 feet AMSL. Based on our review of the existingelevations shown on the Grading Plans, grading for the proposed future pad will include about 5½feet of cut in the northeastern portion of the future pad to about as much as 1 foot of cut in thesouthwestern portion of the future pad.

The existing south-descending slope, located south of the southern property boundary, will be gradedto have a maximum height of 12 feet and as steep as about 3H:1V on the south side of the proposedHadley Fruit Orchard Building, as steep as about 2H:1V south of the proposed parking and driveareas, and as steep as about 14H:1V south of the proposed future pad. Retaining walls may also beplanned as part of the proposed retail development. A gentle, 5-foot high west-descending cut slopeis shown on the grading plans on the east side of the future pad. Concrete flatwork, asphalticconcrete pavements, underground utilities and landscaping are also anticipated as part of the project.

For the purpose of this report, maximum column loads of about 35 kips and maximum perimeterwall loads of 2 kips per linear foot were assumed as preliminary structural loads for the purpose ofthis report. The actual design foundation loads should be provided to Moore Twining whenavailable. In the event that the maximum foundation loads exceed those assumed for design, therecommendations of this report may not be applicable and may need to be revised.

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4.0 INVESTIGATIVE PROCEDURES

The field exploration and laboratory testing programs conducted for this investigation aresummarized in the following subsections.

4.1 Field Exploration: The field exploration consisted of a site reconnaissance, drillingtest borings, and soil sampling.

4.1.1 Site Reconnaissance: The site reconnaissance consisted of walking the siteand noting visible surface features. The reconnaissance was conducted by Mr. Amer Razaq ofMoore Twining on May 4, 2013. The features noted are described in the background informationsection of this report.

4.1.2 Drilling Test Borings: Prior to drilling, the site was marked for UndergroundService Alert for members to mark out the locations of existing public utilities.

The depths and locations of the test borings were selected based on the size of the structures, typeof construction, estimated depths of influence of the anticipated foundation loads, and the subsurfacesoil conditions encountered.

On May 5, 2015, five (5) test borings were drilled at the site to depths ranging from about 5 to 21¼feet below site grades (BSG). The borings were drilled with a conventional truck-mounted CME-75drill rig equipped with 8-inch outside diameter (O.D.) hollow-stem augers.

During the drilling of the test borings, bulk samples of soil were obtained for laboratory testing. Thetest borings were drilled under the direction of a Moore Twining staff engineer. The soilsencountered in the test borings were logged during drilling by a representative of our firm. The fieldsoil classification was in accordance with the Unified Soil Classification System and consisted ofparticle size, color, and other distinguishing features of the soil.

The presence and elevation of free water, if any, in the borings were noted and recorded duringdrilling and immediately following completion of the borings.

Test boring locations were determined with reference to existing site features shown on the site plan.The locations, as described, should be considered accurate to within about 10 feet. The locationsof the test borings are described on the boring logs in Appendix B. The test borings were looselybackfilled with material excavated during the drilling operations; thus, some settlement should beanticipated at the boring locations.

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4.1.3 Soil Sampling: Standard penetration tests were conducted in the test borings,and both disturbed and relatively undisturbed soil samples were obtained.

The standard penetration resistance, N-value, is defined as the number of blows required to drive astandard split barrel sampler into the soil. The standard split barrel sampler has a 2-inch O.D. anda 1d-inch inside diameter (I.D.). The sampler is driven by a 140-pound weight free falling30 inches. The sampler is lowered to the bottom of the bore hole and set by driving it an initial6 inches. It is then driven an additional 12 inches and the number of blows required to advance thesampler the additional 12 inches is recorded as the N-value.

Relatively undisturbed soil samples for laboratory tests were obtained by pushing or driving aCalifornia modified split barrel ring sampler into the soil. The soil was retained in brass rings,2.5 inches O.D. and 1-inch in height. The lower 6-inch portion of the samples were placed in close-fitting, plastic, airtight containers which, in turn, were placed in cushioned boxes for transport to thelaboratory. Soil samples obtained were taken to Moore Twining's laboratory for classification andtesting.

4.2 Laboratory Testing: The laboratory testing was programmed to determine selectedphysical and engineering properties of the soils underlying the site. The tests were conducted ondisturbed and relatively undisturbed samples considered representative of the subsurface soilsencountered.

The results of laboratory tests are summarized in Appendix C. These data, along with the fieldobservations, were used to prepare the final test boring logs in Appendix B.

5.0 FINDINGS AND RESULTS

The findings and results of the field exploration and laboratory testing are summarized in thefollowing subsections.

5.1 Surface Conditions: At the time of our investigation, the subject site was generallybarren ground covered by silty sand and gravel. Agave Road crosses the northern portion of the sitein an east-west orientation. The southeastern portion of the site, adjacent to Morongo Trail (alsoknown as Thunder Road) is overlain by a thin layer of gravel and a row of palm trees with a strip ofgrass lawn between the palm trees and Thunder Road. A south-descending slope, approximately 8feet in height, is located just north of Agave Road, and has a slope inclination as steep as about 3Horizontal to 1 Vertical (3H:1V). South of the southern property boundary but considered part ofthe limits of work, a steeper, south-descending slope, with a maximum height of about 10 feet, islocated south of the proposed building pads and parking and drive areas and has an inclination ofabout 3H:1V. Additional descriptions of these site features are included in the “Site Description”section of this report.

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5.2 Soil Profile: The soils encountered in the borings conducted for this investigationconsisted of silty sands with gravel and varying amounts of cobbles, well graded gravel with sandand poorly graded sand with gravel and cobbles. These near surface soils were underlain byinterbedded layers of well graded gravel with silt and sand, silty gravel with sand, poorly graded sandwith silt, and silty sand extending to the maximum depth explored, about 21¼ feet BSG. The soillayers described above are also anticipated to contain localized boulders; however, the presence ofboulders could not be confirmed due to the small size of the boreholes (8 inches in diameter) thatwere drilled.

The foregoing is a general summary of the soil conditions encountered in the test borings drilled forthis investigation. Detailed descriptions of the soils encountered at each test boring location arepresented in the logs of borings in Appendix B. The stratification lines in the logs represent theapproximate boundary soil types; the actual in-situ transition may be gradual.

5.3 Soil Engineering Properties: The following is a description of the soil engineeringproperties as determined from our field exploration and laboratory testing.

Silty Sands with Gravel and Cobbles: The silty sands with varying amounts of gravel and cobbleswere described as medium dense to very dense, as determined by standard penetration resistance,N-values, ranging from 12 to 67 blows per foot. The moisture content of the silty sands with varyingamounts of gravel and cobbles ranged from about 3 to 4 percent. Two (2) samples revealed drydensities of 124.7 and 126.2 pounds per cubic foot. A sieve analysis conducted on a near surfacesample from boring B-1 indicated 27.6 percent gravel retained on the No. 4 sieve and 15.3 percentfines (silt and clay). An expansion index test conducted on the same sample indicated an expansionindex value of 0. A sieve analysis conducted on a near surface silty sand sample from boring B-2indicated 8.0 percent gravel retained on the No. 4 sieve and 26.5 percent fines (silt and clay). Adirect shear test conducted on the same sample indicated an internal angle of friction of 25 degreesand 150 pounds per square foot of cohesion. A consolidation test conducted on the same samplefrom boring B-2 indicated moderate compressibility characteristics (3.5 percent consolidation undera load of 8 kips per square foot). Another sieve analysis conducted on a deeper silty sand samplefrom boring B-4 indicated 13.7 percent gravel retained on the No. 4 sieve and 20.6 percent fines (siltand clay). A direct shear test conducted on the same sample indicated an internal angle of frictionof 34 degrees and 0 pounds per square foot of cohesion.

Well Graded Gravel with Silt and Sand and Well Graded Gravel with Sand: The well gradedgravel with silt and sand and well graded gravel with sand were described as medium dense to dense,as determined by standard penetration resistance, N-values of 13 to 34 blows per foot. The moisturecontent of a well graded gravel sample with silt and sand was 1 percent.

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Silty Gravel with Sand and Cobbles: The silty gravel with sand and cobbles were described asdense to verydense, as determined by standard penetration resistance, N-values, of 41 to greater than50 blows per foot. The moisture content of a silty gravel sample with sand and cobbles was about1 percent.

Poorly Graded Sands with Silt: The poorly graded sands with silt were described as dense, asdetermined by standard penetration resistance, N-values, of 43 and greater than 50 blows per foot.

Poorly Graded Sands with Gravel: The poorly graded sands with gravel were described as verydense, as determined by a standard penetration resistance, N-value of 63 blows per foot. A sieveanalysis conducted on a near surface poorly graded sand sample with gravel from boring B-4indicated 29.5 percent gravel retained on the No. 4 sieve and 3.1 percent fines (silt and clay). Anexpansion index test conducted on the same near surface sample indicated an expansion index valueof 0.

R-value Test: One R-value test conducted on a near surface well graded gravel with sand samplecollected from depths of about 0 foot to 3½ feet BSG in boring B-3 indicated an R-value of 64.

Chemical Tests: Chemical tests performed on two (2) near surface soil samples collected at depthsof 5 to 6½ feet BSG from boring B-1 and from 3½ to 5 feet BSG from boring B-4 indicated pHvalues of 5.9 and 5.2; minimum resistivityvalues of 15,000 and 6,300 ohms-centimeter; not-detectedand 0.0040 percent by weight concentrations of sulfate (reporting limit of 0.00060 percent byweight); and 0.0072 and 0.0071 percent by weight concentrations of chloride (reporting limit of0.00060 percent by weight).

5.4 Groundwater Conditions: Groundwater was not encountered in the test boringsdrilled at the time of our May 4, 2015 field exploration to the maximum depth explored, about 21¼feet BSG. Based on our review of water well data on the Department of Water Resources web site,a well located about ½ mile west of the site indicated that groundwater has ranged from about 443to 460 feet BSG between the years 2005 and 2010.

It should be recognized, however, that groundwater elevations fluctuate with time, since they aredependent upon seasonal precipitation, irrigation, land use, and climatic conditions as well as otherfactors. Therefore, water level observations at the time of the field investigation may vary fromthose encountered both during the construction phase and the design life of the project. Theevaluation of such factors was beyond the scope of this investigation and report.

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6.0 EVALUATION

The data and methodologyused to develop conclusions and recommendations for project design andpreparation of construction specifications are summarized in the following subsections. Theevaluation was based upon the subsurface soil conditions determined from this investigation and ourunderstanding of the proposed construction. The conclusions obtained from the results of ourevaluations are described in the Conclusions section of this report.

6.1 Existing Surface and Subsurface Improvements: At the time of our investigation,the subject site was generally barren ground covered by silty sand and gravel. Agave Road crossesthe northern portion of the site in an east-west orientation. Underground utilities are also anticipatedbelow the existing roadway. A south-descending slope, located south of the southern boundary butwithin the limits of work, is vegetated on portions of the slope and includes two trees. Whereexisting vegetation is to be removed, these areas should be stripped of all vegetation and top soil,and removal of trees and vegetation should remove all root balls and roots greater than ¼ inch indiameter.

As part of site preparation, the existing paved Agave Road (where it crosses through the subject site),underground utilities and all associated backfill soils within areas of proposed improvements whichare sensitive to settlement should be removed and the excavations should be backfilled withengineered fill.

There is a potential that undocumented fill soils may exist at the site due to prior site grading forAgave Road and manufactured slopes, including the areas of the slopes along the southern portionof the site. Due to the granular nature of the on-site soils and absence of debris, fill soils could notbe differentiated from native soils in the borings that were drilled. As part of the site preparation,unless documentation can be provided indicating fill soils encountered at the site were compactedas engineered fill, then all fill soils encountered during site preparation should be over-excavated andplaced back as engineered fill in accordance with the recommendations of this report.

6.2 Processing Onsite Soils with Gravel, Cobbles and Boulders for Use AsEngineered Fill: The near surface soils and soils at depths where cuts are planned are anticipatedto contain coarse gravel, cobbles and potentially some boulders. In order to allow testing of the on-site soils for maximum density/optimum moisture determination in accordance with ASTM D1557and allow determination of the relative compaction of compacted fill soils, the percentage of rockmaterial retained on the 3/4-inch sieve (i.e., coarse gravel, cobbles and boulders) is required to benot more than 30 percent. Thus, the oversize gravel, cobbles and boulders would need to beremoved or processed by some methods such that the materials retained on the 3/4-inch sieve are 30percent or less. In addition to the requirements described above, this report also recommends thatrock greater than 6 inches in the largest dimension not be used within engineered fill soils.

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In order to provide additional information for use in estimating the screening and processingrequirements of the cobbles and boulders in the onsite materials, backhoe pits could be excavatedby contractors, or as part of the bid process, to allow the exposed soil conditions to be directlyobserved by the contractor’s bidding the work.

Based on the subsurface soil conditions with excessive coarse gravel and cobbles and potentiallysome boulders, the contractor will need to determine the methods they will use to achieve thespecified requirements for engineered fill. These may include screening the material to remove thelarger coarse gravel size fraction, or processing the material such as by screening and crushing thelarger gravel, cobbles and boulders and blending the materials to achieve the gradation requirementsfor engineered fill. The particle-size recommendations for engineered fill are included in Section8.5.1 of this report.

6.3 Existing and Proposed Graded Slopes: Graded slopes with inclinations of as steepas about 3 Horizontal to 1 Vertical (3H:1V) and heights of as much as about 10 feet exist in thesouthern portions of the site. The eastern side of the slope in the southern portion of the site (southof the southern property boundary, but within the limit of work) is currently covered by vegetationand two trees and the western side of the slope is not vegetated. Based on our observations, theslopes did not exhibit any obvious signs of slope instability and there were no signs of excessivesurface erosion. The grading plan indicates that cut and fill slopes with a repose ranging from 2H:1Vto 3H:1V are planned in the southern portion of the site with a maximum height of about 12 feet.

The top of the proposed slopes should be developed and maintained to rapidly drain surface and roofrunoff away from cut or fill slopes - both during and after construction. To accomplish this, usebrow ditches, berms or other measures to intercept and safely redirect flow. In addition, upslopedrainage such as lined brow ditches or subdrains should be used to divert water away from gradedslopes and to reduce erosion potential. Lined (concrete or asphalt) gutters, “U-gutters,” swales, etc.should be provided at the bottom of slopes. Drainage should be directed into natural swales andenergy dissipaters such as gravel or rip-rap should be used to minimize erosion.

Graded slopes should be planted with ground cover vegetation to reduce erosion potential. Theexisting native low lying shrubs, trees should remain covering the slopes, if possible. If the existingvegetation is disturbed, shallow rooted ground cover, as well as deeper rooted trees or bushes, shouldbe planted on the disturbed or reconstructed portions of the slopes to reduce the potential for erosionand aid in surficial slope stability.

The grading plans for this project also show some graded slopes planned north of the site; however,these slopes are north of the northern property boundary and are outside the “limit of work” shownon the grading plans. Thus, this report did not include any investigation for slopes outside the limitof work.

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6.4 Expansive Soils: In evaluation of the potential for expansive soils at the site,expansion index testing was performed on representative samples of the near surface soils which areanticipated to be within the zone of influence of the planned improvements. The expansion indextesting was performed in accordance with ASTM D4829. The soils tested were classified byexpansion potential in accordance with Table 1 of ASTM D4829 and are summarized in AppendixC of this report. The results of expansion index testing indicated that the near surface samples testedhave a very low expansion potential, with expansion index values of 0. Therefore, specialprocedures to address expansive soils concerns are not anticipated for the project.

6.5 Static Settlement and Bearing Capacity of Shallow Foundations: The potentialfor excessive total and differential static settlement of foundations and slabs-on-grade is ageotechnical concern that was evaluated for this project. The increases in effective stress tounderlying soils which can occur from new foundations and structures, placement of fill, withdrawalof groundwater, etc. can cause vertical deformation of the soils, which can result in damage to theoverlying structures and improvements. The differential component of the settlement is often themost damaging. In addition, the allowable bearing pressures of the soils supporting the foundationswere evaluated for shear and punching type failure of the soils resulting from the imposed foundationloads.

This report recommends that footings for the proposed buildings be supported on engineered fillsoils in order to limit total and differential static settlements of foundations to 1 inch total and ½ inchdifferential in 40 feet. A net allowable soil bearing pressure of 3,000 pounds per square foot, fordead-plus-live loads, may be used for design.

The net allowable soil bearing pressure is the additional contact pressure at the base of thefoundations caused by the structure. The weight of the soil backfill and weight of the footing maybe neglected. The net allowable soil bearing pressure presented was selected using the Terzaghibearing capacity equations for foundations considering a minimum factor of safety of 3.0 and basedon the anticipated static settlements noted in this report.

A structural engineer experienced in foundation and slab-on-grade design should determine thethickness, reinforcement, design details and concrete specifications for the proposed buildingfoundations and slabs-on-grade based on the anticipated settlements estimated in this report.

6.6 Seismic Ground Rupture and Design Parameters: The project site is not locatedin an Alquist-Priolo Earthquake Fault Zone. The closest active or potentially active fault is the SanGorgonio Pass Fault Zone located approximately 0.6 miles (1.0 kilometers) northwest of the site.Accordingly, the potential for ground rupture at the site is considered low.

It is our understanding that the 2013 CBC will be used for structural design, and that seismic sitecoefficients are needed for design.

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Based on the 2013 CBC, a Site Class D represents the on-site soil conditions with standardpenetration resistance, N-values averaging between 15 and 50 blows per foot in the upper 100 feetbelow site grade.

A table providing the recommended seismic coefficient and earthquake spectral responseacceleration values for the project site is included in the Foundation Recommendations section ofthis report. A Maximum Considered Earthquake (geometric mean) peak ground accelerationadjusted for site effects (PGAM) of 0.873g was determined for the site using the Ground MotionParameter Calculator provided by the United States Geological Survey(http://earthquake.usgs.gov/designmaps/us/application.php).

6.7 Liquefaction and Seismic Settlement: Liquefaction and seismic settlement areconditions that can occur under seismic shaking from earthquake events. Liquefaction describes aphenomenon in which a saturated, cohesionless soil loses strength during an earthquake as a resultof induced shearing strains. Lateral and vertical movements of the soil mass, combined with lossof bearing can result. Fine, well sorted, loose sand, shallow groundwater conditions, higher intensityearthquakes, and particularly long duration of ground shaking are the requisite conditions forliquefaction. One of the most common phenomena that occurs during seismic shaking is the inducedsettlement of loose, unconsolidated sediments. This can occur in unsaturated and saturated granularsoils, however, seismic settlements are typically largest where liquefaction occurs (saturated soils).

Due to the depth of groundwater at this site (anticipated to be greater than 400 feet BSG),liquefaction is not considered a potential hazard at this site. However, due to some of the mediumdense soils encountered in boring B-1, dry seismic settlements of up to about 1¼ inches total and ¾inch differential in 40 linear feet were estimated. The analyses were conducted using the computerprogram LIQUEFYPRO by Civiltech. A design horizontal ground acceleration of 0.873g and anearthquake magnitude of 7.6 were used in the analysis. Soil parameters, such as wet unit weight, N-value, fines content, and depth of N-value tests, were input for the soil layers encountered throughoutthe depths explored (see test boring logs, Appendix B).

6.8 Asphaltic Concrete (AC) Pavements: Recommendations for asphaltic concretepavement structural sections are presented in the "Recommendations" section of this report forproposed asphaltic concrete (AC) pavements. The structural sections were designed using the gravelequivalent method in accordance with the California Department of Transportation HighwayDesignManual. The analysis was based on traffic index values ranging from 5.0 to 7.0. The appropriatepaving section should be determined by the project civil engineer or applicable design professionalbased on the actual vehicle loading (traffic index) values. If traffic loading is anticipated to begreater than assumed, the pavement sections should be re-evaluated.

It should be noted that if pavements are constructed prior to the construction of the buildings, theadditional construction truck traffic should be considered in the selection of the traffic index value.If more frequent or heavier traffic is anticipated and higher Traffic Index values are needed, MooreTwining should be contacted to provide additional pavement section designs.

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One (1) R-value test was conducted on a near surface sample of well graded gravel with sandcollected between the depths of about 0 and 3½ feet BSG, which indicated an R-value of 64. Basedon the results of the testing, the procedures of the Caltrans Highway Design Manual and consideringthe extent of grading planned for the project, an R-value of 50 was used to determine the pavementsection thickness recommendations.

6.9 Portland Cement Concrete (PCC) Pavements: Recommendations for Portlandcement concrete (PCC) pavement structural sections are presented in the "Recommendations"section of this report. The PCC pavement sections are based upon the amount and type of trafficloads being considered and the Resistance or R-value of the subgrade soils which will support thepavement. The measure of the amount and type of traffic loads are based upon an index ofequivalent axle loads (EAL) from the loading of heavy trucks called a traffic index (T.I).

In evaluation of the pavement design for this project, a sample of the near surface soils anticipatedto be representative of the soils which will support pavements was obtained and R-value testingperformed in accordance with California Test Method 301. The R-value test result is summarizedin Appendix C of this report.

The recommendations provided in this report for PCC pavements are based on a trash truckaccessing the trash enclosure area twice a week and daily and the design procedures contained in thePortland Cement Association "Thickness Design of Highway and Street Pavements.”

The PCC pavement sections were designed for a life of 20 years, a load safety factor of 1.1, a singleaxle weight of 20,000 pounds, and a tandem axle weight of 35,000 pounds. A modulus of subgradereaction, K-value, for the pavement section, of 230 psi/in was used for the pavement designconsidering the pavements to be underlain by 4 inches of aggregate base.

6.10 Soil Corrosion: The risk of corrosion of construction materials relates to thepotential for soil-induced chemical reaction. Corrosion is a naturally occurring process whereby thesurface of a metallic structure is oxidized or reduced to a corrosion product such as iron oxide (i.e.,rust). The metallic surface is attacked through the migration of ions and loses its original strengthby the thinning of the member.

Soils make up a complex environment for potential metallic corrosion. The corrosion potential ofa soil depends on numerous factors including soil resistivity, texture, acidity, field moisture andchemical concentrations. In order to evaluate the potential for corrosion of metallic objects incontact with the onsite soils, chemical testing of soil samples was performed by Moore Twining aspart of this report. The test results are included in Appendix C of this report. Conclusions regardingthe corrosion potential of the soils tested are included in the Conclusions section of this report basedon the National Association of Corrosion Engineers (NACE) corrosion severity ratings listed in theTable No. 1 below.

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Table No. 1Soil Resistivity and Corrosion Potential Ratings

Soil Resistivity (ohm cm) Corrosion Potential Rating

>20,000 Essentially non-corrosive

10,000 - 20,000 Mildly corrosive

5,000 - 10,000 Moderately corrosive

3,000 - 5,000 Corrosive

1,000 - 3,000 Highly corrosive

<1,000 Extremely corrosive

The results of soil sample analyses indicate that the near-surface soils exhibit a “moderatelycorrosive” to “mildly corrosive” corrosion potential to buried metal objects. Appropriate corrosionprotection should be provided for buried improvements based on the “moderately corrosive”corrosion potential. If piping or concrete are placed in contact with imported soils, these soils shouldbe analyzed to evaluate the corrosion potential of these soils.

If the manufacturers or suppliers cannot determine if materials are compatible with the soil corrosionconditions, a professional consultant, i.e., a corrosion engineer, with experience in corrosionprotection should be consulted to provide design parameters. Moore Twining does not providecorrosion engineering services.

6.11 Sulfate Attack of Concrete: Degradation of concrete in contact with soils due tosulfate attack involves complex physical and chemical processes. When sulfate attack occurs, theseprocesses can reduce the durability of concrete by altering the chemical and microstructural natureof the cement paste. Sulfate attack is dependent on a variety of conditions including concretequality, exposure to sulfates in soil/groundwater and environmental factors. The standard practicefor geotechnical engineers in evaluation of the soils anticipated to be in contact with concrete is toperform testing to determine the sulfates present in the soils. The test results are then compared withthe provisions of ACI 318, section 4.3 to provide guidelines for concrete exposed to sulfate-containing solutions. Common methods used to resist the potential for degradation of concrete dueto sulfate attack from soils include, but are not limited to the use of sulfate-resisting cements, air-entrainment and reduced water to cement ratios. The test results are included in Appendix C of thisreport. Conclusions regarding the sulfate test results are included in the Conclusions section of thisreport.

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The soil corrosion data should be provided to the manufacturers or suppliers of materials that willbe in contact with soils (pipes or ferrous metal objects, etc.) to provide assistance in selecting theprotection and materials for the proposed products or materials. If the manufacturers or supplierscannot determine if materials are compatible with the soil corrosion conditions, a professionalconsultant, i.e., a corrosion engineer, with experience in corrosion protection should be consultedto provide design parameters.

7.0 CONCLUSIONS

Based on the data collected during the field and laboratory investigations, our geotechnicalexperience in the vicinity of the project site, and our understanding of the anticipated construction,the following general conclusions are presented.

7.1 The site is considered suitable for the proposed construction with regard to supportof the proposed structures and pavements, provided the recommendations containedin this report are followed. It should be noted that the recommended designconsultation and observation of clearing, and earthwork activities by Moore Twiningare integral to this conclusion.

7.2 The soils encountered in the borings conducted for this investigation consisted ofsilty sands with gravel and varying amounts of cobbles, well graded gravel with sandand poorly graded sand with gravel and cobbles. These near surface soils wereunderlain by interbedded layers of well graded gravel with silt and sand, silty gravelwith sand, poorly graded sand with silt, and silty sand extending to the maximumdepth explored, about 21¼ feet BSG.

7.3 Due to the coarse gravel, cobble and boulder content anticipated for the onsite soils,in order to allow testing of the on-site soils for maximum density/optimum moisturedetermination in accordance with ASTM D1557 and allow determination of therelative compaction of compacted fill soils, the percentage of rock material retainedon the 3/4-inch sieve (i.e., coarse gravel, cobbles and boulders) is required to be notmore than 30 percent. Thus, the oversize gravel, cobbles and boulders would needto be removed or removed and processed from the onsite soils by some methods suchthat the materials retained on the 3/4-inch sieve are 30 percent or less prior to reuseas engineered fill.

7.4 The near surface soils exhibited a very low expansion potential.

7.5 Groundwater was not encountered to the maximum depth explored, 21¼ feet BSG,in the test borings drilled at the time of our May 4, 2015 field exploration.

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7.6 This report recommends over-excavation of the upper soils to support of the newstructures on engineered fill and reduce the potential for excessive differential staticsettlement. Static settlements of 1 inch total and ½ inch differential in 40 linear feetshould be anticipated for foundations supported on engineered fill prepared inaccordance with the recommendations of this report.

7.7 Due to the depth of groundwater, liquefaction is not considered a potential hazard atthis site. However, due to some of the medium dense soils encountered in boring B-1, dry seismic settlements of up to about 1¼ inches total and ¾ inch differential in40 linear feet were estimated.

7.8 Chemical testing of soil samples indicated the soils exhibit a “moderatelycorrosive”to “mildly corrosive” corrosion potential.

7.9 Chemical analyses indicated a “negligible” potential for sulfate attack on concreteplaced in contact with the near surface soils.

7.10 The site is not located in an Alquist-Priolo Earthquake Fault Zone and the potentialfor fault rupture on the site is estimated to be low.

8.0 RECOMMENDATIONS

Based on the evaluation of the field and laboratory data and our geotechnical experience in thevicinity of the project, the following recommendations are presented for use in the project design andconstruction. However, this report should be considered in its entirety. When applying therecommendations for design, the background information, procedures used, findings, evaluation, andconclusions should be considered. The recommended design consultation and constructionmonitoring by Moore Twining are integral to the proper application of the recommendations. TheContractor is required to comply with the requirements and recommendations presented in thisreport.

Where the requirements of a governing agency, utility agency or pipe manufacturer differ from therecommendations of this report, the more stringent recommendations should be applied to theproject.

8.1 General

8.1.1 Moore Twining should be provided the opportunity to review the finalgrading plans and foundation plans before the plans are released for biddingpurposes so that any relevant recommendations can be presented.

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8.1.2 When the actual foundation loads are known, this information should beprovided to Moore Twining for review to confirm the recommendations forsite preparation are suitable. In the event the foundation loads are differentthan assumed, the recommendations in this report may need to be revised.

8.1.3 A preconstruction meeting including, as a minimum, the owner, generalcontractor, earthwork contractor, foundation and paving subcontractors, andMoore Twining should be scheduled by the general contractor at least oneweek prior to the start of clearing and grubbing. The purpose of the meetingshould be to discuss critical project requirements and scheduling.

8.1.4 A demolition plan should be developed to identifying the existingimprovements to be removed.

8.1.5 The onsite soils contain gravel, cobbles and potentially boulders. Coarsegravel, cobbles and boulders would need to be removed or removed andprocessed by some methods such that the materials retained on the 3/4-inchsieve are 30 percent or less prior to reuse of the soils as engineered fill. Inaddition to the requirements described above, this report also recommendsthat rock greater than 6 inches in the largest dimension not be used withinengineered fill soils. In order to provide additional information for use inestimating the screening and processing requirements of the cobbles andboulders in the onsite materials, backhoe pits could be excavated bycontractors, or as part of the bid process, to allow the exposed soil conditionsto be directly observed by the contractor’s bidding the work. The contractorwill need to determine the methods they will use to achieve the specifiedrequirements for engineered fill and include this work in the bid.

8.1.6 The Contractor(s) bidding on this project should determine if the informationincluded in the construction documents are sufficient for accurate bidpurposes. If the data are not sufficient, the Contractor should conduct, orretain a qualified geotechnical engineer to conduct, supplemental studies andcollect information as required to prepare accurate bids.

8.2 Site Grading and Drainage

8.2.1 It is critical to develop and maintain site grades which will drain surface androof runoff away from foundations and floor slabs - both during and afterconstruction. Adjacent exterior finished grades should be sloped a minimumof two percent for a distance of at least ten feet away from the structures, oras necessary to preclude ponding of water adjacent to foundations, whicheveris more stringent. Adjacent exterior grades which are paved should be slopedat least 1 percent away from the foundations.

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8.2.2 It is recommended that landscape planted areas, etc. not be placed adjacentto the building foundations and/or interior slabs-on-grade. Trees should besetback from the proposed structures at least 10 feet or a distance equal to theanticipated drip line radius of the mature tree. For example, if a tree has ananticipated drip-line diameter of 30 feet, the tree should be planted at least 15feet away (radius) from proposed or existing buildings.

8.2.3 Landscaping after construction should direct rainfall and irrigation runoffaway from the structures and should establish positive drainage of water awayfrom the structures. Care should be taken to maintain a leak-free sprinklersystem.

8.2.4 The curbs where pavements meet irrigated landscape areas or uncovered openareas should be extended to the bottom of the aggregate base section. Thisshould reduce subgrade moisture from irrigation and runoff from migratinginto the aggregate base soils and reducing the life of the pavements.

8.2.5 Landscape and planter areas should be irrigated using low flow irrigation(such as drip, bubblers or mist type emitters). The use of plants with lowwater requirements are recommended.

8.2.6 Rain gutters and roof drains should be provided, and connected directly to thesite storm drain system. As an alternative, the roof drains should extend aminimum of 5 feet away from the structures and the resulting runoff directedaway from the structures at a minimum of 2 percent.

8.2.7 In the event subsurface storm water disposal systems, bioswales or similardesigns are planned, the proposed locations and details of these featuresshould be provided to Moore Twining for review and comment. If thesetypes of features are required, sufficient setbacks to existing improvementsshould be maintained, and/or specific measures such as deepened curbs,cutoffs, liners, etc. should be incorporated in the designs to reduce thepotential for excessive settlement of improvements due to moisture andfreewater migration from storm water disposal systems.

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8.3 Manufactured Slope Gradients, Setbacks, Grading, Drainage, Protection, andMaintenance

8.3.1 Cut or fill slopes planned within the “limit of work” and having a maximumheight of 15 feet should be graded at a repose of 2 H to 1V, or flatter, forstability, and to reduce erosion potential.

8.3.2 Structures, foundations and improvements should be setback from native, cutand fill slopes with a repose of 4H:1V or steeper to provide adequatefoundation support and protection against erosion. Greater setbacks may berequired for drainage design purposes. For slopes 10 feet high or greater, theminimum structural setback from the structures to ascending cut or fill slopesis 10 feet or ½ the slope height (H/2), whichever is greater. For slopes lessthan 10 feet high, the minimum structural setback from ascending slopes is5 feet. Setbacks should be designed anticipating that some slope erosion willoccur and that sediment will have to be removed periodically from the baseof the slope. A higher frequency of slope maintenance should be expectedfor the first few seasons after slope grading. Structures, foundations andimprovements above the top of a descending native, cut or fill slope shouldbe setback a minimum distance from the top of the slope equal to one-thirdof the height (H/3) of the slope, and not less than 5 feet, whichever is themost stringent. Improvements such as pavements, sidewalks, flatwork, etc.constructed adjacent to descending slopes or within the setback zone wouldhave an increased potential for damage due to slope movement or erosion.At a minimum, improvements such as these are recommended to be setbacka distance of at least one-half the setback recommended for buildingfoundations.

8.3.3 Develop and maintain site grades which will rapidly drain surface and roofrunoff away from cut or fill slopes - both during and after construction. Toaccomplish this, use brow ditches, berms or other measures to intercept andsafely redirect flow. In addition, upslope drainage such as lined brow ditchesor subdrains should be used to divert water away from graded slopes and toreduce erosion potential. Lined (concrete or asphalt) gutters, “U-gutters,”swales, etc. should be provided at the bottom of slopes. Drainage should bedirected into natural swales and energy dissipaters such as gravel or rip-rapshould be used to minimize erosion.

8.3.4 Graded slopes should be planted with ground cover vegetation to reduceerosion potential. The existing native low lying shrubs, trees should remaincovering the slopes, if possible. If the existing vegetation is disturbed,shallow rooted ground cover, as well as deeper rooted trees or bushes, shouldbe planted on the disturbed or reconstructed portions of the slopes to reducethe potential for erosion and aid in surficial slope stability.

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8.3.5 Irrigation in the areas of manufactured slopes should be of a drip type systemwithout surface runoff.

8.3.6 Irrigation lines between the structures and on slopes steeper than 3H to 1Vshould not be pressurized when not in use (i.e., main supply lines). Allirrigation lines and sprinklers should be monitored for leaks. All leaks anddamage should be repaired promptly.

8.4 Site Preparation

8.4.1 Stripping should be conducted in all areas of existing improvements toremove surface vegetation and root systems (if any). The general depth ofstripping should be sufficiently deep to remove the root systems and organictopsoils. The actual depth of stripping should be reviewed by our firm at thetime of construction. Deeper stripping may be required in localized areas.Stripping and clearing of debris should extend laterally a minimum of 10 feetoutside areas of planned excavation. These materials will not be suitable foruse as engineered fill; however, stripped topsoil may be stockpiled and reusedin landscape areas at the discretion of the owner.

8.4.2 For trees to be removed, all roots larger than ¼ inch in diameter and anyaccumulation of organic matter that will result in an organic content morethan 3 percent by weight should be removed and not used as engineered fill.The bottom of the excavation should be scarified to a minimum depth of 8inches and compacted as engineered fill prior to backfilling operations.Moore Twining should be contacted to observe removal of the tree roots.

8.4.3 Existing underground utilities located within areas of proposed improvementswhich are sensitive to settlement should be removed and backfilled withengineered fill. In addition, all existing trench backfill soils and materialsshould be removed and the excavations should be backfilled with engineeredfill. If other utilities are encountered during grading outside the building padsand overbuild zone and are not scheduled to remain, these utilities should beremoved in their entirety and all loose backfill associated with these utilitiesshould be over-excavated and backfilled as engineered fill. Utilities to beremoved should be completely removed and disposed of off-site and shouldnot be crushed and buried in-place. Loosened soils resulting from theremoval of the utilities should also be over-excavated to at least 12 inchesbelow the bottom of the improvements to be removed, moisture conditioned,and compacted as engineered fill. Prior to backfill of the excavations, thebottom of the excavations conducted to remove the loose soils and utilitiesshould be scarified to a depth of 8 inches, moisture conditioned andcompacted as engineered fill.

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8.4.4 After site stripping, removal of root systems and removal of existing surfaceand subsurface improvements (if any), the building pads and all foundationsshould be over-excavated to at least 18 inches below preconstruction sitegrades, to a minimum of 12 inches below the bottom of the footings, to thedepth to remove undocumented fill soils, and to at least 12 inches below thebottom of existing improvements to be removed (if any), whichever isgreater.

The over-excavation for both building pads should include the entire buildingfootprints and all foundations, a minimum of 5 feet beyond the foundationsand a minimum of 3 feet beyond all concrete slabs directly adjacent to thebuildings such as walkways, etc., whichever is greater. The bottom of theexcavation should be scarified 8 inches in depth, moisture conditioned towithin optimum to three (3) percent above optimum moisture content andcompacted as engineered fill.

8.4.5 The plans should show the limits of over-excavation for the building pads asdescribed above in section 8.4.5.

8.4.6 It is recommended that extra care be taken by the contractor to ensure that thehorizontal and vertical extent of the over-excavation and compaction conformto the site preparation recommendations presented in this report. MooreTwining is not responsible for measuring and verifying the horizontal andvertical extent of over-excavation and compaction. The contractor shouldverify in writing to the owner and Moore Twining that the horizontal andvertical over-excavation limits were completed in conformance with therecommendations of this report, the project plans, and the specifications (themost stringent applies). It is recommended that this verification be performedby a licensed surveyor. This verification should be provided prior torequesting pad certification from Moore Twining or excavating forfoundations.

8.4.7 Following stripping and removal of surface and subsurface improvements,areas to receive fill outside the building pad over-excavation limits (exceptfill slopes as noted in Section 8.4.9 of this report), pavements, and exteriorslabs-on-grade should be prepared by over-excavation to a minimum of 12inches below preconstruction site grade, to at least 12 inches below thebottom of improvements to be removed, whichever is greater. The bottomof the over-excavation should be scarified to a minimum depth of 8 inches,moisture conditioned to between optimum and three (3) percent aboveoptimum moisture content and compacted as engineered fill. The upper 12inches of subgrade beneath the pavement areas should be compacted to atleast 95 percent of the maximum dry density as determined by ASTM TestMethod D1557.

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8.4.8 Following stripping and removal of existing surface and subsurfaceimprovements, areas to receive miscellaneous lightly (less than 1 kip perfoot) loaded foundations such as site walls, trash enclosure walls andretaining walls, should be over-excavated to the bottom of foundations; to atleast 12 inches below preconstruction site grades; to the depth required toremove existing undocumented fills; and to at least 12 inches belowsubsurface improvements (structures, utilities, etc.) to be removed, whicheveris greater. The over-excavation should extend to at least 3 feet beyond theedge of the foundations. If site walls are planned along property lines andover-excavation cannot extend beyond the property line, then the over-excavation should extend up to the property line. The bottom of the over-excavation should be scarified to a depth of at least 8 inches, moistureconditioned and compacted as engineered fill.

8.4.9 Following stripping and removal of surface and subsurface improvements,areas of fill slopes with a repose of 3H to 1V or steeper should be preparedby excavation to at least 24 inches below preconstruction site grades. Thebase of the excavation at the toe of the slope should be sloped a minimum of1 percent into the upslope direction. The limit of over-excavation shouldextend a minimum of 5 feet beyond the toe of the slope. During slopeconstruction, near level benches should be cut as the height of the fillprogresses so that new fills will be placed on a nearly level grade.

8.4.10 All fill required to bring the site to final grades should be placed asengineered fill. In addition, all native soils over-excavated should becompacted as engineered fill.

8.4.11 The contractor should locate all on-site water wells (if any). All wellsscheduled for demolition should be abandoned per state and localrequirements. The contractor should obtain an abandonment permit from thelocal environmental health department, and issue certificates of destructionto the owner and Moore Twining upon completion. At a minimum, wells inbuilding areas (and within 5 feet of building perimeters) should have theircasings removed to a depth of at least 8 feet below preconstruction site gradesor finished pad grades, whichever is deeper. In parking lot or landscapeareas, the casings should be removed to a depth of at least 5 feet below sitegrades or finished grades. The wells should be capped with concrete and theresulting excavations should be backfilled as engineered fill.

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8.4.12 The moisture content and density of the compacted soils should bemaintained until the placement of concrete. If soft or unstable soils areencountered during excavation or compaction operations, our firm should benotified so the soils conditions can be examined and additionalrecommendations provided to address the pliant areas.

8.4.13 Final grading shall produce building pads ready to receive a slab-on-gradewhich is smooth, planar, and resistant to rutting. The finished pad (beforeaggregate base is placed) shall not depress more than one-half (½) inch underthe wheels of a fully loaded water truck, or equivalent loading. If depressionsmore than one-half (½) inch occur, the contractor shall perform remedialgrading to achieve this requirement at no cost to the owner.

8.4.14 The Contractor should be responsible for the disposal of concrete, asphalticconcrete, soil, spoils, etc. (if any) that must be exported from the site.Individuals, facilities, agencies, etc. may require analytical testing and otherassessments of these materials to determine if these materials are acceptable.The Contractor should be responsible to perform the tests, assessments, etc.to determine the appropriate method of disposal.

8.5 Engineered Fill

8.5.1 The on-site near surface soils encountered are predominantly silty sands withgravel, well graded gravel with sand and silt, well graded gravel with sand,poorly graded sand with gravel and silty gravel with sand. The onsite soilsare anticipated to include varying amounts of cobbles and potentiallyboulders. Due to the oversize coarse gravel, cobbles and boulders, the onsitesoils will need to be processed such as by screening, or screening, crushingand blending in order to meet the particle size requirements for engineeredfill for this project. If rock material is crushed in order to be reused asengineered fill, the crushed materials will need to be blended with the on-sitesoils to create a well-graded material for use as engineered fill in accordancewith the recommendations of this report.

Due to the coarse fraction, the on-site near surface soils will not be suitablefor use as engineered fill unless the material is processed to meet thespecified gradation for engineered fill. Onsite soils that are free of organics(less than 3 percent by weight), free of debris and can be processed to meetthe specified gradation may be used as engineered fill below therecommended aggregate base. Processing of the onsite materials by rockremoval, screening, crushing and blending or other acceptable methodsshould be anticipated to achieve the following recommended gradations forengineered fill:

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Table No. 2Allowable Particle Size Requirement for On-Site Processed Soils

Sieve Size Percent Material Passing Required

6 inch sieve 100

3/4 inch sieve 70-100

No. 4 sieve 40 - 100

No. 200 sieve 0 - 40

Processing of the onsite soils such as screening larger gravel, cobbles andboulders should be anticipated to remove the rock material and establish therecommended gradation for engineered fill in accordance with this report. Ifsoils other than those considered in this report are encountered, MooreTwining should be notified to provide alternate recommendations.

8.5.2 The compactability of the native soils is dependent upon the moisturecontents, subgrade conditions, degree of mixing, type of equipment, as wellas other factors. The evaluation of such factors was beyond the scope of thisreport; therefore, it is recommended that they be evaluated by the contractorduring preparation of bids and construction of the project.

8.5.3 Import fill soil (if any) should be non-recycled, non-expansive and granularin nature with the following acceptance criteria recommended.

Percent Passing 3-Inch Sieve 100Percent Passing No. 4 Sieve 85 - 100Percent Passing No. 200 Sieve 10 - 40Expansion Index (ASTM D4829) Less than 15Organics Less than 3 percent by weightR-Value Minimum 50*Sulfates < 0.05 percent by weightMin. Resistivity > 5,000 ohms-cm

* for pavement areas only

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Prior to being transported to the site, the import material shall be certified bythe Contractor and the supplier (to the satisfaction of the Owner and MooreTwining) that the soils do not contain any environmental contaminatesregulated by local, state or federal agencies having jurisdiction. In addition,Moore Twining should be requested to sample and test the material todetermine compliance with the above geotechnical criteria. Contractorsshould provide a minimum of 7 working days to complete the testing.

8.5.4 Native and imported engineered fill soil should be placed in loose liftsapproximately 8 inches thick, moisture-conditioned to between optimummoisture content and three (3) percent above optimum moisture content, andcompacted to a dry density of at least 92 percent of the maximum dry densityas determined by ASTM Test Method D1557. Additional lifts should not beplaced if the previous lift did not meet the required dry density or if soilconditions are not stable. The upper 12 inches of fill and subgradecompacted in pavement areas should be compacted to a minimum of 95percent of the maximum dry density as determined by ASTM Test MethodD1557.

8.5.5 In-place density testing should be conducted in accordance with ASTM D6938 (nuclear methods) at a frequency of at least:

Table No. 3Minimum Test Frequency

Area Minimum Test Frequency

Building Pads 1 test per 5,000 square feet percompacted lift, but not less than twotests per building pad per lift

Pavement Subgrade andMass Grading OutsideBuilding Pads

1 test per 5,000 square feet percompacted lift

Utility Lines 1 test per 150 feet per lift

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8.5.6 Open graded gravel and rock material such as ¾-inch crushed rock or ½-inchcrushed rock should not be used as backfill including trench backfill. In theevent gravel or rock is required by a regulatory agency for use as backfill(Contractor to obtain a letter from the agency stating the requirement for rockand/or gravel as backfill), all open graded materials shall be fully encased ina geotextile filter fabric, such as Mirafi 140N, to prevent migration of finegrained soils into the porous material. Gravel and rock cannot be usedwithout the written approval of Moore Twining. If the contractor elects touse crushed rock (and if approved by Moore Twining), the contractor will beresponsible for slurry cut off walls at the locations directed by MooreTwining. Crushed rock should be placed in thin (less than 8 inch) lifts anddensified with a minimum of three (3) passes using a vibratory compactor.

8.5.7 Aggregate base below the building slabs should comply with State ofCalifornia Department of Transportation requirements for a non-recycledClass 2 aggregate base or Crushed Aggregate Base (CAB) from the StandardSpecifications for Public Works Construction. Alternatively, CrushedMiscellaneous Base (CMB), or a recycled Class 2 aggregate base, may beused for pavement areas outside the building and overbuild zones, providedthat the recycled materials are accepted by the Owner and adequate qualitycontrol testing is conducted. Aggregate base should be compacted to aminimum relative compaction of 95 percent. Prior to importing the aggregatebase material, the contractor should submit documentation demonstrating thatthe material meets all the quality requirements (i.e., gradation, R-value, sandequivalent, durability, etc.) for the applicable aggregate base. Documentationshould be provided to the Owner, Architect and Moore Twining and reviewedand approved prior to delivery of the aggregate base to the site.

8.6 Conventional Shallow Spread Foundations

8.6.1 A structural engineer experienced in foundation design should recommendthe thickness, design details and concrete specifications for the foundationsbased on the estimated settlements. The following static settlements shouldbe anticipated for design: 1) a total static settlement of 1 inch; 2) a differentialstatic settlement of ½-inch in 40 feet, 3) a total seismic settlement of 1¼inches, and 4) a differential seismic settlement of ¾ inches in 40 feet.

8.6.2 Foundations supported on subgrade soils prepared as recommended in theSite Preparation section of this report may be designed for a maximum netallowable soil bearing pressure of 3,000 pounds per square foot for dead-plus-live loads. This value may be increased by one-third for short durationwind or seismic loads.

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8.6.3 All foundations should have a minimum depth of 12 inches below the lowestadjacent grade, or greater as required to achieve the slope setbackrecommendations in Section 8.3 of this report. In addition, all footings forthe new buildings should have a minimum width of 12 inches, regardless ofload.

8.6.4 The foundations should be continuous around the perimeter of the structuresto reduce moisture migration beneath the structures. Continuous perimeterfoundations should be extended through doorways and/or openings that arenot needed for support of loads.

8.6.5 The values in Table No. 4 were developed using the Ground MotionParameter Calculator provided by the United States Geological Survey(http://earthquake.usgs.gov/) in accordance with the 2013 CBC, a site latitudeof 33.92341 degrees, and a longitude of -116.80632degrees.

TABLE NO. 4

Seismic Factor 2013 CBC Value

Site Class D

Maximum Considered Earthquake (geometric mean) peak ground acceleration

adjusted for site effects (PGAM)

0.873g

Mapped Maximum Considered Earthquake(geometric mean) peak ground acceleration

ASCE 7-10 (PGA)

0.873g

Spectral Response At Short Period (0.2 Second),Ss

2.249

Spectral Response At 1-Second Period, S1 1.103

Site Coefficient (based on Spectral Response AtShort Period), Fa

1.0

Site Coefficient (based on spectral response at 1-second period) Fv

1.5

Maximum considered earthquake spectral responseacceleration for short period, SMS

2.249

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TABLE NO. 4

Seismic Factor 2013 CBC Value

Maximum considered earthquake spectral responseacceleration at 1 second, SM1

1.655

Five percent damped design spectral responseaccelerations for short period, SDs

1.499

Five percent damped design spectral responseaccelerations at 1-second period, SD1

1.103

8.6.6 Foundation excavations should be observed by Moore Twining prior to theplacement of steel reinforcement and concrete to verifyconformance with theintent of the recommendations of this report. The Contractor is responsiblefor proper notification to Moore Twining and receipt of written confirmationof this observation prior to placement of steel reinforcement.

8.6.7 Structural loads for lightly (less than 1.5 kips per lineal foot) loadedmiscellaneous foundations (such as screen walls for the proposed trashenclosures) should be supported on subgrade soils prepared in accordancewith the “Site Preparation” section of this report. The screen walls for thetrash enclosure may be supported by footings extending to a minimum depthof 12 inches below the lowest adjacent finished grade and a minimum widthof 12 inches. These improvements may be designed for a maximumallowable soil bearing pressure of 1,500 pounds per square foot for dead-plus-live loads for footings. This value may be increased by one-third forshort duration wind or seismic loads.

8.6.8 Sight lighting and pylon signs (if any) may be supported on a drilled-cast-in-hole reinforced concrete foundation (pier). An allowable skin friction of 200pounds per square foot may be used to resist axial loads. Lateral loadresistance may be estimated using the 2013 CBC non-constrained procedure(Section 1807.3.2.1). The allowable passive resistance of the native soilsmay be assumed to be equal to the pressure developed by a fluid with adensity of 325 pounds per square foot per foot of depth to a maximum of3,250 pounds per square foot. The passive pressure may be assumed to actover twice the pier diameter. The passive resistance of the surface soils to adepth of 12 inches, or to the depth where the horizontal setback from thefoundation to a descending slope is less than 3 feet, whichever is greater,should be neglected.

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8.6.9 The bottom surface area of concrete footings or concrete slabs in directcontact with engineered fill can be used to resist lateral loads. An allowablecoefficient of friction of 0.45 can be used for design. In areas where slabs areunderlain by a synthetic moisture barrier, an allowable coefficient of frictionof 0.10 can be used for design.

8.6.10 The allowable passive resistance of the native soils and engineered fill maybe assumed to be equal to the pressure developed by a fluid with a density of325 pounds per cubic foot. The upper 6 inches of subgrade in landscapedareas should be neglected in determining the total passive resistance.

8.7 Interior Slabs-on-Grade

The slabs on the project that should be prepared as interior slabs include: the interiorfloor slab and all concrete slabs on grade directly adjacent to the buildings.

8.7.1 Interior slabs-on-grade should be constructed over 4 inches of non-recycledaggregate base over engineered fill placed for the building pad preparation inaccordance with the Site Preparation section of this report.

8.7.2 The recommendations provided herein are intended only for the design ofinterior concrete slabs-on-grade and their proposed uses, which do notinclude construction traffic (i.e., cranes, cement mixers, and rock trucks, etc.).The building contractor should assess the slab section and determine itsadequacy to support any proposed construction traffic.

8.7.3 The slabs and underlying subgrade should be constructed in accordance withcurrent American Concrete Institute (ACI) standards.

8.7.4 ACI recommends that the interior slab-on-grade should be placed directly ona vapor retarder when the potential exists that the underlying subgrade orsand layer could be wet or saturated prior to placement of the slab-on-grade.It is recommended that Stegowrap 15 should be used where floor coverings,such as carpet and tile, are anticipated or where moisture could permeate intothe interior and create problems. The vapor retarder should overlay the

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compacted aggregate base. It should be noted that placing the PCC slabdirectly on the vapor barrier will increase the potential for cracking andcurling; however, ACI recommends the placement of the vapor retardingmembrane directly below the slab to reduce the amount vapor emissionthrough the slab-on-grade. Based on discussions with Stego Industries,L.L.C. (telephone 949-493-5460), the Stegowrap can be placed directly onthe aggregate base and the concrete can be placed directly on the Stegowrap.It is recommended that the design professional obtain written confirmationfrom Stego Industries that this product is suitable for the specific projectapplication. It is recommended that the slab be moist cured for a minimumof 7 days to reduce the potential for excessive cracking. The underslabmembrane should have a high puncture resistance (minimum ofapproximately 2,400 grams of puncture resistance), high abrasion resistance,rot resistant, and mildew resistant. It is recommended that the membrane beselected in accordance with the current ASTM C 755, Standard Practice ForSelection of Vapor Retarder For Thermal Insulation and conform to thecurrent ASTM E 154 Standard Test Methods for Water Vapor RetardersUsed in Contact with Earth Under Concrete Slabs, on Waters, or as GroundCover. It is recommended that the vapor barrier selection and installationconform to the current ACI Manual of Concrete Practice, Guide for ConcreteFloor and Slab Construction (302.1R), Addendum, Vapor Retarder Locationand current ASTM E 1643, Standard Practice for Installation of Water VaporRetarders Used In Contact with Earth or Granular Fill Under Concrete Slabs.In addition, it is recommended that the manufacturer of the floor covering andfloor covering adhesive be consulted to determine if the manufacturers haveadditional recommendations regarding the design and construction of theslab-on-grade, testing of the slab-on-grade, slab preparation, application ofthe adhesive, installation of the floor covering and maintenance requirements.It should be noted that the recommendations presented in this report are notintended to achieve a specific vapor emission rate.

8.7.5 The membrane should be installed so that there are no holes or uncoveredareas. All seams should be overlapped and sealed with the manufacturerapproved tape continuous at the laps so they are vapor tight. All perimeteredges of the membrane, such as pipe penetrations, interior and exteriorfootings, joints, etc., should be caulked per manufacturer’s recommendations.

8.7.6 Tears or punctures that may occur in the membrane should be repaired priorto placement of concrete per manufacturer’s recommendations. Oncerepaired, the membrane should be inspected by the contractor and the ownerto verify adequate compliance with manufacture’s recommendations.

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8.7.7 The moisture retarding membrane is not required beneath exposed concretefloors, such as warehouses and garages, provided that moisture intrusion intothe structures are permissible for the design life of the structures.

8.7.8 Additional measures to reduce moisture migration should be implemented forfloors that will receive moisture sensitive coverings. These include: 1)constructing a less pervious concrete floor slab by maintaining a water-cement ratio of 0.52 or less in the concrete for slabs-on-grade, 2) ensuringthat all seams and utility protrusions are sealed with tape to create a "watertight" moisture barrier, 3) placing concrete walkways or pavements adjacentto the structures, 4) providing adequate drainage away from the structures, 5)moist cure the slabs for at least 7 days, and 6) locating lawns, irrigatedlandscape areas, and flower beds away from the structures.

8.7.9 The Contractor shall test the moisture vapor transmission through the slab,the pH, internal relative humidity, etc., at a frequency and method asspecified by the flooring manufacturer or as required by the plans andspecifications, whichever is most stringent. The results of vapor transmissiontests, pH tests, internal relative humidity tests, ambient building conditions,etc. should be within floor manufacturer’s and adhesive manufacturer’sspecifications at the time the floor is placed. It is recommended that the floormanufacturer and subcontractor review and approve the test data prior tofloor covering installation.

8.7.10 To reduce the potential for damaging slabs during construction the followingrecommendations are presented: 1) design for a differential slab movementof ½ inch relative to interior columns; and 2) the construction equipmentwhich will operate on slabs or pavements should be evaluated by thecontractor prior to loading the slab.

8.7.11 Backfill the zone above the top of footings at interior column locations,building perimeters, and below the bottom of slabs with an approved backfillas recommended herein for the area below interior slabs-on-grade. Thisprocedure should provide more uniform support for the slabs which mayreduce the potential for cracking.

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8.8 Exterior Slabs-On-Grade

The recommendations for exterior slabs provided below are not intended for use forslabs subjected to vehicular traffic, rather lightly loaded sidewalks, curbs, andplanters, etc. outside the overbuild zone. The slabs on the project to be prepared asexterior flatwork include: all sidewalks not including slabs adjacent to the buildings.All concrete slabs on grade adjacent to the buildings should meet therecommendations of the “Interior Slabs-on-Grade” section of theserecommendations.

8.8.1 Exterior improvements that subject the subgrade soils to a sustained loadgreater than 150 pounds per square foot should be prepared in accordancewith recommendations presented in this report for interior slabs-on-grade.Moore Twining can provide alternative design recommendations for exteriorslabs, if requested.

8.8.2 Subgrade soils for exterior slabs should be prepared as recommended in the“Site Preparation” section of this report. Upon completion of the over-excavation and compaction of subgrade soils, the exterior slabs should besupported on 4 inches of aggregate base overlying subgrade soils prepared inaccordance with the recommendations provided in the “Site Preparation“section of this report. The recommended 4 inch aggregate base layer may beomitted if a higher risk of shrinkage cracking of exterior slabs-on-grade isacceptable to the owner.

8.8.3 The moisture content of the subgrade soils should be verified to be slightlyabove optimum moisture content within 48 hours of placement of the slab-on-grade. If necessary to achieve the recommended moisture content, thesubgrade could be over-excavated, moisture conditioned as necessary andcompacted as engineered fill.

8.8.4 The exterior slabs-on-grade adjacent to landscape areas should be designedwith thickened edges which extend to at least a depth of 6 inches below thebottom of the slabs-on-grade.

8.8.5 Since exterior sidewalks, curbs, etc. are typically constructed at the end of theconstruction process, the moisture conditioning conducted during earthworkcan revert to natural dry conditions. Placing concrete walks and finish workover dry or slightly moist subgrade should be avoided. It is recommendedthat the general contractor notify Moore Twining to conduct in-placemoisture and density tests prior to placing concrete flatwork. Written testresults indicating passing density and moisture tests should be in the generalcontractor’s possession prior to placing concrete for exterior flatwork.

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8.9 Asphaltic Concrete (AC) Pavements

Recommendations are provided below for new asphaltic concrete pavements plannedas part of the new construction.

8.9.1 The subgrade soils for asphaltic concrete pavements should be over-excavated and compacted as recommended in the “Site Preparation” sectionof the recommendations in this report.

8.9.2 The following pavement sections are based on an R-value of 50 and trafficindex values ranging from 5.0 to 7.0 and a minimum aggregate base thicknessof 4 inches. It should be noted that if pavements are constructed prior toconstruction of the buildings, the traffic index value should account forconstruction traffic. The actual traffic index values applicable to the siteshould be determined by the project civil engineer.

Table No. 5Two-Layer Asphaltic Concrete Pavements

TrafficIndex

ACthickness,

inches

ABthickness,

inches

CompactedSubgrade,

inches

5.0 3.0 4.0 12

5.5 3.0 4.0 12

6.0 3.0 4.0 12

6.5 3.5 4.5 12

7.0 3.5 5.5 12AC - Asphaltic Concrete compacted as recommended in this reportAB - Class II Aggregate Base, Crushed Aggregate Base (CAB), or Crushed

Miscellaneous Base (CMB) with minimum R-value of 78 and compactedto at least 95 percent relative compaction (ASTM D1557)

Subgrade - Subgrade soils compacted to at least 95 percent relative compaction(ASTM D1557)

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8.9.3 The curbs where pavements meet irrigated landscape areas or uncovered openareas should extend at least to the bottom of the aggregate base section. Thisshould reduce subgrade moisture from irrigation and runoff from migratinginto the base section and reducing the life of the pavements.

8.9.4 If actual pavement subgrade materials are significantly different from thosetested for this study due to unanticipated grading or soil importing, thepavement sections should be re-evaluated for the changed subgradeconditions.

8.9.5 If the paved areas are to be used during construction, or if the type andfrequencyof traffic are greater than assumed in design, the pavement sectionsshould be re-evaluated for the anticipated traffic.

8.9.6 Pavement section design assumes that proper maintenance, such as sealingand repair of localized distress, will be performed on an as needed basis forlongevity and safety.

8.9.7 Pavement materials and construction method should conform to the State ofCalifornia Standard Specifications.

8.9.8 It is recommended that the base 2 inch thick course of asphaltic concreteconsist of a ¾ inch maximum medium gradation. The top course or wearcourse should consist of a ½ inch maximum medium gradation.

8.9.9 The asphaltic concrete, including the joint density, should be compacted toan average relative compaction of 93 percent, with no single test value beingbelow a relative compaction of 91 percent and no single test value beingabove a relative compaction of 97 percent of the referenced laboratory densityaccording to AASHTO T209 or ASTM D2041.

8.9.10 The asphalt concrete should comply with Type "B" asphalt concrete asdescribed in Section 39 of the State of California Standard SpecificationRequirements. The Contractor shall provide an asphalt concrete mix designprepared and signed by a California registered civil engineer and approved byMoore Twining prior to construction.

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8.10 Portland Cement Concrete (PCC) Pavements

Recommendations for Portland Cement Concrete pavement structural sections arepresented in the following subsections. The PCC pavement design assumes aminimum modulus of rupture of 550 psi. The design professional should specifywhere Portland cement concrete pavements are used based on the anticipated typeand frequency of traffic.

8.10.1 The subgrade soils for Portland cement concrete pavements should be over-excavated and compacted as recommended in the “Site Preparation” sectionof the recommendations in this report.

8.10.2 The following pavement section designs are based on a design modulus ofsubgrade reaction, K-value. of 230 psi/in over the native compacted soil. Thedesign thicknesses were prepared based on the procedures outlined in thePortland Cement Association (PCA) document, “Thickness Design forConcrete Highway and Street Pavements,” assuming the following: 1)minimum modulus of rupture of 550 psi for the concrete, 2) a design life of20 years, 3) load transfer by aggregate interlock or dowels, 4) no concreteshoulder, 5) a load safety factor of 1.1, and 6) truck loading consisting of 1single axle load of 20 kips and two tandem axle loads of 35 kips each.

Table No. 6Two-Layer Portland Cement Concrete Pavements

ADTT PCC LayerThickness(inches)

AggregateBase Layer

(inches)

CompactedSubgrade(inches)

0.29 trucks per day(2 trucks per week)

5.5 4.0 12.0

1 truck per day(7 trucks per week)

6.0 4.0 12.0

ADTT - Average Daily Truck Traffic based on a loaded garbage/dumpster truckPCC - Portland Cement Concrete (minimum Modulus of Rupture=550 psi)Subgrade - Subgrade soils compacted to at least 95 percent relative compaction (ASTM D-

1557)

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8.10.3 The PCC pavement should be constructed in accordance with AmericanConcrete Institute requirements, the requirements of the project plans andspecifications, whichever is the most stringent. The pavement designengineer should include appropriate construction details and specificationsfor construction joints, contraction joints, joint filler, concrete specifications,curing methods, etc.

8.10.4 Concrete used for PCC pavements shall possess a minimum flexural strength(modulus of rupture) of 550 pounds per square inch. A minimumcompressive strength of 4,000 pounds per square inch, or greater as requiredby the pavement designer, is recommended. Specifications for the concreteto reduce the effects of excessive shrinkage, such as maximum waterrequirements for the concrete mix, allowable shrinkage limits, contractionjoint construction requirements, etc. should be provided by the designer of thePCC slabs.

8.10.5 The pavement section thickness design provided above assumes the designand construction will include sufficient load transfer at construction joints.Coated dowels or keyed joints are recommended for construction joints totransfer loads. The joint details should be detailed by the pavement designengineer and provided on the plans.

8.10.6 Contraction and construction joints should include a joint filler/sealer toprevent migration of water into the subgrade soils. The type of joint fillershould be specified by the pavement designer. The joint sealer and fillermaterial should be maintained throughout the life of the pavement.

8.10.7 Contraction joints should have a depth of at least one-fourth the slabthickness, e.g., 1.5-inch for a 6-inch slab. Specifications for contraction jointspacing, timing and depth of sawcuts should be included in the plans andspecifications.

8.10.8 Stresses are anticipated to be greater at the edges and construction joints ofthe pavement section. A thickened edge is recommended on the outside ofslabs subjected to wheel loads.

8.10.9 Joint spacing in feet should not exceed twice the slab thickness in inches,e.g., 12 feet by 12 feet for a 6-inch slab thickness. Regardless of slabthickness, joint spacing should not exceed 15 feet.

8.10.10Lay out joints to form square panels. When this is not practical, rectangularpanels can be used if the long dimension is no more than 1.5 times the short.

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8.10.11Isolation (expansion) joints should extend the full depth and should be usedonly to isolate fixed objects abutting or within paved areas.

8.10.12Pavement section design assumes that proper maintenance such as sealingand repair of localized distress will be performed on a periodic basis.

8.11 Slopes and Temporary Excavations

8.11.1 It is the responsibility of the contractor to provide safe working conditionswith respect to excavation slope stability. The contractor is responsible forsite slope safety, classification of materials for excavation purposes, andmaintaining slopes in a safe manner during construction. The grades,classification and height recommendations presented for temporary slopes arefor consideration in preparing budget estimates and evaluating constructionprocedures.

8.11.2 Temporary excavations should be constructed in accordance with OSHArequirements. Temporary cut slopes should not be steeper than 1.5:1,horizontal to vertical, and flatter if possible. If excavations cannot meet thesecriteria, the temporary excavations should be shored.

8.11.3 In no case should excavations extend below a 2H to 1V zone below utilities,foundations and/or floor slabs which are to remain after construction.Excavations which are required to be advanced below the 2H to 1V envelopeshould be shored to support the soils, foundations, and slabs.

8.11.4 Shoring should be designed by an engineer with experience in designingshoring systems and registered in the State of California.

8.11.5 Excavation stability should be monitored by the contractor. Slope gradientestimates provided in this report do not relieve the contractor of theresponsibility for excavation safety. In the event that tension cracks ordistress to the structures occurs, during or after excavation, the owners andMoore Twining should be notified immediately and the contractor shouldtake appropriate actions to minimize further damage or injury.

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8.12 Utility Trenches

8.12.1 The utility trench subgrade should be prepared by excavation of a neat trenchwithout disturbance to the bottom of the trench. If sidewalls are unstable, theContractor shall either slope the excavation to create a stable sidewall orshore the excavation. All trench subgrade soils disturbed during excavation,such as by accidental over-excavation of the trench bottom, or by excavationequipment with cutting teeth, should be compacted to a minimum of 92percent relative compaction prior to placement of bedding material. TheContractor is responsible for notifying Moore Twining when these conditionsoccur and arrange for Moore Twining to observe and test these areas prior toplacement of pipe bedding. The Contractor shall use such equipment asnecessary to achieve a smooth undisturbed native soil surface at the bottomof the trench with no loose material at the bottom of the trench. TheContractor shall either remove all loose soils or compact the loose soils asengineered fill prior to placement of bedding, pipe and backfill of the trench.

8.12.2 The trench width, type of pipe bedding, the type of initial backfill, and thecompaction requirements of bedding and initial backfill material for utilitytrenches (storm drainage, sewer, water, electrical, gas, cable, phone,irrigation, etc.) should be specified by the project Civil Engineer or applicabledesign professional in compliance with the manufacturer’s requirements,governing agency requirements and this report, whichever is more stringent.The contractor is responsible for contacting the governing agency todetermine the requirements for pipe bedding, pipe zone and final backfill.The contractor is responsible for notifying the Owner and Moore Twining ifthe requirements of the agency and this report conflict, the most stringentapplies. For flexible polyvinylchloride (PVC) pipes, these requirementsshould be in accordance with the manufacturer’s requirements or ASTM D-2321, whichever is more stringent, assuming a hydraulic gradient exists(gravel, rock, crushed gravel, etc. cannot be used as backfill on the project).The width of the trench should provide a minimum clearance of 8 inchesbetween the sidewalls of the pipe and the trench, or as necessary to providea trench width that is 12 inches greater than 1.25 times the outside diameterof the pipe, whichever is greater. As a minimum, the pipe bedding shouldconsist of 4 inches of compacted (92 percent relative compaction) select sandwith a minimum sand equivalent of 30 and meeting the followingrequirements: 100 percent passing the 1/4 inch sieve, a minimum of 90percent passing the No. 4 sieve and not more than 10 percent passing the No.200 sieve. The haunches and initial backfill (12 inches above the top of pipe)should consist of a select sand meeting these sand equivalent and gradation

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requirements that is placed in maximum 6-inch thick lifts and compacted toa minimum relative compaction of 92 percent using hand equipment. Thefinal fill (12 inches above the pipe to the surface) should be on-site orimported, non-expansive materials moisture conditioned to between optimumand three (3) percent above optimum moisture content and compacted to aminimum of 92 percent relative compaction. The project civil engineershould take measures to control migration of moisture in the trenches suchas slurry collars, etc.

8.12.3 If ribbed or corrugated HDPE or metal pipes are used on the project, then thebackfill should consist of select sand with a minimum sand equivalent of 30,100 percent passing the 1/4 inch sieve, a minimum of 90 percent passing theNo. 4 sieve and not more than 10 percent passing the No. 200 sieve. Thesand shall be placed in maximum 6-inch thick lifts, extending to at least 1foot above the top of pipe, and compacted to a minimum relative compactionof 92 percent using hand equipment. Prior to placement of the pipe, as aminimum, the pipe bedding should consist of 4 inches of compacted (92percent relative compaction) sand meeting the above sand equivalent andgradation requirements for select sand bedding. The width of the trenchshould meet the requirements of ASTM D2321 listed in Table No. 7(minimum manufacturer requirements), or as necessary to provide sufficientspace to achieve the required compaction, whichever is greater. As analternative to the trench width recommended above and the use of the selectsand bedding, a lesser trench width for HDPE pipes may be used if the trenchis backfilled with a 2-sack sand-cement slurry from the bottom of the trenchto 1 foot above the top of the pipe.

Table No. 7Minimum Trench Widths for HDPE Pipe with

Sand Bedding Initial Backfill

Inside Diameter of HDPEPipe (inches)

Outside Diameter ofHDPE Pipe (inches)

Minimum Trench Width(inches) per ASTM D2321-00

12 14.2 30

18 21.5 39

24 28.4 48

36 41.4 64

48 55 80

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8.12.4 Open graded gravel and rock material such as ¾-inch crushed rock or ½-inchcrushed rock should not be used as backfill including trench backfill. In theevent gravel or rock is required by a regulatory agency for use as backfill(Contractor to obtain a letter from the agency stating the requirement for rockand/or gravel as backfill), all open graded materials shall be fully encased ina geotextile filter fabric, such as Mirafi 140N, to prevent migration of finegrained soils into the porous material. Gravel and rock cannot be usedwithout the written approval of Moore Twining. If the contractor elects touse crushed rock (and if approved by Moore Twining), the contractor will beresponsible for slurry cut off walls at the locations directed by MooreTwining. Crushed rock should be placed in thin (less than 8 inch) lifts anddensified with a minimum of three (3) passes using a vibratory compactor.

8.12.5 Utility trench backfill placed in or adjacent to building areas, exterior slabsor pavements should be placed in 8 inch lifts, moisture conditioned tobetween optimum and three (3) percent above the optimum moisture contentand compacted to at least 92 percent of the maximum dry density asdetermined by ASTM Test Method D1557. Lift thickness can be increasedif the contractor can demonstrate the minimum compaction requirements canbe achieved. The contractor should use appropriate equipment and methodsto avoid damage to utilities and/or structures during placement andcompaction of the backfill materials.

8.12.6 On-site soils and approved imported engineered fill may be used as finalbackfill (12 inches above the pipe to the ground surface) in trenches

8.12.7 Jetting of trench backfill is not allowed to compact the backfill soils.

8.12.8 Where utility trenches extend from the exterior to the interior limits of abuilding, lean concrete should be used as backfill material for a minimumdistance of 2 feet laterally on each side of the exterior building line to preventthe trench from acting as a conduit to exterior surface water.

8.12.9 Storm drains and/or utility lines should be designed to be “watertight.” Ifencountered, leaks should be immediately repaired. Leaking storm drainand/or utility lines could result in trench failure, sloughing and/or soilmovement causing damage to surface and subsurface structures, pavements,flatwork, etc. In addition, landscaping irrigation systems should bemonitored for leaks. The Contractor is required to video inspect or pressuretest the wet utilities prior to placement of foundations, slabs-on-grade orpavements to verify that the pipelines are constructed properly and are“watertight.” The Contractor shall provide the Owner a copy of the resultsof the testing. The Contractor is required to repair all noted deficiencies atno cost to the owner.

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8.12.10The plans should note that all utility trenches, including electrical lines,irrigation lines, etc. should be compacted to a minimum relative compactionof 92 percent per ASTM D-1557 except for the upper 12 inches belowpavements which should be compacted to at least 95 percent relativecompaction.

8.12.11Utility trenches should not be constructed within a zone defined by a line thatextends at an inclination of 2 horizontal to 1 vertical downward from thebottom of building foundations.

8.13 Corrosion Protection

8.13.1 Based on the ASTM Special Technical Publication 741 and the analyticalresults of sample analyses indicate the samples had resistivity values of15,000 and 6,300 ohms-centimeter, with pH values of 5.9 and 5.2,respectively. Based on the resistivity value, the soils exhibit a “mildlycorrosive” to “moderately corrosive” corrosion potential. Therefore, buriedmetal objects should be protected in accordance with the manufacturer'srecommendations based on a “moderately corrosive” corrosion potential.The evaluation was limited to the effects of soils to metal objects; corrosiondue to other potential sources, such as stray currents and groundwater, wasnot evaluated. If piping or concrete are placed in contact with deeper soils orengineered fill, these soils should be analyzed to evaluate the corrosionpotential of these soils.

8.13.2 Corrosion of concrete due to sulfate attack is not anticipated based on theconcentration of sulfates determined for the near-surface soils (not-detectedand 0.0040 percent by dry weight concentrations of sulfate). According toprovisions of ACI 318, section 4.3 , the sulfate concentration falls in thenegligible classification (0.00 to 0.10 percent by weight) for concrete.Therefore, no restrictions are required regarding the type, water-to-cementratio, or strength of the concrete used for foundation and slabs due to thesulfate content. However, a low water to cement ratio is recommended forslabs on grade as recommended in the “Interior Slab on Grade” section of thisreport.

8.13.3 These soil corrosion data should be provided to the manufacturers orsuppliers of materials that will be in contact with soils (pipes or ferrous metalobjects, etc.) to provide assistance in selecting the protection and materialsfor the proposed products or materials. If the manufacturers or supplierscannot determine if materials are compatible with the soil corrosionconditions, a professional consultant, i.e., a corrosion engineer, with

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experience in corrosion protection should be consulted to design parameters.Moore Twining is not a corrosion engineer; thus, cannot providerecommendations for mitigation of corrosive soil conditions. It isrecommended that a corrosion engineer be consulted for the site specificconditions.

9.0 DESIGN CONSULTATION

9.1 Moore Twining should be provided the opportunity to review those portions of thecontract drawings and specifications that pertain to earthwork operations andfoundations prior to finalization to determine whether they are consistent with ourrecommendations. This service is not part of this current contractual agreement.

9.2 It is the client's responsibility to provide plans and specification documents for ourreview prior to their issuance for construction bidding purposes.

9.3 If Moore Twining is not afforded the opportunity for review, we assume no liabilityfor the misinterpretation of our conclusions and recommendations. This review isdocumented by a formal plan/specification review report provided by MooreTwining.

10.0 CONSTRUCTION MONITORING

10.1 It is recommended that Moore Twining be retained to observe the excavation,earthwork, and foundation phases of work to determine that the subsurface conditionsare compatible with those used in the analysis and design.

10.2 Moore Twining can conduct the necessary observation and field testing to provideresults so that action necessary to remedy indicated deficiencies can be taken inaccordance with the plans and specifications. Upon completion of the work, awritten summary of our observations, field testing and conclusions will be providedregarding the conformance of the completed work to the intent of the plans andspecifications. This service is not, however, part of this current contractualagreement.

10.3 In the event that the earthwork operations for this project are conducted such that theconstruction sequence is not continuous, (or if construction operations disturb thesurface soils) it is recommended that the exposed subgrade that will receive floorslabs be tested to verify adequate compaction and/or moisture conditioning. Ifadequate compaction or moisture contents are not verified, the fill soils should beover-excavated, scarified, moisture conditioned and compacted are recommended inthe Recommendations of this report.

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10.4 The construction monitoring is an integral part of this investigation. This phase ofthe work provides Moore Twining the opportunity to verify the subsurface conditionsinterpolated from the soil borings and make alternative recommendations if theconditions differ from those anticipated.

10.5 If Moore Twining is not afforded the opportunity to provide engineering observationand field-testing services during construction activities related to earthwork,foundations, pavements and trenches; then, Moore Twining will not be responsiblefor compliance of any aspect of the construction with our recommendations orperformance of the structures or improvements if the recommendations of this reportare not followed. It is recommended that if a firm other than Moore Twining isselected to conduct these services that they provide evidence of professional liabilityinsurance of at least $3,000,000 and review this report. After their review, the firmshould, in writing, state that they understand and agree with the conclusions andrecommendations of this report and agree to conduct sufficient observations andtesting to ensure the construction complies with this report's recommendations.Moore Twining should be notified, in writing, if another firm is selected to conductobservations and field-testing services prior to construction.

10.6 Upon the completion of work, a final report should be prepared by Moore Twining.This report is essential to ensure that the recommendations presented areincorporated into the project construction, and to note anydeviations from the projectplans and specifications. The client should notify Moore Twining upon thecompletion of work to prepare a final report summarizing the observations during sitepreparation activities relative to the recommendations of this report. This service isnot, however, part of this current contractual agreement.

11.0 NOTIFICATION AND LIMITATIONS

11.1 The conclusions and recommendations presented in this report are based on theinformation provided regarding the proposed construction, and the results of the fieldand laboratory investigation, combined with interpolation of the subsurfaceconditions between boring locations. The nature and extent of subsurface variationsbetween borings may not become evident until construction.

11.2 If variations or undesirable conditions are encountered during construction, MooreTwining should be notified promptly so that these conditions can be reviewed andour recommendations reconsidered where necessary. It should be noted thatunexpected conditions frequently require additional expenditures for properconstruction of the project.

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11.3 If the proposed construction is relocated or redesigned, or if there is a substantiallapse of time between the submission of our report and the start of work (over 12months) at the site, or if conditions have changed due to natural cause or constructionoperations at or adjacent to the site, the conclusions and recommendations containedin this report should be considered invalid unless the changes are reviewed and ourconclusions and recommendations modified or approved in writing.

11.4 Changed site conditions, or relocation of proposed structures, may require additionalfield and laboratory investigations to determine if our conclusions andrecommendations are applicable considering the changed conditions or time lapse.

11.5 The conclusions and recommendations contained in this report are valid only for theproject discussed in Section 3.4, Anticipated Construction. The use of theinformation and recommendations contained in this report for structures on this sitenot discussed herein or for structures on other sites not discussed in this report is notrecommended. The entity or entities that use or cause to use this report or anyportion thereof for other structures or site not covered by this report shall hold MooreTwining, its officers and employees harmless from any and all claims and provideMoore Twining’s defense in the event of a claim.

11.6 This report is issued with the understanding that it is the responsibility of the clientto transmit the information and recommendations of this report to developers,owners, buyers, architects, engineers, designers, contractors, subcontractors, andother parties having interest in the project so that the steps necessary to carry outthese recommendations in the design, construction and maintenance of the project aretaken by the appropriate party.

11.7 This report presents the results of a geotechnical engineering investigation only andshould not be construed as an environmental audit or study.

11.8 Our professional services were performed, our findings obtained, and ourrecommendations prepared in accordance with generally-accepted engineeringprinciples and practices. This warranty is in lieu of all other warranties eitherexpressed or implied.

11.9 Reliance on this report by a third party (i.e., that is not a party to our writtenagreement) is at the party's sole risk. If the project and/or site are purchased byanother party, the purchaser must obtain written authorization and sign an agreementwith Moore Twining in order to rely upon the information provided in this report fordesign or construction of the project.

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A-1 E88904.01-01APPENDIX A

DRAWINGS

Drawing No. 1 - Site Location Map

Drawing No. 2 - Test Boring Location Map

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B-1 E88904.01-01

APPENDIX B

LOGS OF BORINGS

This appendix contains the final logs of borings. These logs represent our interpretation of thecontents of the field logs and the results of the field and laboratory tests.

The logs and related information depict subsurface conditions only at these locations and at theparticular time designated on the logs. Soil conditions at other locations may differ from conditionsoccurring at these test boring locations. Also, the passage of time may result in changes in the soilconditions at these test boring locations.

In addition, an explanation of the abbreviations used in the preparation of the logs and a descriptionof the Unified Soil Classification System are provided at the end of Appendix B.

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C-1 E88904.01-01APPENDIX C

RESULTS OF LABORATORY TESTS

This appendix contains the individual results of the following tests. The results of the moisturecontent and dry density tests are included on the test boring logs in Appendix B. These data, alongwith the field observations, were used to prepare the final test boring logs in Appendix B.

These Included: To Determine:

Moisture Content(ASTM D2216)

Moisture contents representative of field conditions atthe time the sample was taken.

Dry Density(ASTM D2216)

Dry unit weight of sample representative of in-situ orin-place undisturbed condition.

Grain-SizeDistribution (ASTM D422)

Size and distribution of soil particles, i.e., sand, graveland fines (silt and clay).

Expansion Index(ASTM D4829)

Swell potential of soil with increases in moisturecontent.

Consolidation(ASTM 2435)

The amount and rate at which a soil samplecompresses when loaded, and the influence ofsaturation on its behavior.

Direct Shear (ASTM D3080)

Soil shearing strength under varying loads and/ormoisture conditions.

R-Value(CTM 301)

The capacity of a subgrade or subbase to support apavement section designed to carry a specified trafficload.

Sulfate Content(ASTM D4327)

Percentage of water-soluble sulfate as (SO4) in soilsamples. Used as an indication of the relative degree ofsulfate attack on concrete and for selecting the cementtype.

Chloride Content(ASTM D4327)

Percentage of soluble chloride in soil. Used to evaluatethe potential attack on encased reinforcing steel.

Resistivity(ASTM D1125)

The potential of the soil to corrode metal.

pH (ASTM D4972) The acidity or alkalinity of subgrade material.

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GEOTECHNICAL ENGINEERING INVESTIGATION PROPOSED HADLEY FRUIT ORCHARDS … · 2018. 8. 27. · ph:...

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