Murrieta City Council
May 20, 2025

GEOTECHNICAL EVALUATION

MULTI-FAMILY DEVELOPMENT, WHITEWOOD I

NE CORNER WHITEWOOD ROAD AND CLINTON

KEITH ROAD

MURRIETA, CALIFORNIA

Prepared For SANCERRA MANAGEMENT, LLC
2618 SAN MIGUEL DRIVE, SUITE 1223
Newport Beach, Ca 92660
Prepared By LEIGHTON AND ASSOCIATES, INC.
41715 ENTERPRISE CIRCLE N SUITE 103
TEMECULA, CA 92590
Project Number 13142.005
July 20, 2023

July 20,
2023
Project No. 13142.005
Sancerra Management, LLC
2618 San Miguel Drive, Suite 1223
Newport Beach, California 92660
Attention: Mr. Adam Smith
Subject: G eotechnical Evaluation
Multi-Family Development - Whitewood I
NE Corner Whitewood Road and Clinton Keith Road
Murrieta, California
In acc
ordance with our proposal dated May 3, 2022, we are pleased to present this report summarizing our geotechnical evaluation of the subject project . We understand that Sancerra Management is looking to develop this property for construction of multi-family residential structures.

Based on our review, the subject site appears feasible from a geotechnical perspective provided our recommendations included herein are implemented during design and construction phases. However, bedrock rippability and resulting production and disposal of oversize materials generated during anticipated earthwork may present significant impacts on construction/grading cost. The magnitude of this geologic/grading concern can be better defined when site grading plans are developed.

We apprec
iate this opportunity to be of service. If you have any questions regarding this report, please call us at your convenience.

Respectfully submitted,
LEIGHTON AND ASSOCIATES, INC.

Joe Roe, CEG
Sr. Principal Geologist/PM
[email protected]
Simon I. Saiid, GE
Senior Principal Engineer
[email protected]
Distribution: (1) addressee (pdf via email)
Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

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TABLE OF CONTENTS
Section Page

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

1.1 Purpose and Scope ................................................................................... 1

1.2 Site and Project Description ....................................................................... 1

1.2.1 Summary ......................................................................................................... 1

1.2.2 Project Location ............................................................................................... 2

1.2.3 Project Setting and Surrounding Land Uses ................................................... 2

1.2.4 Project Description .......................................................................................... 2

2.0 FIELD EXPLORATION ........................................................................................ 3

2.1 Field Exploration ........................................................................................ 3

2.2 Laboratory Testing ..................................................................................... 3

3.0 GEOLOGIC SETTINGS ....................................................................................... 4

3.1 Regional Geology ...................................................................................... 4

3.2 Subsurface Soil Conditions ........................................................................ 4

3.2.1 Undocumented fill (not mapped) ..................................................................... 4

3.2.2 Topsoil/Colluvium (not mapped) ...................................................................... 5

3.2.3 Surficial Materials (Topsoil/Residual Soils/Alluvial Deposits) .......................... 5

3.2.4 Cretaceous-age Granitic Rock (Kgr ) ............................................................. 5

3.3 Surface and Groundwater .......................................................................... 6

3.4 Rippability .................................................................................................. 6

3.5 Faulting ...................................................................................................... 7

3.6 Ground Shaking / 2019 CBC Site-Specific Seismic Coefficients ............... 7

3.7 Secondary Seismic Hazards ...................................................................... 8

3.7.1 Dynamic Settlement (Liquefaction and Dry Settlement) .................................. 8

3.8 Collapsible Soils ........................................................................................ 8

3.9 Erosion ....................................................................................................... 9

3.10 Slope Stability ............................................................................................ 9

3.11 Infiltration Rates ......................................................................................... 9

4.0 SUMMARY OF CONCLUSIONS AND RECOMMENDATIONS ......................... 10

4.1 General .................................................................................................... 10

4.2 Earthwork ................................................................................................. 10

4.2.1 Site Preparation and Remedial Grading ........................................................ 10

4.2.2 Cut Lots ......................................................................................................... 11

4.2.3 Suitability of Site Soils for Fills ....................................................................... 11

4.2.4 Oversize Rock ............................................................................................... 12

4.2.5 Shrinkage and Bulking ................................................................................... 12

4.2.6 Utility Trenches .............................................................................................. 13

4.2.7 Drainage ........................................................................................................ 13

4.2.8 Slope Construction ........................................................................................ 14 Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

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4.3 Preliminary Foundation Design ................................................................ 14

4.3.1 Design Parameters – Spread/Continuous Shallow Footings ......................... 14

4.3.2 Vapor Retarder .............................................................................................. 15

4.3.3 Settlement Estimates ..................................................................................... 15

4.4 Retaining Walls ........................................................................................ 15

4.5 Foundation Setback from Slopes ............................................................. 16

4.6 Geochemical Characteristics ................................................................... 17

4.7 Concrete Flatwork .................................................................................... 18

4.8 Preliminary Pavement Design Parameters .............................................. 18

4.9 Continued Geotechnical Services ............................................................ 19

5.0 LIMITATIONS ..................................................................................................... 20 REFERENCES .............................................................................................................. 21

LIST OF TABLES
TABLE 1 - 2019 CBC SEISMIC COEFFICIENTS PER USGS GENERAL PROCEDURE ............................. 8 TABLE 2 - SUMMARY OF INFILTRATION TEST RESULTS (ADD TABLE # AND FIX FONT) .......................... 9 TABLE 3 - EARTHWORK SHRINKAGE ESTIMATES ............................................................................. 12 TABLE 4 - RETAINING WALL DESIGN EARTH PRESSURES (STATIC, DRAINED) .................................. 16 TABLE 5 - FOOTING SETBACKS ...................................................................................................... 17 TABLE 6 - ASPHALT PAVEMENT SECTIONS ..................................................................................... 18

ATTACHMENTS
Figure 1 – Site Location Map
Figure 2 – Regional Geology Map
Figure 3 – Expl oration Location Map

Appendix A – Geotechnical Field Explorations
Appendix A-1 – Logs of Exploratory Borings – This Study Appendix A-2 – Seismic Refraction Survey
Appendix A-3 – Exploration Logs – Previous Studies

Appendix B – Geotechnical Laboratory Testing
Appendix B-1 – This Study
Appendix B-2 – Previous Studies

Appendix C – Percolation Test Data
Appendix D – General Earthwork and Grading Specifications Appendix E– GBA Important Information about This Geotechnical Engineering Report Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

1 1.0 INTRODUCTION

1.1 Purpose and Scope
This update geotechnical evaluation report is for the proposed Whitewood I Multi-family Residential Development, located northeast of the intersection of Whitewood Road and Clinton Keith Road, in Murrieta, California. Our scope of services for this geotechnical report included the following:
 Review of previous site-specific geotechnical reports and other available geologic information and relevant publications listed in the references at the end of this report.  Site markout, utility clearance, and excavation of eight (8) backhoe excavated test trenches across the site, visually logged by a engineering geologist from our technical staff. Approximate locations of these exploratory excavations along with previous explorations (Leighton, 2006) are depicted on Figure 3, Exploration Location Map. The logs of test pits are presented in Appendix A, Geotechnical Field Explorations.
 Laboratory testing was performed on representative samples collected during the field exploration. Test results along with previous testing are included in Appendix B, Geotechnical Laboratory Testing.
 Infiltration/percolation testing at current ground surface at four (4) representative site locations, P-1 through P-4, see Figure 3. Results of percolation testing are included in Appendix C, Percolation Test Data.
 Due to the presence of granitic rock in areas of potential deep excavations, a preliminary rock rippability/geophysical study performed by a subcontracted geophysical consulting firm to further evaluate bedrock rippability. The geophysical study is included in Appendix A-2, Seismic Refraction Survey.  Geotechnical engineering review and analyses performed or as directed by a California Registered Geotechnical Engineer (GE). A Certified Engineering Geologist (CEG) performed engineering geology review of site geologic hazards.  Preparation of this report, which presents the results of our geotechnical review and preliminary recommendations for foundation design and earthwork construction.

This report is not intended to be used as an environmental site assessment (Phase I ESA or other). A Phase I ESA is being prepared by Leighton and will be submitted under a separate cover.

1.2 Site and Project Description

1.2.1 Summary
The Project site comprises 17.26 acres of land designated by the City of Murrieta for Multiple-Family Residential land uses. The discretionary approval associated with the Project includes a Development Plan Permit and Tentative Tract Map. The Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

2 Development Plan Permit establishes the building layout and architecture proposed for the Project. Approval of the Development Plan Permit and Tentative Tract Map would allow for development of the property with 243 multi-family residential dwelling units and an amenity area.

1.2.2 Project Location
The Project site consists of approximately 17.26 acres in the northeastern portion of the City of Murrieta. From a regional perspective, the Project site is located 0.26 mile west of the French Valley area of unincorporated Riverside County. Interstate 215 (I-215) is located 0.6 mile west of the Project site. Specifically, the Project site is located east of Whitewood Road, north of Clinton Keith Road. The Project site encompasses Assessor’s Parcel Numbers (APNs) 392-330-003, -007, -020, and - 021.

1.2.3 Project Setting and Surrounding Land Uses
The Project site contains two existing residences in the eastern half of site and the western half of the site is undeveloped. Elevations range between approximately 1,385 feet above mean sea level (amsl) in the southeast corner to 1,480 feet amsl along the western boundary.

To the west of the Project site is an existing residential development. North and east of the Project site are several existing homes. South of the Project site is undeveloped land designated for multiple-family residential land uses.

1.2.4 Project Description
The Project consists of a Development Plan Permit and Tentative Tract Map on a

17.26 acre site. The Project would provide for development of 243 multi-family residential homes at a density of 15.1 dwelling units per acre (du/ac). The Project also includes construction of a recreational pool area with a ±900sf restroom and pool equipment building, tot lot and 65,120 SF of total common open space areas throughout the site. . The proposed 243 dwelling unit project consists of 2- and 3- story townhomes. A total of 629 parking spaces would be provided with 10% of spaces designated as future electric vehicle (EV) spaces. Grading proposed by the Project would result in 16.93 acres of disturbance t o the Project sitewith the balance of the land remaining undiustrubed. Access to the Project would be provided by two (2) full access driveways, one located on Arendt Lane, and the other located on Whitewood Road. The project will also construct a ±12” offsite EMWD master plan sewer line within Arendt Lane, continuing easterly within Clinton Keith Road and terminating near the northwest corner of Clinton Keith Road and Menifee Road.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

3 2.0 FIELD EXPLORATION

2.1 Field Exploration
As a part of this geotechnical update, we performed a geologic reconnaissance and supplemental subsurface evaluation to further review near surface soil and bedrock characteristics. During this supplemental exploration, eight (8) backhoe trenches were excavated at selected areas of the site, see Figure 3. Bulk samples were obtained from the excavations for laboratory testing and evaluation. Logging and sampling of the trenches was performed by an engineering geologist from our office. The logs of trenches are presented in Appendix A of this report. The approximate locations of these exploratory excavations along with pertinent information from previous studies are shown on Figure 3, Exploration Location Map. After logging and sampling, the excavations were loosely backfilled with materials generated during excavation and wheel rolled.

During the field phase of investigation, infiltration/percolation testing were also performed at four (4) representative testing locations within the site , see Figure 3 for locations of infiltration borings P-1 through P-4. Results of percolation testing are included in Appendix C.

A seismic refraction survey was performed by Atlas Geophysics in areas of anticipated bedrock grading cuts within the central and eastern portions of the site. The purpose of their survey was to further evaluate the general depth to and rippability of resistant granitic bedrock. The results of this geophysical study are discussed in section 3.4 and a detailed report presenting the results are provided in Appendix A-2.

2.2 Laboratory Testing
Laboratory tests were performed on representative bulk samples to provide a basis for development of remedial earthwork and geotechnical design parameters. Selected samples were tested to determine the following parameters: Gradation/sieve analysis (ASTM D 6913), expansion potential (ASTM D 4829), R-value (ASTM D 2844), Atterberg Limits (ASTM D 4318) and corrosion potential (DOT CA 417, 422, 643) . Results of our laboratory testing are presented in Appendix B.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

4 3.0 GEOLOGIC SETTINGS

3.1 Regional Geology
The subject property is located within the Peninsular Ranges, a prominent natural geomorphic province comprising the southwestern part California. It is generally characterized by northwestward-trending, steep, elongated ranges and valleys.

Specifically, this site is situated in the southwestern portion of the stable Perris Block, an eroded mass of Cretaceous and older crystalline and metamorphic bedrock. Thin sedimentary, metamorphic and volcanic units locally mantle the bedrock with alluvial deposits filling in the lower valley and drainage areas.

The Perris Block is bounded by the San Jacinto fault zone to the northeast, the Elsinore fault zone to the southwest, the east-west compressional faults of the Transverse Ranges Physiographic Province to the north, and to the southeast by the poorly defined northern edge of the Temecula Basin.

Published geologic maps (References), and reports by Leighton (2006) as well as our site-specific geologic mapping and exploration indicate that surface and subsurface materials within this site predominately consist of artificial fill, residual topsoil/colluvium , local deposits of shallow alluvium, and granitic bedrock comprised of Cretaceous-age granodiorite and gabbro, see Figure 2, Regional Geology Map for the site and surrounding geologic units. Test pit logs (TP -1 through 8) and seismic velocity profiles (SL-1 through SL-3) conducted specific to this area are shown on Figure 3, Exploration Location Map, the accompanying data is presented in Appendix A.

3.2 Subsurface Soil Conditions
Based on our exploration and interpretation of recovered samples and bedrock outcrops, the site is locally mantled with thin deposits of topsoil/residual soils/alluvium underlain by granitic bedrock at shallow depth. Granitic bedrock cropping out at the surface was observed in some areas of the site. Thin alluvial deposits locally infill some topographic depressions and drainages. Cleared of debris and oversized materials, these surficial materials and weathered bedrock may be re-used and incorporated as fill during grading.

Descriptions of the earth materials encountered during this investigation are presented on the logs in Appendix A and further described below.

3.2.1 Undocumented fill (not mapped)
Although not encountered, undocumented fill is anticipated around all existing (and abandoned) building pads, roadways, and utility lines. This fill is expected to have been generated from onsite/local sources and consist of similar materials to the underlying deposits.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

5 3.2.2 Topsoil/Colluvium (not mapped)
Highly weathered residual soils and colluvial deposits mantle weathered bedrock locally across the site. These surface deposits are generally thin (0.5 to 3 ft.) and often grade downward into less weathered bedrock material. See test pit logs in Appendix A.

3.2.3 Surficial Materials (Topsoil/Residual Soils/Alluvial Deposits) Native deposits of topsoil/residual soils and alluvial deposits are anticipated at the ground surface and localized topographic depressions/drainages and may extend to a depth of 5 feet bgs (see TP-4). The materials generally consist of relatively loose silty to clayey sands and sandy clay with variable amounts of gravel and cobbles (and potential boulders ). Based on our observations and experience, these materials are potentially compressible and considered unsuitable for support of settlement-sensitive structures and/or additional engineered fill. Based on our laboratory testing, these material possess very low to l ow expansion potential (EI<51).

3.2.4 Cretaceous-age Granitic Rock (Kgr )
The majority of the project area is underlain by Cretaceous-aged granitic bedrock.

The igneous bedrock varies in composition from that of monzogranite and granodiorite to that of gabbro. As observed during our field investigation, the condition of the near-surface bedrock varies from that of highly disintegrated rock that has weathered becoming soil -like deposits (regolith) to that of relatively unweathered, hard, very dense, igneous rock. Where exposed, the rocks of granodiorite composition are generally gray to grayish brown in color and gabbroic bedrock is generally gray to dark gray.

Variability of the rock composition exposed to climatic processes acting on the bedrock over time appear to control the thickness of the weathered zone. Because of this, the hardness of the near -surface bedrock is considerably variable within the site. Some test pits were unable to be advance deeper than a foot from the current surface with a conventional rubber-tired backhoe (John Deere 310) in good working condition. In other areas, the weathered zone was quite thick and our excavations and existing road cuts were able to extend over 10 feet in depth below the ground surface. Severely weathered bedrock (expected in upper 2 feet bgs) is considered unsuitable for support of engineered fill loads and/or improvements in its current state and should be removed and replaced as compacted fill.

Due to the locally shallow depth to resistant bedrock, oversize materials will be generated during the grading process. Any rocks over 12 inches in maximum dimension are considered to be oversized and must be handled in accordance with Section 4.2.4 of this report.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

6 3.3 Surface and Groundwater
No surface water was observed at the time of our exploration. Several unnamed ephemeral drainages have formed small washes or canyons that generally drain to the east through the site. Historic groundwater in the vicinity of the subject site is reported to be between approximately 25 to 35 feet below the surface (State of California, Station 336034N1171668W001). Groundwater levels can be expected to fluctuate seasonally within the area and local perched groundwater may be encountered at the transition to impermeable bedrock.

3.4 Rippability
The hummocky landforms and surface outcrops of resistant rock indicate the bedrock is variable in composition and degree of weathering and thus non-uniform in its hardness and resistance to excavation (rippability). Based on these observations and Leighton’s previous work in the area (See References), the rippability and resulting production and disposal of oversize materials generated during earthwork may present significant impacts on construction/grading cost.

The results of site- specific seismic refraction survey addressing rippabilty are presented in Appendix A-2 and discussed further below. The magnitude of this geologic/grading concern can be better defined when site grading plans are developed
Based on our geotechnical exploration and the seismic refraction survey conducted by Atlas Geophysics (See, Appendix A -2), we anticipate the granitic bedrock to be rippable to a depth of 5 to 10 feet with conventional heavy earth moving equipment in good operating conditions (Caterpillar D9L or D10 with single shank ripper and rock teeth) . Marginally rippable to unrippable rock may be encountered a depth greater than 10 feet of the planned depth of excavation (see A-2, Figures, 4a -4c). Very difficult/unrippable rock to probable blasting rock or buried core stones (P-wave velocities typically >5,500 feet/second) may also exist at shallower depths in some areas of the site due to presence of core stone or boulders. In addition, due to differential weathering of the bedrock materials, very heavy ripping and/or other specialized excavation techniques may be required to maintain desired excavation rates . Depth and feasibility of excavation cuts and evaluation of areas of potential for burial of oversized materials should be further evaluated when project grading plans become available.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

7 3.5 Faulting
The subject site, like the rest of Southern California, is located within a seismically active region near the active margin between the North American and Pacific tectonic plates. The principal source of seismic activity is movement along the northwest-trending regional fault systems including the San Andreas, San Jacinto and Elsinore fault zones.

As defined by the California Geologic Survey (CGS), an active fault is one that has had surface displacement within the Holocene Epoch (roughly the last 11,000 years). These definitions are used in delineating Earthquake Fault Zones as mandated by the Alquist -Priolo Earthquake Fault Zoning Act whereby requiring fault hazard investigations on sites located within AP Fault Zones to preclude new construction of inhabited structures across the trace of active faults.

No active or potentially active faults were observed on- site or trending to the project site. The subject site is not included within an Earthquake Fault Zone as created by the Alquist -Priolo Act or Riverside County Fault Hazard Zones. The nearest recognized active faults, are the Temecula Segment of the Elsinore Fault Zone, measured to be 3.6 miles (5.8 km) generally southwest of the site and the San Jacinto Valley Segment of the San Jacinto Fault Zone, approximately 16.0 miles (25.8km) northeast of the site.

3.6 Ground Shaking / 2019 CBC Site-Specific Seismic Coefficients The seismic design parameters based on the 2019 CBC were calculated utilizing an interactive program based on current United States Geological Survey (USGS) website using ASCE 7 -16 procedures, as well as OSHPD seismic maps For the purpose of preliminary design, the site- specific seismic coefficients are provided below. Based on ASCE 7- 16 as the Design Code Reference Document and site Class C, the seismic coefficients for this site are summarized in table below.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

8 Table 1 - 2019 CBC Seismic Coefficients per USGS General Procedure Categorization/Coefficient Design Value
(g)
Site Longitude (-117.1602) Site Latitude (33.5989)
Site Class Definition C
Mapped Spectral Response Acceleration at 0.2s Period, Ss 1.44 Mapped Spectral Response Acceleration at 1s Period, S1 0.54 Short Period Site Coefficient at 0.2s Period, Fa 1.20 Long Period Site Coefficient at 1s Period, Fv 1.47
Adjusted Spectral Response Acceleration at 0.2s Period, SMS 1.72 Adjusted Spectral Response Acceleration at 1s Period, SM1 0.78 Design Spectral Response Acceleration at 0.2s Period, SDS 1.15 Design Spectral Response Acceleration at 1s Period, SD1 0.52 *g- Gravity acceleration

3.7 Secondary Seismic Hazards
Ground shaking can induce “secondary” seismic hazards such as liquefaction, dynamic densification in loose and/or wet granular soil, and differential subsidence along ground fissures, seiches and tsunamis . The potential for differential subsidence along ground fissures, seiches and tsunamis is also considered non-existent on this site.

3.7.1 Dynamic Settlement (Liquefaction and Dry Settlement) Assuming that loose, near -surface soils will be removed and recompacted in accordance with the recommendations of Section 4.0 of this report in the areas of development, the potential for liquefaction or dynamic settlement due to the design earthquake event to affect structures at this site is considered negligible. Following completion of the recommended remedial grading, we estimate that the total and differential settlements of approximately one inch and ½ inch in 40 feet, respectively.

3.8 Collapsible Soils
Potential for collapsible soils is limited to deposits of unconsolidated granular alluvium and porous residual soils/ topsoiltopso il. As such, t his hazard is mitigated by the remedial grading recommendations of Section 4 .0. Upon completion of earthwork grading the potential for collapsible soil to affect the project is negligible.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

9 3.9 Erosion
Based on earth materials present and the proposed erosion control measures and surface drainage improvements the loss of site materials due to erosion upon completion of grading is considered low.

3.10 Slope Stability
Cut and fill slopes with a maximum height of approximately 20 feet at 2:1 (horizontal to vertical) are anticipated. Planned cut slopes will expose granitic bedrock . All slopes should be provided with appropriate surface drainage features and landscaped (with drought tolerant vegetation) as soon as possible after grading to minimize the potential for erosion. Brow ditches should be constructed at the top of cut slopes. Drainage should be directed such that surface runoff on the slope face is minimized.

3.11 Infiltration Rates
Four (4) percolation tests were performed in representative locations (P-1 through P-4) within the site, see Figure 3. The field percolation tests were performed in general accordance with the criteria recommended by the County of Riverside. The results of the testing indicated indicate rates of 0.0 to 1.18 inch-per-hours at 4-5 feet below existing grades. Percolation/infiltration rates appear highly dependent on density and clay -rich weathering profiles within the bedrock where present. No factor of safety was assigned to these rates.

Results reported below are the most conservative tested readings in minutes per inch drop and then infiltration rates were determined using the “Porchet Method converted to inches per hour. Field test data are included in Appendix C.

Table 2 - Summary of Infiltration Test Results (add table # and fix font) Test
Hole #
Depth
BGS (ft)
Infiltration
Rate (in/hr) Soil Description
P-1 4.0 0.45 Clayey SAND (SC)
P-2 4.0 1.18 Silty SAND (SM))
P-3 5.0 0.11 Weathered Kgr (SM)
P-4 5.0 0.68 Clayey Sand (SC)

Based on our testing the onsite soils possess moderate to poor infiltration rates or permeability. Even where infiltration is feasible based on soil characterization, the depth to shallow bedrock may preclude the use of onsite stormwater infiltration systems.

Shallow bedrock is hard and resistant and will allow water to migrate laterally or cause mounding on the bedrock. Direct infiltration is not recommended.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

10 4.0 SUMMARY OF CONCLUSIONS AND RECOMMENDATIONS

4.1 General
Based on our review of the referenced reports and the results of this supplemental evaluation, the proposed residential development is considered feasible from a geotechnical viewpoint, provided the recommendations presented in this report are implemented during design and construction phases.

4.2 Earthwork
Earthwork should be performed in accordance with the following recommendations and the Earthwork and Grading Specifications Appendix D. The recommendations contained in Appendix D, are general grading specifications provided for typical grading projects and some of the recommendations may not be strictly applicable to this project. The specific recommendations contained in the text of this report supersede the general recommendations in Appendix D. The contract between the developer and earthwork contractor should be worded such that it is the responsibility of the contractor to place the fill properly in accordance with the recommendations of this report, the specifications in Appendix D, applicable Riverside County Grading Ordinances, notwithstanding the testing and observation of the geotechnical consultant.

4.2.1 Site Preparation and Remedial Grading
Prior to grading, the proposed structural improvement areas (i.e. all structural fill areas, pavement areas, buildings, etc.) of the site should be cleared of surface and subsurface obstructions, heavy vegetation, root balls and boulders. Roots and debris should be disposed of offsite. Septic tanks or seepage pits, if encountered, should be abandoned in accordance with the County of Riverside Department of Health Services guidelines.

Undocumented fill, surficial topsoil, highly weathered bedrock, and most alluvial deposits are potentially compressible in their present state and may settle under the surcharge of fills and possess collapse potential. In areas supporting additional fill soils or structural improvements, these soils should be removed down to competent bedrock or as determined by the engineering geologist during removals. Acceptability of all removal bottoms should be reviewed by a representative of Leighton under the direction of the geotechnical engineer or engineering geologist. The removal bottom elevations, methodology of testing or verifying of removal limits should be documented in the as -graded geotechnical report.

Based on the results of our testing and evaluation, the removal depths are generally expected to range from approximately 2 to 7 feet below existing grade over much of the site. Deeper removal may be required in localized areas. The removal limit should be established by a 1:1 (horizontal:vertical) projection from Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

11 the edge of fill soils supporting settlement -sensitive structures downward and outward to competent material identified by the geotechnical consultant.

Removals will also include benching into competent material as the fills rise. Areas adjacent to existing structures, including roadways, may require special monitoring. Temporary slopes in these areas should be no steeper than 1:1.

Friable materials, if encountered, may require additional layback.

4.2.2 Cut Lots
If applicable, in areas of exposed bedrock or competent alluvial material, in order to provide a uniform compacted fill, we recommend that cut lots be overexcavated to a minimum depth of 5 feet below finish grade and then capped with compacted fill. We further recommend streets be overexcavated to a depth of 2 feet below the deepest utility and then brought back up to design grades with compacted fill.

4.2.3 Suitability of Site Soils for Fills
The onsite soils are generally suitable for re -use as compacted fill, provided they are free of debris, organic matter, and oversize rock. Fills placed within 10 feet of finish pad grades or slope faces should contain no rocks over 12 inches in maximum dimension. Fills placed within 5 feet of finish pad grades or slope faces should contain no rocks over 6 inches in maximum dimension. In addition, clayey soils (EI> 21), if present, should be placed at depth greater than 3 feet below finished grades where feasible. All structural fill should be compacted throughout to 90 percent of the ASTM D 1557 laboratory maximum density, at or slightly above optimum moisture.

Areas to receive structural fill and/or other surface improvements should be approved by the geotechnical consultant then scarified to a minimum depth of 8 inches, conditioned to at least optimum moisture content, and recompacted. Fill soils should be placed at a minimum of 90 percent relative compaction (based on ASTM D1557) and near or above optimum moisture content. Placement and compaction of fill should be performed in accordance with local grading ordinances under the observation and testing of the geotechnical consultant. The optimum lift thickness to produce a uniformly compacted fill will depend on the type and size of compaction equipment used. In general, fill should be placed in uniform lifts not exceeding 8 inches in thickness.

Fill slope keyways will be necessary at the toe of all fill slopes and at fill -over-cut contacts. Keyway schematics, including dimensions and subdrain recommendations, are provided in Appendix D. All keyways should be excavated into dense bedrock as determined by the geotechnical engineer or engineering geologist. The cut portions of all slope and keyway excavations should be geologically mapped and approved by a geologist prior to fill placement.

Fills placed on slopes steeper than 5:1 (horizontal:vertical) should be benched into dense soils (see Appendix D for benching detail). Benching should be of sufficient depth to remove all loose material. A minimum bench height of 2 feet into approved material should be maintained at all times. A grading contractor with Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

12 experience in the handling and placement of oversize rock should be selected for this project.

4.2.4 Oversize Rock
Oversized rocks (greater than 12 inches in maximum dimension) were visible on- site and are anticipated to be encountered during grading. Rock in excess of 12 inches in maximum dimension may not be placed in any fill within 10 feet of finish grade. Oversized rock may be placed in fills more than 10 feet below finish grade, if placed in accordance with the following guidelines and the specifications contained in Appendix D.

Within the upper 5 feet of finish grade, fill soils should not contain rock greater than 6 inches in maximum dimension in order to facilitate foundation and utility trench excavation. For fill soils between 5 and 10 feet below finish grade, the fill may contain rock up to 12 inches in maximum dimension and should be mixed with sufficient soil to eliminate voids. Rocks greater than 36 inches in diameter may be placed on a case-by-case basis. Granular soil used to fill voids in rock fills should be flooded during placement with a sufficient amount of water to wash soil into all voids. Material filling voids should be compacted to a minimum of 90 percent of the soil’s maximum dry density. The outer 20 feet (10 feet vertically) of all fill slopes should not contain rocks greater than 12 inches. Subdrains should be provided at the base of all rock fills to minimize the potential for a build- up of hydrostatic pressure.

Due to the anticipated abundant volume of oversize rock, grading contractors should develop a strategy to bury or otherwise use the oversize materials (i.e. crush for aggregate base, gravels, etc.). Alternative uses of rock will require appropriate testing to confirm rock suitability.

4.2.5 Shrinkage and Bulking
The volume-change of excavated onsite materials upon recompaction is expected to vary with materials, density, insitu moisture content, location, and compaction effort. The in- place and compacted densities of soil materials vary and accurate overall determination of shrinkage and bulking cannot be made. Therefore, we recommend site grading include, if possible, a balance area or ability to adjust import quantities to accommodate some variation. Based on our experience with similar materials, the following values are provided as guidelines:

Table 3 - Earthwork Shrinkage Estimates
Geologic Unit Estimated Shrinkage/Bulking
Surficial Soils/alluvium 10 15 percent shrinkage
Rippable bedrock (D.G.) 0-5% bulking
Marginally rippable bedrock 5-15% bulking
Nonrippable bedrock (blasting) 15 to 25% bulking

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

13 4.2.6 Utility Trenches
Utility trenches should be backfilled with compacted fill in accordance with the Standard Specifications for Public Works Construction, (“Greenbook”), 20 21 Edition. Fill material above the pipe zone should be placed in lifts not exceeding 8 inches in uncompacted thickness and should be compacted to at least 90 percent relative compaction (ASTM D 1557) by mechanical means only. Site soils may generally be suitable as trench backfill provided these soils are screened of rocks over 1½ inches in diameter and organic matter. The upper 6 inches of backfill in all pavement areas should be compacted to at least 95 percent relative compaction.

Excavation of utility trenches should be performed in accordance with the project plans, specifications and the “Greenbook”. The contractor should be responsible for providing a "competent person" as defined in Article 6 of the California Construction Safety Orders. Contractors should be advised that sandy soils (such as fills generated from the onsite alluvium) could make excavations particularly unsafe if all safety precautions are not properly implemented. In addition, excavations at or near the toe of slopes and/or parallel to slopes may be highly unstable due to the increased driving force and load on the trench wall. Spoil piles from the excavation(s) and construction equipment should be kept away from the sides of the trenches.

4.2.7 Drainage
All drainage should be directed away from structures a minimum of 1% by means of approved permanent/temporary drainage devices. Adequate surface drainage of any building pad should be provided to avoid wetting of foundation soils.

Irrigation adjacent to buildings should be avoided when possible. As an option, sealed-bottom planter boxes and/or drought resistant vegetation should be used within 5-feet of buildings.

Subdrains are recommended in canyon fills and in fill -over-cut keyways. Fills generally saturate at or near the contact with relatively impermeable granitics. Fill to bedrock contacts exposed on fill-over-cut slopes can present seepage problems once irrigation of the slopes and upper pad areas begins. Subdrains within the fill- over-cut keyways can reduce the seepage and outlet the excess water to suitable discharge areas. Subdrain details are provided in the General Earthwork and Grading Specifications (Appendix D).

Canyon subdrains up to 500 lineal feet should consist of 6-inch diameter perforated pipe. Canyon subdrains that are longer than 500 lineal feet are not anticipated for the proposed development. A 20- foot section of non- perforated pipe should be placed at the outlet location. The connection between the perforated and non- perforated pipe should be sealed with a minimum 6-inch thick, concrete cut-off wall placed a minimum of 2 feet beyond the perimeter of the gravel “burrito”. All outlets should be protected with a concrete apron and cover. Subdrain pipe should be Schedule 40 PVC (or equivalent) placed in accordance with Appendix D.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

14 4.2.8 Slope Construction
Compacted fill slopes at 2:1 (horizontal:vertical) are considered grossly stable for static and pseudostatic conditions. Higher or steeper slopes should be subject to further review and evaluation. Any new 2:1 slope using the onsite soils compacted to minimum 90 percent should also be stable under short- and long -term conditions. The outer portion of new fill slopes should be either overbuilt by 2 feet (minimum) and trimmed back to the finished slope configuration or compacted in vertical increments of 5 feet (maximum) by a weighted sheep foot roller as the fill is placed. The slope face should then be track -walked by dozers of appropriate weight to achieve the final slope configuration and compaction to the slope face.

New fill slopes should be provided a toe of slope keyway as depicted in Appendix D. If fill is placed against existing cut slope, the minimum fill width should be 15 feet per Appendix D. All cut slopes should be observed and mapped by a Leighton geologist to confirm the exposed conditions are stable.

Slope faces are inherently subject to erosion, particularly if exposed to rainfall and irrigation. Landscaping and slope maintenance should be conducted as soon as possible in order to increase long-term surficial stability. Berms should be provided at the top of fill slopes. Drainage should be directed such that surface runoff on the slope face is minimized

4.3 Preliminary Foundation Design
Shallow spread or continuous wall footings bearing on a newly placed properly compacted fill are anticipated for the proposed structures.

4.3.1 Design Parameters – Spread/Continuous Shallow Footings Footings should be embedded at least 12-inches below lowest adjacent grade for the proposed structures. Footing embedment should be measured from lowest adjacent finished grade, considered as the top of interior slabs-on-grade or the finished exterior grade, excluding landscape topsoil, whichever is lower.

Footings located adjacent to utility trenches or vaults should be embedded below an imaginary 1:1 (horizontal:vertical) plane projected upward and outward from the bottom edge of the trench or vault, up towards the footing.  Bearing Capacity: For footings founded on properly compacted fill soil, an allowable vertical bearing capacity of 2,000 pounds -per-square-foot (psf) should be used. The bearing pressure value may be increased by 250 psf for each additional foot of embedment or each additional foot of width to a maximum vertical bearing value of 3, 500 psf. These bearing values may be increased by one- third when considering short -term seismic or wind loads. All continuous perimeter or interior footings should be reinforced with at least one No. 5 bar placed both top and bottom.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

15  Lateral loads: Lateral loads may be resisted by friction between the footings and the supporting subgrade. A maximum allowable frictional resistance of 0.35 may be used for design. In addition, lateral resistance may be provided by passive pressures acting against foundations poured neat against properly compacted granular fill. We recommend that an allowable passive pressure based on an equivalent fluid pressure of 350 pounds-per-cubic-foot (pcf) be used in design. These friction and passive values have already been reduced by a factor-of-safety of 1.5.

Slab-on-grade floors utilized with conventional foundations should be designed with a minimum thickness of 5 inches or as indicated by the project structural engineer consistent with a modulus of subgrade reaction of 200 pounds -per- square-inch per inch (pci) and reinforced in accordance with the structural engineer’s recommendations.

4.3.2 Vapor Retarder
A moisture retarder should be installed underneath all slabs where moisture condensation is undesirable. The vapor retarder should be sealed at all penetrations and laps and properly installed in accordance with the recommendations of the architect, concrete subcontractor, and the manufacturer’s recommendations. Moisture vapor retarders may retard but not eliminate moisture vapor movement from the underlying soils up through the slabs. Moisture vapor transmission may be additionally reduced by use of concrete additives. A slipsheet or equivalent should be utilized above the concrete slab if crack-sensitive floor coverings (such as ceramic tiles, etc.) are to be placed directly on the concrete slab

4.3.3 Settlement Estimates
For settlement estimates, we assumed that column loads will be no larger than 90 kips, with bearing wall loads not exceeding 10 kips per foot of wall. If greater column or wall loads are required, we should re- evaluate our foundation recommendation, and re-calculate settlement estimates.

Buildings located on properly compacted fill soils as required per Section 4.2 should be designed in anticipation of 1 inch of total settlement and 1/2- inch of differential settlement within a 40-foot horizontal run.

4.4 Retaining Walls
Retaining wall earth pressures are a function of the amount of wall yielding horizontally under load. If the wall can yield enough to mobilize full shear strength of backfill soils, then the wall can be designed for "active" pressure. If the wall cannot yield under the applied load, the shear strength of the soil cannot be mobilized and the earth pressure will be higher. Such walls should be designed for "at rest" conditions. If a structure moves toward Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

16 the soils, the resulting resistance developed by the soil is the "passive" resistance.

Retaining walls backfilled with non-expansive soils should be designed using the following equivalent fluid pressures:

Table 4 - Retaining Wall Design Earth Pressures (Static, Drained) Loading
Conditions
Equivalent Fluid Density (pcf)
Level Backfill 2:1 Backfill
Active 35 55
At-Rest 55 65
Passive* 300 150 (2:1, sloping down)
*This assumes level condition in front of the wall will remain for the duration of the project, not to exceed 3,000 psf at depth. If sloping down (2:1) grades exist in front of walls, then they should be designed using passive values reduced to ½ of level backfill passive resistance values.

Unrestrained (yielding) cantilever walls should be designed for the active equivalent-fluid weight value provided above for very low to low expansive soils that are free draining. In the design of walls restrained from movement at the top (non-yielding) such as basement or elevator pit/utility vaults, the at-rest equivalent fluid weight value should be used. Total depth of retained earth for design of cantilever walls should be measured as the vertical distance below the ground surface measured at the wall face for stem design, or measured at the heel of the footing for overturning and sliding calculations. Should a sloping backfill other than a 2:1 (horizontal:vertical) be constructed above the wall (or a backfill is loaded by an adjacent surcharge load), the equivalent fluid weight values provided above should be re-evaluated on an individual case basis by us. Non-standard wall designs should also be reviewed by Leighton prior to construction to check that the proper soil parameters have been incorporated into the wall design.

All retaining walls should be provided with appropriate drainage. The outlet pipe should be sloped to drain to a suitable outlet. Typical wall drainage design is illustrated in Appendix D, Retaining Wall Backfill and Subdrain Detail . Wall backfill should be non- expansive (EI ≤ 21) and compacted by mechanical methods to a minimum of 90 percent relative compaction (ASTM D 1557). Clayey site soils should not be used as wall backfill.

Walls should not be backfilled until wall concrete attains the 28-day compressive strength and/or as determined by the Structural Engineer that the wall is structurally capable of supporting backfill. Lightweight compaction equipment should be used, unless otherwise approved by the Structural Engineer.

4.5 Foundation Setback from Slopes
We recommend a minimum horizontal setback distance from the face of slopes for all structural footings (retaining and decorative walls, flatwork, building footings, pools, etc.).

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

17 This distance is measured from the outside bottom edge of the footing horizontally to the slope face (or the face of a retaining wall) and should be a minimum of H/2, where H is the slope height (in feet).

Table 5 - Footing Setbacks
Slope Height Recommended Footing Setback
<5 feet 5 Feet minimum
5 to 15 feet 7 feet minimum
The soils within the structural setback area generally possess poor lateral stability and improvements (such as retaining walls, pools, sidewalks, fences, pavements, decorative flatwork, etc.) constructed within this setback area will be subject to lateral movement and/or differential settlement. Potential distress to such improvements may be mitigated by providing a deepened footing or a pier and grade-beam foundation system to support the improvement. The deepened footing should meet the setback described above.

Modifications of slope inclinations near foundations may increase the setback and should be reviewed by the design team prior to completion of design or implementation.

4.6 Geochemical Characteristics
The results of limited laboratory testing indicated negligible exposure to concrete per ACI 318. Further testing should be performed at the completion of grading to confirm soluble- sulfate content of near finish subgrade soils.

The results of the resistivity test indicate that the underlying soil is very mildly-corrosive to buried ferrous metals per ASTM STP 1013. The samples tested for water -soluble chloride content indicate a low potential for corrosion of steel in concrete due to the chloride content of the soil. Additional testing for general corrosion potential to ferrous materials should also be performed at the completion of rough grading to confirm these results remain valid for all aspects of design.

As a general mitigation measure, ferrous pipe buried in moist to wet earth materials should be avoided by using high -density polyethylene (HDPE), polyvinyl chloride (PVC) and/or other non- ferrous pipe when possible. Ferrous pipe can also be protected by polyethylene bags, tap or coatings, di-electric fittings or other means to separate the pipe from on-site soils. Plastic and vitrified clay piping do not warrant any special precautions.

Standard concrete cover over reinforcing steel may be used for concrete structures and pipe in contact with site soils possessing negligible sulfate reactions.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

18 4.7 Concrete Flatwork
Sidewalk/Flatwork should conform to applicable City standards. A representative of Leighton should verify subgrade soil expansion, moisture conditions and compaction prior to formwork and reinforcement placement. If subgrade soils possess expansion index greater than 21, we recommend a minimum 8-inch deepened edge be constructed for all flatwork to reduce moisture variation in subgrade soils along concrete edges adjacent to open (unfinished) or irrigated landscape areas.

4.8 Preliminary Pavement Design Parameters
The preliminary pavement design provided below is based on an assumed R-value of 58 for subgrade soils and traffic indices as listed in table below. The following range of pavement sections is to be used for preliminary planning purposes based on design guidelines included Caltrans Highway Design Manual.

Table 6 - Asphalt Pavement Sections
General Traffic Condition* Traffic Index
(TI)**
Asphalt Concrete
(inches)
Aggregate Base*
(inches)
Parking Areas 4.5 3.0 4.0
Private Street 5.0 3.0 6.0
General Local Street 6.0 4.0 6.0
Collector/Enhanced Local 7.0 4.0 6.0
*Per City minimum or as calculated

Tests of the exposed subgrade soils during rough grading should be performed to verify the R-value and confirm required pavement sections. Appropriate TI data should also be selected by the project civil engineer or traffic engineering consultant for finalization of the pavement sections. The pavement sections should meet or exceed County of Riverside standards.

The subgrade soils in the upper 6 inches should be properly compacted to at least 9 5 percent relative compaction and should be moisture-conditioned to near optimum and kept in this condition until the pavement section is constructed. Proof-rolling subgrade to identify localized areas of yielding subgrade (if any) should be performed prior to placement of aggregate base and under the observation of the geotechnical consultant.

Minimum relative, compaction requirements for aggregate base should be 95 percent of the maximum laboratory density as determined by ASTM D1557. Base rock should conform to the “Standard Specifications for Public Works Construction” (green book) current edition or Caltrans Class 2 aggregate base having a minimum R-value of 78.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

19 The preliminary pavement sections provided in this section are meant as minimum, if thinner or highly variable pavement sections are constructed, increased maintenance and repair may be needed.

4.9 Continued Geotechnical Services
Our geotechnical recommendations are contingent upon Leighton and Associates, Inc., providing geotechnical observation and testing services during continued earthwork and foundation construction. Leighton and Associates, Inc. should review site foundation and landscape plans when available, to comment further on geotechnical aspects of this project and check to see general conformance of final project plans to recommendations presented in this report, or provide additional recommendations as considered necessary.

Leighton and Associates, Inc. should be retained to provide geotechnical observation and testing during excavation and all phases of earthwork. Our conclusions and recommendations should be reviewed and verified by us during construction and revised accordingly if geotechnical conditions encountered vary from our findings and interpretations. Geotechnical observation and testing should be provided during:
 Remedial earthwork and all cut slope excavations;
 Preparation of subgrade in all areas to receive fill;  Excavation and preparation of residential building pads;  After excavation of all slabs and footings and prior to placement of steel or concrete to confirm the slabs and footings are founded in firm, compacted fill from of loose debris;
 Utility trench backfilling and compaction.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

20 5.0 LIMITATIONS
This report was necessarily based in part upon data obtained from a limited number of observances, site visits, soil samples, tests, analyses, histories of occurrences, spaced subsurface explorations and limited information on historical events and observations.

Such information is necessarily incomplete. The nature of many sites is such that differing characteristics can be experienced within small distances and under various climatic conditions. Changes in subsurface conditions can and do occur over time. This investigation was performed with the understanding that the subject site is proposed for residential development. The client is referred to Appendix E regarding important information provided by the Geoprofessional Business Association (GBA) on geotechnical engineering studies and reports and their applicability.

This report was prepared for Sancerra Management (Client), based on their needs, directions, and requirements at the time of our investigation. This report is not authorized for use by and is not to be relied upon by any party except our Client, and its successors and assignees as owner of the property, with whom Leighton and Associates, Inc. has contracted for the work. Use of or reliance on this report by any other party is at that party's risk. Unauthorized use of or reliance on this report constitutes an agreement to defend and indemnify Leighton and Associates, Inc. from and against any liability which may arise as a result of such use or reliance, regardless of any fault, negligence, or strict liability of Leighton and Associates, Inc.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

21 REFERENCES
American Concrete Institute (ACI), 20 14, Building Code Requirements for Structural Concrete (ACI 318- 14) and Commentary, an ACI Standard, reported by ACI Committee 318.

American Society of Civil Engineers (ASCE), 2016, Minimum Design Loads for Buildings and Other Structures, ASCE/SEI 7-16, Third Printing, Errata Incorporated through March 15.

Atlas Technical Consultants, 2022, Seismic R efraction Study, Whitewood Parcel 1, Murrieta, California, Atlas No. 122142SWG, dated June 17th.

Blake, T. F., 2000, EQSEARCH, Version 3.00, A Computer Program for the Estimation of Peak Horizontal Acceleration from Southern California Historical Earthquake Catalogs, User’s Manual, 94pp., with update data, 2015.

California Building Standards Commission, 2019 California Building Code (CBC), California Code of Regulations, Title 24, Part 2, Volume 2 of 2, Based on 2015 International Building Code, Effective January 1, 2017.

California Geologic Survey, 2018, Earthquake Fault Zones, A Guide for Government Agencies, Property Owners/Developers, and Geoscience Practitioners for Assessing Fault Rupture Hazards in California, Department of Conservation, Division of Mines and Geology, Special Publication 42, Revised 2018.

California Department of Water Resources , Interactive Website, Viewed 5/30/2022, Water Data Library, http://www.water.ca.gov/waterdatalibrary/

Hart, E.W., 1999, Fault -Rupture Hazard Zones in California, Alquist -Priolo Earthquake Fault Zoning with Index to Special Study Zones Maps: Department of Conservation, Division of Mines and Geology, Special Publication 42. Revised 1997. Supplement 1 and 2 added 1999.

Federal Emergency Management Agency (FEMA), 2019, Flood Insurance Rate Map, Riverside County, California, Map Number 06065 C1390G, map scale 1”=1000’, dated 8/28/2008.

Leighton and Associates, Inc., 2021, Desktop Geotechnical Review Multi -Family Development Emblem at Murrieta NE Corner Whitewood Road and Clinton Keith Road Murrieta, California Project No. 13142.003, dated December 20, 2021.

Leighton and Associates, Inc., 2006, Geotechnical Review and Preliminary Geotechnical Investigation, Great Lands Murrieta 320, Murrieta Area, Riverside County, California Project No. 111952.001, dated August 3, 2006.

Geotechnical Evaluation July 20, 2023
Multi-Family Development - Whitewood I– Riverside County, CA Project No. 13142.005

22 Morton, D.M., 2003, Geologic Map of the 7.5’ Murrieta Quadrangle, Riverside County, California, Version 1.0, United States Geologic Survey Open- File Report 03-189, scale 1:24,000.

OSHPD, 2022, Seismic Design Maps, on OSHPD Website to Calculate Seismic Response and Design Parameters based on ASCE 7-16 Seismic Procedures, https://seismicmaps.org/
Public Works Standard, Inc., 2021, Greenbook, Standard Specifications for Public Works Construction: BNI Building News, Anaheim, California.

Riverside County Information Technology, 2021 , Map My County (website), http://mmc.rivcoit.org/MMC_Public/Viewer.html?Viewer=MMC_Public Riverside County, TMLA, Building and Safety Department, 2006, Conditions of Approval, County Geologic Report No. 1466, Preliminary Geotechnical Investigation, Tentative Tract 32026, (Lakeside Estates Project), Lake Elsinore Area, Riverside County, dated April 27, 2006.

Robert Hidey Architects (RHA), 2022, Whitewood I – Conceptual Site plan, Murrieta, CA, Dated April 22, 2022.
³
0 2,000 4,000
Feet
Approximate
Site Boundary
Scale:1 " = 2,000 '
Project: 13142.005
Date: June 2022

SITE LOCATION MAP
Whitewood I
Northeast Corner Whitewood Road and
Clinton Keith Road
Murrieta, California
Eng/Geol: SIS/MSB/JAR
Base Map: ESRI ArcGIS Online 2022
Map Saved as V:\Drafting\13142\005\Maps\13142-005_F01_SLM_2022-06-06.mxd on 6/6/2022 12:03:00 PM Author: Leighton Geomatics (mmurphy)
FIGURE 1
%&h(
Qps
Qps
Qps
Kpvg
Kpvt Kvh
Qvoa
Kgb
Qya
Qyf
Kgb
Qyf
Kpvg
Kgb
Kgb
Kpvt
Kpvg
Kpvg
Qvoa
Kgb
Kgb
Trmu
Kgb
Kgb
QTws Qps
Kgb
Tvh
Kgb
QTws Qps
Los Alamos Rd
Antelope Rd
Clinton Keith Rd
Briggs Rd
Whitewood Rd
FIGURE 2
Scale:1 " = 2,000 '
Project: 13142.005
Date: June 2022

REGIONAL GEOLOGY MAP
Approximate
Site Location
³
0 2,000 4,000
Feet
Legend
!
!
!
!
! !
!!
!!
!
!
!
!
! !!!
!
!
!
!
Qya - Young axial-channel deposits
Qyf - Young alluvial-fan deposits
Kgb - Gabbro, undifferentiated
Trmu - Rocks of Menifee Valley,
undifferentiated
Kpvg - Paloma Valley Ring Complex
Kpvt - Paloma Valley Ring Complex
Qps - Pauba Formation
Tvh - Basalt of Hogbacks
Qvoa - Very old axial-channel deposits
Map Saved as P:\Drafting\13142\005\Maps\13142-005_F02_RGM_2022-06-06.mxd on 6/28/2022 9:29:25 AM Reference: USGS, 2006 Geologic map of the San
Bermardino and Santa Ana 30'x60 quadrangle,
California Version 1,0 Open File Report 2006-1217.

Author: Leighton Geomatics (mmurphy)
Whitewood I
Northeast Corner Whitewood Road and
Clinton Keith Road
Murrieta, California
Eng/Geol: SIS/MSB/JAR
³
Map Saved as V:\Drafting\13142\005\Maps\13142-005_F03_ELM_2022-06-06.mxd on 6/28/2022 11:46:19 AM Base Map: Bing Maps, 2016 2022
Reference: Conceptual Site Plan by Sancerra, 4/22/2022. 1 " = 100 '
Author: Leighton Geomatics (mmurphy)
Legend
"**Ñ
Approximate Location of Test Pit (T.P.)
(Leighton, Current Study)
&( Approximate Location of Percolation Test
% %
Approximate Location of Seismic Line
(Leighton, Current Study)
;)§
Approximate Location of Test Pit (T.P.)
(Leighton, 2006)
% %
Approximate Location of Seismic Line
(Leighton, 2006)
Approximate Site Boundary
TP-7
P-4
TP-40
SL-1
SL-3
2020
Whitewood I
Northeast Corner Whitewood Road and Clinton Keith Road
Murrieta, California
0 100 200
Feet
Scale:

Project: 13142.005 Eng/Geol:

Date: June 2022
FIGURE 3SIS/MSB/JAR

EXPLORATION LOCATION MAP

APPENDIX A-1

Logs of Exploration Borings – This Study

LOG OF TEST PIT
PROJECT NO.: 13142.005 LOGGED BY: MSB
PROJECT NAME: Whitewood I DATE: 5-20-22
Excavation Equipment:

TEST
PIT#
SAMPLE

TYPE & DEPTH
LAB

TEST USCS DESCRIPTION
TP-1

B-1 (0-4’)

Corrosion
& Sieve

SM-SWg

Topsoil
0-1.5’ Well graded Sand with Silt and gravel, light brown to dark reddish brown, appears dry, medium angular sand
Granitic Rock (Kgr)

1.5-4.0’, Highly weathered breaking to light brown, coarse angular sand with granitic texture Practical Refusal (J.D. 310 Backhoe) @ 4’ No Groundwater Encountered

LOG OF TEST PIT
PROJECT NO.: 13142.005 LOGGED BY: MSB
PROJECT NAME: Whitewood I DATE: 5-20-22
Excavation Equipment:

TEST
PIT#
SAMPLE

TYPE & DEPTH LAB TEST USCS DESCRIPTION
TP-2

SC

Topsoil
0-1.5’ Clayey sand, brown, relatively dry
Granitic Rock (Kgr)

1.5-2.0’ Highly weathered, gray breaking to gravelly sand Practical Refusal (J.D. 310 Backhoe) @ 4’ No Groundwater Encountered

LOG OF TEST PIT
PROJECT NO.: 13142.005 LOGGED BY: MSB
PROJECT NAME: Whitewood I DATE: 5-20-22
Excavation Equipment:

TEST
PIT#
SAMPLE

TYPE & DEPTH LAB TEST USCS DESCRIPTION
TP-3

SC-SM

Topsoil
0-1.0’ Clayey, Silty SAND, red brown, dry, ripped compacted granitic residual soil Granitic Rock (Kgr)

1.0-2.0’ Weathered Diorite Bedrock, brown breaking to dry, coarse gravelly sand Practical Refusal (J.D. 310 Backhoe) @ 2’ No Groundwater Encountered

LOG OF TEST PIT
PROJECT NO.: 13142.005 LOGGED BY: MSB
PROJECT NAME: Whitewood I DATE: 5-20-22
Excavation Equipment:

TEST
PIT#
SAMPLE

TYPE & DEPTH LAB TEST USCS DESCRIPTION
TP-4

B-1 (0-4’)

R-Value,
SE, Sieve

SM

Quaternary Alluvium (Qal)
0-4.6’ Silty SAND, dark yellowish brown, appears dry, fine to medium grained sand Granitic Rock (Kgr)

4.6-5.5’+ Highly weathered, brown breaking to coarse angular sand Practical Refusal (J.D. 310 Backhoe) @ 5.5’ No Groundwater Encountered

LOG OF TEST PIT
PROJECT NO.: 13142.005 LOGGED BY: MSB
PROJECT NAME: Whitewood I DATE: 5-20-22
Excavation Equipment:

TEST
PIT#
SAMPLE

TYPE & DEPTH LAB TEST USCS DESCRIPTION
TP-5

B-1 (0-7’)

AL, EI,
Seive

CL

SWg
Quaternary Alluvium (Qal)
0-2.5’ Sandy Lean Clay, medium dense, dark yellowish brown Granitic Rock (Kgr)

2.5-3.0’+ breaking to coarse angular, gravelly sand
Practical Refusal (J.D. 310 Backhoe) @ 3’ No Groundwater Encountered

LOG OF TEST PIT
PROJECT NO.: 13142.005 LOGGED BY: MSB
PROJECT NAME: Whitewood I DATE: 5-20-22
Excavation Equipment:

TEST
PIT#
SAMPLE

TYPE & DEPTH
LAB

TEST USCS DESCRIPTION
TP-6

B-1 (1.5-4.5’)

Sieve

SM

SM
Quaternary Alluvium (Qal)
0-1.5’ Silty SAND, dark yellowish-brown, fine-grained sand Granitic Rock (Kgr)

1.5-4.5’+ breaking to medium silty sand
Practical Refusal (J.D. 310 Backhoe) @ 4.5’ No Groundwater Encountered

LOG OF TEST PIT
PROJECT NO.: 13142.005 LOGGED BY: MSB
PROJECT NAME: Whitewood I DATE: 5-20-22
Excavation Equipment:

TEST
PIT#
SAMPLE

TYPE & DEPTH
LAB

TEST USCS DESCRIPTION
TP-7

SC/ML

Topsoil
0-2.0’ Silty SAND and Sandy SILT, loose, red brown
Granitic Rock(Kgr)

2.0-2.5’+ gray, slightly weathered, appearing, dry breaking to well graded sand Practical Refusal (J.D. 310 Backhoe) @ 2.5’ No Groundwater Encountered

LOG OF TEST PIT
PROJECT NO.: 13142.005 LOGGED BY: MSB
PROJECT NAME: Whitewood I DATE: 5-20-22
Excavation Equipment:

TEST
PIT#
SAMPLE

TYPE & DEPTH LAB TEST USCS DESCRIPTION
T-8

B-1 (1.5-3.5’)

AL, Sieve

SC

Quaternary Alluvium (Qal)
0-1.5’ Sandy CLAY, medium dense, red, dry
Granitic Rock (Kgr)

1.5-3.5’ Weathered, clayey, fine textured breaking to clayey, gravelly, medium grained sand Practical Refusal (J.D. 310 Backhoe) @ 3.5’ No Groundwater Encountered

APPENDIX A-2

Seismic Refraction Survey (Atlas, 2022)

SEISMIC REFRACTION STUDY
WHITEWOOD PARCEL 1
Murrieta, California
PREPARED FOR:

Leighton Group, Inc.
17781 Cowan
Irvine, CA 92614
PREPARED BY:

Atlas Technical Consultants LLC
6280 Riverdale Street
San Diego, CA 92120
June 17, 2022

6280 Riverdale Street
San Diego, CA 92120
(877) 215-4321 | oneatlas.com
June 17, 2022
Atlas No. 122142SWG
Report No. 1

MR. JOE ROE, PG, CEG
LEIGHTON GROUP, INC.
17781 COWAN
IRVINE, CA 92614

Subject: Seismic Refraction Study
Whitewood Parcel 1
Murrieta, California

Dear Mr. Roe:

In accordance with your authorization, Atlas has performed a seismic refraction study pertaining to the subject project located in Murrieta, California. Specifically, our evaluation consisted of performing three seismic refraction traverses within a section of land located northwest of the corner of Arendt Lane and Clinton Keith Road. The purpose of our study was to develop subsurface velocity profiles of the traverses, depth to bedrock, and apparent rippability of the subsurface materials. Our field services were conducted on May 20 th, 2022. This data report
presents our methodology, equipment used, analysis, and results.

If you have any questions, please call us at (619) 280-4321.

Respectfully submitted,
Atlas Technical Consultants LLC

Samson Lozano Patrick F. Lehrmann, P.G., P.Gp.

Senior Staff Geophysicist Principal Geologist/Geophysicist PWG:SL:PFLds
Distribution: [email protected]

Atlas No. 122142SWG
Report No. 1
Page | i

CONTENTS

1. INTRODUCTION ............................................................................................................ ....... 1

2. SCOPE OF SERVICES ......................................................................................................... 1

3. SITE AND PROJECT DESCRIPTION ................................................................................... 1

4. STUDY METHODOLOGY ..................................................................................................... 1

5. DATA ANALYSIS ................................................................................................................... 3

6. RESULTS AND CONCLUSIONS .......................................................................................... 3

7. LIMITATIONS ........................................................................................................................ 4

8. SELECTED REFERENCES .................................................................................................. 4

TABLE
Table 1 – Rippability Classification ............................................................................................... 3

FIGURES
Figure 1 Site Location Map
Figure 2 Seismic Line Location Map
Figure 3 Site Photographs
Figure 4a P-Wave Profile, SL-1
Figure 4b P-Wave Profile, SL-2
Figure 4c P-Wave Profile, SL-3

Atlas No. 122142SWG
Report No. 1
Page | 1

1. INTRODUCTION
In accordance with your authorization, Atlas has performed a seismic refraction study pertaining to a portion of the Whitewood Parcel 1 project located at the corner of Arendt Lane and Clinton Keith Road in Murrieta, California (Figure 1). Specifically, our evaluation consisted of performing three seismic refraction traverses at the site. The purpose of our study was to develop subsurface velocity profiles of the traverses, depth to bedrock, and apparent rippability of the subsurface materials. Our field services were conducted on May 20
th, 2022. This data report presents our
methodology, equipment used, analysis, and results.

2. SCOPE OF SERVICES
Our scope of services included:
• Performance of three seismic P-wave refraction traverse at the project site. • Compilation and analysis of the data collected.
• Preparation of this data report presenting our results and conclusions.

3. SITE AND PROJECT DESCRIPTION
The project site is generally located within a plot of undeveloped land, interspersed with private residences, northwest of the Arendt Lane and Clinton Keith Road intersection in Murrieta, California (Figure 1). Three seismic traverses, labeled SL-1, SL-2 and SL-3, were conducted as part of our study. The general line locations were selected by you and your office. Figures 2 and 3 present the general site conditions. Based on our discussions with you, it is our understanding that your office requested this study in advance of construction activities for the subject project.

We also understand that the results of our study may be used in the formulation of design and construction parameters for the project.

4. STUDY METHODOLOGY
A seismic P-wave (compression wave) refraction study was conducted at the project to develop subsurface velocity profiles of the areas studied, and to assess the depth to bedrock and apparent rippability of the subsurface materials. The seismic refraction method uses first-arrival times of refracted seismic waves to estimate the thicknesses and seismic velocities of subsurface layers.

Seismic P-waves generated at the surface, using a hammer and plate, are refracted at boundaries separating materials of contrasting velocities. These refracted seismic waves are then detected by a series of surface vertical component 14-Hz geophones and recorded with a 24-channel Geometrics StrataView seismograph. The travel times of the seismic P-waves are used in conjunction with the shot-to-geophone distances to obtain thickness and velocity information on the subsurface materials.

Atlas No. 122142SWG
Report No. 1
Page | 2
The general location and length of the line for the three seismic traverses (SL-1, SL-2 and SL-3) was determined by surface conditions, site access, and depth of investigation, as determined by you. Shot points (signal generation locations) were conducted along the lines, at the ends, midpoint, and intermediate points between the ends and the midpoint.

In general, classical seismic refraction theory requires that subsurface velocities increase with depth (generalized reciprocal method (GRM) and time-intercept modeling). In classical analysis methods a layer having a velocity lower than that of the layer above will not generally be detectable by the seismic refraction method and, therefore, could lead to errors in the depth calculations of subsequent layers. In addition, lateral variations in velocity such as those caused by core stones, intrusions, or boulders can also result in the misinterpretation of the subsurface conditions. Application of seismic tomography methods, as was performed for this project by Atlas, produces velocity models which, in general, are not subject to this limitation. However, even the application of seismic tomography analysis does have certain limitations regarding vertical and horizontal resolution. When a velocity anomaly target is of similar scale length to the seismic wavelet (or smaller), then diffraction behavior dominates because scattering is governing the loci of the wavefronts. For travel time analysis a target feature must be at a scale vs. its depth that is detectable relative to the scale length of the seismic wavelet we produce and receive. There is therefore a general limit to what scale of feature seismic tomography methods can detect regarding relatively small velocity anomaly features, related to both source and to medium velocities, and also travel time uncertainties. In effect, some relatively smaller scale features including "thin" velocity inversion layers or voids, and some types of lateral and vertical velocity variations caused by core stones and intrusions might not be detected in our results. In general, the effective depth of evaluation for a seismic refraction traverse is approximately one-third to one-fifth of the length of the spread.

In general, the seismic P-wave velocity of a material can be correlated to rippability (see Table 1 below), or to some degree “hardness.” Table 1 is based on published information from the Caterpillar Performance Handbook (Caterpillar, 2018) , as well as our experience with similar materials, and assumes that a Caterpillar D-9 dozer ripping with a single shank is used. We emphasize that the cutoffs in this classifi cation scheme are approximate and that rock characteristic, such as fracture spacing and orientation, play a significant role in determining rock quality or rippability. The rippability of a mass is also dependent on the excavation equipment used and the skill and experience of the equipment operator.

For trenching operations , the rippability values should be scaled downward. For example, velocities as low as 3,500 feet/second may indicate difficult ripping during trenching operations.

In addition, the presence of boulders, which can be troublesome in narrow trenching operations, should be anticipated.

Atlas No. 122142SWG
Report No. 1
Page | 3
Table 1 – Rippability Classification
Seismic P-wave Velocity Rippability
0 to 2,000 feet/second Easy
2,000 to 4,000 feet/second Moderate
4,000 to 5,500 feet/second Difficult, Possible Blasting 5,500 to 7,000 feet/second Very Difficult, Probable Blasting Greater than 7,000 feet/second Blasting Generally Required

It should be noted that the rippability cutoffs presented in Table 1 are slightly more conservative than those published in the Caterpillar Performance Handbook. Accordingly, the above classification scheme should be used with discretion, and contractors should not be relieved of making their own independent evaluation of the rippability of the on-site materials prior to submitting their bids.

5. DATA ANALYSIS
As previously indicated, three seismic refraction traverses were conducted as part of our study.

The collected data were processed and analyzed using Rayfract® Version 3.36 (Intelligent Resources Inc., 2021) which employs wave path analysis. Rayfract first provides forward modeling of refraction, transmission, and diffraction and then back-projects travel-time residuals along wave paths also known as Fresnel volumes instead of conventional analysis by rays. This increases the numerical robustness of the invers ion. A smooth minimum-structure 1-D starting velocity-depth profile model is determined automatically directly from the seismic travel-time data first arrival picks and elevation data to produce subsurface velocities by horizontally averaging via the Delta t-V method. The Delta t-V method is based on common mid-point (CMP) sorted travel times and assumes multiple horizontal layers with constant interior velocity gradients (Rohdewald 2007, and Gebrande 1985). Modeled seismic rays follow circular arcs inside each modeled layer.

The Delta t-V starting model is then refined with 2D Wavepath Eikonal Traveltime (WET) inversion method (Schuster, 1993). The resulting 2-D WET velocity model provides a 2-D tomographic image of the P-wave velocities which can be used to estimate subsurface geologic conditions.

Both vertical and lateral velocity information is contained in the tomography model. Changes in layer velocity are generally revealed as gradients rather than discrete contacts, which typically are more representative of actual conditions.

6. RESULTS AND CONCLUSIONS
As previously indicated, three seismic traverses were performed in accessible areas at the project site. Figures 4a through 4c present the velocity models generated from our analysis. The results from our seismic study revealed distinct layers/zones in the near surface that likely represent soil and colluvium overlying bedrock with varying degrees of weathering. Distinct vertical and lateral velocity variations are evident in the models. These inhomogeneities are likely related to the

Atlas No. 122142SWG
Report No. 1
Page | 4
presence of remnant boulders, intrusions, and differential weathering of the bedrock materials. It is also evident in the tomography models that the depth to bedrock is varied across the site.

Based on the refraction results, variability in the excavatability (including depth of rippability) of the subsurface materials should be expected across the project area. Furthermore, blasting may be required depending on the excavation, depth, location, equipment used, and desired rate of production. In addition, oversized materials should be expected. A contractor with excavation experience in similarly difficult conditions should be consulted for expert advice on excavation methodology, equipment, and production rate.

7. LIMITATIONS
The field evaluation and geophysical analyses presented in this report have been conducted in general accordance with current practice and the standard of care exercised by consultants performing similar tasks in the project area. No warranty, express or implied, is made regarding the conclusions, recommendations, and opinions presented in this report. There is no evaluation detailed enough to reveal every subsurface condition. Variations may exist and conditions not observed or described in this report may be present. Uncertainties relative to subsurface conditions can be reduced through additional subsurface exploration. Additional subsurface surveying will be performed upon request.

This document is intended to be used only in its entirety. No portion of the document, by itself, is designed to completely represent any aspect of the project described herein. Atlas should be contacted if the reader requires additional information or has questions regarding the content, interpretations presented, or completeness of this document. This report is intended exclusively for use by the client. Any use or reuse of the findings, conclusions, and/or recommendations of this report by parties other than the client is undertaken at said parties’ sole risk.

8. SELECTED REFERENCES
Caterpillar, Inc., 2018, Caterpillar Performance Handbook, Edition 48, Caterpillar, Inc., Peoria, Illinois.

Gebrande H. and Miller H., 1985, Refraktionsseismik (in German). In: F. Bender (Editor), Angewandte Geowissenschaften II. Ferdinand Enke, Stuttgart; pp. 226-260. ISBN 3-432- 91021-5.

Intelligent Resources Inc., 2021, Rayfract® Version 4.02.

Mooney, H.M., 1976, Handbook of Engineering Geophysics, dated February.

Rimrock Geophysics, 2003, Seismic Refraction Interpretation Program (SIPwin), V-2.76.

Rohdewald S., 2007, XTV inversion. See http://rayfract.com/xtv_inversion.pdf

Atlas No. 122142SWG
Report No. 1
Page | 5
Schuster, G.T. and Quintus-Bosz, A., 1993, Wavepath eikonal traveltime inversion: Theory.

Geophysics, 58(9), 1314-1323.

Telford, W.M., Geldart, L.P., Sheriff, R.E., and Keys, D.A., 1976, Applied Geophysics, Cambridge University Press.

SITE LOCATION MAP
Figure 1
Whitewood Parcel 1 Refraction Study
Murrieta, California
Date: 06/22
N
Project No.: 122142SWG
SL-3
SL-1
SL-2
Clinton Keith Road
Approximate Locations
Of Seismic Lines
Figure 2

SEISMIC LINE LOCATION
MAP
Whitewood Parcel 1 Refraction Study
Murrieta, California
Date: 06/22
N
Project No.: 122142SWG
SL-1
192
0 SL-2
192
0SL-3
240
0 Clinton Keith Road
Arendt Lane
approximate scale in feet
100 2000
Figure 3
Whitewood Parcel 1 Refraction Study
Murrieta, California
Date: 06/22

SITE PHOTOGRAPHS
SL-1 through SL-3
Project No.: 122142SWG
SL-1
SL-2 SL-3

P-WAVE PROFILE
SL-1
Figure 4a
Project No.: 122142SWG Date: 06/22

TOMOGRAPHY MODEL
SL-1
Note: Contour Interval = 1,000 feet per second
Velocity (ft/s)
Distance (ft)
Relative Elevation (ft)
Whitewood Parcel 1 Refraction Study
Murrieta, California
NE SW
3000
3000
5000 5000
7000 7000
9000
9000
11000 13000
15000
0 20 40 60 80 100 120 140 160 180 200
SL-1 RMS error 3.1%=0.74ms 20 WET itr. 50Hz Width 3.0% initial DELTATV.GRD v. 3.36 -60
-40
-20
0 20
2000 4000 6000 8000 10000 12000 14000 16000

P-WAVE PROFILE
SL-2
Figure 4b
Project No.: 122142SWG Date: 06/22

TOMOGRAPHY MODEL
SL-2
Note: Contour Interval = 1,000 feet per second
Velocity (ft/s)
Distance (ft)
Relative Elevation (ft)
Whitewood Parcel 1 Refraction Study
Murrieta, California
S N
4000
4000
6000
6000
8000
8000
10000
10000
12000
14000
0 20 40 60 80 100 120 140 160 180
SL-2 RMS error 2.9%=0.68ms 20 WET itr. 50Hz Width 3.0% initial DELTATV.GRD v. 3.36 -100
-80
-60
-40
-20
0 2000 4000 6000 8000 10000 12000 14000

P-WAVE PROFILE
SL-3
Figure 4c
Project No.: 122142SWG Date: 06/22

TOMOGRAPHY MODEL
SL-3
Note: Contour Interval = 1,000 feet per second
Velocity (ft/s)
Distance (ft)
Relative Elevation (ft)
Whitewood Parcel 1 Refraction Study
Murrieta, California
S N
4000
6000
8000
10000
12000
14000
16000
0 50 100 150 200
SL-3 RMS error 3.2%=0.79ms 20 WET itr. 50Hz Width 3.0% initial DELTATV.GRD v. 3.36 -100
-80
-60
-40
-20
0 20
2000 4000 6000 8000 10000 12000 14000 16000 18000

APPENDIX A-3

Exploration Logs Previous Study (Leighton 2006)

TEST PITS
Sample TYP~
Depth (FI? & Depth Geol. Unit Description
Test Pit # 0-2.5 SM Artificial Fill (Afu) Brown (10YR5/3), dry to damp, massive, medium dense, SAND with gravel TP-33 2.5-4.0 S W Topsoil/Colluvium Dark Brown (10YR3/3), damp, massive, medium dense, slightly silty SAND

4.0-6.0 Granite (Kgr) Light Gray, damp, very dense, weathered granite, breaking to coarse SAND Refusal @ 6.0 ft, no G.W., backfilled with native soil 7/7/06 Sample Type USCS
(FI? a Depth Geol. Unit Description
Test Pit # 0-3.0 SSM Topsoil Brown (10YR3/3), dry, massive, loose to medium dense, slightly silty SAND with Kgr gravel TP-34 3.0-5.0 8-5 SW Weathered Granite (Kgr) Light Gray, dry, very dense, slightly weathered granite, breaking to medium coarse angular cobbles

5.0+ Refusal @ 5.0 ft, no G.W., backfilled with native soil 7/7/06 Sample Type
Depth (n3 & Depth Geol. Unit Description
Test Pit # 0-2.0 8-8 SM Artificial Fill (Afu) Brown (10YR5/3), dry, massive, dense, silty SAND TP-35 2.0-4.0 SM Weathered Gabbro (Kgb) Dark Gray, damp, dense, weathered gabbro breaking to fine to medium SAND

4.0+ Refusal @ 4.0 ft, no G.W., backfilled with native soil 7/7/06 Sample Type
Depth (m & Depth USCS Geol. Unit Description
Test Pit # 0-2.0 SW-SM ' Topsoil/Collwium Brown (10YR5/3), dry, loose to medium dense, silty SAND TP-36 2.0-8.0 B-9 SM Weathered Granite (Kgr) Light Gray, damp, medium dense, very weathered granite breaking to medium silty SAND

8.0+ Refusal@ 8.0 R, no G.W., backfilled with native soil 7/7/06 Sample Type USCS
Depth (FI? & Depth Geol. Unit Description
Test Pit # 0-1.5 SM Topsoil/Colluvium Reddish Brown (7.5YR3/4), dry, massive, dense, silty SAND TP-37 1.5-5.0 SM Weathered Gabbro (Kgb) Light Brown, dry, dense, weathered gabbro breaking to medium to coarse SAND

5.0+ Refusal @ 5.0 ft, no G.W., backfilled with native soil 7/7/06

TEST PITS
TP-38 1.0-3.0 ium to coarse SAND
SP Weathered Gabbro (Kgb)
Sample Type (fT) a Depth USCS Geol. Unit Description
Test Pit # 0-1.0 SM Artificial Fill (Afu) Brown (10YR5/3), dry , massive, dense, silty SAND TP-40 1.0-1.5 B-10 SP Weathered Gabbro (Kgb) Lt. Brown, dry, dense, weathered gabbro breaking to coarse SAND

1.5+ Refusal @ 1.5 ft, no G.W., bacK~lled with native soil 7/7/06 4 Leighlan MODIFIED PROCTOR COMPACTION TEST
ASTM D 1557
Project Name: BCCK 320 Tested By : GEB Date: 07/13/06
Project No. : 111952-001 Input By : JHW Date: 07/14/06
Boring No.: TP-36 Depth (ft.) 5-8
Sample No. : B-9
Soil Identification: Dark Brown Silty Sand (SM)
Preparation Method: Moist
Dry Manual Ram
Mold Volume (R') ( Ram We@ht = 10 1b.; Drop = 18 h
Maximum Dry Density (pcf) 1 124.0 1 Optimum Moisture Content (O/O)~ 10.5 1

PROCEDURE USED
Procedure A
Soil Passing No. 4 (4.75 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
May be used if +#4 is 20% or less
Procedure B
Soil Passing 318 in. (9.5 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
Use if +#4 is >20% and +3/8 in. is
20% or less
Procedure C
Soil Passing 314 in. (19.0 mrn) Sievt
Mold : 6 in. (152.4 mrn) diameter
Layers : 5 (Five)
Blows per layer : 56 (fifty-six)
Use if +3/8 in. is 1201 and +3h in.
is <30%
Particle-Size Distribution:
m

SEISMIC REFRACTION SURVEY

PROPOSED RESIDENTIAL DEVELOPMENT

MURRIETA, CALIFORNIA
PREPARED FOR:

Leighton & Associates, Inc.
4171 5 Enterprise Circle N., Suite 103
Temecula, California 92590-566 1
PREPARED BY:

Southwest Geophysics, Inc.
7438 Trade Street
San Diego, California 92 12 1
July 25,2006
Project No. 1061 12
YOUR rWsbw SOLUTION
July 25,2006
Mr. MifchBornyasz
rsigbn & Associates, Inc.
41715 Enteqnise Circle N., Suite 103
Temecula, California 92590-5661
Subjeot: Seismic Refraction Survey
Proposed Residential Development
Murrieta, California
Project No. 1061 12
Dear Mr. Bornyasz:

In acco~ with your authakdion, we have perfomcd a seismic refraction survey for a pro- posed resideatid development to be located wrth of Clinton Keith Road, east of Meadowlark Lam, west of Menifee Road, and south of Baxter Road in Mwrieb, Calif&. Specifically, -our services included the perfoxmance of eight stismic refraction traverses at prt-selected locati~lss in the project area. The purpose of the survey was to evaluate the apparent rippdility of the sub- surf- mat* and to devekrp a ziubsurfwe velocity profile of the areas surveyed. This report presents the survey methodology, equipment used, dysis, aod findings. to be of service on this project. Should you have my @om contact the undersigned at your convenience.

Sincerely,
SO-ST GEOPHYSICS, INC.

Patrick Leu P.G., RGp.

Principal GeologistlGeophysicist
Distrihtkn: Addressee (electronic)
Hans van de Vmgt, C.E.G., R.Gp.

Principal Geologist/Geophysicist
Proposed Residential Development
Murrieta, California
July 25,2006
Project No. 1061 12

TABLE OF CONTENTS
Page

1. INTRODUCTION ............................................................................... ..................................... 1

2. SCOPE OF SERVICES ............................................................................................................ 1

3. SITE AND PROJECT DESCRIPTION .. ..................................................................... ............ 1

4. SURVEY METHODOLOGY ..... . . .. . .. . .. . . .. . ... . . . . .. . .. . .. . . .. . . . . .. . . .. . .. . .. .. . . . . . . .. . . .. . .. . . . .... .. . . .. , . ..... . . . . ..2

5. RESULTS ....................................... ......................................................... .... ...... ...... . ................ 3

6. CONCLUSIONS AND RECOMMENDATIONS ................................................................... 4

7. LIMITATIONS.. . . . .. .. .. . . . . .. .... .. .. .. .. .. . . .. .. .. .. . . .. . . .. . . . . .. .. . . . . . ... . .. . . .. . . . . .. .. . . . . . . .. . . .. . .. ... .. . . .. . . .. . . .. . . .. .. .. .5

8. SELECTED REFERENCES . . .. .. .. . . .. .. . . .. . . .. ... . .. . . . .. .. .. . . .. . . .. . . .. . . .. .. ... . .. .. .. . . .. . .. . .. . . . . . . . . .. . . . . . .... .. ... .6 Tables
Table 1 - Rippability Classification ................................................................................................ 3 Table 2 - Seismic Traverse Results ................................................................................................. 4 Figures
Figure 1
Figure 2a
Figure 2b
Figure 2c
Figure 3a
Figure 3b
Figure 4a
Figure 4b
Figure
4c
Figure 4d
- Site Location Map
- Seismic Line Location Map, Lines SL-1 through SL-4
- Seismic Line Location Map, Lines SL-5 and SL-8
- Seismic Line Location Map, Lines SL-6 and SL-7
- Site Photographs
- Site Photographs
- Seismic Profiles, SL-1 and SL-2
- Seismic Profiles, SL-3 and SL-4
- Seismic Profiles, SL-5 and SL-6
- Seismic Profiles, SL-7 and SL-8
Proposed Residential Development
Murrieta, California
July 25,2006
Project No. 1061 12

1. INTRODUCTION
In accordance with your authorization, we have performed a seismic refraction survey for a pro- posed residential development to be located north of Clinton Keith Road, east of Meadowlark Lane, west of Menifee Road, and south of Baxter Road in Murrieta, California (Figure 1). Spe- cifically, our services included the performance of eight seismic refraction traverses at pre- selected locations in the project area. The purpose of the survey was to evaluate the apparent rip- pability of the subsurface materials and to develop a subsurface velocity profile of the areas surveyed. This report presents the survey methodology, equipment used, analysis, and findings.

2. SCOPE OF SERVICES
Our scope of services included:

Review of a site map provided by your office.

Performance of eight seismic refraction profiles.

Compilation and geophysical analysis of the data collected.

Preparation of this report presenting our findings and conclusions.

3. SITE AND PROJECT DESCRIPTION
The subject site consists of several parcels of land comprising approximately 320 acres. Many of the parcels are occupied with single family homes whereas the remaining land is generally unde- veloped. The project area is generally bounded to the south by Clinton Keith Road, to the west by Meadowlark Lane, to the east by Menifee Road, and to the north by Baxter Road. Several addi- tional dirt roads transect the project area. Topography in the study area consists of low lying hills and small drainages. Numerous granitic rock outcrops are present on site (Figures 2a, 2b, and 2c).

Vegetation consists of annual grass, scattered brush and scattered trees (Figures 3a and 3b).

Based on our discussions with you, it is our understanding that the purpose of our survey is to provide preliminary subsurface geophysical data for use in the planning phase of the proposed development. Details regarding proposed excavation depths or locations were not available at the time of our survey; however, it is anticipated that cuts will be less than 30 feet deep.

Proposed Residential Development
Murrieta, California
July 25,2006
Project No. 1061 12
-- - - - - - - - - - - --

4. SURVEY METHODOLOGY
A P-wave (compression wave) refraction survey was conducted at the site to evaluate the apparent rippability of the subsurface materials and to develop a subsurface velocity profile of the site. The seismic refraction method uses first-arrival times of refracted seismic waves to estimate the thick- nesses and seismic velocities of subsurface layers. P-waves generated at the surface using a hammer and plate, are refracted at boundaries separating materials of contrasting velocities. These refracted seismic waves are then detected by a series of vertical component geophones at the sur- face and recorded with a 24-channel Geometries Strataview seismograph. The travel times of the P-waves are used in conjunction with the shot-to-geophone distances to obtain thickness and ve- locity information on the subsurface materials. Eight seismic lines/profiles were conducted at the site (SL-1 through SL-8). The locations and length of the lines were selected by your office prior to our survey. The approximate locations of the lines are depicted on Figures 2a, 2b, and 2c. Shot points were located at each end of the line and at the midpoint.

The refraction method requires that subsurface velocities increase with depth. A layer having a velocity lower than that of the layer above will not be detectable by the seismic refraction method and, therefore, could lead to errors in the depth calculations of subsequent layers. In addition, lat- eral velocity variations, such as those caused by core stones or intrusions, can also result in the misinterpretation of the subsurface conditions.

In general, seismic wave velocities can be correlated to material density and/or rock hardness. The relationship between rippability and seismic velocity is empirical and assumes a homogenous mass. Localized areas of differing composition, texture, and/or structure may affect both the measured data and the actual rippability of the mass. The rippability of a mass is also dependent on the excavation equipment used and the skill and experience of the equipment operator.

The rippability values presented in Table 1 are based on our experience with similar materials and assume that a Caterpillar D-9 dozer ripping with a single shank is used. We emphasize that the cutoffs in this classification scheme are approximate and that rock characteristics, such as fracture Proposed Residential Development
Murrieta, California
July 25,2006
Project No. 1061 12
density and orientation, play a significant role in determining rock rippability. These characteris- tics may also vary with location and depth.

Table 1 - Rippability Classification
Seismic P-wave Velocity Rippability
0 to 2,000 feetlsecond Easy
2,000 to 4,000 feetlsecond Moderate
4,000 to 5,500 feedsecond Difficult, Possible Local Blasting 5,500 to 7,000 feedsecond Very Difficult, Probable Local to General Blasting Greater than 7,000 feedsecond Blasting Generally Required For trenching operations, the rippability values should be scaled downward. For example, veloci- ties as low as 3,500 feetlsecond may indicate difficult ripping during trenching operations. In addition, the presence of boulders, which can be troublesome in a narrow trench, should be an- ticipated.

It should be noted that the rippability cutoffs presented in Table 1 are slightly more conservative than those published in the Caterpillar Performance Handbook (Caterpillar, 2004). Accordingly, the above classification scheme should be used with discretion and contractors should not be re- lieved of making their own independent evaluation of the rippability of the on-site materials prior to submitting their bids.

5. RESULTS
Table 2 lists the average P-wave velocities and depths calculated from the seismic refraction trav- erses conducted during this evaluation. The approximate locations of the seismic refraction traverses are shown on Figures 2a, 2b, and 2c. The layer profiles are included in Figures 4a, 4b, 4c and 4d. Please note the vertical scale changes for the profiles. It should also be noted that, as a general rule, the effective depth of evaluation for a seismic rehction traverse is approximately one-third to one-fifth the length of the refraction line. The lengths of the seismic refraction lines are listed with their interpretations in Table 2.

Proposed Residential Development
Munieta, California
July 25,2006
Project No. 1061 12

6. CONCLUSIONS AND RECOMMENDATIONS
The results from our seismic survey indicate three distinct layers in the area of our seismic lines.

Based on our site observations and discussions with you, these layers have been interpreted to generally consist of topsoiVcolluvium overlying weathered granitic rock with less weathered rock at depth.

Table 2 - Seismic Traverse Results
Based on the seismic refi-action results, the layer velocities are generally consistent in the areas surveyed. However, the layer thicknesses are variable. During our site visit, we noted the presence of numerous rock outcrops. The presence of these outcrops at the site, indicate differential weath- ering of the onsite granitics. Furthermore, significant scatter was noted in the first-arrivals Rippability*
Moderate
Moderate
Blasting Generally Required
Easy
Moderate
Blasting Generally Required
Moderate
Moderate
Blasting Generally Required
Moderate
Moderate
Blasting Generally Required
Moderate
Moderate
Blasting Generally Required
Easy
Moderate
Blasting Generally Required
%Y
Moderate
Blasting Generally Required
Moderate
Moderate
Blasting Generally Required
Traverse No.

And Length
SL- 1
230 feet
SL-2
230 feet
SL-3
230 feet
SL-4
230 feet
SL-5
230 feet
SL-6
230 feet
SL-7
230 feet
SL-8
230 feet
* Rippability criteria
P-wave Velocity
feethecond
V1 = 2,450
V2 = 3,800
V3 > 10,000
V1 = 1,950
V2 = 3,050
V3 > 10,000
V1 = 2,150
V2 = 3,900
V3 = 9,250
V1 = 2,450
V2 = 3,650
V3 = 8,350
V1 = 2,500
V2 = 3,200
V3 > 10,000
V1 = 1,800
V2 = 3,800
V3 = 9,700
V1 = 1,700
V2 = 3,200
V3 > 10,000
V1 = 2,450
V2 = 3,500
V3 > 10,000
based on the use of a Caterpillar
Approximate Depth to
Bottom of Layer in feet
2- 18
23 - 55
---
2- 11
27 - 38
---
1-7
16-32
---
1-7
13-40
---
1-16
49 - 58
---
1-11
28 - 40
---
1-5
34 - 52
---
2-8
14 - 26
---
D-9 dozer ripping with a single shank
Proposed Residential Development
Munieta, California
July 25,2006
Project No. 1061 12
indicating the presence of inhomogeneities in the subsurface materials. Accordingly, significant variability in the excavatability (including excavation depth) of the subsurface materials should be expected across the project area. A contractor with excavation experience in similar conditions should be consulted for expert advice on excavation methodology, equipment, production rate, and oversized materials. Following the completion of a site grading plan, we recommend that an additional rippability study be conducted in the areas of proposed cuts in order to provide area specific excavatability information.

7. LIMITATIONS
The field evaluation and geophysical analyses presented in this report have been conducted in general accordance with current practice and the standard of care exercised by consultants per- forming similar tasks in the project area. No warranty, expressed or implied, is made regarding the conclusions, recommendations, and opinions presented in this report. There is no evaluation detailed enough to reveal every subsurface condition. Variations may exist and conditions not ob- served or described in this report may be present. Uncertainties relative to subsurface conditions can be reduced through additional subsurface exploration. Additional subsurface surveying will be performed upon request.

This document is intended to be used only in its entirety. No portion of the document, by itself, is designed to completely represent any aspect of the project described herein. Southwest Geophys- ics, Inc. should be contacted if the reader requires additional information or has questions regarding the content, interpretations presented, or completeness of this document. This report is intended exclusively for use by the client. Any use or reuse of the findings, conclusions, andlor recommendations of this report by parties other than the client is undertaken at said parties' sole risk.

Proposed Residential Development
Murrieta, California
July 25,2006
Project No. 1061 12

8. SELECTED REFERENCES
Caterpillar, Inc., 2004, Caterpillar Performance Handbook, Edition 35, Caterpillar, Inc., Peoria, Illinois.

Mooney, H.M., 1976, Handbook of Engineering Geophysics, dated February.

Rimrock Geophysics, 2003, Seismic Refraction Interpretation Programs (SIPwin), V-2.76.

Telford, W.M., Geldart, L.P., Sheriff, R.E., and Keys, D.A., 1976, Applied Geophysics, Cambridge University Press.

SEtShnrc PROFILES,
a
-28
-t@
dl)
SEJSMIC PROFILES, Proposed Res#entEal Dsvskpmbnt
Muniero. Calllbmie
8Lb AND SL-6 Rd#t No.: log112 I f28b:QIm Figure 4c
I1 ill
0 so U1) l80 2.0 ft
mAWCIwrar
SEISMiC PROFILES,

APPENDIX B-1

Geotechnical Laboratory Testing (this study)

Project Name: Tested By: F. Mina Date: 06/03/22
Project No. : Input By: M. Vinet Date: 06/06/22
Boring No.: Checked By: M. Vinet
Sample No.: Depth (ft.) 0 - 2.5
Soil Identification:
1 2 1 2
25 25 Trial 1 = 28

24.12 23.41 23.24 22.92 Trial 2 = 28

23.08 22.42 21.16 20.92 Ave. LL = 28

13.79 13.59 13.65 13.67 (see equation below)

11.19 11.21 27.70 27.59
28 11
17 CL
PI at "A" - Line = 0.73(LL-20) 5.84
One - Point Liquid Limit Calculation
LL =Wn(N/25)
(Wn = water content, N = number of blows)

PROCEDURES USED
Wet Preparation
Multipoint - Wet
X Dry Preparation
One-point
Procedure A
Multipoint Test
X Procedure B
One-point Test
Dry Wt. of Soil + Cont. (g)
Wt. of Container (g)
Moisture Content (%) [Wn]
Liquid Limit
Plastic Limit
Plasticity Index
Classification
Number of Blows [N]
Wet Wt. of Soil + Cont. (g)

LIQUID LIMIT PLASTIC LIMIT
Sandy Lean Clay s(CL), Dark Yellowish Brown.

TEST
NO.

ATTERBERG LIMITS
ASTM D 4318
Sancerra/Whitewood I/Geo
13142.005
TP-5
B-1
0 10
20 30
40 50
60 0 10 20 30 40 50 60 70 80 90
10 Plasticity Index (PI)
Liquid Limit (LL)

0.121
CL or OL
ML or OL
MH or OH
For classification of fine-
grained soils and fine-
grained fraction of coarse-
grained soils
"A" Line
7 4
CH or OH
CL- ML
26 27
28 29
30 10
100
Moisture Content (%)
Number of Blows
20 25 30 40 50 60 70 80 90

Project Name: Tested By: F. Mina Date: 06/03/22
Project No. : Input By: M. Vinet Date: 06/06/22
Boring No.: Checked By: M. Vinet
Sample No.: Depth (ft.) 1.5 - 3.5
Soil Identification:
1 2 1 2
25 25 Trial 1 = 31

22.84 22.12 22.84 22.06 Trial 2 = 31

21.87 21.23 20.72 20.10 Ave. LL = 31

13.65 13.77 13.85 13.77 (see equation below)

11.80 11.93 30.86 30.96
31 12
19 CL
PI at "A" - Line = 0.73(LL-20) 8.03
One - Point Liquid Limit Calculation
LL =Wn(N/25)
(Wn = water content, N = number of blows)

PROCEDURES USED
Wet Preparation
Multipoint - Wet
X Dry Preparation
One-point
Procedure A
Multipoint Test
X Procedure B
One-point Test
Dry Wt. of Soil + Cont. (g)
Wt. of Container (g)
Moisture Content (%) [Wn]
Liquid Limit
Plastic Limit
Plasticity Index
Classification
Number of Blows [N]
Wet Wt. of Soil + Cont. (g)

LIQUID LIMIT PLASTIC LIMIT
Clayey Sand (SC), Reddish Brown.

TEST
NO.

ATTERBERG LIMITS
ASTM D 4318
Sancerra/Whitewood I/Geo
13142.005
TP-8
B-1
0 10
20 30
40 50
60 0 10 20 30 40 50 60 70 80 90
10 Plasticity Index (PI)
Liquid Limit (LL)

0.121
CL or OL
ML or OL
MH or OH
For classification of fine-
grained soils and fine-
grained fraction of coarse-
grained soils
"A" Line
7 4
CH or OH
CL- ML
29 30
31 32
33 10
100
Moisture Content (%)
Number of Blows
20 25 30 40 50 60 70 80 90

Project Name: Sancerra/Whitewood I/Geo Tested By : M. Vinet Date: 06/06/22 Project No. : 13142.005 Data Input By: M. Vinet Date: 06/06/22 Boring No. TP-1
Sample No. B-1
Sample Depth (ft) 0 - 4.0
100.00
100.00

0.00 0.00
100.00
1 1
850
Timer
45 25.0402

25.0371

0.0031
127.56
128
ml of Extract For Titration (B) 30
ml of AgNO3 Soln. Used in Titration (C) 0.4
PPM of Chloride (C -0.2) * 100 * 30 / B 20
PPM of Chloride, Dry Wt. Basis 20

6.80 21.0
pH TEST, DOT California Test 643
TESTS for SULFATE CONTENT
CHLORIDE CONTENT and pH of SOILS
SULFATE CONTENT, DOT California Test 417, Part II
Soil Identification:

Moisture Content (%)
Temperature °C
pH Value
(SW-SM)g
Wt. of Crucible + Residue (g)
Dry Weight of Soil + Container (g)
Weight of Container (g)
Duration of Combustion (min)
Wet Weight of Soil + Container (g)
Wt. of Residue (g) (A)
Beaker No.

Crucible No.

Furnace Temperature (°C)
Time In / Time Out
Weight of Soaked Soil (g)
PPM of Sulfate, Dry Weight Basis
PPM of Sulfate (A) x 41150
CHLORIDE CONTENT, DOT California Test 422
Wt. of Crucible (g)

Project Name: Tested By : M. Vinet Date:

Project No. : Data Input By: M. Vinet Date:

Boring No.: Depth (ft.) :

Sample No. :

Soil Identification:*
*California Test 643 requires soil specimens to consist only of portions of samples passing through the No. 8 US Standard Sieve before resistivity testing.  Therefore, this test method may not be representative for coarser materials.

Wt. of Container (g)10.00 19000

0.00 100.00
Moisture Content (%) (MCi)
Wet Wt. of Soil + Cont. (g)
Specimen
No.
1 2
Water
Added (ml)
(Wa)
50 Adjusted
Moisture
Content
(MC) Dry Wt. of Soil + Cont. (g)
19000

1.000
Chloride Content
(ohm-cm)

29.80 Moisture Content Sulfate Content
5 Min. Resistivity
DOT CA Test 643DOT CA Test 417 Part II DOT CA Test 422
(%) (ppm) (ppm)
DOT CA Test 643
4 83
116
149
A
500.003 1100023.20
14000
11000 23.2 128 20 6.80 21.0

SOIL RESISTIVITY TEST
DOT CA TEST 643
Temp. (°C)pH
Soil pH
14000
11000
100.00

0.00 MC =(((1+Mci/100)x(Wa/Wt+1))-1)x100
Sancerra/Whitewood I/Geo 06/06/22
06/06/22
0 - 4.0
13142.005
TP-1
B-1
Container No.

Initial Soil Wt. (g) (Wt)
Box Constant12000 12000
(SW-SM)g
Resistance
Reading
(ohm)

16.60 Soil
Resistivity
(ohm-cm)
0 2000
4000
6000
8000
10000
12000
14000
16000
18000
20000

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0
Soil Resistivity (ohm-cm)
Moisture Content (%)
Minimum resistivity
read here

Project Name: Tested By: F. Mina Date: 6/2/22
Project No. : Checked By: M. Vinet Date: 6/6/22
Boring No.: Depth: 0 - 2.5
Sample No. : Location:

Sample Description:

Dry Wt. of Soil + Cont. (gm.)
Wt. of Container No. (gm.)
Dry Wt. of Soil (gm.)
Weight Soil Retained on #4 Sieve
Percent Passing # 4
in distilled water for the period of 24 h or expansion rate < 0.0002 in./h.

Rev. 03-08

0.51676/3/22
0 1345
Expansion Index (EI meas) = ((Final Rdg - Initial Rdg) / Initial Thick.) x 1000 8:00
1405 0.5167

16.7 1.0
17 Expansion Index ( Report ) = Nearest Whole Number or Zero (0) if Initial Height is > than Final Height Add Distilled Water to the Specimen
Wt. of Container (gm.)
112.4

0.5000
10 0.5000
6/3/22 9:00

1.0 1.0
9:35 1.06/2/22
6/2/22
114.3
Moisture Content (%)
Date
9:25
Void Ratio
Pore Volume (cc)
Degree of Saturation (%) [ S meas]
124.6
Time
After TestBefore Test
Wet Wt. of Soil + Cont. (gm.)
7 0.499
Dry Density (pcf)
Wet Density (pcf)
Specific Gravity (Assumed)
Specimen Height (in.)
Wt. of Mold (gm.)

99.9 4.01

2.70 378.7

0.0 593.9
378.7

0.2 1.0167
621.3
N/A
Sancerra/Whitewood I/Geo
13142.005
TP-5
B-1
ASTM D 4829
EXPANSION INDEX of SOILS
Sandy Lean Clay s(CL), Dark Yellowish Brown.

MOLDED SPECIMEN

4.01 1.0000
7Container No.

Specimen Diameter (in.)
Wt. Comp. Soil + Mold (gm.)
180.8

2.70 379.0
180.8

16.2 0.333

70.1 180.8
621.3
130.7
Elapsed Time
(min.)
Dial Readings
(in.)

87.851.2
Pressure
(psi)

0.322Total Porosity

SPECIMEN INUNDATION

66.6 Dry Wt. of Soil + Cont. (gm.)

9.0 350.5
325.7

0.475

50.5 Project Name: Tested By: F. Mina Date: 6/2/22
Project No. : Checked By: M. Vinet Date: 6/6/22
Boring No.: Depth: 1.5 - 3.5
Sample No. : Location:

Sample Description:

Dry Wt. of Soil + Cont. (gm.)
Wt. of Container No. (gm.)
Dry Wt. of Soil (gm.)
Weight Soil Retained on #4 Sieve
Percent Passing # 4
in distilled water for the period of 24 h or expansion rate < 0.0002 in./h.

Rev. 03-08

0.52556/3/22
0 1310
Expansion Index (EI meas) = ((Final Rdg - Initial Rdg) / Initial Thick.) x 1000 8:00
1370 0.5255

25.5 1.0
26 Expansion Index ( Report ) = Nearest Whole Number or Zero (0) if Initial Height is > than Final Height Add Distilled Water to the Specimen
Wt. of Container (gm.)
109.6

0.5000
10 0.5000
6/3/22 9:00

1.0 1.0
10:10 1.06/2/22
6/2/22
112.4
Moisture Content (%)
Date
10:00
Void Ratio
Pore Volume (cc)
Degree of Saturation (%) [ S meas]
122.5
Time
After TestBefore Test
Wet Wt. of Soil + Cont. (gm.)
7 0.538
Dry Density (pcf)
Wet Density (pcf)
Specific Gravity (Assumed)
Specimen Height (in.)
Wt. of Mold (gm.)

99.9 4.01

2.70 378.7

0.0 606.1
378.7

0.2 1.0255
637.2
N/A
Sancerra/Whitewood I/Geo
13142.005
TP-8
B-1
ASTM D 4829
EXPANSION INDEX of SOILS
Clayey Sand (SC), Reddish Brown.

MOLDED SPECIMEN

4.01 1.0000
7Container No.

Specimen Diameter (in.)
Wt. Comp. Soil + Mold (gm.)
200.0

2.70 372.6
200.0

17.3 0.350

74.3 200.0
637.2
128.6
Elapsed Time
(min.)
Dial Readings
(in.)

87.048.6
Pressure
(psi)

0.333Total Porosity

SPECIMEN INUNDATION

69.0 Dry Wt. of Soil + Cont. (gm.)

9.0 350.3
325.5

0.500

50.3 Project Name: Date: 6/2/22
Project Number: 13142.005 Technician: F. Mina
Boring Number: TP-4 Depth (ft.): 0 - 4.0
Sample Number: B-1
Sample Description:

TEST SPECIMEN A B C
MOISTURE AT COMPACTION % 8.8 9.4 10.9
HEIGHT OF SAMPLE, Inches 2.50 2.49 2.50
DRY DENSITY, pcf 117.7 117.7 116.3
COMPACTOR AIR PRESSURE, psi 350 350 350
EXUDATION PRESSURE, psi 770 471 180
EXPANSION, Inches x 10exp-4 0 0 0
STABILITY Ph 2,000 lbs (160 psi) 25 29 55
TURNS DISPLACEMENT 4.39 4.52 5.42
R-VALUE UNCORRECTED 75 71 47
R-VALUE CORRECTED 75 71 47
DESIGN CALCULATION DATA a b c
GRAVEL EQUIVALENT FACTOR 1.0 1.0 1.0
TRAFFIC INDEX 5.0 5.0 5.0
STABILOMETER THICKNESS, ft. 0.39 0.46 0.85
EXPANSION PRESSURE THICKNESS, ft. 0.00 0.00 0.00

EXPANSION PRESSURE CHART EXUDATION PRESSURE CHART R-VALUE BY EXPANSION: N/A
R-VALUE BY EXUDATION: 58
EQUILIBRIUM R-VALUE: 58

R-VALUE TEST RESULTS
ASTM D 2844
Sancerra/Whitewood I/Geo
Silty Sand (SM), Dark Yellowish Brown. N/ASample Location:

0.00 0.50

1.00 1.50

2.00 2.50

3.00 3.50

4.00 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00
COVER THICKNESS BY EXPANSION in
feet
COVER THICKNESS BY STABILOMETER in
feet
0 10
20 30
40 50
60 70
80 90
0100200300400500600700800

R-VALUE
EXUDATION PRESSURE (psi)

Sand Equivalent; TP-4, B-1 (05-23-22)
Project Name: F. Mina Date:

Project No. : F. Mina Date:

Client: M. Vinet Date:
28 7 27 4 #DIV/0! 28 50
09:15 09:25 09:27 09:47 12.2 3.5 29
09:17 09:27 09:29 09:49 12.4 3.4 28
#REF! #REF! #REF! #REF!
T1 = Starting Time T3 = Settlement Starting Time Sand Equivalent = R2 / R1 * 100 T2 = ( T1 + 10 min) Begin Agitation T4 = ( T3 + 20 min) Take Clay Reading (R1) Record SE as Next Higher Integer R2
29 SAND EQUIVALENT TEST
ASTM D 2419 / DOT CA Test 217
6/6/22
T1 T2 T3 T4Boring No.
6/6/22
6/6/22
Tested By:

Computed By:

Checked By:

Depth (ft.) Average
SESoil Description SER1
TP-4 B-1 0 - 4.0 Silty Sand (SM)
13142.005
Sancerra/Whitewood I/Geo
Sancerra Communities - Whitewood, LLC
Sample No.

Project Name: Tested By: FLM Date: 06/03/22
Project No.: 13142.005 Checked By: MRV Date: 06/06/22
Boring No.: TP-1 Depth (feet): 0 - 4.0
Sample No.: B-1
Soil Identification: Well-Graded Sand with Silt and Gravel (SW-SM)g, Dark Reddish Brown.

Whole Sample Sample Passing
#4 Whole Sample Sample
passing #4
B B Wt. of Air-Dry Soil + Cont.(g) 2147.7 994.2
2147.7 994.3 Wt. of Dry Soil + Cont. (g) 2120.8 994.2 673.2 673.2 Wt. of Container No._____(g) 673.2 673.2
1447.0 321.1 Moisture Content (%) 1.9 0.0
B
969.3
673.0

2.0 (mm.)
1 1/2"
1"
3/4"
1/2"
3/8"
#4
#8
#16
#30
#50
#100
#200
GRAVEL: 24 %
SAND: 69 %
FINES: 7 %
GROUP SYMBOL: (SW-SM)g 15.38

1.63 Remarks:
292.5
137.2
202.2
245.3
273.5

0.075
PAN
144.0
178.2
342.64.750

2.360

1.180

0.600

0.300

0.150
Passing #4 Material After Wet Sieve

37.500
U. S. Sieve Size

25.000

19.000

12.500

9.500
Whole Sample

87.7 100.0

76.3 64.5

6.8 95.6

18.0 11.3
Wt. Air-Dried Soil + Cont.(g)

90.0 Cumulative Weight of Dry Soil Retained (g)
Sample Passing #4

PARTICLE-SIZE DISTRIBUTION (GRADATION)
ASTM D 6913
Container No.:

Sancerra/Whitewood I/Geo
Moisture ContentsCalculation of Dry Weights
of SOILS USING SIEVE ANALYSIS
Dry Wt. of Soil (g)

64.3 Wt. of Container (g)
Container No.

0.0 100.0

43.7 28.3
Percent Passing
(%)
Wt. of Dry Soil + Container (g)
Wt. of Container (g)
Dry Wt. of Soil Retained on # 200 Sieve (g)

49.6 Cu = D60/D10 =
Cc = (D30)²/(D60*D10) =

24 : 69 : 7
B-1
Jun-22
Boring No.:

Depth (feet): 0 - 4.0 Soil Type :

Project Name:

PARTICLE - SIZE

DISTRIBUTION
ASTM D 6913
Soil Identification: Well-Graded Sand with Silt and Gravel (SW-SM)g, Dark Reddish Brown.
(SW-SM)g
GR:SA:FI : (%)
Sancerra/Whitewood I/Geo
Project No.:

TP-1 Sample No.:
13142.005
SAND

SILT FINE

HYDROMETER

3.0" 1 1/2" 3/4" 3/8" #4 #8 #16 #30 #50 #100 #200 U.S. STANDARD SIEVE OPENING U.S. STANDARD SIEVE NUMBER

GRAVEL FINES

FINE CLAY COARSE COARSE MEDIUM
0 10
20 30
40 50
60 70
80 90
100

0.0010.0100.1001.00010.000100.000

PERCENT FINER BY WEIGHT
PARTICLE - SIZE (mm)
"
Sieve; TP-1, B-1 (05-23-22)
Project Name: Tested By: FLM Date: 06/03/22
Project No.: 13142.005 Checked By: MRV Date: 06/06/22
Boring No.: TP-4 Depth (feet): 0 - 4.0
Sample No.: B-1
Soil Identification: Silty Sand (SM), Dark Yellowish Brown.

P 1177.6
1177.6 1169.8
716.2 716.2
453.6 1.7
P
1046.5
716.2
330.3
(in.) (mm.)
3" 75.000
1" 25.000
3/4" 19.000
1/2" 12.500
3/8" 9.500
#4 4.750
#8 2.360
#16 1.180
#30 0.600
#50 0.300
#100 0.150
#200 0.075
GRAVEL: 1 %
SAND: 71 %
FINES: 28 %
GROUP SYMBOL: SM N/A
N/A
Remarks:
329.0

58.6 27.5
259.3 42.8
After Wet Sieve Wt. of Dry Soil + Container (g)
Wt. of Container (g)
Dry Wt. of Soil Retained on # 200 Sieve (g)
100.0

99.5 Wt. of Dry Soil + Cont. (g)

89.7 97.89.8
100.0

46.6 Dry Wt. of Soil (g)
Cu = D60/D10 =
Cc = (D30)²/(D60*D10) =

0.0 2.4
PAN
187.9
Moisture Content of Total Air - Dry Soil

75.1 Wt. of Container No._____ (g)
Container No.

Percent Passing (%)
Wt. of Air-Dry Soil + Cont. (g)
113.1
100.0
100.0
Wt. of Air-Dried Soil + Cont.(g)
Moisture Content (%)
100.0
Wt. of Container (g)
U. S. Sieve Size Cumulative Weight
Dry Soil Retained (g)

PARTICLE-SIZE DISTRIBUTION (GRADATION)
ASTM D 6913
Container No.:

Sancerra/Whitewood I/Geo
of SOILS USING SIEVE ANALYSIS

3.0" 1 1/2" 3/4" 3/8" #4 #8 #16 #30 #50 #100 #200 U.S. STANDARD SIEVE OPENING U.S. STANDARD SIEVE NUMBER

GRAVEL FINES

FINE CLAY COARSE COARSE MEDIUM
13142.005
SAND

SILT FINE

HYDROMETER
Sancerra/Whitewood I/Geo
Project No.:

TP-4 Sample No.:

Soil Type :

PARTICLE - SIZE

DISTRIBUTION
ASTM D 6913
Soil Identification: Silty Sand (SM), Dark Yellowish Brown.

SM
GR:SA:FI : (%)
Boring No.:

Depth (feet): 0 - 4.0
Project Name:

B-1
Jun-221 : 71 : 28
0 10
20 30
40 50
60 70
80 90
100

0.0010.0100.1001.00010.000100.000

PERCENT FINER BY WEIGHT
PARTICLE - SIZE (mm)
"
Sieve; TP-4, B-1 (05-23-22)
Project Name: Tested By: FLM Date: 06/03/22
Project No.: 13142.005 Checked By: MRV Date: 06/06/22
Boring No.: TP-5 Depth (feet): 0 - 2.5
Sample No.: B-1
Soil Identification: Sandy Lean Clay s(CL), Dark Yellowish Brown.

M 1075.2
1075.2 1045.2
666.5 666.5
378.7 7.9
M
843.6
666.5
177.1
(in.) (mm.)
3" 75.000
1" 25.000
3/4" 19.000
1/2" 12.500
3/8" 9.500
#4 4.750
#8 2.360
#16 1.180
#30 0.600
#50 0.300
#100 0.150
#200 0.075
GRAVEL: 0 %
SAND: 45 %
FINES: 55 %
GROUP SYMBOL: s(CL) N/A
N/A
Remarks:
171.6

74.4 54.7
133.9 64.6
After Wet Sieve Wt. of Dry Soil + Container (g)
Wt. of Container (g)
Dry Wt. of Soil Retained on # 200 Sieve (g)
100.0

99.9 Wt. of Dry Soil + Cont. (g)

93.6 98.55.5
100.0

24.1 Dry Wt. of Soil (g)
Cu = D60/D10 =
Cc = (D30)²/(D60*D10) =

0.0 0.2
PAN

97.1 Moisture Content of Total Air - Dry Soil

84.4 Wt. of Container No._____ (g)
Container No.

Percent Passing (%)
Wt. of Air-Dry Soil + Cont. (g)

59.2 100.0
100.0
Wt. of Air-Dried Soil + Cont.(g)
Moisture Content (%)
100.0
Wt. of Container (g)
U. S. Sieve Size Cumulative Weight
Dry Soil Retained (g)

PARTICLE-SIZE DISTRIBUTION (GRADATION)
ASTM D 6913
Container No.:

Sancerra/Whitewood I/Geo
of SOILS USING SIEVE ANALYSIS

3.0" 1 1/2" 3/4" 3/8" #4 #8 #16 #30 #50 #100 #200 U.S. STANDARD SIEVE OPENING U.S. STANDARD SIEVE NUMBER

GRAVEL FINES

FINE CLAY COARSE COARSE MEDIUM
13142.005
SAND

SILT FINE

HYDROMETER
Sancerra/Whitewood I/Geo
Project No.:

TP-5 Sample No.:

Soil Type :

PARTICLE - SIZE

DISTRIBUTION
ASTM D 6913
Soil Identification: Sandy Lean Clay s(CL), Dark Yellowish Brown. s(CL)
GR:SA:FI : (%)
Boring No.:

Depth (feet): 0 - 2.5
Project Name:

B-1
Jun-220 : 45 : 55
0 10
20 30
40 50
60 70
80 90
100

0.0010.0100.1001.00010.000100.000

PERCENT FINER BY WEIGHT
PARTICLE - SIZE (mm)
"
Sieve; TP-5, B-1 (05-23-22)
Project Name: Tested By: FLM Date: 06/03/22
Project No.: 13142.005 Checked By: MRV Date: 06/06/22
Boring No.: TP-6 Depth (feet): 1.5 - 4.5
Sample No.: B-1
Soil Identification: Silty Sand (SM), Dark Yellowish Brown. 123 1110.6
1110.6 1102.5
699.5 699.5
403.0 2.0
123
1057.7
699.5
358.2
(in.) (mm.)
3" 75.000
1" 25.000
3/4" 19.000
1/2" 12.500
3/8" 9.500
#4 4.750
#8 2.360
#16 1.180
#30 0.600
#50 0.300
#100 0.150
#200 0.075
GRAVEL: 1 %
SAND: 86 %
FINES: 13 %
GROUP SYMBOL: SM N/A
N/A
Remarks:
351.1

38.9 12.9
311.0 22.8
After Wet Sieve Wt. of Dry Soil + Container (g)
Wt. of Container (g)
Dry Wt. of Soil Retained on # 200 Sieve (g)
100.0

99.2 Wt. of Dry Soil + Cont. (g)

73.4 92.630.0
100.0
107.0
Dry Wt. of Soil (g)
Cu = D60/D10 =
Cc = (D30)²/(D60*D10) =

0.0 3.1
PAN
246.3
Moisture Content of Total Air - Dry Soil

56.5 Wt. of Container No._____ (g)
Container No.

Percent Passing (%)
Wt. of Air-Dry Soil + Cont. (g)
175.3
100.0
100.0
Wt. of Air-Dried Soil + Cont.(g)
Moisture Content (%)
100.0
Wt. of Container (g)
U. S. Sieve Size Cumulative Weight
Dry Soil Retained (g)

PARTICLE-SIZE DISTRIBUTION (GRADATION)
ASTM D 6913
Container No.:

Sancerra/Whitewood I/Geo
of SOILS USING SIEVE ANALYSIS

3.0" 1 1/2" 3/4" 3/8" #4 #8 #16 #30 #50 #100 #200 U.S. STANDARD SIEVE OPENING U.S. STANDARD SIEVE NUMBER

GRAVEL FINES

FINE CLAY COARSE COARSE MEDIUM
13142.005
SAND

SILT FINE

HYDROMETER
Sancerra/Whitewood I/Geo
Project No.:

TP-6 Sample No.:

Soil Type :

PARTICLE - SIZE

DISTRIBUTION
ASTM D 6913
Soil Identification: Silty Sand (SM), Dark Yellowish Brown.

SM
GR:SA:FI : (%)
Boring No.:

Depth (feet): 1.5 - 4.5
Project Name:

B-1
Jun-221 : 86 : 13
0 10
20 30
40 50
60 70
80 90
100

0.0010.0100.1001.00010.000100.000

PERCENT FINER BY WEIGHT
PARTICLE - SIZE (mm)
"
Sieve; TP-6, B-1 (05-23-22)
Project Name: Tested By: FLM Date: 06/03/22
Project No.: 13142.005 Checked By: MRV Date: 06/06/22
Boring No.: TP-8 Depth (feet): 1.5 - 3.5
Sample No.: B-1
Soil Identification: Clayey Sand (SC), Reddish Brown.

Whole Sample Sample Passing
#4 Whole Sample Sample
passing #4
SR SR Wt. of Air-Dry Soil + Cont.(g) 2100.0 997.8
2100.0 997.8 Wt. of Dry Soil + Cont. (g) 2017.6 997.8 696.4 696.4 Wt. of Container No._____(g) 696.4 696.4
1321.7 301.4 Moisture Content (%) 6.2 0.0
SR
861.7
696.4

2.0 (mm.)
1 1/2"
1"
3/4"
1/2"
3/8"
#4
#8
#16
#30
#50
#100
#200
GRAVEL: 4 %
SAND: 50 %
FINES: 46 %
GROUP SYMBOL: SC 15.38

1.63 Remarks:
159.3

15.3 36.0

64.8 104.8

0.075
PAN

10.7 24.3

46.64.750

2.360

1.180

0.600

0.300

0.150
Passing #4 Material After Wet Sieve

37.500
U. S. Sieve Size

25.000

19.000

12.500

9.500
Whole Sample

98.2 100.0

96.5 95.2

45.5 100.0

75.8 62.9
Wt. Air-Dried Soil + Cont.(g)

99.2 Cumulative Weight of Dry Soil Retained (g)
Sample Passing #4

PARTICLE-SIZE DISTRIBUTION (GRADATION)
ASTM D 6913
Container No.:

Sancerra/Whitewood I/Geo
Moisture ContentsCalculation of Dry Weights
of SOILS USING SIEVE ANALYSIS
Dry Wt. of Soil (g)

0.0 Wt. of Container (g)
Container No.
100.0

91.6 85.0
Percent Passing
(%)
Wt. of Dry Soil + Container (g)
Wt. of Container (g)
Dry Wt. of Soil Retained on # 200 Sieve (g)

4.0 Cu = D60/D10 =
Cc = (D30)²/(D60*D10) =

4 : 50 : 46
B-1
Jun-22
Boring No.:

Depth (feet): 1.5 - 3.5 Soil Type :

Project Name:

PARTICLE - SIZE

DISTRIBUTION
ASTM D 6913
Soil Identification: Clayey Sand (SC), Reddish Brown.

SC
GR:SA:FI : (%)
Sancerra/Whitewood I/Geo
Project No.:

TP-8 Sample No.:
13142.005
SAND

SILT FINE

HYDROMETER

3.0" 1 1/2" 3/4" 3/8" #4 #8 #16 #30 #50 #100 #200 U.S. STANDARD SIEVE OPENING U.S. STANDARD SIEVE NUMBER

GRAVEL FINES

FINE CLAY COARSE COARSE MEDIUM
0 10
20 30
40 50
60 70
80 90
100

0.0010.0100.1001.00010.000100.000

PERCENT FINER BY WEIGHT
PARTICLE - SIZE (mm)
"
Sieve; TP-8, B-1 (05-23-22)

APPENDIX B-2

Previous Studies Geotechnical Laboratory

4 Leighton MODIFIED PROCTOR COMPACTION TEST
ASTM D 1557
Project Name: BCCK 320 Tested By : GEB Date: 07/13/06
Project No. : 11 1952-001 Input By : JHW Date: 07/14/06 Boring No.: TP-3 Depth (ft.) 2-4 (Tag: 0-2)
Sample No. : B-2
Soil Identification: Olive Silty Sand (SM)
Preparation Method: Moist
Dry Manual Ram
Mold Volume (ft3) 1 Ram Weight = 10 lb,; Drop = 18 in.

Maximum Dry Density (pcf) 1 129.0 1 Optimum Moisture Content (o/o)~ 10.0 I Weight of Container (9)
Moisture Content (%)
Wet Density (~cf)
Dry Density (pd)

PROCEDURE USED
IIC] ProcedureA
Soil Passing No. 4 (4.75 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
May be used if +#4 is 20% or less

54.50 7.32
135.0
125.8
Procedure B
Soil Passing 318 in. (9.5 rnm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
Use if +#4 is >20% and +3/8 in. is
20% or less
Procedure C
Soil Passing 314 in. (19.0 rnm) Sievc
Mold : 6 in. (152.4 mm) diameter
Layers : 5 (Five)
Blows per layer : 56 (fifty-six)
Use if +3/8 in. is >20°/0 and +3/4 in.
is <30%

51.40 9.64
141.3
128.9
Particle-Size Distribution:
m

51.40 12.67
142.5
126.4
MX TP-3, 8-2 @ 24 (Tag 0-2)
4 Leighlon MODIFIED PROCTOR COMPACTION TEST
ASTM D 1557
Project Name: BCCK 320 Tested By : GEB Date: 07/13/06
Project No. : 111952-001 Input By : JHW Date: 07/14/06
Boring No.: TP-28 Depth (ft.) 0-5
Sample No. : 8-4
Soil Identification: Dark Brown Silty Sand (SM)
Preparation Method: Moist X Mechanical Ram
Dry El Manual Ram
MoldVolume((t3) 1 RatnWeight=10/b.; D~mp=18ih.

Maximum Dry Density (pd) 1 133.5 1 Optimum Moisture Content (O/O)~ 8m0 I

PROCEDURE USED
[Ilj ProcedureA
Soil Passing No. 4 (4.75 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers: 5 (Five)
Blows per layer : 25 (twenty-five)
May be used if +#4 is 20% or less
Procedure B
Soil Passing 318 in. (9.5 rnm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
Use if +#4 is >20% and +3/8 in. is
20°h or less
ProcedureC
Soil Passing 314 in. (19.0 mm) Sievc
Mold : 6 in. (152.4 mm) diameter
Layers : 5 (Five)
Blows per layer : 56 (fifty-six)
Use if +3/8 in. is >20% and +3/4 in.
is <30%
Particle-Size Distribution:

Gs
Atterberg Limits:
1 Moisture Content (%)
MX TP-28, 6-4 @ 0-5
4 Leighlon MODIFIED PROCTOR COMPACTION TEST
ASTM D 1557
Project Name: BCCK 320 Tested By : GEB Date: 07/13/06
Project No.: 11 1952-001 Input By : JHW Date: 07/24/06
Boring No.: TP-32 Depth (ft.) 4-8 (Tag: 0-5)
Sample No. : 8-7
Soil Identification: Dark Brown Sandy Silt s(ML)
Preparation Method: Moist
Dry Manual Ram
Mold Volume (R3) (1 Ram Weight = 10 Ib.; Dmp = 18 in
Maximum Dry Density (pcf) 1124.0 Optimum Moisture Content (~/o)vI

PROCEDURE USED
[XI ProcedureA
Soil Passing No. 4 (4.75 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
May be used if +#4 is 20Y0 or less
Procedure B
Soil Passing 318 in. (9.5 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
Use if +#4 is 220% and +3/8 in. is
20% or less
Procedure C
Soil Passing 314 in. (19.0 mm) Sievc
Mold : 6 in. (152.4 mm) diameter
Layers : 5 (Five)
Blows per layer : 56 (fifty-six)
Use if +3/8 in. is >20°/6 and +3h in.
is ~30%
Particle-Size Distribution:
-
Moisture Content (%)
MX TP32, 8-7 @ 4-8 (Tag 05)
4 Leighlan MODIFIED PROCTOR COMPACTION TEST
ASTM D 1557
Project Name: BCCK 320 Tested By : GEB Date: 07/13/06
Project No. : 111952-001 Input By : JHW Date: 07/14/06
Boring No.: TP-36 Depth (ft.) 5-8
Sample No. : B-9
Soil Identification: Dark Brown Silty Sand (SM)
Preparation Method: Moist
Dry Manual Ram
Mold Volume (R') ( Ram We@ht = 10 1b.; Drop = 18 h
Maximum Dry Density (pcf) 1 124.0 1 Optimum Moisture Content (O/O)~ 10.5 1

PROCEDURE USED
Procedure A
Soil Passing No. 4 (4.75 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
May be used if +#4 is 20% or less
Procedure B
Soil Passing 318 in. (9.5 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
Use if +#4 is >20% and +3/8 in. is
20% or less
Procedure C
Soil Passing 314 in. (19.0 mrn) Sievt
Mold : 6 in. (152.4 mrn) diameter
Layers : 5 (Five)
Blows per layer : 56 (fifty-six)
Use if +3/8 in. is 1201 and +3h in.
is <30%
Particle-Size Distribution:
m
Boring No.

Sample No.

Depth (ft)
TP-28
B-4
0-5
8 0 0.1 0.2 0.3
Horizontal Deformation (in.)

3.00 2.50
G=
2 2.00
Y
V)
V)

1.50 (0
z
2 1.00
V)

0.50 0.00

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 Normal Stress (ksf)
Sam~le TYW:
90% Remold
Soil Identification:

Dark Brown Silty Sand (SM)
Normal Stress (kipIft2)
Peak Shear Stress (kipIft2)
Shear Stress @ End of Test (ksf)
Deformation Rate (in./min.)
Initial Sample Height (in.)
Diameter (in.)
Initial Moisture Content (%)
Dry Density (pcf)
Saturation (%)
Soil Height Before Shearing (in.)
Final Moisture Content (O/O)

1.000

0.861
0 0.705

0.0500

1.000

2.415

8.10 120.3

54.5 0.9963

15.0 4 Leiyhton

2.000
1 1.397

1.394

0.0500

1.000

2.415

8.10 120.2

54.4 0.9912

14.2 4.000
A 2.747
A 2.741

0.0500

1.000

2.415

8.10 120.2

54.4 0.9865

13.5 DIRECT SHEAR TEST RESULTS
Consolidated Undrained
Project No.: 111952-001
BCCK 320
07-06
DS TP-32, 8-7 @ 4-8 (Tag 0-5)

3.00 2.50
ci=
2 2.00
Y
V)
V)
aJ $. 1.50
6 2 1.00 V)

0.50 0.00
0 0.1 0.2 0.3
Horizontal Deformation (in.)

3.00 -

2.50 0
Normal Stress (kipfft2)
Peak Shear Stress (kipIft2)
Shear Stress @ End of Test (ksf)
Deformation Rate (in./min.)
Initial Sample Height (in.)
Diameter (in.)
Initial Moisture Content (O/O)
Dry Density (pcf)
Saturation (%)
Soil Height Before Shearing (in.)
Final Moisture Content (Oh)
A L

2.00 - Y
V)
8 b 1.50 -
V)

1.000

0.976
0 0.748

0.0500

1.000

2.415

11.10 111.7

58.9 0.9997

19.7 6
2 1.00 -
V)

0.50 2.000
1 1.478

1.372

0.0500

1.000

2.415

11.10 111.7

58.9 0.9875

19.4 .... 0.00 m...,,...

4.000
A 2.466
A 2.466

0.0500

1.000

2.415

11.10 111.6

58.8 0.9857

18.4 .,..

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 Normal Stress (ks9
....

Boring No.

Sample No.

Depth (ft)
TP-32
8-7
4-8 (Tag: O-
....,,...

Sample Tv~e:
90% Remold
Soil Identification:

Dark Brown Sandy Silt s(ML)
,,,,,,,,,,,,,,,,,,,

DIRECT SHEAR TEST RESULTS
Consolidated Undrained
,,,,~
Project No.: 111952-001
BCCK 320
07-06
EXPANSION INDEX of SOILS
ASTM D 4829
Project Name: (BCCK) 320 Tested By: RAL Date: 07/14/06
Project No. : 111952-001 Checked By: LF Date: 0712 1/06 Boring No.: TP-3 Depth (ft.) 0-2
Sample No. : B- 1
Soil Identification: Olive brown sandy lean clay s(CL)
1000.00
Wt. of Container No.

Dry Wt. of Soil 1000.00
Weight Soil Retained on #4 Sieve 0.00
100.00
SPECIMEN INUNDATION in distilled water for the period of 24 h or expansion rate < 0.0002 in./h

MOLDED SPECIMEN
Specimen Diameter (in.)
Specimen Height (in.)
Wt. Comp. Soil + Mold (g)
Wt. of Mold (9)
Specific Gravity (Assumed)
Container No.

Wet Wt. of Soil + Cont. (g)
Dry Wt. of Soil + Cont. (g)
Wt. of Container
Moisture Content (To)
Wet Density (~cf)
Dry Density (pd)
Void Ratio
Total Porosity
Pore Volume (CC)
Degree of Saturation (%) [ S meas]
Before Test

4.01 1 .OOOO
541.00
163.70

2.70 0
769.00
689.70

0.00 11.50
113.8
102.1

0.652

0.395

81.7 47.6
Date
07/14/06
07/14/06
After Test

4.01 1.0530
426.80

0.00 2.70
0 590.50
502.10
163.70

26.12 122.3

96.9 0.739

0.425

92.6 95.4
Expansion Index (EI
meas) = ((Final Rdg - Initial Rdg) / Initial Thick.) x 1000 Expansion Index ( EI ) 50 = EI meas - (50 -S meas)x((65+EI meas) / (220-S meas)) Time
11:48
11:58

54.0 52
Add Distilled Water to the Specimen
Pressure (psi)

1.0 1.0
07/14/06
07/17/06
07/17/06
Elapsed Time
(min.)
0 10
16:35
8: 13
9:34
Dial Readings
(in.)

0.1520

0.1510

1.0 1.0
1 .O
277
4095
4176

0.2025

0.2050

0.2050
EXPANSION INDEX of SOILS
ASTM D 4829
Project Name: (BCCK) 320 Tested By: RAL Date: 07/14/06
Project No. : 11 1952-001 Checked By: LF Date: 07/24/06 Boring No.: TP-32 Depth (ft.) 0-5
Sample No. : 8-7
Soil Identification: Very dark brown sandy silt s(ML)
1000.00
Wt. of Container No.

Dry Wt. of Soil 1000.00
Weight Soil Retained on #4 Sieve 0.00
100.00
SPECIMEN INUNDATION in distilled water for the period of 24 h or expansion rate < 0.0002 in./h After Test

4.01 1.0340
438.90

0.00 2.70
0 640.60
563.20
201.70

21.41 128.0
105.5

0.599

0.374

80.1 96.6

MOLDED SPECIMEN
Specimen Diameter (in.)
Specimen Height (in.)
Wt. Comp. Soil + Mold (g)
Wt. of Mold (9)
Specific Gravity (Assumed)
Container No.

Wet Wt. of Soil + Cont. (g)
Dry Wt. of Soil + Cont. (g)
Wt. of Container (9)
Moisture Content
Wet Density (pd)
Dry Density (~d)
Void Ratio
Total Porosity
Pore Volume (CC)
Degree of Saturation (Oh) [ S rneas]
l~x~ansion Index (EI WE.) = ((Final Rdg - Initial Rdg) / Initial Thick.) x 1000 1 36.0 1 Before Test

4.01 1 .OOOO
599.40
201.70

2.70 0
798.10
725.50

0.00 10.01
120.0
109.1

0.546

0.353

73.1 49.5
Dial Readings
(in.)

0.1470

0.1450
Elapsed Time
(min.)
0 10
Date
07/14/06
07/14/06
--
Expansion Index ( EI ) 5o = EI meas - (50 -S rneas)x((65+EI meas) / (220-S rneas)) Add Distilled Water to the Specimen
36 Ti me
13:23
13:33
Pressure (psi)

1.0 1.0

0.1790

0.1810

0.1810
183
4001
4080

1.0 1.0

1.0 07/14/06
07/17/06
07/17/06
16:36
8: 14
9:33
# >tv 4 Leighton R-VALUE TEST RESULTS
PROJECT NAME: BCCK Brenson Comm. PROJECT NUMBER: 11 1952-001 SAMPLE NUMBER B-1 SAMPLE LOCATION TP-3,O-2'
SAMPLE DESCRIPTION: s(CL) TECHNICIAN. SCF
DATE SAMPLED 7/7/2006

EXPANSION PRESSURE CHART EXUDATION PRESSURE CHART
80 70
60 W
3 50
a
2 40
30 20
COVER THICKNESS BY EXPANSION an feet 10
0 R-VALUE BY EXPANSION: 60 800 700 600 500 400 300 200 100 o R-VALUE BY EXUDATION: 43 EXUOATlON PRESSURE (PSI)
EQUILIBRIUM R-VALUE: 43

TEST SPECIMEN
MOISTURE AT COMPACTION %
HEIGHT OF SAMPLE, Inches
DRY DENSITY, pcf
COMPACTOR PRESSURE, psi
EXUDATION PRESSURE, psi
EXPANSION, Inches x l0exp-4
STABILITY Ph 2,000 Ibs (160 psi)

TURNS DISPLACEMENT

R-VALUE UNCORRECTED

R-VALUE CORRECTED

DESIGN CALCULATION DATA

GRAVEL EQUIVALENT FACTOR

TRAFFIC INDEX
STABILOMETER THICKNESS, ft.

EXPANSION PRESSURE THICKNESS, ft.
c

21.4 2.50
105.3
50 291
0 78

3.91 40
40 a

20.7 2.48
105.6
75 549
16 58

3.60 55
55 a
1 .O

5.0 0.72

0.53 b

21.2 2.56
104.7
50 319
6 72

3.72 45
45 b
1 .O

5.0 0.88

0.20 c
1 .O

5.0 0.96

0.00 TEST SPECIMEN a b c
MOISTURE AT COMPACTION % 11.2 11.7 12.1
HEIGHT OF SAMPLE, Inches 2.51 2.48 2.38
DRY DENSITY, pd 122.3 122.5 124.6
COMPACTOR PRESSURE, psi 275 225 150
EXUDATION PRESSURE, psi 355 290 244
EXPANSION, Inches x l0exp-4 29 16 0
STABILITY Ph 2,000 Ibs (160 psi) 28 30 32
TURNS DISPLACEMENT 4.06 4.20 4.37
R-VALUE UNCORRECTED 74 72 70
R-VALUE CORRECTED 74 72 66
DESIGN CALCULATION DATA a b c
GRAVEL EQUIVALENT FACTOR 1 .O 1 .O 1 .O
TRAFFIC INDEX 5.0 5.0 5.0
STABILOMETER THICKNESS, ft. 0.42 0.45 0.54
EXPANSION PRESSURE THICKNESS, ft. 0.97 0.53 0.00
Leighton R-VALUE TEST RESULTS
PROJECT NAME: BCCK Brenson Comm. PROJECT NUMBER: 11 1952-001 SAMPLE NUMBER: B-7 SAMPLE LOCATION: TP-32,O-5
SAMPLE DESCRIPTION. s(ML) TECHNICIAN: SCF
DATE SAMPLED 7/7/2006

EXPANSION PRESSURE CHART EXUDATION PRESSURE CHART
400 90
B 350
s 80
C
g 300
70 I
5 250 m
2 60 ln
2 200
ln W
ln 3 50
; 150 d.
0 I
2 t- 40
a 100
# 0
0 50 30
0 00 20
000 050 100 150 200 250 300 350 400
COVER THICKNESS BY EXPANSION mfeet 10
0 R-VALUE BY EXPANSION: 70 800 700 600 500 400 300 200 100 o R-VALUE BY EXUDATION: 73 EXUDATION PRESSURE (ps)
EQUILIBRIUM R-VALUE: 70

SOIL RESISTIVITY TEST
DOT CA TEST 532 / 643
Project Name: (BCCK) 320 Tested By : VJ Date: 07/13/06
Project No. : 111952-001 Data Input By: LF Date: 07/21/06 Boring No.: TP-3 Depth (ft.) : 0-2
Sample No. : B-1
Soil Identification: s(CL)
2500

10.0 15.0 20.0 25.0 30.0 35.0 40.0
Moisture Content (%)

SOIL RESISTIVITY TEST
DOT CA TEST 532 / 643
Project Name: (BCCK) 320 Tested By : VJ Date: 07/13/06
Project No. : 111952-001 Data Input By: LF Date: 07/21/06 Boring No.: TP-32 Depth (ft.) : 0-5
Sample No. : 8-7
Soil Identification: s(ML)
1700

10.0 15.0 20.0 25.0
Moisture Content (%)
TESTS for SULFATE CONTENT
CHLORIDE CONTENT and pH of SOILS
Project Name: (BCCK) 320 Tested By : VJ Date: 07/13/06
Project No. : 111952-001 Data Input By: LF Date: 07/21/06 Soil Identification:

Wet Weight of Soil + Container (g)
Dry Weight of Soil + Container (g)
Weight of Container (g)
Moisture Content (%)
Weight of Soaked Soil (q)
SULFATE CONTENT, DOT California Test 417, Part I1
Beaker No.

Crucible No.

Furnace Temperature (OC)
Time In / Time Out
Duration of Combustion (min)
Wt. of Crucible + Residue (g)
CHLORIDE CONTENT, DOT California Test 422
1 I I I 1
202.60
195.90

66.31 5.17
100.55
Wt. of Crucible (g)
Wt. of Residue (g) (A)
PPM of Sulfate (A) x 41150
PPM of Sulfate, Dry Weight Basis
213.65
202.72

52.29 7.27
100.70
13 29
830
7:20 / 8:05
45 20.1308
14 30
830
7:20 / 8:05
45 17.6214

20.1275

0.0033
135.79
143
ml of Chloride Soln. For Titration (B) / 30

17.6193

0.0021

86.42 93
30 ml of AgN03 Soln. Used in Titration (C)
I PPM of Chloride, Dry Wt. Basis 53 237 1

I I I I
PPM of Chloride (C -0.2) * 100 * 30 / B

I I I I

0.7 2.4

I I I I
50 pH TEST, DOT California Test 5321643
220
pH Value
Temperature OC

6.07 22.4

7.92 22.3

APPENDIX C

Percolation Data

48 8°
9:35:00
10:05:00
10:05:00
10:35:00
10:35:00
11:05:00
11:05:00
11:35:00
11:35:00
11:45:00
11:45:00
11:55:00
11:55:00
12:05:00
12:05:00
12:15:00
12:15:00
12:25:00
12:25:00
12:35:00
12:35:00
12:45:00
12:45:00
12:55:00

2.3 2.3

1.8 1

1.5 1.2

1.1 1.2
Tested by: MSB Date Tested 5.23.22
Soil Unit: Highly Weathered Kgr Depth of Test Hole (in.) Test depth 60 Test Hole Number: P-1 Project Whitewood I
Date Excavated: 5.23.22 Project Number 13142.005
inches/hour* minute/inch

30.00 2.50 11.80 9.30 0.87 3
USCS Soil Type: Tan Clayey Sand (SC) Diameter (in.) Sunny ~75 Time Δt (min) Initial Water Depth
(inches)
Final Water Depth
(inches)
Change In Water Level
(inches)
Infiltration/Percolation
Rate

30.00 2.30 8.60 6.30 0.57 5

30.00 2.20 9.00 6.80 0.61 4

10.00 1.80 4.00 2.20 0.56 5

30.00 2.30 7.00 4.70 0.41 6

10.00 1.50 3.20 1.70 0.43 6

10.00 1.00 2.70 1.70 0.42 6

10.00 1.10 2.90 1.80 0.45 6

10.00 1.20 3.10 1.90 0.48 5

10.00 0.90 2.60 1.70 0.42 6

10.00 0.90 2.80 1.90 0.47 5

2.50 3.10

10.00 1.10 2.90 1.80 0.45 6

2.20 Date: Apr-20
* Based on Prochet Method
Percolation Project Number: 13142.005
Leighton
Test Data
Project Name: Whitewood I
P-1

0.000.05

0.100.150.20

0.25 0.300.350.40

0.450.500.55

0.60 0.650.700.75

0.800.850.90

0.95 1.00
0 50 100 150 200 250
Infiltration Rate
(in./hr)
Time (min)

48 8°
9:39:00
10:09:00
10:09:00
10:39:00
10:39:00
10:49:00
10:49:00
10:59:00
10:59:00
11:09:00
11:09:00
11:19:00
11:19:00
11:29:00
11:29:00
11:39:00
Date:

Jun-22
* Based on Prochet Method
Percolation Project Number: 13142.005
Leighton
Test Data
Project Name: Whitewood I
P-2

10.00 1.80 6.30 4.50 1.18 2

10.00 1.80 6.10 4.30 1.12 2

10.00 1.00 5.80 4.80 1.24 2

10.00 1.40 6.60 5.20 1.36 2

10.00 1.10 5.60 4.50 1.16 2

10.00 1.60 6.90 5.30 1.39 2

30.00 1.10 13.90 12.80 1.20 2
inches/hour* minute/inch

30.00 1.10 13.10 12.00 1.12 3
USCS Soil Type: Silty Sand (SM) Diameter (in.) Sunny ~75 Time Δt (min) Initial Water Depth
(inches)
Final Water Depth
(inches)
Change In Water Level
(inches)
Infiltration/Percolation
Rate
Tested by: MSB Date Tested 5.23.22
Soil Unit: Qal over Weathered Kgr Depth of Test Hole (in.) Test Hole Number: P-2 Project Whitewood I
Date Excavated: 5.23.22 Project Number 13142.005

0.00 1.00

2.00 3.00

4.00 0 20 40 60 80 100 120 140
Infiltration Rate
(in./hr)
Time (min)

60 8°
9:15:00
9:45:00
9:45:00
10:15:00
10:15:00
10:45:00
10:45:00
11:15:00
11:15:00
16:15:00
16:15:00
16:45:00
16:45:00
17:15:00

2.3 2.3

1.8 1

1.5 1.2

1.1 1.2
Date:

Jun-22
* Based on Prochet Method
Percolation Project Number: 13142.005
Leighton
Test Data
Project Name: Whitewood I
P-3

2.20 2.50 3.10

30.00 48.84 49.20 0.36 0.11 83

30.00 48.60 48.84 0.24 0.07 125

30.00 48.12 48.60 0.48 0.14 62

30.00 48.00 48.12 0.12 0.03 250

30.00 47.64 48.00 0.36 0.10 83

30.00 46.20 46.44 0.24 0.06 125
inches/hour* minute/inch

30.00 45.24 46.20 0.96 0.24 31
USCS Soil Type: Reddish BrownSilty Sand (SM) Diameter (in.) Sunny ~75 Time Δt (min) Initial Water Depth
(inches)
Final Water Depth
(inches)
Change In Water Level
(inches)
Infiltration/Percolation
Rate
Tested by: MSB Date Tested 5.23.22
Soil Unit: Highly Weathered Kgr Depth of Test Hole (in.) Test depth 60 Test Hole Number: P-3 Project Whitewood I
Date Excavated: 5.23.22 Project Number 13142.005

0.000.050.10

0.150.200.25

0.30 0.350.400.45

0.500.550.60

0.65 0.700.750.80

0.850.900.95

1.00 0 50 100 150 200 250
Infiltration Rate
(in./hr)
Time (min)

60 8°
9:17:00
9:47:00
9:47:00
10:17:00
10:17:00
10:47:00
10:47:00
11:17:00
11:17:00
11:27:00
11:27:00
11:37:00
11:37:00
11:47:00
11:47:00
11:57:00
11:57:00
12:07:00
12:07:00
12:17:00
12:17:00
12:27:00
12:27:00
12:37:00

2.3 2.3

1.8 1

1.5 1.2

1.1 1.2
Tested by: MSB Date Tested 5.23.22
Soil Unit: Highly Weathered Kgr Depth of Test Hole (in.) Test depth 60 Test Hole Number: P-4 Project Whitewood I
Date Excavated: 5.23.22 Project Number 13142.005
inches/hour* minute/inch

30.00 53.00 54.80 1.80 0.89 17
USCS Soil Type: Tan Clayey Sand (SC) Diameter (in.) Sunny ~75 Time Δt (min) Initial Water Depth
(inches)
Final Water Depth
(inches)
Change In Water Level
(inches)
Infiltration/Percolation
Rate

30.00 56.64 57.60 0.96 0.79 31

30.00 54.84 56.64 1.80 1.15 17

10.00 53.40 53.80 0.40 0.57 25

30.00 52.59 53.40 0.81 0.36 37

10.00 54.62 55.08 0.46 0.77 22

10.00 53.16 53.40 0.24 0.33 42

10.00 53.52 54.08 0.56 0.82 18

10.00 57.88 57.96 0.08 0.24 125

10.00 58.36 58.56 0.20 0.68 50

10.00 56.48 56.88 0.40 0.90 25

2.50 3.10

2.20 Date: Jun-22
* Based on Prochet Method
Percolation Project Number: 13142.005
Leighton
Test Data
Project Name: Whitewood I
P-4

0.00 0.25

0.50 0.75

1.00 1.25

1.50 1.75

2.00 0 50 100 150 200 250 300 350 400
Infiltration Rate
(in./hr)
Time (min)

APPENDIX D

General Earthwork and Grading Specifications
-i-
LEIGHTON AND ASSOCIATES, INC.

GENERAL EARTHWORK AND GRADING SPECIFICATIONS FOR ROUGH GRADING

TABLE OF CONTENTS
Section Page

1.0 GENERAL 1

1.1 Intent 1

1.2 The Geotechnical Consultant of Record 1

1.3 The Earthwork Contractor 2

2.0 PREPARATION OF AREAS TO BE FILLED 2

2.1 Clearing and Grubbing 2

2.2 Processing 3

2.3 Overexcavation 3

2.4 Benching 3

2.5 Evaluation/Acceptance of Fill Areas 3

3.0 FILL MATERIAL 4

3.1 General 4

3.2 Oversize 4

3.3 Import 4

4.0 FILL PLACEMENT AND COMPACTION 4

4.1 Fill Layers 4

4.2 Fill Moisture Conditioning 5

4.3 Compaction of Fill 5

4.4 Compaction of Fill Slopes 5

4.5 Compaction Testing 5

4.6 Frequency of Compaction Testing 5

4.7 Compaction Test Locations 6

5.0 SUBDRAIN INSTALLATION 6

6.0 EXCAVATION 6

7.0 TRENCH BACKFILLS 6

7.1 Safety 6

7.2 Bedding & Backfill 7

7.3 Lift Thickness 7

7.4 Observation and Testing 7
Standard Details
C - Canyon Subdrains
E - Transition Lot Fills and Side Hill Fills
Rear of Text
Rear of Text
LEIGHTON AND ASSOCIATES, INC.

General Earthwork and Grading Specifications
-1-

1.0 General

1.1 Intent

These General Earthwork and Grading Specifications are for the grading and earthwork shown on the approved grading plan(s) and/or indicated in the geotechnical report(s). These Specifications are a part of the recommendations contained in the geotechnical report(s). In case of conflict, the specific recommendations in the geotechnical report shall supersede these more general Specifications. Observations of the earthwork by the project Geotechnical Consultant during the course of grading may result in new or revised recommendations that could supersede these specifications or the recommendations in the geotechnical report(s).

1.2 The Geotechnical Consultant of Record

Prior to commencement of work, the owner shall employ the Geotechnical Consultant of Record (Geotechnical Consultant). The Geotechnical Consultants shall be responsible for reviewing the approved geotechnical report(s) and accepting the adequacy of the preliminary geotechnical findings, conclusions, and recommendations prior to the commencement of the grading.

Prior to commencement of grading, the Geotechnical Consultant shall review the "work plan" prepared by the Earthwork Contractor (Contractor) and schedule sufficient personnel to perform the appropriate level of observation, mapping, and compaction testing.

During the grading and earthwork operations, the Geotechnical Consultant shall observe, map, and document the subsurface exposures to verify the geotechnical design assumptions. If the observed conditions are found to be significantly different than the interpreted assumptions during the design phase, the Geotechnical Consultant shall inform the owner, recommend appropriate changes in design to accommodate the observed conditions, and notify the review agency where required. Subsurface areas to be geotechnically observed, mapped, elevations recorded, and/or tested include natural ground after it has been cleared for receiving fill but before fill is placed, bottoms of all "remedial removal" areas, all key bottoms, and benches made on sloping ground to receive fill.

The Geotechnical Consultant shall observe the moisture-conditioning and processing of the subgrade and fill materials and perform relative compaction testing of fill to determine the attained level of compaction. The Geotechnical Consultant shall provide the test results to the owner and the Contractor on a routine and
frequent basis.

LEIGHTON AND ASSOCIATES, INC.

General Earthwork and Grading Specifications
-2-

1.3 The Earthwork Contractor

The Earthwork Contractor (Contractor) shall be qualified, experienced, and knowledgeable in earthwork logistics, preparation and processing of ground to receive fill, moisture-conditioning and processing of fill, and compacting fill. The Contractor shall review and accept the plans, geotechnical report(s), and these Specifications prior to commencement of grading. The Contractor shall be solely responsible for performing the grading in accordance with the plans and specifications.

The Contractor shall prepare and submit to the owner and the Geotechnical Consultant a work plan that indicates the sequence of earthwork grading, the number of "spreads" of work and the estimated quantities of daily earthwork contemplated for the site prior to commencement of grading. The Contractor shall inform the owner and the Geotechnical Consultant of changes in work schedules and updates to the work plan at least 24
hours in advance of such
changes so that appropriate observations and tests can be planned and accomplished. The Contractor shall not assume that the Geotechnical Consultant is aware of all grading operations.

The Contractor shall have the sole responsibility to provide adequate equipment and methods to accomplish the earthwork in accordance with the applicable grading codes and agency ordinances, these Specifications, and the recommendations in the approved geotechnical report(s) and grading plan(s). If, in the opinion of the Geotechnical Consultant, unsatisfactory conditions, such as unsuitable soil, improper moisture condition, inadequate compaction, insufficient buttress key size, adverse weather, etc., are resulting in a quality of work less than required in these specifications, the Geotechnical Consultant shall reject the work and may recommend to the owner that construction be stopped until the conditions are rectified.

2.0 Preparation of Areas to be Filled

2.1 Clearing and Grubbing

Vegetation, such as brush, grass, roots, and other deleterious material shall be sufficiently removed and properly disposed of in a method acceptable to the owner, governing agencies, and the Geotechnical Consultant.

The Geotechnical Consultant shall evaluate the extent of these removals depending on specific site conditions. Earth fill material shall not contain more than 1 percent of organic materials (by volume). No fill lift shall contain more than 5 percent of organic matter. Nesting of the organic materials shall not be allowed.

LEIGHTON AND ASSOCIATES, INC.

General Earthwork and Grading Specifications
-3-
If potentially hazardous materials are encountered, the Contractor shall stop work in the affected area, and a hazardous material specialist shall be informed immediately for proper evaluation and handling of these materials prior to continuing to work in that area.

As presently defined by the State of California, most refined petroleum products (gasoline, diesel fuel, motor oil, grease, coolant, etc.) have chemical constituents that are considered to be hazardous waste. As such, the indiscriminate dumping or spillage of these fluids onto the ground may constitute a misdemeanor, punishable by fines and/or imprisonment, and shall not be allowed.

2.2 Processing

Existing ground that has been declared satisfactory for support of fill by the Geotechnical Consultant shall be scarified to a minimum depth of 6 inches.

Existing ground that is not satisfactory shall be overexcavated as specified in the following section. Scarification shall continue until soils are broken down and free of large clay lumps or clods and the working surface is reasonably uniform, flat, and free of uneven features that would inhibit uniform compaction.

2.3 Overexcavation

In addition to removals and overexcavations recommended in the approved geotechnical report(s) and the grading plan, soft, loose, dry, saturated, spongy, organic-rich, highly fractured or otherwise unsuitable ground shall be overexcavated to competent ground as evaluated by the Geotechnical Consultant during grading.

2.4 Benching

Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical units), the ground shall be stepped or benched. The lowest bench or key shall be a minimum of 15
feet wide and at least 2 feet deep, into competent
material as evaluated by the Geotechnical Consultant. Other benches shall be excavated a minimum height of 4 feet into competent material or as otherwise recommended by the Geotechnical Consultant. Fill placed on ground sloping flatter than 5:1 shall also be benched or otherwise overexcavated to provide a flat subgrade for the fill.

2.5 Evaluation/Acceptance of Fill Areas

All areas to receive fill, including removal and processed areas, key bottoms, and benches, shall be observed, mapped, elevations recorded, and/or tested prior to being accepted by the Geotechnical Consultant as suitable to receive fill. The Contractor shall obtain a written acceptance from the Geotechnical Consultant LEIGHTON AND ASSOCIATES, INC.

General Earthwork and Grading Specifications
-4-
prior to fill placement. A licensed surveyor shall provide the survey control for determining elevations of processed areas, keys, and benches.

3.0 Fill Material

3.1 General

Material to be used as fill shall be essentially free of organic matter and other deleterious substances evaluated and accepted by the Geotechnical Consultant prior to placement. Soils of poor quality, such as those with unacceptable gradation, high expansion potential, or low strength shall be placed in areas acceptable to the Geotechnical Consultant or mixed with other soils to achieve satisfactory fill material.

3.2 Oversize

Oversize material defined as rock, or other irreducible material with a maximum dimension greater than 8 inches, shall not be buried or placed in fill unless location, materials, and placement methods are specifically accepted by the Geotechnical Consultant. Placement operations shall be such that nesting of oversized material does not occur and such that oversize material is completely surrounded by compacted or densified fill. Oversize material shall not be placed within 10
vertical feet of finish grade or within 2 feet of future utilities or underground construction.

3.3 Import

If importing of fill material is required for grading, proposed import material shall meet the requirements of Section

3.1. The potential import source shall be given
to the Geotechnical Consultant at least 48 hours (2 working days) before importing begins so that its suitability can be determined and appropriate tests performed.

4.0 Fill Placement and Compaction

4.1 Fill Layers

Approved fill material shall be placed in areas prepared to receive fill (per Section 3.0) in near-horizontal layers not exceeding 8
inches in loose thickness.

The Geotechnical Consultant may accept thicker layers if testing indicates the grading procedures can adequately compact the thicker layers. Each layer shall be spread evenly and mixed thoroughly to attain relative uniformity of material and moisture throughout.

LEIGHTON AND ASSOCIATES, INC.

General Earthwork and Grading Specifications
-5-

4.2 Fill Moisture Conditioning

Fill soils shall be watered, dried back, blended, and/or mixed, as necessary to attain a relatively uniform moisture content at or slightly over optimum.

Maximum density and optimum soil moisture content tests shall be performed in accordance with the American Society of Testing and Materials (ASTM Test Method D1557).

4.3 Compaction of Fill

After each layer has been moisture-conditioned, mixed, and evenly spread, it shall be uniformly compacted to not less than 90 percent of maximum dry density (ASTM Test Method D1557). Compaction equipment shall be adequately sized and be either specifically designed for soil compaction or of proven reliability to efficiently achieve the specified level of compaction with uniformity.

4.4 Compaction of Fill Slopes

In addition to normal compaction procedures specified above, compaction of slopes shall be accomplished by backrolling of slopes with sheepsfoot rollers at increments of 3 to 4
feet in fill elevation, or by other methods producing
satisfactory results acceptable to the Geotechnical Consultant. Upon completion of grading, relative compaction of the fill, out to the slope face, shall be at least 90 percent of maximum density per ASTM Test Method D1557.

4.5 Compaction Testing

Field-tests for moisture content and relative compaction of the fill soils shall be performed by the Geotechnical Consultant. Location and frequency of tests shall be at the Consultant's discretion based on field conditions encountered.

Compaction test locations will not necessarily be selected on a random basis. Test locations shall be selected to verify adequacy of compaction levels in areas that are judged to be prone to inadequate compaction (such as close to slope faces and at the fill/bedrock benches).

4.6 Frequency of Compaction Testing

Tests shall be taken at intervals not exceeding 2 feet in vertical rise and/or 1,000 cubic yards of compacted fill soils embankment. In addition, as a guideline, at least one test shall be taken on slope faces for each 5,000 square feet of slope face and/or each 10 feet of vertical height of slope. The Contractor shall assure that fill construction is such that the testing schedule can be accomplished by the Geotechnical Consultant. The Contractor shall stop or slow down the earthwork construction if these minimum standards are not met.

LEIGHTON AND ASSOCIATES, INC.

General Earthwork and Grading Specifications
-6-

4.7 Compaction Test Locations

The Geotechnical Consultant shall document the approximate elevation and horizontal coordinates of each test location. The Contractor shall coordinate with the project surveyor to assure that sufficient grade stakes are established so that the Geotechnical Consultant can determine the test locations with sufficient accuracy. At a minimum, two grade stakes within a horizontal distance of 100 feet and vertically less than 5 feet apart from potential test locations shall be provided.

5.0 Subdrain Installation

Subdrain systems shall be installed in accordance with the approved geotechnical report(s), the grading plan. The Geotechnical Consultant may recommend additional subdrains and/or changes in subdrain extent, location, grade, or material depending on conditions encountered during grading. All subdrains shall be surveyed by a land surveyor/civil engineer for line and grade after installation and prior to burial. Sufficient time should be allowed by the Contractor for these surveys.

6.0 Excavation

Excavations, as well as over-excavation for remedial purposes, shall be evaluated by the Geotechnical Consultant during grading. Remedial removal depths shown on geotechnical plans are estimates only. The actual extent of removal shall be determined by the Geotechnical Consultant based on the field evaluation of exposed conditions during grading. Where fill-over-cut slopes are to be graded, the cut portion of the slope shall be made, evaluated, and accepted by the Geotechnical Consultant prior to placement of materials for construction of the fill portion of the slope, unless otherwise recommended by the Geotechnical Consultant.

7.0 Trench Backfills

7.1 Safety

The Contractor shall follow all OSHA and Cal/OSHA requirements for safety of trench excavations.

LEIGHTON AND ASSOCIATES, INC.

General Earthwork and Grading Specifications
-7-

7.2 Bedding and Backfill

All bedding and backfill of utility trenches shall be performed in accordance with the applicable provisions of Standard Specifications of Public Works Construction. Bedding material shall have a Sand Equivalent greater than 30 (SE>30). The bedding shall be placed to 1 foot over the top of the conduit and densified by jetting. Backfill shall be placed and densified to a minimum of 90 percent of relative compaction from 1 foot above the top of the conduit to the surface.

The Geotechnical Consultant shall test the trench backfill for relative compaction.

At least one test should be made for every 300 feet of trench and 2 feet of fill.

7.3 Lift Thickness

Lift thickness of trench backfill shall not exceed those allowed in the Standard Specifications of Public Works Construction unless the Contractor can demonstrate to the Geotechnical Consultant that the fill lift can be compacted to the minimum relative compaction by his alternative equipment and method.

7.4 Observation and Testing

The jetting of the bedding around the conduits shall be observed by the Geotechnical Consultant.

NATURAL
GROUND
/
�----------::::-::::-::::-::::-::::-::::-::::-::::-::::-::::-::::-::::-::::-::::-::::-::::-::::-::::-::::-::::-- -� "'�" ---��--------_:COMPACTED FILL:._-_-_---
�------ - -

TYPICAL

BENCHING
-----------------�---.----..o..._-_-�_-_-_-_-_-_�---_-�----,,......... ----�----------::::-::::-::::-::::-::::-::::-::::-::::0

SUBDRAIN
(See Alternates A and B)

FILTER MATERIAL

SUBDRAIN ALTERNATE A PERFORATED PIPE SURROUNDED
WITH FILTER MATERIAL FILTER MATERIAL SHALL BE CLASS 2 PERMEABLE MATERIAL PER STATE OF CALIFORNIA STANDARD SPECIFICATION, OR APPROVED ALTERNATE.

FILTER MATERIAL (9FT 3/FT) CLASS 2 GRADING AS FOLLOWS:

Sieve Size
1"
3/4"
3/8"
No.4
No.8
No. 30
No. 50
No.200
Percent Passing
100
90-100
40-100
25-40
18-33
5-15
0-7
0-3
SUBDRAIN ALTERNATE A-1 SUBDRAIN ALTERNATE A-2
ALTERNATE B-1

PERFORATED PIPE
6" 0 MIN.

SUBDRAIN ALTERNATE B
3/4" MAX. GRAVEL OR

APPROVED EQUIVALENT
(9FT 3 /FT)
ALTERNATE B-2
0 PERFORATED PIPE IS OPTIONAL PER

GOVERNING AGENCY'S REQUIREMENTS

DETAIL OF CANYON SUBDRAIN TERMINAL
DESIGN

FINISHED GRADE
10' MIN. BACKFILL
r- 15' MIN.---i---i--20' MIN.
5' MIN PERFORATED
6"0MIN.
· • 6"0 MIN.----i
I

NON-PERFORATED

FILTER FABRIC
(MIRAFI 140N OR

APPROVED EQUIVALENT)
�
t :g ·e
1------------------,,------------------------,------------g CANYON

SUBDRAIN

GENERAL EARTHWORK AND GRADING
SPECIFICATIONS a.

E
�gSTANDARD DETAILS C
L...-----------------''------------------------1--------------' c.:

OVERBURDEN

OR UNSUITABLE

MATERIAL

CUT-FILL TRANSITION LOT OVEREXCAVATION
REMOVE

UNSUITABLE
\. GROUND \_..- ----

SIDE HILL FILL FOR CUT PAD

OVEREXCAVATE

AND RECOMPACT
(REPLACEMENT FILL)
/
/
/
----
/
/
/
/
4' MIN. <'\(/'

NATURAL
GROUND
�__-
__----
/
/
/
/
/

FINISHED CUT PAD
L...=��.,......-.J.J-------- SEE STANDARD DETAIL FOR SUBDRAINS

WHEN REQUIRED BY GEOTECHNICAL CONSUL TANT
KEY
2'MIN. �

DEPTH UNWEATHERED BEDROCK OR MATERIAL APPROVED

BY THE GEOTECHNICAL CONSULTANT
�
t .!!!ii= 51
·� 1------------------------.---------------"T"""-------------1!!!

TRANSITION LOT FILLS

AND SIDE HILL FILLS

GENERAL EARTHWORK AND GRADING

SPECIFICATIONS

STANDARD DETAILS E
a.

E
�gLeighton
.__ ___________________ __,_ ______________ _.__ _________ ____.a:

APPENDIX E

GBA Guidelines

Geotechnical-Engineering Report
Important Information about This
Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes.

While you cannot eliminate all such risks, you can manage them. The following information is provided to help.

The Geoprofessional Business Association (GBA)
has prepared this advisory to help you – assumedly
a client representative – interpret and apply this
geotechnical-engineering report as effectively as
possible. In that way, you can benefit from a lowered
exposure to problems associated with subsurface
conditions at project sites and development of
them that, for decades, have been a principal cause
of construction delays, cost overruns, claims,
and disputes. If you have questions or want more
information about any of the issues discussed herein,
contact your GBA-member geotechnical engineer.

Active engagement in GBA exposes geotechnical
engineers to a wide array of risk-confrontation
techniques that can be of genuine benefit for
everyone involved with a construction project.

Understand the Geotechnical-Engineering Services
Provided for this Report
Geotechnical-engineering services typically include the planning, collection, interpretation, and analysis of exploratory data from widely spaced borings and/or test pits. Field data are combined with results from laboratory tests of soil and rock samples obtained from field exploration (if applicable), observations made during site reconnaissance, and historical information to form one or more models of the expected subsurface conditions beneath the site. Local geology and alterations of the site surface and subsurface by previous and proposed construction are also important considerations. Geotechnical engineers apply their engineering training, experience, and judgment to adapt the requirements of the prospective project to the subsurface model(s). Estimates are made of the subsurface conditions that will likely be exposed during construction as well as the expected performance of foundations and other structures being planned and/or affected by construction activities.

The culmination of these geotechnical-engineering services is typically a geotechnical-engineering report providing the data obtained, a discussion of the subsurface model(s), the engineering and geologic engineering assessments and analyses made, and the recommendations developed to satisfy the given requirements of the project. These reports may be titled investigations, explorations, studies, assessments, or evaluations.

Regardless of the title used, the geotechnical-engineering report is an engineering interpretation of the subsurface conditions within the context of the project and does not represent a close examination, systematic inquiry, or thorough investigation of all site and subsurface conditions.

Geotechnical-Engineering Services are Performed
for Specific Purposes, Persons, and Projects,
and At Specific Times
Geotechnical engineers structure their services to meet the specific needs, goals, and risk management preferences of their clients. A geotechnical-engineering study conducted for a given civil engineer will not likely meet the needs of a civil-works constructor or even a different civil engineer. Because each geotechnical-engineering study is unique, each geotechnical-engineering report is unique, prepared solely for the client.

Likewise, geotechnical-engineering services are performed for a specific project and purpose. For example, it is unlikely that a geotechnical- engineering study for a refrigerated warehouse will be the same as one prepared for a parking garage; and a few borings drilled during a preliminary study to evaluate site feasibility will not be adequate to develop geotechnical design recommendations for the project.

Do not rely on this report if your geotechnical engineer prepared it:
• for a different client;
• for a different project or purpose;
• for a different site (that may or may not include all or a portion of the original site); or
• before important events occurred at the site or adjacent to it; e.g., man-made events like construction or environmental remediation, or natural events like floods, droughts, earthquakes, or groundwater fluctuations.

Note, too, the reliability of a geotechnical-engineering report can be affected by the passage of time, because of factors like changed subsurface conditions; new or modified codes, standards, or regulations; or new techniques or tools. If you are the least bit uncertain about the continued reliability of this report, contact your geotechnical engineer before applying the recommendations in it. A minor amount of additional testing or analysis after the passage of time – if any is required at all – could prevent major problems.

Read this Report in Full
Costly problems have occurred because those relying on a geotechnical- engineering report did not read the report in its entirety. Do not rely on an executive summary. Do not read selective elements only. Read and refer to the report in full.

You Need to Inform Your Geotechnical Engineer
About Change
Y our geotechnical engineer considered unique, project-specific factors when developing the scope of study behind this report and developing the confirmation-dependent recommendations the report conveys.

Typical changes that could erode the reliability of this report include those that affect:
• the site’s size or shape;
• the elevation, configuration, location, orientation,
function or weight of the proposed structure and
the desired performance criteria;
• the composition of the design team; or
• project ownership.

As a general rule, always inform your geotechnical engineer of project or site changes – even minor ones – and request an assessment of their impact. The geotechnical engineer who prepared this report cannot accept responsibility or liability for problems that arise because the geotechnical engineer was not informed about developments the engineer otherwise would have considered.

Most of the “Findings” Related in This Report
Are Professional Opinions
Before construction begins, geotechnical engineers explore a site’s subsurface using various sampling and testing procedures. Geotechnical engineers can observe actual subsurface conditions only at those specific locations where sampling and testing is performed. The data derived from that sampling and testing were reviewed by your geotechnical engineer, who then applied professional judgement to form opinions about subsurface conditions throughout the site. Actual sitewide-subsurface conditions may differ – maybe significantly – from those indicated in this report. Confront that risk by retaining your geotechnical engineer to serve on the design team through project completion to obtain informed guidance quickly, whenever needed.

This Report’s Recommendations Are
Confirmation-Dependent
The recommendations included in this report – including any options or alternatives – are confirmation-dependent. In other words, they are not final, because the geotechnical engineer who developed them relied heavily on judgement and opinion to do so. Y our geotechnical engineer can finalize the recommendations only after observing actual subsurface conditions exposed during construction. If through observation your geotechnical engineer confirms that the conditions assumed to exist actually do exist, the recommendations can be relied upon, assuming no other changes have occurred. The geotechnical engineer who prepared this report cannot assume responsibility or liability for confirmation-dependent recommendations if you fail to retain that engineer to perform construction observation.

This Report Could Be Misinterpreted
Other design professionals’ misinterpretation of geotechnical- engineering reports has resulted in costly problems. Confront that risk by having your geotechnical engineer serve as a continuing member of the design team, to:
• confer with other design-team members;
• help develop specifications;
• review pertinent elements of other design professionals’ plans and specifications; and
• be available whenever geotechnical-engineering guidance is needed.

Y ou should also confront the risk of constructors misinterpreting this report. Do so by retaining your geotechnical engineer to participate in prebid and preconstruction conferences and to perform construction- phase observations.

Give Constructors a Complete Report and Guidance
Some owners and design professionals mistakenly believe they can shift unanticipated-subsurface-conditions liability to constructors by limiting the information they provide for bid preparation. To help prevent the costly, contentious problems this practice has caused, include the complete geotechnical-engineering report, along with any attachments or appendices, with your contract documents, but be certain to note conspicuously that you’ve included the material for information purposes only. To avoid misunderstanding, you may also want to note that “informational purposes” means constructors have no right to rely on the interpretations, opinions, conclusions, or recommendations in the report. Be certain that constructors know they may learn about specific project requirements, including options selected from the report, only from the design drawings and specifications. Remind constructors that they may perform their own studies if they want to, and be sure to allow enough time to permit them to do so. Only then might you be in a position to give constructors the information available to you, while requiring them to at least share some of the financial responsibilities stemming from unanticipated conditions. Conducting prebid and preconstruction conferences can also be valuable in this respect.

Read Responsibility Provisions Closely
Some client representatives, design professionals, and constructors do not realize that geotechnical engineering is far less exact than other engineering disciplines. This happens in part because soil and rock on project sites are typically heterogeneous and not manufactured materials with well-defined engineering properties like steel and concrete. That lack of understanding has nurtured unrealistic expectations that have resulted in disappointments, delays, cost overruns, claims, and disputes.

To confront that risk, geotechnical engineers commonly include explanatory provisions in their reports. Sometimes labeled “limitations, ” many of these provisions indicate where geotechnical engineers’ responsibilities begin and end, to help others recognize their own responsibilities and risks. Read these provisions closely. Ask questions.

Y our geotechnical engineer should respond fully and frankly.

Geoenvironmental Concerns Are Not Covered
The personnel, equipment, and techniques used to perform an environmental study – e.g., a “phase-one” or “phase-two” environmental site assessment – differ significantly from those used to perform a geotechnical-engineering study. For that reason, a geotechnical-engineering report does not usually provide environmental findings, conclusions, or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Unanticipated subsurface environmental problems have led to project failures. If you have not obtained your own environmental information about the project site, ask your geotechnical consultant for a recommendation on how to find environmental risk-management guidance.

Obtain Professional Assistance to Deal with
Moisture Infiltration and Mold
While your geotechnical engineer may have addressed groundwater, water infiltration, or similar issues in this report, the engineer’s services were not designed, conducted, or intended to prevent migration of moisture – including water vapor – from the soil through building slabs and walls and into the building interior, where it can cause mold growth and material-performance deficiencies.

Accordingly, proper implementation of the geotechnical engineer’s recommendations will not of itself be sufficient to prevent moisture infiltration. Confront the risk of moisture infiltration by including building-envelope or mold specialists on the design team.

Geotechnical engineers are not building-envelope or mold specialists.

Copyright 2019 by Geoprofessional Business Association (GBA). Duplication, reproduction, or copying of this document, in whole or in part, by any means whatsoever, is strictly prohibited, except with GBA ’s specific written permission. Excerpting, quoting, or otherwise extracting wording from this document is permitted only with the express written permission of GBA, and only for purposes of scholarly research or book review. Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind.

Any other firm, individual, or other entity that so uses this document without being a GBA member could be committing negligent or intentional (fraudulent) misrepresentation.

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