geotechnical study moorpark pump station - phase 2...

FUGRO CONSULTANTS, INC.

GEOTECHNICAL STUDY MOORPARK PUMP STATION - PHASE 2

CALLEGUAS MUNICIPAL WATER DISTRICT MOORPARK, CALIFORNIA

Prepared for: PERLITER & INGALSBE

April 2011 Fugro Job No. 04.61100021

April 15, 2011 Project No. 04.61100021

Perliter & Ingalsbe 2369 Lincoln Avenue Altadena, California 91001

Attention: Mr. Amar Shah, PE

Subject: Geotechnical Study, Moorpark Pump Station Phase 2, Calleguas Municipal Water District, Moorpark, California

Dear Mr. Shah:

Fugro is pleased to submit this geotechnical report for the proposed Moorpark Pump Station Phase 2 project for the Calleguas Municipal Water District. The proposed pump station site is located on the east side of Spring Road south of Arroyo Simi in the City of Moorpark, California. Our work was performed in general accordance with our proposal dated November 9, 2010, and was authorized by Perliter & Ingalsbe on December 31, 2010.

Our findings and recommendations for the proposed pump station project are summarized in this report and include descriptions of our field exploration and laboratory testing programs, review of previous data, interpretation of subsurface conditions, and geotechnical design recommendations for the proposed facilities.

We appreciate the opportunity to provide geotechnical services on this project. Please call if you have any questions regarding the information presented in our geotechnical report.

Sincerely,


Todd E. Curtis, PE Gregory S. Denlinger, GE Staff Engineer Principal Geotechnical Engineer

Lori E. Prentice, CEG Principal Engineering Geologist

Copies Submitted: (5) Addressee and Pdf


4820 McGrath Street, Suite 100Ventura, California 93003-7778

Tel: (805) 650-7000Fax: (805) 650-7010

A member of the Fugro group of companies with offices throughout the world.

Perliter & Ingalsbe Engineers April 15, 2011 (Project No. 04.61100021)

CONTENTS

Page

1.0 INTRODUCTION........................................................................................................ 1 1.1 Project And Site Description.............................................................................. 1 1.2 Scope of Work................................................................................................... 2

1.2.1 Task 1 - Data Review ............................................................................ 2 1.2.2 Task 2 - Subsurface Exploration ........................................................... 2 1.2.3 Task 3 - Laboratory Testing .................................................................. 2 1.2.4 Task 4 - Geotechnical Evaluation and Report Preparation ................... 3

1.3 Previous Work on Site....................................................................................... 3

2.0 FINDINGS.................................................................................................................. 4 2.1 Site Conditions .................................................................................................. 4 2.2 Geologic Conditions .......................................................................................... 4

2.2.1 Regional Geologic Setting..................................................................... 4 2.2.2 Local Geologic Setting .......................................................................... 4

2.3 Subsurface Conditions ...................................................................................... 4 2.3.1 Artificial Fill ............................................................................................ 4 2.3.2 Alluvium................................................................................................. 5 2.3.3 Groundwater.......................................................................................... 5

3.0 SEISMICITY AND GEOHAZARDS ............................................................................ 6 3.1 Faulting and Seismicity ..................................................................................... 6

3.1.1 Ground Rupture Potential...................................................................... 6 3.1.2 Strong Ground Motions ......................................................................... 6

3.2 Liquefaction Potential ........................................................................................ 7 3.2.1 Liquefaction Related Settlements.......................................................... 8 3.2.2 Ground Lurching and Lateral Movement ............................................... 9

3.3 Seismically Induced Settlement in "Dry" Sand .................................................. 9 3.4 Landsliding ........................................................................................................ 10 3.5 Tsunami and Seiche.......................................................................................... 10 3.6 2010 CBC Seismic Design Parameters ............................................................ 10

4.0 RECOMMENDATIONS.............................................................................................. 11 4.1 Earthwork and Grading ..................................................................................... 11

4.1.1 General.................................................................................................. 11 4.1.2 Site Preparation..................................................................................... 12 4.1.3 Excavation Considerations.................................................................... 12 4.1.4 Overexcavation and Subgrade Preparation .......................................... 12 4.1.5 Fill Selection and Compaction............................................................... 13 4.1.6 Geosynthetic Reinforced Fill Blanket .................................................... 14 4.1.7 Temporary Slopes ................................................................................. 14 4.1.8 Temporary Shoring................................................................................ 15 4.1.9 Permanent Slopes................................................................................. 15

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CONTENTS - CONTINUED

Page

4.1.10 Site Drainage and Control of Seep Water ............................................. 15 4.2 Foundation Design and Construction ................................................................ 16

4.2.1 General.................................................................................................. 16 4.2.2 Footing Design Criteria.......................................................................... 16 4.2.3 Modulus of Subgrade Reaction for Mat-Type Foundations................... 16 4.2.4 Sliding and Passive Resistance ............................................................ 17 4.2.5 Static Settlement ................................................................................... 17 4.2.6 Seismic Settlement................................................................................ 18 4.2.7 Lateral Movement.................................................................................. 18

4.3 Below Grade Walls and Vaults.......................................................................... 18 4.3.1 General.................................................................................................. 18 4.3.2 Footing Design ...................................................................................... 18 4.3.3 Lateral Earth Pressures......................................................................... 19 4.3.4 Surcharge Pressures............................................................................. 20 4.3.5 Drainage Measures ............................................................................... 20 4.3.6 Compaction Adjacent to Walls .............................................................. 21 4.3.7 Resistance to Uplift ............................................................................... 21

4.4 Pipeline Design Criteria..................................................................................... 21 4.4.1 Trench Excavations............................................................................... 21 4.4.2 Pipe Zone and Trench Backfill .............................................................. 22 4.4.3 Modulus of Soil Reaction....................................................................... 23 4.4.4 Thrust Resistance ................................................................................. 24

4.5 Soil Chemistry Testing ...................................................................................... 25

5.0 LIMITATIONS............................................................................................................. 25 5.1 Report Use ........................................................................................................ 25 5.2 Potential Variation in Subsurface Conditions .................................................... 25 5.3 Hazardous Materials ......................................................................................... 26 5.4 Local Practice.................................................................................................... 26 5.5 Plan Review ...................................................................................................... 26 5.6 Construction Monitoring .................................................................................... 26

6.0 REFERENCES........................................................................................................... 27

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TABLES

Page

Table 1. Summary of Groundwater Measurements ........................................................... 6 Table 2. USGS Probabilistic Seismic Hazard Deaggregation Results............................... 7 Table 3. Summary of 2010 CBC Seismic Design Parameters........................................... 11 Table 4. Equivalent Fluid Weights for Developing Lateral Earth Pressures ...................... 19 Table 5. Ultimate Frictional Resistance ............................................................................. 24 Table 6. Summary of Chemical Test Results..................................................................... 25

PLATES

Plate

Vicinity Map......................................................................................................................... 1 Exploration Location Plan ................................................................................................... 2 Regional Geologic Map....................................................................................................... 3 Subsurface Cross Section A-A'........................................................................................... 4

APPENDICES

APPENDIX A SUBSURFACE EXPLORATION Log of Drill Hole No. DH-4 ............................................................................................. Plate A-1 Log of Drill Hole No. DH-5 ............................................................................................. Plate A-2 Log of Drill Hole No. DH-6 ............................................................................................. Plate A-3 Log of Drill Hole No. DH-7 ............................................................................................. Plate A-4 Key to Terms & Symbols Used on Logs........................................................................ Plate A-5

APPENDIX B LABORATORY TEST RESULTS Summary of Laboratory Test Results ............................................................................ Plate B-1 Plasticity Chart .............................................................................................................. Plate B-2 Compaction Test Results .............................................................................................. Plate B-3 Consolidation Test Results............................................................................................ Plate B-4

APPENDIX C FUGRO (2002) GEOTECHNICAL STUDY DATA - MOORPARK PUMP STATION PHASE 1

APPENDIX D LIQUEFACTION EVALUATION


1.0 INTRODUCTION

1.1 PROJECT AND SITE DESCRIPTION

This report presents the findings and recommendations of our geotechnical study conducted for Perliter & Ingalsbe (P&I) and to aid in the design of the Calleguas Municipal Water District's (CMWD) proposed Moorpark Pump Station Phase 2 project. The proposed pump station will be located on the east side of Spring Road south of Arroyo Simi in Moorpark, California as shown on Plate 1 - Vicinity Map. A preliminary layout of the proposed pump station and related facilities is shown on Plate 2 - Exploration Location Plan. Existing as-built conditions associated with the construction of the Moorpark Pump Station Phase 1 project are shown on Plate 2 together with pre-development (Phase 1) topography.

We understand the Phase 2 Pump Station project will include:

• 57-foot by 163-foot pump station building,

• Separate 10-foot by 25-foot reinforced concrete mat foundations to support two diesel generators,

• Separate 4-foot by 8-foot reinforced concrete mat foundations to support two hydro turbine units,

• Diesel storage tank pad with canopy structure,

• Pipeline construction involving pipes up to 66-inches-diameter and invert depths of up to 17 feet deep,

• Two concrete vaults approximately 14 feet deep, and

• Miscellaneous asphalt concrete pavements.

The pump station will have below-grade piping, can-type vertical turbines approximately 23 feet below ground surface (bgs), large pumps, motors, electrical panels, and a 10-ton crane. We anticipate the proposed pump station building will be supported on shallow foundations approximately 4 to 8 feet below finished grade with an at-grade structural concrete floor slab. We anticipate that other lightly loaded structures will also be founded on shallow footings and at-grade concrete slabs.

We anticipate that thickened mat foundations will be used to support the proposed diesel generators and hydro turbines. Valve vaults will probably be supported on below-grade, mat-slab foundations.

Site grading plans were not available for use in preparing this report. However, we anticipate that grading will consist of minor cutting and filling with the majority of the grading occurring in the area of the existing basin. Final site grades will likely be within a few feet of the existing grade and probably range from about elevation (El.) 533 to 538 feet (NAVD88).

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1.2 SCOPE OF WORK

The scope of this geotechnical study is outlined in our proposal dated November 9, 2010. Authorization for our services was provided by a signed proposal from P&I dated December 31, 2010. The work performed for this study consisted of data review, subsurface exploration, laboratory testing, geotechnical analyses, and reporting. Work tasks performed for this study are described below.

1.2.1 Task 1 - Data Review

Fugro reviewed selected geologic and geotechnical data available in our files including data in our 2002 geotechnical study and data acquired during the Phase 1 site grading.

1.2.2 Task 2 - Subsurface Exploration

Prior to subsurface exploration, we performed a site reconnaissance to locate the explorations for utility clearance. We coordinated site access with CMWD and contacted Underground Service Alert and CMWD for utility clearance prior to drilling.

The field exploration program consisted of excavating four, 8-inch diameter hollow-stem auger drill holes on January 14, 2011. The drilling subcontractor for the project was AWD Services, Inc. (AWD) of Oak View, California. The drill holes were excavated using a CME 75 truck-mounted drill rig to depths of about 11 to 51 feet and near the locations shown on Plate 2. The sample intervals, N-values, descriptions of the subsurface conditions encountered, and other field and lab data are presented on the logs of the drill holes in Appendix A - Subsurface Exploration.

The drill holes were sampled at selected depths using a 3.25-inch outside diameter modified California split spoon sampler with liners and an unlined 2-inch outside diameter standard penetration test (SPT) sampler. The samplers were driven into the material at the bottom of the drill hole using a 140-pound automatic trip hammer with a 30-inch drop. The blow count (N-value) is the number of blows from the hammer that were needed to drive the sampler 1 foot, after the sampler had been seated approximately 6 inches into the material at the bottom of the hole. Bulk samples were collected from drill cuttings.

1.2.3 Task 3 - Laboratory Testing

Laboratory testing was performed on selected earth materials sampled in the drill holes advanced for this study to estimate the engineering parameters for design. The testing program consisted of moisture/density relationships, fines content (percent passing the No. 200 sieve), Atterberg limits, consolidation testing, corrosion/chemical analysis (pH, resistivity, sulfates, and chlorides), and modified Proctor compaction. Soil chemical analysis was performed by Cooper Testing Laboratories in Palo Alto, California.

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1.2.4 Task 4 - Geotechnical Evaluation and Report Preparation

Geotechnical evaluations were performed to assess geohazards and geotechnical design considerations. This geotechnical report summarizes the data obtained for this project and provides our findings, opinions, and recommendations for the following:

• Site conditions observed during field exploration; • Soil and groundwater conditions at exploration locations; • Site geology, faulting, and seismicity; • Potential impact of seismically induced geohazards such as ground rupture, strong

ground motion, liquefaction, settlement, landsliding, tsunami and seiche; • Ground motion and seismic design data in accordance with the 2010 California

Building Code (CBC); • Liquefaction potential and estimated seismically induced settlement and lateral

movement; • Earthwork and remedial grading for foundations and pavements; • Excavation potential; • Suggested specifications for on-site and select fill material; • Permanent slopes, temporary slopes, and shoring considerations; • Dewatering considerations for temporary construction conditions; • Foundation recommendations for shallow foundations; • Lateral earth pressure design parameters for retaining and below-grade walls; and • Pipe bedding and backfill considerations.

1.3 PREVIOUS WORK ON SITE

Fugro conducted a geotechnical study for the Phase 1 portion of the pump station project in 1999 (Fugro, 2002). Subsurface exploration work performed for Phase 1 included drilling three hollow-stem-auger drill holes to depths of between about 41 to 55 feet and advancing five cone penetrometer test (CPT) soundings to depths of between about 38 and 72.5 feet. Approximate locations of the Phase 1 subsurface explorations are shown on Plate 2 and the logs of the drill holes and CPTs are presented in Appendix C - Fugro (2002) Geotechnical Study Data - Moorpark Pump Station Phase 1.

Phase 1 project elements included a pump station building, electrical substation, piping, valve vaults, and asphalt concrete paving. Grading for that portion of the project was conducted between June 2007 and February 2009, and consisted of removal (overexcavation) of onsite soils to an approximate El. 528 to 530 in the Phase 2 portion of the site. The excavated areas were backfilled and the site graded to the conditions shown on Plate 2. Fugro observed the grading activities and provided field density testing of the fill and backfill materials.

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2.0 FINDINGS

2.1 SITE CONDITIONS

The site is located in a gently sloping, northwest-draining alluvial valley area that is a tributary to Arroyo Simi. The site was graded substantially during construction of the Phase 1 pump station from June 2007 through February 2009. Existing grades and improvements are shown on Plate 2. The Phase 2 site is located southeast of the existing Phase 1 pump station building and the Southern California Edison electrical equipment facility in an area that is currently graded as a detention basin. The basin is surrounded by about 2- to 3-foot-high 2h:1v earthen slopes and is vegetated with seasonal grasses and shrubs. Drainage is accomplished by sheet flow to a catch basin at the northern end of the basin. An access road is present around three sides of the basin. Total relief of the site is approximately 6 feet.

Drainage of the surrounding access road is directed either to Spring Road or to a concrete v-ditch and catch basin along the site’s eastern property line. Site catch basins drain to a storm drain running under the access road east of the detention basin that also transports runoff from the upstream tributary through the project site northwest to Arroyo Simi.

2.2 GEOLOGIC CONDITIONS

2.2.1 Regional Geologic Setting

The proposed pump station project is located within the Transverse Ranges geologic/geomorphic province of California. That province is characterized by generally east-west-trending mountain ranges composed of sedimentary and volcanic rocks ranging in age from Cretaceous to Recent. Major east-trending folds, reverse faults, and left-lateral strike-slip faults reflect regional north-south compression and are characteristic of the Transverse Ranges.

2.2.2 Local Geologic Setting

The local geologic setting as mapped by Dibblee (1992) is shown on Plate 3 - Regional Geologic Map. Mapping by Dibblee indicates that the site vicinity is underlain by a variable thickness of interlayered granular and fine-grained alluvium. Older alluvium/Saugus Formation is anticipated to be preset below the alluvium at depths on the order of about 50 to 60+ feet.

2.3 SUBSURFACE CONDITIONS

2.3.1 Artificial Fill

Artificial fill placed during grading for Phase 1 was encountered in each of the four drill holes advanced for this study. Fill material generally consisted of loose to medium dense silty sand (SM) and clayey sand (SC) at the locations explored. Fill material was encountered to a depth of 3 to 4.5 feet bgs in the drill holes advanced within the detention basin (DH-5 through DH-7) and 7 feet bgs in the drill hole along the access road (DH-4). The base of the fill materials encountered is estimated to range of about El. 527.5 to 530 feet (NAVD88).

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Laboratory test results for selected samples of the alluvium had total unit weights ranging from 131 to 133 pounds per cubic foot (pcf). Dry unit weights for the selected samples ranged from 116 to 119 pcf. Moisture contents for selected samples ranged from approximately 12 to 14 percent. The maximum density and optimum moisture content for compaction as determined by ASTM D1557 was estimated to be 131 pcf and 8.0 percent from laboratory testing performed during Phase 1 grading. Based on the maximum density curve data used during Phase 1 grading, relative compaction of the selected samples ranges from 89 to 96 percent.

2.3.2 Alluvium

Alluvium encountered in the four drill holes advanced for this study generally consisted of:

• In the upper 25 feet, subsurface material appears to consist primarily of medium dense to locally dense clayey sand (SC) to clayey gravel (GC) and very stiff sandy lean clay (CL);

• From 25 to 35 feet, subsurface conditions appear to consist primarily of medium dense clayey sand (SC) to very stiff sandy clay (CL) with interbedded with loose to medium dense silty sand (SM) layers;

• From 35 to 51 feet, subsurface material loose to medium dense silty sand (SM), silty gravel with sand (GM), and clayey sand (SC) interbedded with layers of very stiff lean clay with sand (CL).

The subsurface conditions observed during this study and by Fugro (2002) for Phase 1 suggest the subsurface conditions are predominantly sand lean clay (CL) and clayey sand (SC) in the upper 25 feet to 35 feet of the soil profile. Correlations based on cone Penetration Test (CPT) and drill hole logs suggests the alluvial stratigraphy beneath the site is interbedded and, as shown on Plate 4 - Subsurface Cross Section A-A’, the strata do not appear to be laterally continuous.

2.3.3 Groundwater

Groundwater was encountered in one drill hole advanced for the current study and in three drill holes advanced during the study for Phase 1 (Fugro, 2002). Table 1 - Summary of Groundwater Measurements provides information on the depth to groundwater encountered in drill holes excavated for this and our previous geotechnical study for Phase 1.

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Table 1. Summary of Groundwater Measurements

Drill Hole Estimated

Ground Surface (feet)

Date Drilled Total Depth (feet)

Approximate Groundwater Depth (feet)

Estimated Groundwater

Elevation (feet)

DH-1* 529 07/28/1999 55.5 42 487

DH-2* 531 07/29/1999 51.5 42 489

DH-3* 526 07/29/1999 41.5 36 490

DH-5 532 01/14/2011 51.5 35 497

* Data from Fugro (2002) - See Appendix D

The Arroyo Simi channel, located about 550 feet north of the site, appears to be at an El. of about 510 feet, based on the USGS topographic map, and flows year-round.

We understand the excavations for pump station (i.e., pump cans and valve vaults) may extend as much as 23 feet bgs. Therefore, groundwater is not anticipated to impact construction of the site facilities. We note that groundwater levels can vary seasonally (i.e., mainly as result of precipitation) or with flow volumes in Arroyo Simi as well as within the creek bed/alluvial valley that the site is located in. Also, local perched groundwater conditions may be encountered and count result in groundwater seepage into excavations.

3.0 SEISMICITY AND GEOHAZARDS

3.1 FAULTING AND SEISMICITY

The project area is located in a seismically active portion of California. The project improvements most likely will be subject to earthquake-related strong ground shaking during their design life, potentially resulting in damage to improvements. The closest active fault is the Simi-Santa Rosa fault. The Simi-Santa Rosa fault trace is mapped approximately three quarters of a mile to the south of the project site.

3.1.1 Ground Rupture Potential

No active or potentially active faults are known to traverse the pump station site, based on the US Geological Survey (USGS) Quaternary fault database website (USGS, 2008b), and in our opinion, the potential for ground surface rupture is low.

3.1.2 Strong Ground Motions

As described in Section 3.1 Faulting and Seismicity of this report, the Simi-Santa Rosa fault trace is located approximately ¾-mile south of the project site. In addition, numerous active or potentially active faults within a 15-mile radius of the site have potential to generate strong ground motion.

Ground motions were obtained from the 2008 Interactive Deaggregations (Beta) website (USGS, 2008a) and the 2010 California Building Code (CBC). California Geological Survey

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(CGS, 2008), Special Publication (SP) 117A (pg. 9 and 16) defers to the USGS website to determine a uniform hazard spectrum for a specified location in terms of latitude and longitude, and is performed in lieu of using the ground shaking hazard maps included in the CGS Seismic Hazard Zone Reports. Review of USGS (2008a) website estimates peak horizontal ground accelerations for the project area of about 0.54g for a 475-year return period (10 percent probability of exceedance in 50 years) and 0.89g for a 2,475-year return period (2 percent probability of exceedance in 50 years).

Table 2. USGS Probabilistic Seismic Hazard Deaggregation Results

Return Period (years)

Mean Magnitude (Mw)

Source Distance (km)

Peak Horizontal Ground Acceleration

475 6.8 12.7 0.54g

2475 6.8 8.6 0.89g

3.2 LIQUEFACTION POTENTIAL

Liquefaction is described as the sudden loss of soil strength because of a rapid increase in soil pore water pressures due to cyclic loading during a seismic event. In order for liquefaction to occur, three general geotechnical characteristics must be present: 1) groundwater must be present within the potentially liquefiable zone; 2) the potentially liquefiable soil must meet certain grain size and classification characteristics; and 3) the potentially liquefiable granular soil must be of low to moderate relative density. If those criteria are met and strong ground motion occurs, then those soils may liquefy, depending upon the intensity and cyclic nature of the strong ground motion. Liquefaction that produces surface effects generally occurs in the upper 40 to 50 feet of the soil column, although the phenomenon is not restricted to depths of less than 50 feet.

Soils generally considered susceptible to liquefaction and groundwater were encountered within 50 feet of the ground surface, suggesting that liquefaction is possible at the site. Groundwater was encountered in the hole DH-5 at an approximate El. 497 feet and for the purpose of this evaluation, was used as the design groundwater elevation for our evaluation of liquefaction. The subsurface profile and material properties considered in our evaluation of liquefaction analysis are based on data obtained from the deep drill holes excavated on the site (DH-2 [Fugro, 2002] and DH-5 [this study]).

For liquefaction evaluation, the 2010 CBC suggests peak ground acceleration can be assumed equal to 0.4SDS to approximate the peak ground acceleration for a 475-year return period seismic event. This approximated value is approximately 0.51g (See Table 3) and is less than the USGS (2008a) estimate of about 0.54g for a 475-year return period earthquake event. Therefore, we assumed a peak ground acceleration of 0.54g for our evaluation of liquefaction at the site. Earthquake magnitude and source distance for this evaluation was estimated from the USGS probabilistic hazard analysis for a 475-year return period resulting in a mean moment magnitude of Mw=6.8 at an approximate distance of 12.7 kilometers.

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Liquefaction triggering analysis was performed in accordance with the NCEER workshop procedures summarized by Youd and Idriss (2001). Liquefaction evaluation data is presented in Appendix D - Liquefaction Evaluation. The analysis of DH-2 suggests the subsurface profile is generally not susceptible to classic liquefaction based on the water content and Atterberg limit data. The analysis of drill hole DH-5 indicates the presence of an approximately 11-foot-thick potentially liquefiable layer of granular, non-plastic soil between a depth of about 35 and 46 feet bgs. Factors of safety with respect to liquefaction triggering in this zone are estimated to range from about 0.7 to 1.0.

3.2.1 Liquefaction Related Settlements

Liquefaction related settlement (settlement occurring post-earthquake as a result of reconsolidation of liquefied sandy soils) was estimated using NCEER workshop methods summarized by Youd and Idriss (2001) and calculated using the liquefaction analysis program WSLiq developed by Kramer (2008) for the Washington State Department of Transportation. Assuming all layers with a factor of safety against liquefaction less than 1 liquefy, estimated strains may result in settlement of up to about 1 inch.

Due to the depth of the potentially liquefiable soil zone and the likely interbedded profile within this zone, the likelihood of significant surface manifestation and loss of bearing is low. However, some potential vertical settlement should be considered in the design and anticipated in the event of occurrence of a significant earthquake. Based on the data available from the drill holes and CPT soundings at the site, in our opinion, settlements from liquefaction of up to 1 inch should be considered in the design of the project.

Differential settlements from liquefaction are difficult to estimate. SCEC (1999) suggests that differential settlement from liquefaction at level sites and underlain by relatively uniform natural soils can be assumed to be about 50 percent of the estimated total settlement. Because the site conditions are variable, we recommend that differential settlement be assumed to be two-thirds of the total settlement or about 2/3 inch. The distance over which that differential settlement could occur is not known but could be at least equal to and possibly less than 50 feet (the approximate distance between DH-5 and DH-2). The liquefaction settlement estimates should be considered in conjunction with earthquake-induced settlement of unsaturated soils and from static settlement from structure loads.

The risks from liquefaction and whether specific mitigations are needed or warranted should be determined by the owner. The estimated settlement from liquefaction from this study is generally consistent with the findings provided in Fugro (2002), and we understand that mitigation measures to address liquefaction and seismic settlement were not incorporated into the design or construction of the Phase 1 Pump Station. On the basis of our general experience with similar projects, incorporation of remedial measures to mitigate liquefaction is generally uncommon at sites with similar estimated liquefaction ground response.

However, on the basis of discussions with Perliter & Ingalsbe, we have included the provision of incorporating a layer of geogrid reinforced soil beneath the proposed structures in an effort to help attenuate, but not eliminate, differential settlement from liquefaction. Specific

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details of the geogrid reinforced fill layer are provided in Section 4.1.6 Geosynthetic Reinforced Fill Blanket.

3.2.2 Ground Lurching and Lateral Movement

In our opinion, the consequences of liquefaction are generally anticipated to consist of ground surface settlement of the magnitude described above. Past experience suggests that lateral deformation of the ground can also occur as a result of liquefaction. The occurrences of lateral spreading is generally associated with sites where liquefaction is possible and: 1) the ground surface is gently sloping or 2) there is a free face condition such as a road cut or river bank.

Existing analytical methods of assessing potential deformations caused by lateral spreading are based on a small number of case histories and generally involve layers of liquefiable soils of greater than a meter. The procedures are generally considered reasonable in assessing risks where significant lateral deformations are possible (deformations of a meter or greater). The ability to reasonably predict small lateral spreading deformations is, however, considered significantly limited.

The nearest free face condition is approximately 7 feet high and located approximately 250 feet northwest of the proposed pump station at the northwest end of the Phase 1 construction; however, considering the depth of potentially liquefiable zone and the likely discontinuous or interbedded nature of the potentially liquefiable zone, the potential for large movements from lurching and lateral spreading at the site is considered to be low.

The risk of lateral spreading deformation should not be considered non-existent, and as a result, potential lateral movement of up to 1 inch should be anticipated and is recommended for design purposes in Section 4.2.7 Lateral Movement of this report.

3.3 SEISMICALLY INDUCED SETTLEMENT IN "DRY" SAND

Granular soils above groundwater can be susceptible to settlement from earthquake shaking. Settlements result from densification of loose granular soils, and the behavior is different from liquefaction. Sampler blow count data presented on the drill hole logs indicate that layers of loose to medium dense granular soils are present above the groundwater level and could be susceptible to earthquake-induced settlement.

We used the method described in Pradel (1998) to estimate the amount of settlement that could occur during a seismic event. Ground motions used for this evaluation were the same as those assumed in the assessment of liquefaction at the site.

The analysis used the subsurface data obtained in the drill holed DH-2 (Fugro, 2002) and DH-5 excavated to a maximum depth of about 51 (DH-5) to 55 (DH-2) feet. Sampler blow count data presented on the drill hole logs suggest that granular earth materials above groundwater are generally loose to medium dense. Assuming groundwater is at an elevation of 497 feet, we estimate the seismically induced settlement should be less than about 1/2 inch.

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3.4 LANDSLIDING

As discussed by Fugro (2002) for the Phase 1 pump station study, no large-scale landslides are shown on the regional geologic maps in the vicinity of the proposed pump station site. In addition, we did not observe geomorphic features suggestive of pre-existing landslides at the site. Overall, the potential for slope instability is considered low.

3.5 TSUNAMI AND SEICHE

Tsunamis are long-period sea waves created by the effects of seismic events or submarine landslides, occurring locally, or often many thousands of miles away. Tsunamis have historically caused little damage in southern California. The location of the pump station site well away from the ocean indicates that tsunamis are not concern.

Seiches are seismic waves in landlocked bodies of water such as lakes. The site is located well away from large land-locked bodies of water; hence, seiches are not considered a concern.

3.6 2010 CBC SEISMIC DESIGN PARAMETERS

As discussed above, there is a potential for liquefaction at the project site because of the presence of relatively loose granular soil layers below the groundwater level. Therefore, based on the 2010 CBC requirements, the site is classified as Site Class F and a site response analysis is required. However, per Section 20.3.1 of ASCE 7-05, a site response is not required for structures with a fundamental period of vibration (T) equal to or less than 0.5 seconds and spectral accelerations can be assessed using the site class without considering liquefaction. Based on our understanding of the proposed structures, we have assumed the proposed structures will have fundamental periods of vibrations of less than 0.5 seconds and that code-based seismic parameters can be developed without considering liquefaction.

Based on the data obtained from this and our previous study, the site can be considered to meet the criteria in Section 1613 of CBC (2010) for Site Class D (if liquefaction is not considered). Table 3 presents seismic design parameters developed in general accordance with the 2010 CBC for Site Class D conditions. The seismic design coefficients were determined using the USGS Java Ground Motion Parameter Calculator available at the following web site: http://earthquake.usgs.gov/research/hazmaps/design/index.php.

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http://earthquake.usgs.gov/research/hazmaps/design/index.php


Table 3. Summary of 2010 CBC Seismic Design Parameters

Parameter Value

Latitude N 34.275358

Longitude W 118.873521

SS 1.897

S1 0.743

Site Class (per Table 1613.5.2 of 2010 CBC) as allowed by Section 20.3.1 of ASCE 7-05 D

Fa 1.0

Fv 1.5

SMS 1.897

SM1 1.114

SDS 1.265

SD1 0.743

4.0 RECOMMENDATIONS

4.1 EARTHWORK AND GRADING

4.1.1 General

The proposed pump station will be located within the existing detention basin that was graded as part of the Phase 1 construction. The thickness of fill in this area is anticipated to range from 3 to 4 feet within the basin, and approximately 6 feet under the perimeter access road. Based on the preliminary design concepts and existing site topography, the basin will likely be filled to achieve the Phase 2 site grades. The proposed diesel tank pad is located in the area occupied by an existing access road and that area may be at or near the planned grade.

On the basis of discussions with Fugro personnel present during the Phase 1 grading, portions of the proposed diesel tank pad may be outside the original limits of Phase 1 grading. Though select fill material was observed in drill hole DH-4, areas of nonstructural fill and backfill may be present within the diesel tank pad footprint and may not be suitable for the support of the proposed diesel tank pad.

Existing artificial fill was placed during the construction of Phase 1 as compacted fill. However, because those soils have been exposed to wetting and drying cycles and possibly disturbance associated with weed abatement work, the fill materials have experienced some weathering and the relative compaction of the surficial soils may be less than existed at the time the materials were placed. Based on past experience, weathering and reduction of the relative compaction fill is probably limited to the upper 12 to 18 inches.

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4.1.2 Site Preparation

Organic material and vegetation, hazardous materials, construction debris, old foundations, unsuitable fill materials, or other deleterious materials should be stripped, removed, and wasted from beneath structures or areas to be graded.

Abandoned underground structures (e.g., wells, drains [including tile drains], pipelines, old foundations, etc.) should be removed or treated in a manner prescribed by the controlling governmental agencies.

4.1.3 Excavation Considerations

Excavation Potential. Drill holes excavated for this study were excavated with a CME-75 drill rig using an 8-inch-diameter hollow-stem auger. The earth materials encountered were excavated with moderate effort of the equipment. Excavation for Phase 1 was achieved with heavy-duty earthmoving equipment in good working condition. Based on our observations during Phase 1 construction and the subsurface explorations, similar equipment should be capable of excavating earth materials at the site.

Groundwater. Groundwater was not encountered in the explorations for this study above a depth of about 35 feet. However, there is a potential for perched water and seepage to be encountered during excavations for pump cans, valve vaults, pipelines and other construction activities involving relatively deep excavations at the site.

4.1.4 Overexcavation and Subgrade Preparation

Overexcavation. Prior to filling, structure areas and areas to be filled should be overexcavated to remove soil unsuitable for foundation support. Recommendations for overexcavation are provided below:

• Areas supporting structural components and pavement within the existing detention basin should be overexcavated to a minimum depth of approximately 18 inches below the existing grade to remove weathered artificial fill unsuitable for support of structural fill;

• In addition to overexcavation of unsuitable soil, overexcavation should be performed to provide a minimum of 3 feet of compacted fill beneath foundations and 1 foot of compacted fill beneath pavement sections.

• The limits of overexcavated areas should extend at least 5 feet beyond structure perimeters and at least 3 feet beyond pavement edges or into firm compacted fill placed during Phase 1 construction;

• The geotechnical engineer should observe the condition of the subgrade exposed after overexcavation. If loose fill or unsuitable earth materials are encountered at or below the subgrade level, additional overexcavation may be recommended.

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• Below-grade vaults should be overexcavated at least 2 feet below the bottom of the lowest foundation element.

• Overexcavated areas should be backfilled with compacted fill materials as described in Section 4.1.5 Fill Selection and Compaction of this report.

Subgrade Preparation. Subsequent to overexcavation, the exposed subgrade should be scarified to a depth of at least 8 inches, moisture-conditioned to within 2 percent of optimum, and compacted to at least 90 percent of the maximum dry density determined from ASTM D1557, latest edition.

4.1.5 Fill Selection and Compaction

Compacted fill materials should replace overexcavated soils and, in general, should be placed beneath proposed structures and adjacent to below-grade walls. Requirements for select fill, onsite fill, and compaction, are provided in this section.

Onsite Fill. Review of the drill hole logs suggests that materials likely to be encountered in cut and areas to be overexcavated at the pump station site could consist of sandy clay, clayey sand, silty sand, and sandy silt, with fines content in excess of 35 percent. Hence, we anticipate that fine-grained portions of onsite soils in cut and overexcavated areas will not be reusable as select fill material. If granular materials meeting the requirements of select fill are encountered, selective stockpiling or screening of those materials may be performed for possible use as select fill. Other than surficial vegetation and debris, organic or other deleterious materials were not encountered during the recent subsurface exploration. If encountered during excavation, selective stockpiling or screening of those materials may be necessary to use as general fill and overexcavation backfill.

Onsite materials such as those generated as part of the recommended overexcavation may be used as overexcavation backfill from the overexcavation subgrade up to within 3 feet of footing bottoms, 2 feet of building slabs and below-grade vaults, and 1 foot of the pavement section subgrade, provided that the materials are free of deleterious or organic materials or oversize material greater than 4 inches in maximum dimension and are compacted as described subsequently.

Onsite materials may also be used for general fill to raise grades as needed in areas away from structures and pavements, provided the materials are free of deleterious or organic materials or oversize material greater than 4 inches in maximum dimension.

Select Fill Material. Select fill should be used beneath structures, as backfill behind below-grade retaining structures, and beneath pavements as noted above. Select fill should be free of organics, debris, oversize rocks or soil clumps, and other deleterious materials. The material should consist of nonexpansive soil (EI ≤20) soil with a plasticity index of less than 10 and a fines content (percent by weight passing the No. 200 sieve) of less than 35 percent. Select fill materials should not have any particles larger that 3 inches in diameter. Also, select fill to be placed as backfill behind below-grade walls or retaining walls should have a sand equivalent of 20 or greater.

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Fill Compaction. Fill materials should be placed in layers that, when compacted, should not exceed 6 to 8 inches in compacted thickness. Each layer should be spread evenly, moisture-conditioned to within 2 percent of optimum, and processed and compacted to obtain a uniformly dense layer. Fill should be placed and compacted on near-horizontal planes, and unless otherwise noted, should be compacted to:

• A minimum of 95 percent of the maximum dry density determined from ASTM D1557, latest edition, for fill placed below structures and pavements, and

• A minimum of 90 percent of the maximum dry density determined from ASTM D1557, latest edition, for fill placed adjacent to below-grade walls (outside of structural areas).

Compacted fill materials should be observed and tested to determine if they satisfy minimum compaction requirements.

Keying and Benching. We recommend that fill placed on slopes steeper than 5h:1v be keyed and benched into existing firm materials. The fill should be initiated from a 2-foot-deep base key excavated into the toe of the slope. The base key should begin at the toe of the finished slope and have a width of at least 10 feet. The base key and the subsequent benches should be sloped at least 2 percent into the slope.

4.1.6 Geosynthetic Reinforced Fill Blanket

A geosynthetic reinforced fill blanket supporting the proposed pump station could be incorporated to potentially reduce the effect of seismic settlement on the proposed structure and related piping. The intent of the geosynthetic reinforced fill blanket is not to remediate potentially liquefiable soils but to provide a layer of reinforced soil between the structure and the zone of potential liquefiable soil to help attenuate differential settlements. The reinforced fill layer should be deeper than proposed utilities and piping to provide a continuously reinforced section across the project site.

The reinforced fill layer should be a minimum of 5 feet thick and extend at least 10 feet beyond the limits of the proposed pump station. Vertical spacing of the reinforcement should be 12 inches. Earth material within the reinforced fill blanket may consist of general or select fill material depending on the location of the fill blanket in relation to proposed structures. The selection of general or select fill is dependent upon the recommendations provided in Section 4.1.5 Fill Placement and Compaction. Geosynthetic reinforcement should consist of Tensar BX1200 Biaxial Geogrid.

4.1.7 Temporary Slopes

The contractor should be made responsible for all safety issues affecting open excavations and temporary slopes and excavations should conform to federal Occupational Safety and Health Administration (OSHA) regulations and any other local ordinances or codes. In general, onsite soils may be classified as OSHA Type C soil materials, and in our opinion, temporary slopes up to 25 feet high should be excavated at an inclination of 1-1/2h:1v or flatter.

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Slopes should not be considered stable if seepage can daylight on the slope or groundwater is expected within the planned depths of excavation. If excavations need to extend below the groundwater table, dewatering should be provided in advance of the excavation to avoid the potential for groundwater to daylight on the slope.

The contractor should continuously monitor temporary slopes and slopes should be monitored periodically by a representative of Fugro. Recommendations to lay back excavations to a shallower slope may be warranted based on conditions observed in the field.

4.1.8 Temporary Shoring

Temporary slopes can be shored using trench shields, sheet pilings, or braced excavations. Soil pressures required for the design of temporary trench shoring can be evaluated using the suggested geotechnical parameters provided above or alternative methods selected by the contractor that satisfies the OSHA guidelines. Shoring design for the project should be performed by a registered professional with proven experience in the design of relatively deep shoring in soft soil conditions. The contractor should be responsible for design and implementation of shoring systems and safe working conditions.

Continuous support should be anticipated to minimize potential sloughing of the existing soils in large part because of the presence of existing utilities and improvements near the proposed pipeline alignment. Conventional trench shields provide only for worker safety and do not provide continuous support unless the shield is installed tight against the sidewalls. Local trench wall instability can occur resulting in the accumulation of loose soil debris adjacent to the trench shield. Removal of the loose material is usually not possible and its presence can result in settlement of the trench backfill and surface improvements.

Deeper excavations may require a significant shoring system. The selection, design, and installation of the shoring system needed for the project should be made by the contractor.

4.1.9 Permanent Slopes

Though no slopes are currently proposed for the project, in general, the relatively flat-lying alluvial deposits and strong soil materials suggest that typical 2h:1v slope inclinations in conformance with applicable codes should be satisfactory. Permanent cut slopes should be inclined no steeper than 2h:1v and should not exceed 10 feet in height, without consulting with the geotechnical engineer.

4.1.10 Site Drainage and Control of Seep Water

Runoff should be directed away from temporary or permanent slopes and should not be allowed to flow across slope faces and excavations. Provisions should be included for collecting and pumping seepage or runoff water out of the excavation if water is encountered during construction.

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4.2 FOUNDATION DESIGN AND CONSTRUCTION

4.2.1 General

We understand that the pump station structure will consist of a steel-framed roof and masonry wall structure with a structural reinforced concrete slab. We anticipate that pump station wall foundations and diesel generator and hydro turbine units will be supported on shallow foundations.

From a geotechnical standpoint, either spread or continuous wall footings in conjunction with a reinforced concrete floor slab, or a mat-type foundation can be used for foundation support. Good quality, locally accepted construction techniques should be utilized. All foundation excavations should be observed and approved by the geotechnical engineer prior to placing reinforcement and concrete.

4.2.2 Footing Design Criteria

Footing Support. Footings and mat-type foundations should be underlain by select fill placed in accordance with the recommendations provided in Section 4.1 Earthwork and Grading of this report.

Minimum Footing Embedment. Footings and mat foundations should be embedded a minimum of 24 inches and 12 inches below the lowest adjacent grade, respectively. Foundation excavations should be observed and approved by the geotechnical engineer prior to placement of steel reinforcement

Minimum Footing Dimensions. Footing widths should not be less than 24 inches.

Allowable Bearing Pressure. An allowable net bearing pressure of 2,500 psf may be used for footings with a minimum footing dimension of 2 feet deep and 2 feet wide. The allowable net bearing pressure may be increased by 100 psf for every foot increase in footing width and 200 psf for every foot increase in embedment depth up to a maximum allowable net bearing pressure of 3,500 psf.

Safety Factors and Transient Loads. The recommended allowable bearing pressure incorporates a factor of safety against shear failure in excess of 3.0. However, the recommended bearing pressure recommended above is controlled by static settlement, where the estimated settlement is limited to less than about 3/4 inch. A one-third increase in the allowable bearing pressure may be used for transient loads such as seismic or wind forces.

4.2.3 Modulus of Subgrade Reaction for Mat-Type Foundations

Mat-type foundations can be designed using a Winkler model (i.e., beam on elastic foundation) assuming a modulus of subgrade reaction of 250 pounds per cubic inch. The modulus of subgrade reaction value represents a presumptive value based on soil classification data and is for a 1-foot-square plate. Depending on how the subgrade modulus value is used in design, the value may need to be scaled for size effects, assuming a cohesionless subgrade.

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4.2.4 Sliding and Passive Resistance

Shear resistance may be estimated using a combination of sliding and passive resistance. Shear keys may be used (around the structure perimeter) to augment sliding and passive resistance.

Sliding Resistance. Ultimate sliding resistance generated through a compacted fill or crushed rock-concrete interface can be computed by multiplying the total dead weight structural loads by a coefficient of 0.40.

Passive Resistance. Ultimate passive resistance (for "dry" soils) can be determined using an equivalent fluid weight of 350 pcf for lateral bearing foundation elements bearing against level compacted select fill or undisturbed older alluvium. For 2h:1v descending slope conditions, the equivalent fluid weight for passive resistance should be reduced to 150 pcf. Level backfills should extend out in front of the lateral bearing element at least two times the embedment depth of the lateral bearing element. Otherwise, the reduced passive resistance should be used. Passive resistance should not be used for the upper 1 foot of soil that is not constrained at the ground surface by pavement.

Safety Factors. Sliding and passive resistance may be used together without reduction in conjunction with a recommended minimum factor of safety for static loads of 1.5 against overturning and sliding. For transient loads, the recommended factor of safety is 1.1.

4.2.5 Static Settlement

Settlement will occur as loads are applied to the subsurface through foundation elements. We have assumed that bearing elements will be founded entirely on a relatively uniform layer of compacted select fill underlain by very stiff to dense alluvium. The alluvial materials appear to be overconsolidated; hence, settlement from static loads should occur rather rapidly as loads are applied.

We anticipate that total settlements from static loads should not be greater than about 3/4-inch. Differential settlement from static loads should not be greater than about 1/2 inch over a horizontal distance of 30 feet (distortion of 1/720). The estimated differential settlement of 1/2 inch over a distance of 30 feet is not cumulative over the foundation, but is provided for design purposes as an estimate of the potential settlement between adjacent internal column locations or along continuous footings.

If non-uniform bearing materials are encountered beneath overexcavated limits, additional remedial measures may be required to reduce the potential for differential settlement. Non-uniform bearing materials might include unanticipated soft, expansive, or disturbed soils. A typical remedial measure might consist of additional overexcavation and recompaction of the non-uniform materials.

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4.2.6 Seismic Settlement

As described above, estimated liquefaction-related settlement of up to 1 inch may be anticipated. Estimated dry sand settlement of approximately 0.5 inch should be considered in conjunction with liquefaction related settlement. Seismically induced settlement may occur in addition to estimated static settlements presented above.

For design purposes, total seismic settlement of 1-1/2 inches should be anticipated. Differential settlement due from liquefaction and dry sand settlement may be assumed to be about 1 inch over a horizontal distance of about 50 feet (a ratio of 1/600), which should be added to static distortion values presented above.

We note that the incorporation of geosynthetic reinforcement as outlined in Section 4.1.6 Geosynthetic Reinforced Fill Blanket should help attenuate, but not eliminate, potential differential settlement from liquefaction occurring at depth.

4.2.7 Lateral Movement

Although not anticipated to be large, we recommend that the pump station design accommodate at least 1 inch of potential lateral movement from seismic shaking.

4.3 BELOW GRADE WALLS AND VAULTS

4.3.1 General

Below grade structural walls and pipe vaults are proposed as part of the Phase 2 construction. Pipe vaults are anticipated to consist of concrete box-type structures buried up to about 14 feet. From a geotechnical standpoint, either a system of perimeter footings or a mat foundation can be used to support the proposed vaults, provided the recommendations contained herein are followed and locally accepted, good quality, construction techniques are utilized. All foundation excavations should be observed and approved by the geotechnical engineer prior to placing reinforcement and concrete.

Recommendations for design and construction of retaining walls and vaults are presented below.

4.3.2 Footing Design

From a geotechnical standpoint, either spread or continuous wall footings in conjunction with a reinforced concrete floor slab, or a mat-type foundation can be used for foundation support, assuming recommendations for overexcavation and backfilling given in Section 4.1 Earthwork and Grading also are implemented.

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4.3.3 Lateral Earth Pressures

Vault below-grade walls will be subjected to lateral earth pressures from backfill soils for static and dynamic conditions. This section provides recommendations for the design of retaining walls and below-grade walls for the vaults.

Backfill Material. Backfill materials placed with a line projected at a 45 degree angle up from the base of the wall should consist of select fill meeting the criteria described in Section 4.1.5 Fill Selection and Compaction. Fill material placed outside that zone can consist of either onsite or select material.

Static Pressures. Retaining structures that are free to rotate or translate laterally (e.g., cantilevered retaining walls) through a horizontal distance to wall height ratio of greater than about 0.004 are referred to as unrestrained or yielding retaining structures. Such walls can generally move enough to develop active conditions. Retaining structures that are unable to rotate or deflect laterally (e.g., restrained below-grade or basement walls) are referred to as restrained or non-yielding walls.

Cantilever retaining walls probably will be free to rotate. Below-grade vault walls are not anticipated to be free to rotate and, therefore, should be designed for restrained conditions. In addition, undrained conditions should probably be assumed for design unless drainage is included to preclude the build-up of hydrostatic pressures behind the wall. Recommendations for drainage of retaining and below-grade walls discussed in the following section should be incorporated into the proposed wall design and construction, if the walls are designed for drained conditions.

For estimating lateral earth pressures, the equivalent fluid weights presented in Table 4 - Equivalent Fluid Weights for Developing Lateral Earth Pressures, may be used for design assuming a level backfill consisting of select fill. The equivalent fluid weight for undrained conditions accounts for the buoyant unit weight of soil and includes the unit weight of water.

Table 4. Equivalent Fluid Weights for Developing Lateral Earth Pressures

Equivalent Fluid Weight, pcf Condition

Drained Undrained

Active (Unrestrained) 40 80

At-Rest (Restrained) 55 85

Estimated equivalent fluid pressures should be applied to a vertical plane passing through the backmost extension of the wall. The height of the vertical plane should extend from the point where the vertical plane intersects the ground surface down to the elevation of the

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lowest retaining wall foundation element (e.g., bottom of shear key or passive pressure resisting element).

Recommendations for surcharge pressures and dynamic lateral earth pressures discussed in the following sections can be used, if required, for the design of the proposed vaults.

Dynamic Earth Pressures. For unrestrained walls, the increase in lateral earth pressure due to earthquake loading can be estimated using the Mononobe-Okabe theory, as described by Seed and Whitman (1970). That theory is based on the assumption that sufficient wall movement occurs during seismic shaking to allow active earth pressure conditions to develop. For restrained walls, the increase in lateral earth pressure due to earthquake loading also can be estimated using the Mononobe-Okabe theory. Because that theory is based on the assumption that sufficient movement occurs so that active earth pressure conditions develop during seismic shaking, the applicability of the theory to restrained or basement walls is not direct. However, there is a supporting reference (Nadim and Whitman, 1992) that suggests the theory can be used for such walls.

In the Mononobe-Okabe approach, the total dynamic pressure can be divided into static and dynamic components. In our opinion, the estimated resulting force corresponding to the seismic force increment of dynamic earth pressure can be assumed equal to 12H2 pounds per lineal foot, where H is the height of the retained soil. This force can be assumed to act over the face of the wall following an inverted triangular pressure distribution with the resultant force acting 2/3H above the base of the wall and should be applied in combination with the static active earth pressures presented in Table 4.

4.3.4 Surcharge Pressures

The recommended equivalent fluid weights in Table 4 do not account for surcharge loads acting on the backfill. The surcharge from foundation loads can be neglected provided adjacent footings are setback behind a 1:1 line projected upward from the base of the wall. For surcharge loads acting within the zone created by 1:1 line from the bottom of the wall, the lateral earth pressure from uniform surcharge loads can be estimated as 0.3 times the stress applied at the ground surface. Traffic surcharges can be estimated as an additional 2 feet of soil cover, equal to a uniform pressure of 250 psf. Traffic surcharges can be neglected below a depth of 10 feet from the top of the wall. Lateral pressures for other surcharge loading conditions can be provided, if required.

4.3.5 Drainage Measures

If designed for drained conditions, drainage measures should be implemented to prevent the buildup of hydrostatic pressures behind retaining or below-grade walls. To reduce the potential for the buildup of hydrostatic pressures behind retaining or below-grade walls, a granular, free-draining backfill at least 2 feet in thickness should be placed behind the wall. Provisions should be included for drainage of surface runoff that may tend to collect behind the backs of the walls and for drainage of water away from the fronts of the walls. Also, provisions

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should be included to mitigate the infiltration of surface runoff into the free-draining backfill by placing a minimum of 18 inches of fine-grained low permeability soil over the top of the free-draining backfill.

As an alternative, drainage material can consist of prefabricated geocomposite drainage panels. A suitable outlet for the collected water will need to be provided. If site grades do not allow for drainage by gravity, pumps should be provided or the walls should be designed for undrained backfill conditions.

4.3.6 Compaction Adjacent to Walls

Backfill within 5 feet, measured horizontally, behind the retaining structure should be compacted with lightweight compaction equipment to minimize the potential for causing large compaction stresses. If large or heavy compaction equipment is used, compaction-induced stresses can result in increased lateral earth pressures on the retaining walls in addition to those presented in Table 4. If heavy compaction equipment is to be used, further evaluation of the potential for compaction-induced stresses may be warranted.

4.3.7 Resistance to Uplift

If the proposed vaults are constructed without provisions for subsurface drainage, the vaults could be subject to uplift from hydrostatic forces. Uplift resistance can be provided from: 1) the gross weight of the structure; 2) from friction between the soil and the below grade walls for a vault without footing extensions; 3) from friction between soil interfaces for a vault with footing extensions; and 4) from the weight of soil located above footing extensions beyond the outside walls of the vault.

Uplift forces due to buoyancy can be resisted by the buoyant dead weight of the structure and by friction acting between the exterior walls of the structure and the surrounding soil. The maximum allowable frictional resistance between the soil and the buried concrete structure or along a soil/soil interface can be estimated as 0.2 times the effective overburden stress. The effective overburden stress (in psf) can be estimated using a soil total unit weight of 120 pcf above the groundwater and an effective buoyant unit weight for submerged soil of 60 pounds pcf. If filter fabric or prefabricated drainage panels will be placed between the wall backfill and the ground in close proximity to the structure, the uplift resistance due to friction should be neglected.

4.4 PIPELINE DESIGN CRITERIA

4.4.1 Trench Excavations

Excavations more than 4 feet deep should be excavated, braced, shored, or shielded in accordance with federal and state standards, CMWD project specifications, and safe construction practices. Shoring and bracing of the trench sidewalls may be required in accordance with OSHA regulations.

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The contractor should be responsible for design and implementation of shoring systems and safe working conditions. The following paragraphs provide some general guidelines that could assist the contractor during construction.

On pipeline projects, the contractor typically places the excavated soils adjacent to the trench and spreads those soils so that sideboom, welding trucks, and other vehicles can drive adjacent to the trench on the excavated soils. For situations such as that, the excavated soils may be placed anywhere adjacent to the top of the trench if the stockpiled soil thicknesses are 3 feet or less. If soils are placed thicker than 3 feet or in mounded stockpiles, and not spread out as previously described, then the excavated soils should be placed no closer than 10 feet from vertical trench sidewalls. However, if local soil conditions create a trench-sidewall-stability hazard, a geotechnical engineer should be consulted to evaluate alternative minimum distances needed between the edge of the trench and stored excavated soils so that the potential for trench instabilities can be reduced.

Similarly, heavy equipment should be operated in a safe manner and should be kept an adequate distance from vertical trench sidewalls to prevent a trench-sidewall-stability hazard. The width of that heavy equipment exclusionary zone will vary based on underlying earth materials, depth of trench excavation, the presence or absence of groundwater, and the configuration of the excavated trench. As a general guideline, heavy equipment should be excluded from a zone located between the top of the trench excavation and a 1h:1v projection from the bottom of the adjacent trench sidewall. This is a general guideline and may need to be modified in the field for specific geotechnical conditions. The contractor should consult a qualified geotechnical engineer regarding his excavation procedures.

Groundwater conditions and impacts as described previously should be anticipated.

4.4.2 Pipe Zone and Trench Backfill

General. Compacted fill materials for the proposed pipeline will consist of pipe zone materials and trench backfill materials. The following subsections describe each of those materials. The recommendations for characteristics and placement of those materials are largely derived from the Standard Specifications for Public Works Construction (SSPWC, 2009), Section 306.

Pipe Zone Materials. Pipe zone materials are defined, herein, as those earth materials used as pipeline bedding and shading. Pipe zone materials should consist of clean sand or crushed angular gravel with a minimum sand equivalent (SE) of 30 to facilitate placement and achieve uniform support for the improvements. Gravel should conform to the gradation for 3/4 inch, crushed rock in Table 200-1.2, of the SSPWC (2009). The pipe zone materials should extend from at least 6 inches below the pipe to 12 inches above the crown. The pipe zone materials also should extend at least 12 inches out from the sides of the pipeline or as shown on CMWD standard drawing No. 301, whichever is larger.

On the basis of our observations, the soils encountered during subsurface exploration for the project appear unlikely to comply with the recommendations presented above for pipe

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zone backfill materials. Selected soil samples from drill holes drilled for the project have fines contents in excess of about 20 percent, suggesting that those soils will generally have SEs of less than 30. Therefore, most, if not all, of the pipe zone backfill materials will likely need to be imported to the project site.

Pipe zone materials should be properly placed and mechanically compacted in order to achieve a minimum of 90 percent relative compaction as determined by standard test method ASTM D1557. Sand backfill should be placed in loose lift thicknesses no greater than 8 inches and mechanically compacted with a vibratory compactor. Gravel backfill should be placed in loose lift thicknesses no greater than 8 inches and be "set" using several passes of a vibrating mechanical compactor or suitable alternative. The trench width should be sufficient to allow compaction equipment to operate between the pipe springline and trench wall. Jetting or flooding of pipe zone materials should not be allowed.

Trench Backfill Materials. Trench backfill materials are defined herein, as those materials placed above the pipe zone. Onsite soils should be suitable for use as trench backfill. However, select fill should be placed within the upper 3 feet beneath footing bottom and the upper 1 foot beneath pavement subgrade.

Trench backfill should be spread in loose lifts not to exceed 8 inches in thickness, moisture conditioned to within 2 percent of optimum moisture content and compacted to 90 percent of the maximum dry density as determined from ASTM D1557. The upper 1 foot of the subgrade beneath paved areas should be compacted to 95 percent of the maximum dry density ASTM D1557. Particles larger than 4 inches in maximum dimension should be excluded. Beneath structure foundations, trench backfill in the upper 3 feet should consist of nonexpansive select fill materials, described previously.

Filter Between Pipe Zone and Backfill Materials. From a comparison of gradations for 3/4 inch crushed rock pipe zone material to gradations for possible fine-grained trench backfill materials, there is a potential for fine-grained silt and clay, and sand particles to migrate into the voids of the crushed rock pipe zone materials. Should this occur, settlement of the ground surface is likely to develop. Migration of finer soil particles may occur from seeping groundwater or vibrations. To mitigate potential soil migration, a filter fabric should be placed between the pipe zone and trench backfill material in areas where ground surface settlement would be problematic (e.g., roadways or areas sensitive to surface drainage characteristics). The filter fabric should satisfy requirements for a Type 180N, nonwoven textile per Table 213-2.2, Section 213-2 of the SSPWC (2009).

4.4.3 Modulus of Soil Reaction

Flexible and semi-rigid pipes are typically designed to withstand a certain amount of deflection from the applied earth loads. Those deflections can be estimated with the aid of equations presented by Spangler and Handy (1982) or Howard et al. (1995). We suggest an E'-value of 1,000 psi be used for the project site. The E'-value is for a combined trench/pipeline system that includes a minimum of 12 inches of compacted pipe zone material around the pipeline.

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4.4.4 Thrust Resistance

Frictional Resistance. Where the proposed pipeline changes direction abruptly, resistance to thrust forces can be provided by mobilizing frictional resistance between the pipe and the surrounding soil, by use of a thrust-block, or by a combination of the two. We anticipate that thrust resistance for the pipelines will probably be provided using restrained joints in conjunction with mobilized pipeline/soil frictional resistance. To utilize thrust resistance using frictional resistance, we recommend the following parameters to estimate the ultimate frictional resistance:

• Total unit weight, 125 pcf • Coefficient of lateral pressure, at rest, Ko, 0.9 • Coefficient of friction

0.35 for mortar-coated pipe 0.20 for tape/dip-coated pipe

Use of those parameters results in ultimate friction resistance values presented in Table 5 - Ultimate Frictional Resistance.

Table 5. Ultimate Frictional Resistance

Ultimate Frictional Resistance (psf) Average Depth (feet) For Mortar-Coated Pipe Tape/Dip-Coated Pipe

4 155 90

5 195 112

6 235 135

7 275 157

8 315 180

9 355 202

10 395 225 1 Those values may be used around the perimeter of the pipe.

Thrust-Blocks. Thrust-blocks can be designed based on the potential applied lateral stress imparted by the pipeline. For thrust-blocks bearing directly against undisturbed native soils, the ultimate lateral pressure may be computed using an equivalent fluid weight of 350 pcf up to an ultimate value of 2,500 psf. Where the thrust block is submerged, the equivalent fluid weight should be reduced to 125 pcf. The equivalent fluid weight was estimated using a total unit weight of 125 pcf and an assumed friction angle of 30 degrees.

The estimated lateral displacement needed to develop the ultimate passive pressure may be taken as about 1 percent of block height (e.g., for a 4-foot-high thrust-block a displacement of about 1/2-inch is needed). Lateral bearing should be neglected from the ground surface to a depth of 1 foot below the lowest adjacent grade.

N:\WP\2011\04.61100021\R04.61100021_4-15-11.DOC 24


In consideration of the allowable thrust-block deflection and attendant potential for pipe-joint separation, we recommend that thrust-block design be based on a factor of safety of 2 (that is, use the ultimate value divided by 2 to derive an allowable value). Thrust collars should be spaced (center-to-center spacing) no closer than 3 times the width of the collar (measure from the edge of the collar radially to the edge of the pipe).

4.5 SOIL CHEMISTRY TESTING

Table 6. Summary of Chemical Test Results

Drill Hole Depth (ft) Material Description Resistivity (ohms/cm) pH Chloride

(ppm) Sulfate (ppm)

DH-5 11.5 Clayey Sand (SC) 2,279 7.7 3 <5

A selected soil sample was tested for resistivity, pH, sulfate, and chloride by Cooper Testing Laboratories in Palo Alto, California. The resistivity data indicate that the tested sample is not corrosive to ferrous metals. The measured chloride content was generally low and does not appear to represent a significant potential for corrosion of reinforcing steel with minimum cover requirements. The sulfate measured content is considered negligible in terms of concrete exposure. The test results should be evaluated by a corrosion specialist to confirm the opinions regarding the potential corrosion impacts from the onsite soils to the construction materials proposed for the project.

5.0 LIMITATIONS

5.1 REPORT USE

The conclusions and professional opinions presented in this report were developed by Fugro Consultants, Inc., solely for use by Perliter & Ingalsbe and their agents for use during the design of proposed Moorpark Pump Station Phase 2 project in Moorpark, California.

Although information contained in this report may be of some use for other purposes, it may not contain sufficient information for other parties or uses. If any changes are made to the project as described in this report, the conclusions and recommendations in this report shall not be considered valid unless the changes are reviewed and the conclusions and recommendations of this report are modified or validated in writing by Fugro.

5.2 POTENTIAL VARIATION IN SUBSURFACE CONDITIONS

Earth materials can vary in type, strength, and other geotechnical properties between points of observations and exploration. Additionally, groundwater and soil moisture conditions also can vary seasonally or for other reasons. Therefore, we do not and cannot have a complete knowledge of the subsurface conditions underlying the site. The conclusions and recommendations presented in this report are based on the findings at the points of exploration,

N:\WP\2011\04.61100021\R04.61100021_4-15-11.DOC 25


interpolation and extrapolation of information between and beyond the points of observation, and are subject to confirmation based on the conditions revealed during construction.

5.3 HAZARDOUS MATERIALS

The scope of services did not include any environmental assessments for the presence or absence of hazardous/toxic materials in the soil, surface water, groundwater, or atmosphere. Any statements or absence of statements, in this report or data presented herein regarding odors, unusual or suspicious items, or conditions observed are strictly for descriptive purposes and are not intended to convey engineering judgment regarding potential hazardous/toxic assessment.

5.4 LOCAL PRACTICE

In performing our professional services, we have used generally accepted geologic and geotechnical engineering principles and have applied that degree of care and skill ordinarily exercised, under similar circumstances, by reputable geotechnical engineers currently practicing in this or similar localities. No other warranty, express or implied, is made as to the professional advice included in this report.

5.5 PLAN REVIEW

We recommend that Fugro Consultants, Inc. be provided the opportunity to review and comment on the geotechnical aspects of the project plans and specifications before they are finalized. The purpose of that review will be to evaluate if the recommendations in this report have been properly interpreted and implemented in the design and specifications.

5.6 CONSTRUCTION MONITORING

The construction process is an integral part of the design with respect to geotechnical aspects of a project. Some of the conclusions and recommendations presented herein are based on assumptions made during our geotechnical studies and evaluations. To verify or disprove those assumptions, a representative of our firm should be present during construction to observe subsurface geotechnical conditions as they are exposed. Therefore, we recommend that Fugro be retained during grading and construction of the proposed pump station to observe compliance with the design concepts and geotechnical recommendations and to allow design changes in the event that subsurface conditions or methods of construction differ from those anticipated. Our representative should test and/or observe excavations, fill and backfill placement and compaction, and the construction of foundation systems. In addition, in geologically sensitive areas, an engineering geologist from our firm should observe and map exposures to verify the presence or absence of geohazards.

N:\WP\2011\04.61100021\R04.61100021_4-15-11.DOC 26


6.0 REFERENCES

American Society of Testing and Materials (ASTM) (latest edition), ASTM Annual Book of Standards.

California Building Code (2010), International Conference of Building Officials, January.

California Geological Survey (2008), "Guidelines for Evaluating and Mitigating Seismic Hazards in California," Special Publication 117A, September 11.

Cetin et. al. (2004), "Standard Penetration Test-Based Probabilistic and Deterministic Assessment of Seismic Soil Liquefaction Potential." Journal of Geotechnical and Geoenvironmental Engineering, Volume 130, No. 12, dated December 1.

Dibblee, T.W. Jr. (1992), Geologic Map of the Moorpark Quadrangle, Ventura County, California, Dibblee Geological Foundation Map DF-40.

Dibblee, T.W. Jr. (1992), Geologic Map of the Simi Quadrangle, Ventura County, California, Dibblee Geological Foundation Map DF-39.

Fugro West, Inc. (2002), Geotechnical Study, Moorpark Pump Station, Specification No. 418, Calleguas Municipal Water District, Moorpark, California, dated October 5, 1999, revised September 13, 2002, FWI Project Number 95-42-3927 (1212.008).

Greenbook (2009), "Standard Specifications for Public Works Construction", BNI Building News, BNI Publications, Inc.

Howard, A.K., Kinney, L., and Fuerst, R. (1995), "Prediction of Flexible Pipe Deflection," prepared for U.S. Department of the Interior, Bureau of Reclamation, Technical Service Center, Denver, Colorado, January 31.

Kramer, S.L. (2008). "Evaluation of liquefaction hazards in Washington state", Washington State Department of Transportation, Report No. WA-RD 668.1, December.

Nadim, F. and Whitman, R.V. (1992), "Seismic Analysis and Design of Retaining Walls," ASME, OMAE, Volume II, Safety and Reliability.

Pradel, D. (1998), "Procedure to Evaluate Earthquake-Induced Settlements in Dry Sandy Soils," Journal of Geotechnical and Geoenvironmental Engineering, Vol. 124, No. 4, April, pp. 364-368 (erratum in the October 1998 issue).

Seed, H.B. and Whitman, R.V. (1970), "Design of Earth Retaining Structures for Dynamic Loads," ASCE Specialty Conference on Lateral Stresses in the Ground and Design of Earth Retaining Structures, Ithaca, NY, pp. 103-147.

N:\WP\2011\04.61100021\R04.61100021_4-15-11.DOC 27


N:\WP\2011\04.61100021\R04.61100021_4-15-11.DOC 28

Southern California Earthquake Center (SCEC) (1999), “Recommended Procedures for Implementation of DMG Special Publication 117 Guidelines for Analyzing and Mitigating Liquefaction Hazards in California.“

Spangler, M.G. and Handy, R.L. (1982), "Loads on Underground Conduit", Soil Engineering, Harper and Rowe, 4th edition, pp. 727-761.

U.S. Geological Survey (2008a), Interactive Deaggregations website: http://eqint.cr.usgs.gov/deaggint/2008/index.php.

U.S. Geological Survey (2008b), Quaternary Fault and Fold Database Home website: http://earthquake.usgs.gov/hazards/qfaults/imsintro.php

Wu, J. and Seed, R.B. (2004). "Estimation of liquefaction-induced ground settlement (case studies)," Proceedings, Fifth Conference on Case Histories in Geotechnical Engineering, New York, pp.1-8.

Youd, T.L., Idriss, I.M. (2001). "Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liqeufaction Resistance of Soils”, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 127(10), 297-303.

Youd, T.L., Hansen, C.M., and Bartlett, S.F. (2002). "Revised multilinear regression equations for prediction of lateral spread displacement", Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 130(8), 861-871.

http://eqint.cr.usgs.gov/deaggint/2008/index.php

http://earthquake.usgs.gov/hazards/qfaults/imsintro.php

PLATES

APPENDIX A SUBSURFACE EXPLORATION

1

2

3

4

5

13

14

12

14

ARTIFICIAL FILL (af)Silty SAND (SM): loose to medium dense, light olive

brown, moist

- medium dense, few fine gravels, subrounded

Clayey SAND (SC): loose, dark brown, very moist, fewfine gravels, consisting of subrounded rock and brickfragments

ALLUVIUM (Qal)Clayey SAND (SC): loose, dark brown, very moist to wet - loose, very moist

- medium dense, trace fine gravel, subrounded

116

116

115

117

131

132

129

134

(17)

(15)

(13)

(22)

SA

MP

LER

SMATERIAL DESCRIPTION

PLA

ST

ICIT

YIN

DE

X, %

UN

DR

AIN

ED

SH

EA

RS

TR

EN

GT

H, S

u, k

sf

DE

PT

H, f

t

PLATE A-1

UN

IT D

RY

WE

IGH

T, p

cf

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

LIQ

UID

LIM

IT, %

UN

IT W

ET

WE

IGH

T, p

cf

The log and data presented are a simplification of actual conditions encountered at the time of drilling at the drilled location. Subsurface conditions may differ at other locations and with the passage of time.

SA

MP

LE N

O.

MA

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RIA

LS

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VA

TIO

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WA

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, %

% P

AS

SIN

G#2

00 S

IEV

E

SA

MP

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BLO

W C

OU

NT

DEPTH TO WATER: Not Encountered

LOCATION:

DRILLING METHOD: 8-inch-dia. Hollow Stem AugerHAMMER TYPE: Automatic Trip

DRILLED BY: AWD Services, Inc.LOGGED BY: T Curtis

CHECKED BY: G S Denlinger

SURFACE EL: 536 ft +/- (rel. NAVD88 datum)

COMPLETION DEPTH: 11.5 ft

DRILLING DATE: January 14, 2011BACKFILLED WITH: Native Materials

534

532

530

528

526

524

522

520

518

516

514

512

510

508

506

504

See Plate 2

LOG OF DRILL HOLE NO. DH-4

Project No. 04.61100021Perliter & Ingalsbe Engineers

Moorpark Pump Station - Phase 2Moorpark, California

BORING LOG VENTURA N:\PROJECTS\04_2010\04_6110_0021_MOORPARKPUMPSTATION\EXPLORATIONS\GINT\2011\04_6110_0021_VB11B.GPJ 3/3/11 09:09 a

6

7

8

9

10

11

12

13

14

15

1617

18

12

9

8

12

13

11

17

52

49

36

41

ARTIFICIAL FILL (af)Silty SAND (SM): loose, light olive brown, very moist

Clayey SAND (SC): medium dense, dark brown, verymoist, few fine gravels consisting of asphalt, brick,subrounded rock

ALLUVIUM (Qal)Clayey SAND (SC): medium dense, dark brown, slightly

moist, trace sporadic pinhole pores, fine root hairs andfine clayey gravel pockets

Clayey SAND with gravel (SC): medium dense, darkbrown, slightly moist, little fine gravel, subrounded tosubangular, cobble fragment in sample shoe

Sandy Lean CLAY (CL): stiff, brown, slightly moist

Clayey SAND (SC) to Sandy CLAY (CL): medium denseto very stiff, dark brown, moist, trace pin hole pores andblack manganese specs to 1/32"

Silty to Clayey SAND (SM/SC): medium dense, brown,slightly moist, mostly fine sand

- very moist

117

111

116

115

109

131

121

124

130

127

p 2.836

27

27

23

10

8

(24)

15

(34)

21

(57)

23

(28)

11

(22)

SA

MP

LER


PLA

ST

ICIT

YIN

DE

X, %

UN

DR

AIN

ED

SH

EA

RS

TR

EN

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H, S

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DE

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H, f

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PLATE A-2a

UN

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T, p

cf

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

LIQ

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UN

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T, p

cf


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BO

L

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VA

TIO

N, f

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WA

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NT

, %

% P

AS

SIN

G#2

00 S

IEV

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BLO

W C

OU

NT

DEPTH TO WATER: 35.0 ft

LOCATION:







530

528

526

524

522

520

518

516

514

512

510

508

506

504

502

500

See Plate 2





19

20

2122

23

15

15

22

19

20

47

Silty SAND (SM): medium dense, brown, wet, few finegravel, angular

Silty GRAVEL with sand (GM): loose, brown, wet,disturbed due to interference with gravel or cobbles

- dense, some fine to coarse sand

Lean CLAY with sand (CL): very stiff, dark brown, verymoist, sporadic traces black manganese specs

Clayey SAND (SC): medium dense, brown, wet, few finegravels

118

104

136

127

19

37

NP

23

13

(32)

30

(24)

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EA

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H, f

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PLATE A-2b

UN

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IGH

T, p

cf

34

36

38

40

42

44

46

48

50

52

54

56

58

60

62

64

66

LIQ

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UN

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ET

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T, p

cf


SA

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MA

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LS

YM

BO

L

ELE

VA

TIO

N, f

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WA

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NT

, %

% P

AS

SIN

G#2

00 S

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DEPTH TO WATER: 35.0 ft

LOCATION:







498

496

494

492

490

488

486

484

482

480

478

476

474

472

470

468

466

See Plate 2





24A

24B

25

26

27

28

29

30

12

6

16

14


brown, very moist

ALLUVIUM (Qal)Clayey SAND (SC): medium dense, dark brown, moist,

trace fine gravel, subanguler

Clayey SAND to Sandy Lean CLAY (SC-CL): mediumdense or very stiff, dark brown, moist, trace fine gravelsubangular

stiff, moist, mostly sandy lean CLAY (CL)

- dense or very stiff, moist

- medium dense, moist, mostly clayey SAND (SC)

Silty SAND (SM): dense, brown, moist, few fine gravels,subangular to subrounded

119

112

116

116

133

119

134

133

p 4.0

p 4.5

p 4.0

(23)

(30)

20

(36)

9

(27)

17

(61)

SA

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PLA

ST

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YIN

DE

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UN

DR

AIN

ED

SH

EA

RS

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EN

GT

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sf

DE

PT

H, f

t

PLATE A-3

UN

IT D

RY

WE

IGH

T, p

cf

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

LIQ

UID

LIM

IT, %

UN

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T, p

cf


SA

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LS

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BO

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VA

TIO

N, f

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WA

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, %

% P

AS

SIN

G#2

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IEV

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SA

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LER

BLO

W C

OU

NT


LOCATION:







532

530

528

526

524

522

520

518

516

514

512

510

508

506

504

502

500

See Plate 2





31

32

33A33B

34

7


brown, very moist, few fine gravels, subrounded

- medium dense, moist

ALLUVIUM (Qal)Clayey GRAVEL (GC): medium dense to dense, moist,

possible cobble zone to 9 feet

- at 7.5'; no recovery with mod-cal sampler or re-drivenSPT sampler, coarse gravel or cobble fragements in sptsample shoe

Clayey SAND with gravel (SC): medium dense, darkbrown, slightly moist, little fine to coarse gravel, possiblecobbles, fragments are angular to subangular

- at 13'; trace fine gravel

26

(18)

(22)

22

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DE

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UN

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H, f

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PLATE A-4

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T, p

cf

2

4

6

8

10

12

14

16

18

20

22

24

26

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30

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T, p

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, %

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LOCATION:




SURFACE EL: 531.5 ft +/- (rel. NAVD88 datum)



530

528

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See Plate 2





PLATE A-5

Perliter & Ingalsbe EngineersProject No. 04.61100021

10

Symbol for:

CA Liner Sampler, driven

Vibracore Sample

Pitcher Sample

Lexan Sample

BASALT

Sonic Soil Core Sample

No Sample Recovered

CA Liner Sampler, Bagged

13

(25)

6

11

4

Poorly graded SAND (SP)

COARSE

GRAINED

MATERIAL DESCRIPTION

Silty CLAY (CL-ML)

Silty SAND (SM)

Paving and/or Base Materials

SANDSTONE

Poorly graded GRAVEL (GP)

MUDSTONE

SY

MB

OL

SILTSTONE

Well graded SAND (SW)

Fat CLAY (CH)

MA

TE

RIA

L

SA

MP

LE N

O.

Hand Auger Sample

ANDESITE BRECCIA

7

9

5

Thin-walled Tube, pushed

CONGLOMERATE

3

FINE

GRAINED

ROCK

-12

-14

-16

-18

-20

-22

-24

-26

-28

-30

-32

-34

-36

-38

-40

-42

-44

-46

-48

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

34

36

38

25

Silty, Clayey SAND (SC-SM)

(25)

Elastic SILT (MH)

(25)

(25)

Lean CLAY (CL)

Sampler Driving Resistance

p = Pocket Penetrometer

Q = Unconfined Compressionu = Unconsolidated Undrained Triaxial

Initial or perched water level

Seepages encounteredFinal ground water level

Bulk Bag Sample (from cuttings)

Number of blows with 140 lb. hammer, falling30" to drive sampler 1 ft. after seatingsampler 6"; for example,

CLAYSTONE

LOCATION:

SILT (ML)

2

5

13

9

1

8

7

SA

MP

LES

Clayey SAND (SC)

The drill hole location referencing locallandmarks or coordinates

Well graded GRAVEL (GW)B

LOW

CO

UN

T /

t = Torvane

Blows/ft Description

25

Blow counts for California Liner Samplershown in ( )

Geologic Formation noted in bold font atthe top of interpreted interval

Classification of Soils per ASTM D2487 orD2488

Strength Legend

Length of sample symbol approximatesrecovery length

Water Level Symbols

SURFACE EL: Using local, MSL, MLLW or other datum

KEY TO TERMS & SYMBOLS USED ON LOGS

12

m = Miniature Vane

Samplers and sampler dimensions

Soil Texture Symbol

General Notes

Sloped line in symbol column indicatestransitional boundary

(unless otherwise noted in report text) are as follows:

3 CA Liner Sampler, disturbed

11

1 SPT Sampler, driven

6

8

2

4

CME Core Sample

12

10

BORING LOG KEY VENTURA N:\PROJECTS\04_2010\04_6110_0021_MOORPARKPUMPSTATION\EXPLORATIONS\GINT\2011\04_6110_0021_VB11B.GPJ 2/15/11 02:32 p

30"/30"

20"/24"

DE

PT

H, f

t

RE

C"/

DR

IVE

"

18"/30"

20"/24"

ELE

VA

TIO

N, f

t

50 blows drove sampler 3" duringinitial 6" seating interval

Ref/3"

50 blows drove sampler 6" afterinitial 6" of seating

After driving sampler the initial 6"of seating, 36 blows drovesampler through the second 6"interval, and 50 blows drove thesampler 5" into the third interval

50/6"

86/11"

25 blows drove sampler 12" afterinitial 6" of seating

Rock Quality Designation (RQD) is thesum of recovered core pieces greater than4 inches divided by the length of the coredinterval.

1-3/8" ID, 2" OD

2-3/8" ID, 3" OD

2-3/8" ID, 3" OD

2-7/8" ID, 3" OD

APPENDIX B LABORATORY TEST RESULTS

DH-4 3.0 2 Silty SAND (SM) 131 116 13

DH-4 6.0 3 Clayey SAND (SC) 132 116 14

DH-4 8.5 4 Clayey SAND (SC) 129 115 12

DH-4 11.0 5 Clayey SAND (SC) 134 117 14

DH-5 3.5 7 Clayey SAND (SC) 131 117 12

DH-5 8.5 9 Clayey SAND (SC) 121 111 9

DH-5 11.5 11 Clayey SAND (SC) 130.0 9.0 2279 7.70 3 <5

DH-5 13.5 12 Clayey SAND with gravel (SC) 124 116 8

DH-5 16.0 13 Sandy Lean CLAY (CL) 12 52

DH-5 21.0 14 Clayey SAND (SC) 130 115 13 49 36 23

DH-5 26.1 17 Clayey SAND (SC) 11 36 27 10

DH-5 31.0 18 Clayey SAND (SC) 127 109 17 41 27 8

DH-5 36.0 19 Silty SAND (SM) 15 19 19 NP

DH-5 41.0 20 Silty GRAVEL with sand (GM) 136 118 15 20

DH-5 46.0 22 Lean CLAY with sand (CL) 37 23

DH-5 51.0 23 Clayey SAND (SC) 127 104 22 47

DH-6 3.0 24A Silty SAND (SM) 133 119 12

DH-6 6.0 24B Clayey SAND (SC) 119 112 6

DH-6 13.5 26 Clayey SAND to Sandy Lean CLAY (SC-CL) 134 116 16

DH-6 18.5 28 Clayey SAND to Sandy Lean CLAY (SC-CL) 133 116 14

DH-7 10.0 33A Clayey SAND with gravel (SC) 7

SA

MP

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EX

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NS

ION

IND

EX

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AC

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ES

T

SU(Cell Prs.)

ksfQu,ksf

CksfPI

MC%

UDWpcf

SA

ND

EQ

UIV

ALE

NT

(SE

)

SP

EC

IFIC

GR

AV

ITY

R-V

ALU

E

CO

MP

RE

SS

IVE

ST

RE

NG

TH

TE

ST

S

PHIdeg

SUMMARY OF LABORATORY TEST RESULTS

So4

(ppm)

LA

B S

UM

MA

RY

TA

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EN

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RA

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TS

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-cab

FINES%

MAXDDpcf

AT

TE

RB

ER

GLI

MIT

S

DE

PT

H, f

t


DRILLHOLE

LL

UWWpcf

OPTMC%

DIR

EC

TS

HE

AR

ClR pH

CORROSIVITY TESTS

PLA

TE

B-1


Project N

o. 04.61100021P

erliter & Ingalsbe E

ngineers

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100

21.0

26.1

31.0

36.0

46.0

DH-5

DH-5

DH-5

DH-5

DH-5

36

27

27

19

37

CH or OH

CL or OL

ML or OL

MH or OH

LEGENDlocation

LIQUID LIMIT (LL)

PLASTICITYLIQUIDLIMIT(LL)

PLASTICLIMIT(PL)

Clayey SAND (SC)

Clayey SAND (SC)

Clayey SAND (SC)

Silty SAND (SM)

Lean CLAY with sand (CL)

depth, ft

ATTERBERG LIMITS TEST RESULTS

PLA

ST

ICIT

Y IN

DE

X (

PI)

INDEX (PI)CLASSIFICATION

CL-ML

PLASTICITY CHART

PLATE B-2

13

17

19

19

14

23

10

8

NP

23

PLASTICITY CHART VENTURA N:\PROJECTS\04_2010\04_6110_0021_MOORPARKPUMPSTATION\EXPLORATIONS\GINT\2011\04_6110_0021_VB11B.GPJ 2/15/11 02:35 p



100

105

110

115

120

125

130

135

0 5 10 15 20 25

OPTIMUM WATERCONTENT, %

MOISTURE CONTENT, %

UN

IT D

RY

WE

IGH

T, p

cf

LEGENDMAXIMUM UNIT

DRY WEIGHT, pcf

Test Method: ASTM D1557(Gs = 2.65 to 2.75)

CLASSIFICATION

130.0 9.0

depth, ft

PLATE B-3

COMPACTION TEST RESULTS

(location)

Clayey SAND (SC)

ZERO AIR VOIDS CURVES

11.5DH-5

COMPACTION TEST VENTURA N:\PROJECTS\04_2010\04_6110_0021_MOORPARKPUMPSTATION\EXPLORATIONS\GINT\2011\04_6110_0021_VB11B.GPJ 2/15/11 02:54 p



0

2

4

6

8

10

12

14

16

18

20

22

24

26

28

300.1 1 10 100

DEPTH, ftLOCATION

INITIAL MOISTURE CONTENT, %


16

DH-6

SAMPLE CONDITION

113Clayey SAND (SC)

VERTICAL EFFECTIVE PRESSURE, ksf

ST

RA

IN, %

UNIT DRY WEIGHT, pcf

18.5

PLATE B-4

CONSOLIDATION TEST RESULTS

CONSOLIDATION TEST VENTURA O:\MANAGEMENT\04_2010\04_6110_0021_ MOORPARK_PUMP_STATION\04_LAB DATA\04.6110.0021_SLO_LAB_2-4-11.GPJ 2/15/11 02:37 p



APPENDIX C FUGRO (2002) GEOTECHNICAL STUDY DATA

MOORPARK PUMP STATION - PHASE 1

APPENDIX D LIQUEFACTION EVALUATION


Liquefaction Hazard Evaluation Report by WSLiq Program beta (May, 2009) --------------------------------------------------- Site Name: Moorpark Pump Station - Phase 2 (Drill Hole DH-2) Site Location (N,W) = 34.275 , 118.874 Job No: 04.61100021 Analyst: T.Curtis Date: 4/11/2011 8:26:26 AM --------------------------------------------------- === Soil Profile === Unit: ft The number of soil layers: 12 GWT at top of layer: 10 GWT depth: 34.00 SPT Energy Ratio (%): 85.00 Amplification Factors: a= -0.1500 b= -0.1300 Elevation: 531.00 Ground Surface: Level Layer Descpt. Thickness Unit Weight Nm N160 Vs (ft) (lb/ft3) ft/sec 1 Silty_Sand 2 130.00 20 48.2 870.3 2 Lean_Clay 3 95.00 8 19.3 667.2 3 Clayey_Sand 5 124.00 9 20.1 690.4 4 Clayey_Sand 5 124.00 14 23.8 784.8 5 Lean_Clay 5 125.00 20 28.5 870.3 6 Clayey_Sand 5 138.00 22 27.3 894.7 7 Clayey_Sand 5 138.00 44 48.9 1093.9 8 Poorly-graded_Sand 1 125.00 20 21.0 870.3 9 Clayey_Sand 3 125.00 11 11.2 731.8 10 Clayey_Sand 6 125.00 11 10.7 731.8 11 Clayey_Sand 5 125.00 14 13.1 784.8 12 Clayey_Sand 5 125.00 16 14.6 815.8 Layer FC PI wc/LL D50 Ini. Eff. Ini. Total (%) (mm) Stress (psf) Stress (psf) 1 20 Unsat Unsat 0.000 130.0 130.00 2 50 Unsat Unsat 0.000 402.5 402.50 3 39 Unsat Unsat 0.000 855.0 855.00 4 39 Unsat Unsat 0.000 1475.0 1475.00 5 51 Unsat Unsat 0.000 2097.5 2097.50 6 30 Unsat Unsat 0.000 2755.0 2755.00 7 12 Unsat Unsat 0.000 3445.0 3445.00 8 5 Unsat Unsat 0.000 3852.5 3852.50 9 44 Unsat Unsat 0.000 4102.5 4102.50 10 44 14 0.66 0.000 4477.8 4665.00 11 44 14 0.66 0.000 4822.1 5352.50 12 47 14 0.66 0.000 5135.1 5977.50


Soil Profile Plots


=== Susceptibility Evaluation === ------------------------------------------------------- Threshold: 0.5 Weighting factors: B-I= 0.50 B-S= 0.50 ------------------------------------------------------- Layer PI wc/LL B-I B-S Suscep. Index Potential 1 20.00 0.50 0.00 0.00 0.00 NO 2 20.00 0.50 0.00 0.00 0.00 NO 3 20.00 0.50 0.00 0.00 0.00 NO 4 20.00 0.50 0.00 0.00 0.00 NO 5 20.00 0.50 0.00 0.00 0.00 NO 6 20.00 0.50 0.00 0.00 0.00 NO 7 20.00 0.50 0.00 0.00 0.00 NO 8 20.00 0.50 0.00 0.00 0.00 NO 9 20.00 0.50 0.00 0.00 0.00 NO 10 14.00 0.66 0.01 0.10 0.06 NO 11 14.00 0.66 0.01 0.10 0.06 NO 12 14.00 0.66 0.01 0.10 0.06 NO


=== Initiation === --------------------------------------------------- Initiation - Single Scenario ----------------------------------------- Models Selected : NCEER (Youd et al.) Model ----------------------------------------- ---NCEER Model------------ --- PGA = 0.540 Mw = 6.80--------- Layer (N1)60 CSR CRR FS Nreq ----- ------ ------ ------ ------ ------ Table of FS --------------------------------------- # Depth NCEER ft


=== Effects === --------------------------------------------------- ** Settlement ** ---------------- >>>Single Scenario Results Groud Surface Settlement SINGLE Scenario Model Selected : Tokimatsu & Seed Model ----------------------------------------- Tokimatsu & Seed ================= Total ground surface settlement = 0.00 ft ---------------------------------------------- # Depth thickness ev Weight dh ft ft % ft ---------------------------------------------- 10 37.00 6.0 0.001 0.00 0.00 11 42.50 5.0 0.001 0.00 0.00 12 47.50 5.0 0.001 0.00 0.00 ----------------------------------------------


Liquefaction Hazard Evaluation Report by WSLiq Program beta (May, 2009) --------------------------------------------------- Site Name: Moorpark Pump Station - Phase 2 (Drill Hole DH-5) Site Location (N,W) = 34.275 , 118.874 Job No: 04.61100021 Analyst: T.Curtis Date: 4/11/2011 8:31:41 AM --------------------------------------------------- === Soil Profile === Unit: ft The number of soil layers: 14 GWT at top of layer: 10 GWT depth: 35.00 SPT Energy Ratio (%): 85.00 Amplification Factors: a= -0.1500 b= -0.1300 Elevation: 532.00 Ground Surface: Level Layer Descpt. Thickness Unit Weight Nm N160 Vs (ft) (lb/ft3) ft/sec 1 Silty_Sand 3.5 131.00 15 36.1 800.7 2 Clayey_Sand 1.5 131.00 15 36.1 800.7 3 Clayey_Sand 5 121.00 15 31.6 800.7 4 Clayey_Sand 3.5 121.00 21 35.7 882.7 5 Clayey_Sand_with_gravel 2.5 124.00 35 53.2 1023.7 6 Lean_Clay_with_sand 4 125.00 23 31.6 906.3 7 Clayey_Sand 5 130.00 17 20.9 830.3 8 Silty_to_Clayey_Sand 5 127.00 11 12.2 731.8 9 Silty_to_Clayey_Sand 5 127.00 14 14.3 784.8 10 Silty_Sand 5 130.00 13 12.5 768.1 11 Silty_Gravel_with_sand 3 136.00 20 18.7 870.3 12 Silty_Gravel_with_sand 3 136.00 30 27.4 978.9 13 Lean_Clay_with_sand 4 125.00 30 26.8 978.9 14 Clayey_Sand 1 127.00 15 13.2 800.7 Layer FC PI wc/LL D50 Ini. Eff. Ini. Total (%) (mm) Stress (psf) Stress (psf) 1 15 Unsat Unsat 0.000 229.3 229.25 2 30 Unsat Unsat 0.000 556.8 556.75 3 30 Unsat Unsat 0.000 957.5 957.50 4 30 Unsat Unsat 0.000 1471.8 1471.75 5 30 Unsat Unsat 0.000 1838.5 1838.50 6 52 Unsat Unsat 0.000 2243.5 2243.50 7 49 Unsat Unsat 0.000 2818.5 2818.50 8 36 Unsat Unsat 0.000 3461.0 3461.00 9 41 Unsat Unsat 0.000 4096.0 4096.00 10 19 0 .79 0.000 4582.5 4738.50 11 20 0 .79 0.000 4861.9 5267.50 12 20 0 .79 0.000 5082.7 5675.50 13 50 23 .62 0.000 5318.3 6129.50 14 47 23 .59 0.000 5475.8 6443.00


Soil Profile Plots


=== Susceptibility Evaluation === ------------------------------------------------------- Threshold: 0.5 Weighting factors: B-I= 0.50 B-S= 0.50 ------------------------------------------------------- Layer PI wc/LL B-I B-S Suscep. Index Potential 1 20.00 0.50 0.00 0.00 0.00 NO 2 20.00 0.50 0.00 0.00 0.00 NO 3 20.00 0.50 0.00 0.00 0.00 NO 4 20.00 0.50 0.00 0.00 0.00 NO 5 20.00 0.50 0.00 0.00 0.00 NO 6 20.00 0.50 0.00 0.00 0.00 NO 7 20.00 0.50 0.00 0.00 0.00 NO 8 20.00 0.50 0.00 0.00 0.00 NO 9 20.00 0.50 0.00 0.00 0.00 NO 10 0.00 0.79 1.00 0.44 0.72 YES 11 0.00 0.79 1.00 0.44 0.72 YES 12 0.00 0.79 1.00 0.44 0.72 YES 13 23.00 0.62 0.00 0.01 0.01 NO 14 23.00 0.59 0.00 0.01 0.00 NO


=== Initiation === --------------------------------------------------- Initiation - Single Scenario ----------------------------------------- Models Selected : NCEER (Youd et al.) Model ----------------------------------------- ---NCEER Model------------ --- PGA = 0.540 Mw = 6.80--------- Layer (N1)60 CSR CRR FS Nreq ----- ------ ------ ------ ------ ------ 10 12.5 0.211 0.150 0.71 19.6 11 18.7 0.209 0.214 1.02 19.6 12 27.4 0.207 3.000 14.48 19.4 Table of FS --------------------------------------- # Depth NCEER ft 10 -37.50 0.71 11 -41.50 1.02 12 -44.50 14.48


=== Effects === --------------------------------------------------- ** Settlement ** ---------------- >>>Single Scenario Results Groud Surface Settlement SINGLE Scenario Model Selected : Tokimatsu & Seed Model ----------------------------------------- Tokimatsu & Seed ================= Total ground surface settlement = 0.08 ft ---------------------------------------------- # Depth thickness ev Weight dh ft ft % ft ---------------------------------------------- 10 37.50 5.0 1.610 1.00 0.08 11 41.50 3.0 0.000 1.00 0.00 12 44.50 3.0 0.000 0.00 0.00 13 48.00 4.0 0.001 0.00 0.00 14 50.50 1.0 0.001 0.00 0.00 ----------------------------------------------

geotechnical study moorpark pump station - phase 2...

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