Information_Handout_-_Foundation_Report_Hazel_Ave_OC_(Widen).pdf

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Hazel Avenue at US 50 Interchange Improvement Project - Segment 1
Solicitation number
4703
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Sacramento County, San Francisco City, California

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Foundation Report Summary

This is a Foundation Report prepared by PARIKH Consultants, Inc. for the County of Sacramento, California in cooperation with the California Department of Transportation (Caltrans) and the City of Rancho Cordova. The report provides geotechnical investigation and foundation recommendations for the Hazel Avenue Overcrossing (Widen) project, which involves widening an existing two-span overcrossing over US Route 50. The proposed widened structure will be approximately 269.5 feet in total length with a width varying from 21 feet 2 inches minimum to 25 feet maximum. The investigation included three borings drilled between August 2023 and November 2025, with depths ranging from 100 to 120 feet, supplemented by laboratory testing for soil classification, moisture content, unit weight, plasticity index, particle size analysis, and corrosivity evaluation. The report was completed on April 13, 2026, and is based on General Plans provided by the designer dated April 3, 2026.

The subsurface investigation identified medium stiff to hard lean clay and gravelly materials to approximately 76 feet below the existing surface, underlain by very dense silty sand and gravels to the maximum explored depth. Groundwater elevation was established at 121 feet for design purposes, reflecting significant seasonal and temporal variations documented in the area. Corrosion testing determined that all soil samples are non-corrosive per Caltrans guidelines based on chloride, sulfate, and pH measurements. The geotechnical recommendations include pile capacity calculations for both axial and lateral loading, settlement analysis under embankment fill, slope stability evaluation, and construction notes for cast-in-drilled-hole concrete pile installation. The project site is located in a seismically active area; seismic hazard analysis was performed addressing ground motion parameters, liquefaction potential, lateral spreading, and slope stability considerations. The report notes that subsurface conditions may vary at other locations and that a contingency fund should be provided for unforeseen variations during construction.

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FOUNDATION REPORT

HAZEL AVENUE OC (WIDEN)

COUNTY OF SACRAMENTO, CALIFORNIA

BRIDGE NO: 24-0168

03-SAC-50-PM 15.4/16.9

EA: 03-3E380

Prepared For:

MARK THOMAS

701 University Avenue, Suite 200

Sacramento, CA 95826

April 13, 2026 PARIKH Project No.: 2022-110-GEO

PARIKH CONSULTANTS, INC.

1497 N Milpitas Blvd., Milpitas, CA 95035

(408) 452-9000

CONTENTS PAGE

1.0 INTRODUCTION

2.0 PROJECT DESCRIPTION

3.0 EXCEPTIONS TO POLICY AND PROCEDURES

4.0 GEOTECHNICAL INVESTIGATION

5.0 LABORATORY TESTING PROGRAM

6.0 SITE GEOLOGY AND SUBSURFACE CONDITIONS

6.1 Geology

6.2 Surface Conditions

6.3 Subsurface Conditions

7.0 GROUNDWATER

8.0 AS-BUILT FOUNDATION DATA

9.0 SCOUR EVALUATION

10.0 CORROSION EVALUATION

11.0 SEISMIC INFORMATION

11.1 Ground Motion Hazard

11.2 Other Seismic Hazards

11.2.1 Seismic Sources

11.2.2 Surface Fault Rupture

11.2.3 Liquefaction Potential

11.2.4 Lateral Spreading

11.2.5 Seismic Slope Stability

12.0 GEOTECHNICAL RECOMMENDATIONS

12.1 General

12.2 Pile Capacity

12.2.1 Axial Pile Capacity

12.2.2 Lateral Pile Capacity

12.2.3 Lateral Earth Pressure Capacity

12.3 Approach Fills

12.3.1 Settlement Under Embankment

12.3.2 Slope Stability

13.0 NOTES FOR SPECIFICATIONS

14.0 NOTES FOR CONSTRUCTION (CIDH CONCRETE PILES)

15.0 REPORTS COPY LIST

16.0 INVESTIGATION LIMITATIONS

17.0 REFERENCES

TABLES PAGE

Table 1 – Boring Summary

Table 2 – Groundwater Information

Table 3 – Existing Foundation Details

Table 4 – Corrosion Test Results

Table 5 - Recommended Ground Motion Parameter for Geotechnical Design

Table 6 –Foundation Design Data Sheet

Table 7 –Foundation Factored Design Loads

Table 8 –Foundation Design Recommendation

Table 9 –Pile Data Table

Table 10– Generalized Soil Profile - Abut -1 (Based on R-23-009)

Table 11 – Generalized Soil Profile – Bent 2 & Abut -3 (Based on R-25-011 & R-23-012)

Table 12 – Estimated Immediate and Consolidation Settlement

Table 13 – Slope Stability Analysis Results

Table 14– Expected Difficult Pile Installation

Table 15– Predrilling for Driven Piles

Table 16 – Zones Used to Calculate Side Resistances

Table 17– Geotechnical Report Distribution List

APPENDIX I: SITE MAP

Plate 1: Project Vicinity Map

Plate 2: Site Map

Plate 3: Geologic Map

Plate 4: Fault Map

APPENDIX II: GROUND MOTION DATA SHEET

APPENDIX III: LOG OF TEST BORINGS

APPENDIX IV: FIELD TESTING & LABORATORY TEST RESULTS

APPENDIX V: CALCULATIONS

APPENDIX VI: REFERENCE DOCUMENTS

APPENDIX VII: STRUCTURAL PLANS

FOUNDATION REPORT

HAZEL AVENUE OVERCROSSING (WIDEN)

COUNTY OF SACRAMENTO, CALIFORNIA

BRIDGE NO: 24-0168

03-SAC-50-PM 15.4/16.9

EA: 03-3E380

1.0 INTRODUCTION

This “ Foundation Report” provides foundation information for the proposed “Hazel Avenue

Overcrossing (Widen)” in County of Sacramento, California, hereinafter referred to as

“PROJECT”. The work was performed in general accordance with the scope of work outlined in our proposal to Mark Thomas & Company (Designer).

The scope of work performed for this investigation included a review of the readily available soils and geologic literature pertaining to the project site; site reconnaissance, field investigation; engineering analyses; and preparation of this report. Our geotechnical recommendations are based on General Plans provided by the Designer dated April 3, 2026.

The purpose of this report is to evaluate the general subsurface soil conditions at the project site, to evaluate their engineering properties, and to provide foundation recommendations for the proposed Hazel Avenue OC (Widen). The approximate location of the project site is shown on the Project Vicinity Map (Plate No. 1) and Site Plan (Plate No. 2).

2.0 PROJECT DESCRIPTION

The County of Sacramento (County), in cooperation with the California Department of

Transportation (Caltrans) and the City of Rancho Cordova, is proposing the Hazel Avenue/U.S.

50 (US 50) Interchange Project to modify the existing interchange and extend and grade-separate Hazel Avenue over Folsom Boulevard and the Sacramento Placerville Transportation

Corridor Joint Power Authority (SPTC-JPA) rail corridor. Hazel Avenue will be extended further south to a proposed intersection with the future Atlanta Street (a new roadway to be constructed as part of the Easton Place development).

This project proposes to improve the existing Hazel Avenue interchange on U.S. Route 50 and the roadway associated with the extension and grade separation of Hazel Ave south of Folsom

Blvd. A widening is proposed for the existing Hazel Ave Overcrossing (OC) over US 50 with an additional tie-back retaining wall projected in front of the south abutment to allow for a new auxiliary lane to be added to the eastbound loop on-ramp. A new viaduct bridge is proposed over the Hazel Ave Interchange to improve traffic access to future developments near Aerojet

Rd. A west-bound off-ramp undercrossing and west-bound on-ramp undercrossing are proposed to improve traffic flow and allow for bike path traffic under the ramps. A new overhead structure is proposed to carry traffic on Hazel Ave over Folsom Blvd and the adjacent rail lines, and a new viaduct is proposed at Alder Pond Creek to widen eastbound US 50. The

Mark Thomas

Hazel Ave OC (Widen)

PARIKH Project No.: 2022-110-GEO

April 13, 2026

County of Sacramento will advertise, award, and administer the construction contract for the project.

Hazel Ave OC (Widen)

The existing overcrossing will be widened. It will be two span structure; total length will be

269.5 feet and width of the proposed widen overcrossing will vary from 21′-2′′ minimum to

25′-0′′ maximum.

We understand that project is using NGVD29 vertical datum. It is our understanding that any boring drilled before 1991 used NGVD29 datum for registering elevations. Therefore, as-built borings were considered as NGVD29 datum.

3.0 EXCEPTIONS TO POLICY AND PROCEDURES

Exceptions to the policy are not required.

4.0 GEOTECHNICAL INVESTIGATION

Three (3) borings were drilled to support foundation recommendations for the proposed overcrossing (widen). Boring R-23-009 & R-23-012 were drilled in August 2023. Both borings were advanced with truck mounted CME 75 drill rig using 4.5-inch diameter solid stem auger and rotary wash. The drilling contractor was GeoEx Subsurface Exploration Inc. from Dixon, CA.

Boring R-25-011 was drilled in November 2025. Boring was advanced with truck mounted D 70 drill rig using 4.5-inch diameter solid stem auger and rotary wash. The drilling contractor was

Terra-Ex Subsurface Exploration Inc. from Dixon, CA.

The boring was drilled under the technical supervision of our engineers, who classified and continuously logged the soils encountered during drilling and supervised the collection of soil samples at various depths for visual examination and laboratory testing. The soil samples were visually classified in the field according to the Unified Soil Classification System and then transported to our laboratory for further evaluation and testing. Upon completion of drilling, the borehole was backfilled with cement grout. The location of the borings are shown in the site plan (Plate No.2). The boring depth, station, and relevant information are summarized in

Table 1.

PARIKH Project No.: 2022-110-GEO

Table 1 – Boring Summary

Boring No.

Approx. Location Completion

Date Hammer Energy (1)

Ground Surface

Elevation

Boring

Depth Northing Easting

R-23-009 1992326.5 6785305.4 08/29/2023 89.1% 138±' 120.0±’

R-23-012 1992632.1 6785116.0 08/28/2023 89.1% 138±' 100.0±'

R-25-011 1992480.9 6785271.3 11/11/2025 79.7% 139.6±' 100.25±'

The soil samples were obtained from the borings during drilling at various depths by driving a

2.5-inch Inside Diameter (I. D.) Modified California Sampler or a 1.375-inch I.D. Standard

Penetration Sampler (ASTM Test Method No. 1586). The sampler was driven into the subsurface soils under the impact of a 140 pounds hammer having a free fall of 30 inches. The blow counts required to drive the sampler for the last 12 inches are presented on the LOTB, Appendix III. When correlating standard penetration data in similar soils, the blow counts for the Modified California sampler can be converted to equivalent Standard Penetration Test sampler by multiplying a non-standard sampler conversion factor of 0.65 and 0.41 for cohesive soil and cohesionless soil, respectively, per Caltrans Geotechnical Manual, “Soil Correlations” module (March 2021).

The logs presented in Appendix III were prepared from the field logs which were edited after visual re-examination of the soil samples in the laboratory and results of classification tests on selected soil samples as indicated on the logs.

It should be noted that the descriptions of the soils encountered, and relevant boring information presented on the LOTB depict subsurface conditions only at the locations indicated on the plan and on the particular date noted on the LOTB. Because of the variability from place to place within soil/rock in general, subsurface conditions at other locations may differ from conditions occurring at the boring locations explored. The abrupt stratum changes shown on the logs may be gradational and relatively minor changes in soil types within a stratum may not be noted on the logs due to field limitations. Also, the passage of time may result in a change in the soil conditions at these locations due to environmental changes.

PARIKH engaged NORCAL Geophysical to perform two Seismic Multichannel Analyses of Surface

Waves (MASW) sounding surveys to measure the shear-wave velocities of the subsurface. This method is used to collect surface wave data using a fixed array of geophones and shot points. The seismic arrays were each set out in a line consisting of four-shot points and 24-geophones distributed in a collinear array with a total length of 210 feet. Detailed descriptions of the MASW

PARIKH Project No.: 2022-110-GEO methodology and the results are provided in Appendix IV of this report.

5.0 LABORATORY TESTING PROGRAM

Laboratory tests were performed on selected soil samples recovered from the borings to evaluate the physical and engineering properties of the subsoil. The following tests were performed for this study: Moisture Contents (ASTM D2216), Unit Weight (ASTM D7263), Plasticity Index (AASHTO T 90), Particle Size Analysis (ASTM D422) and Corrosivity Testing (CTM

643, 422, and 417). The laboratory test results are attached in Appendix IV.

6.0 SITE GEOLOGY AND SUBSURFACE CONDITIONS

6.1 Geology

The Project site is located in the Great Central Valley Geomorphic Province. Plate 3 shows the locations of geological units in the Project area. The distribution and description of geological units in the project area were derived from the “Preliminary Geologic Map of the

Sacramento 30´ by 60´ Quadrangle, California”, California Department of Conservation, California Geological Survey.

The project is mapped as being underlain by dredge tailings deposited during gold dredging operations conducted from the early to mid 1900’s. Dredge tailings are visible on historical aerial photographs and topographic maps as being stacked directly at the Project site. The process of dredging involved a large dredge floating in a pool using a series of buckets on a conveyor which dug alluvial material down to a depth of greater than 100 feet. The gravels were separated in the dredge with the fine fraction consisting of sand, silt, and clay discharged into the dredge pool and the gravels discharged and stacked to the rear and sides of the dredge. The significance of the presence of dredge tailings is that a wet fine layer of unknown thickness underlies coarser material.

Well completion reports from the project vicinity suggest that depth to bedrock is greater than 100 feet.

6.2 Surface Conditions

Site topography is relatively flat and slopes gently to the north and north-west. The primary topographic site features are embankments created for the Hazel Avenue

Overcrossing. Surface water appears to be locally derived from Hazel Avenue and US 50.

PARIKH Project No.: 2022-110-GEO

Site geologic and elevation data do not indicate the presence of geologic hazards such as landslides, slope failure, rockfalls, or debris flows.

6.3 Subsurface Conditions

Recently drilled borings (R-23-009, R-23-012 & R-25-011) encountered medium stiff to hard lean clay, lean clay with sand, silt, elastic silt with gravels and cobbles and loose to very dense clayey gravel, silty sand with gravels, poorly graded gravel and cobbles up to

76 feet (Elev. 62 feet) below existing surface underlain by very dense silty sand, well graded sand with silt, silty gravel with sand, poorly graded gravel with clay, clayey gravel to the maximum explored depth of 120 feet (Elev. 18 feet).

We also reviewed the as-built LOTB (1990). Based on the as-built LOTB (1990), gravelly cobbles and occasional boulders were encountered in upper 4-5 feet from the surface.

Below the cobbles and boulders, medium dense to very dense silty fine sand with some interbedded layers of sandy silt, clayey silt, sandy clay and gravels were encountered to the maximum explored depth of 63.5 feet (Elev. 75 feet). As-built LOTB borings and locations are attached in Appendix III.

Due to limitations inherent in geotechnical investigations, it is neither uncommon to encounter unforeseen variations in the soil conditions during construction nor is it practical to determine all such variations during an acceptable program of drilling and sampling for a project of this scope. Such variations, when encountered, generally require additional engineering services to attain a properly constructed project. We, therefore, recommend that a contingency fund be provided to accommodate any additional charges resulting from technical services that may be required during construction.

7.0 GROUNDWATER

Groundwater was encountered at depth 52 feet (Elev. 86 feet) below existing surface on boring R-23-012. Groundwater was not encountered in borings R-23-009 & R-25-011 before switching to rotary wash drilling method. Groundwater measured in other nearby borings drilled for the other proposed structures for this project, shows the groundwater elevation varies between 81.5 feet and 131 feet.

Based on the as-built LOTBs, the groundwater was encountered at about 18.4 feet (Elev.

117.40 feet) below existing surface in 1990. Groundwater was encountered at about 10 feet

(Elev. 126.2 feet) below existing surface in 1958.

PARIKH Project No.: 2022-110-GEO

We also reviewed DWR Well reports from the following reference and summarized in the table below. (https://sgma.water.ca.gov/webgis/?appid=SGMADataViewer#gwlevels)

Table 2 – Groundwater Information

*Well Locations are shown in the map, attached in Appendix VI.

As shown above the groundwater elevation varies significantly within the project area between the years of 1958 and 2023. Considering the groundwater variation, the design ground water elevation of 121 feet is considered for the purpose of engineering analysis.

Please note that groundwater may vary with the passage of time due to seasonal groundwater fluctuation, surface and subsurface flows, ground surface run-off, and other factors that may not be present at the time of investigation.

8.0 AS-BUILT FOUNDATION DATA

Based on the as-built plans of existing Hazel Ave OC (1996), we understand that the existing overcrossing is approximately 270 feet long and 99 feet wide, and is a cast-in-place pre-stressed concrete box girder bridge with two spans having a minimum vertical clearance of 16.17 feet.

Following table shows foundation details based on the as-built plans.

Table 3 – Existing Foundation Details

Support Foundation Type As-built Pile Specified

Tip Elevation (ft) Average As-built Pile

Probable Elevation (ft) Abut 1 Class 70 Steel Pile 104.0 99.0 Bent 2 Class 70 Steel Pile 104.0 99.0 Abut 3 Class 70 Steel Pile 104.0 99.0

DWR Well No* Groundwater Depth

(feet) Approximate Groundwater

Elevation (feet) Date Measured

09N07E16_084405 20 120 04/16/1979

09N07E16_0953688 52.72 87.28 09/19/2008

09N07E16_0953684 53.38 86.62 09/19/2008

09N07E16_0079511 47 93 06/30/2004

09N07E16_087684 35 112 09/05/1979

09N07E16_087637 35 111 09/05/1979

09N07E16L001M -

109 01/1982

118 01/1983

116 01/1984

110 01/1985

110 01/1986

108 01/1987

PARIKH Project No.: 2022-110-GEO

9.0 SCOUR EVALUATION

A scour evaluation is not needed since there is no waterway underneath the structure.

10.0 CORROSION EVALUATION

The available corrosion test results are shown in the table below:

Table 4 – Corrosion Test Results

Boring ID Sample

Depth Soil pH

Minimum

Resistivity

(ohm-cm)

Chloride

Content

(ppm)

Sulfate

Content

(ppm)

Corrosive/

Non-Corrosive

R-23-009 15.0 6.11 3090 4.4 9.5 Non-Corrosive

R-23-012 20.0 6.93 2140 6.1 29.6 Non-Corrosive

According to Caltrans Corrosion Guideline, March 2018 (Version 3.0), Caltrans considers a site to be corrosive to foundation element if one of the following conditions exists for the representative soil/water samples taken at the site:

• Chloride concentration is greater than or equal to 500 ppm,

• Sulfate concentration is greater than or equal to 1,500 ppm,

• pH is 5.5 or less.

Based on the corrosion test results, all soil samples are non-corrosive per Caltrans guidelines.

The test results are presented in Appendix IV.

11.0 SEISMIC INFORMATION

The project is located in a seismically active area of northern California. The major fault zones of the San Andreas Fault system have been major earthquake sources and are expected to be sources of future earthquakes.

The closest active faults to the Project site are the latest Quaternary aged (<15,000 years)

Cordelia and Green Valley faults which lay about 56 miles to the west and south-west. Plate 4 shows the location of the Cordelia and Green Valley faults and others in the project region.

The Cordelia and Green Valley faults are right lateral and part of the San Andreas fault system.

The Cordelia fault dips vertically and strikes about 350°. The Green Valley fault dips from about 59° east to 89° south-west and strikes an average of about 346°.

PARIKH Project No.: 2022-110-GEO

11.1 Ground Motion Hazard

The recommended design response spectrum for the proposed overcrossing structure was determined using the Caltrans ARS Online tool (V3.1.0) which is consistent with the

Caltrans SDC V2.0.

For SDC 2.0, the Design Spectrum is based on the USGS 975-year uniform hazard spectrum only. Effective December 1, 2019, the USGS hazard spectrum is based on the 2014

National Hazard Map per the memorandum from the State Bridge Engineer. The updated

Design Spectrum continues the use of near-fault adjustment factors and basin amplification factors. The only change to these factors is the use of the Campbell-

Bozorgnia (2014) and Chiou-Youngs (2014) basin amplification factors, updated from their

2008 models.

The development of the design ARS curve is based on several input parameters, including site location (longitude/latitude), average shear wave velocity for the top 30m/100 feet

(Vs30), and other site parameters, such as fault characteristics and site-to-fault distances.

Based on information obtained from the geophysical surveys (MASW), the time-average shear wave velocity (VS30) for the upper 100 feet of soil at the site are estimated to be 375 and 393 m/sec. Both shear wave velocities (375 and 393 m/sec) were used in ARS curve and shear wave velocity of 393 m/sec provided upper envelope of the curve. Therefore, shear wave velocity of 393 m/sec was considered for design.

Based on the subsurface data, the site is classified as “Class S2 Soil” per Caltrans SDC, V2.0. The site location and the relevant parameters are summarized in the table below, and the recommended design curve is presented in Appendix II.

PARIKH Project No.: 2022-110-GEO

Table 5 - Recommended Ground Motion Parameter for Geotechnical Design

Site Parameter Design Ground Motion Parameter

(return Period = 975 years)

Locations

Shear-Wave Velocity

����,m/sec

Horizontal

Peak Ground

Acceleration

(��� )(�), g

Mean

Earthquake

M, Moment

Magnitude

Mean Site-source Distance

(km, for Sa at

1s) km Latitudes degrees

Longitude, degrees

38.6307 -121.2172 393 0.18 6.72 114.2

1. Based on the Caltrans web tool ARS Online (Version 3.1.0)

2. No adjustment was needed for basin effect.

Based on the Caltrans Geotechnical Manual, “Embankment” module dated December

2014, a seismic coefficient, kh, of 0.06 (1/3×PGA), should be considered for slope stability evaluation of the approach embankment under seismic conditions (pseudo-static analysis). However, since the abutments are supported on deep foundations and the abutment walls are considered non-sliding walls, a higher kh of 0.09 (1/2×PGA) will be used when evaluating the abutment slope along the longitudinal direction.

11.2 Other Seismic Hazards

Potential seismic hazards may arise from three sources: surface fault rupture, ground shaking and liquefaction.

11.2.1 Seismic Sources

Based on available geological and seismic data, the project site is expected to experience moderate ground shaking. PGA was calculated as 0.18g for the site in Section 11.1.

11.2.2 Surface Fault Rupture

An Earthquake Zones of Required Investigation map and Seismic Hazard Zone Report have not been prepared for the site enclosing Folsom Ranch 7.5 minute Quadrangle. Hence, the

Project does not lay within an Alquist-Priolo Earthquake Fault Zone or Seismic Hazard

Zone.

The USGS Quaternary Fault and Fold Database shows the Project is not located within

1,000 feet of an unzoned fault that is Holocene/Latest Pleistocene (15,000 years) or younger in age.

PARIKH Project No.: 2022-110-GEO

Accordingly, as per the Caltrans Fault Rupture module, a Surface Fault Rupture

Displacement Hazard Analysis is not required.

In assessing seismic risks, we consider that surface fault rupture does not contribute to the seismic hazards at the site during the useful life of the Project. The preceding statements do not make inferences on the potential for aseismic surface cracking.

11.2.3 Liquefaction Potential

Liquefaction is a phenomenon in which saturated cohesionless soils are subject to a temporary but essentially total loss of shear strength under the reversing, cyclic shear stresses associated with earthquake shaking. Submerged cohesionless sands and silts of low relative density are the type of soils, which usually are susceptible to liquefaction.

Clays are generally not susceptible to liquefaction.

The liquefaction potential was evaluated in accordance with the methods proposed in

Liquefaction Evaluation Module of Caltrans Geotechnical Manual (January 2020). The evaluation was done using the boring data from all the available borings using a

Magnitude 6.72 earthquake and a peak ground acceleration of about 0.21g. This method compares the estimates of the earthquake-induced shear stress to the susceptibility of soil liquefaction. According to Bray (2006), liquefaction appears to occur in soils where these fines are either non-plastic or are low plasticity silts and/or silty clays (PI<12%, and

LL<37%), and with high water content relative to their liquid limit (w>0.85 LL).

The soil data were analyzed per Youd (2001) and the analysis results are presented in

Appendix V.

Based on our liquefaction analysis, the liquefaction potential does not exists at the project location.

11.2.4 Lateral Spreading

Per Caltrans Memo to Designers 20-15 dated May 2017, “Lateral Spreading Analysis for

New and Existing Bridges”, lateral spreading is caused by the accumulation of incremental displacements that develop within liquefied soil under cyclic loading. Depending on the number and amplitude of stress pulses, lateral spreading can produce displacements that range from a few inches to tens of feet. Flow liquefaction occurs when a slope becomes unstable under static loading due to strength loss caused by liquefaction.

PARIKH Project No.: 2022-110-GEO

Lateral spreading refers to the more moderate movements of gently sloping ground due to soil liquefaction. The geologic conditions conducive to lateral spreading (gentle surface slope, shallow water table, and liquefiable cohesionless soils) are frequently found along streams and other waterfronts in recent alluvial or deltaic deposits, as well as in loosely-packed, saturated, sandy fills.

In our opinion, the potential for lateral spreading does not exist, since liquefiable soil layers are not identified in our analysis.

11.2.5 Seismic Slope Stability

As discussed in Section 12.3.2, the slope stability of the embankment and the walls should be satisfactory. The pseudo-static analysis was performed with a horizontal seismic coefficient (kh) equal to 0.09g (1/2 × PGA) as discussed in Section 11.1. It appears that seismic slope stability is not a design concern. Slope stability analysis outputs are attached in Appendix V.

12.0 GEOTECHNICAL RECOMMENDATIONS

12.1 General

The subsurface conditions at the project site predominantly consist of medium stiff to hard lean clay, silt and medium dense to very dense granular materials including gravels and cobbles. The materials at shallow depth tend to be more variable in terms of material characteristics and consistency. Our recommendations are based on the plans, dated April

3, 2026, provided by Mark Thomas.

We expect the foundation design will follow the LRFD approach (AASHTO LRFD

Specifications, 8th edition, with California Amendments) with demands under the Service, Strength, and Extreme Limit states.

12.2 Pile Capacity

12.2.1 Axial Pile Capacity

Based on information provided by the designer (Mark Thomas), we understand that

HP14x89 and Cast-in-drilled-hole (CIDH) are considered for the abutments and bent foundation support, respectively.

The estimation of the capacity of CIDH concrete pile follows AASHTO LRFD Specifications.

The methodology is based on procedures proposed by O'Neill and Reese (1999; FHWA-IF-

PARIKH Project No.: 2022-110-GEO

99-025), which utilizes α factor for "Clay" and β factor for "Sand" where β is a function of depths below ground surface and soil friction angle. The computer program “SHAFT”

(Ensoft, Ver. 2017.8.11) was used for axial pile capacity calculation of CIDH piles.

The axial pile capacities of the steel H-piles were analyzed based on guidelines in the

American Petroleum Institute (API) publication (2007). The computer program “APILE”

(Ensoft, Ver. 2019.9.5) was used for axial pile capacity calculation of H- piles. The computer program APILE estimated the axial pile capacity including the frictional resistance along the pile and the end bearing.

Following foundation information was provided by the designer.

Table 6 –Foundation Design Data Sheet

Support Pile Type

Finished

Elevation

(ft)

Cut-Off

Elevation

(ft)

Pile Cap Size (ft) Permissible

Settlement under

Service Load

(in)

Number of

Piles per

Support B (ft) L (ft)

Abutment 1 HP 14x89 159.89 144.12 7.00 21.42 1 8

Bent 2 108” Dia. CIDH 137.00 133.00 N/A N/A 1 1

Abutment 3 HP 14x89 159.12 143.72 7.00 25.33 1 10

Table 7 –Foundation Factored Design Loads

Support

No.

Service-I Limit State

(kips)

Strength Limit State (Controlling Group, kips)

Extreme Limit State

(Controlling Group, kips)

Total

Load

Permanent

Loads

Compression Tension Compression Tension

Per

Support

Per

Support

Per

Support

Max.

Per Pile.

Per

Support

Max.

Per Pile.

Per

Support

Max.

Per

Pile.

Per

Support

Max.

Per

Pile.

Abut 1 878 750 1213 256 N/A 37 750 149 N/A N/A

Bent 2 2062 1563 3036 3036 N/A N/A 1799 1799 N/A N/A

Abut 3 1107 886 1696 252 N/A 33 886 139 N/A N/A

PARIKH Project No.: 2022-110-GEO

Table 8 –Foundation Design Recommendation

Support

No.

Pile

Type

Cut-off

Elevation

(ft)

Service-I Limit State

Load (kips) per

Support

Total

Permissible

Support

Settlement

(inches)

Nominal Resistance (kips)1

Design Tip

Elevation2

(ft)

Specified

Tip

Elevation

(ft)

Strength/Construction Extreme Event

Compression

( ϕqs = 0.7)

Tension

(ϕqs = 0.7)

Compression

(ϕqs = 1)

Tension

(ϕqs = 1) Total Permanent

Abut 1 HP 14x89 144.12 878 750 1.00 370 60 150 -

(a-I) 97.0

(a-II) 114.0

(b-I) 119.0

(c) 117.0

(d) 116.0

97.0

Bent 2 108” Dia. CIDH 133.00 2062 1563 1.00 4340 - 1800 -

(a-I) 50.0

(a-II) 85.0

(c) 90.0

(d) 63.0

48.0

Abut 3 HP 14x89 143.72 1107 886 1.00 360 50 140 -

(a-I) 89.5

(a-II) 116.5

(b-I) 122.5

(c) 123.0

89.5

Notes:

1. Column heading modified from Required Factored Nominal Resistance to Nominal Resistance.

2. Design tip elevations are controlled by: (a-I) Compression (Strength Limit), (b-I) Tension (Strength Limit), (a-II) Compression

(Extreme Event), (b-II) Tension (Extreme Event), (c) Settlement, (d) Lateral Load.

3. The specified tip elevation shall not be raised above the design tip elevations for tension, lateral, and tolerable settlement.

4. Specified tip elev. is lowered by 2 ft from the design tip elev. to account for untested zone of CIDH piles per Caltrans Geotech

Manual (CIDH Module).

5. Lateral pile analysis was performed by the designer (Mark Thomas) and lateral tip elevation was provided by the designer.

Table 9 –Pile Data Table

Location Pile Type

Cut-Off

Elevation

(ft)

Nominal Resistance (kips)

Design Tip Elev. (ft) Specified Tip

Elev. (ft)

Required

Nominal Driving

Resistance (kips) Compression Tension

Abut 1 HP 14x89 144.12 370 60

(a) 97.0 (b) 119.0 (c) 117.0

(d) 116.0

97.0 370

Bent 2 108” Dia. CIDH 133.00 4340 - (a) 50.0 (c) 90.0 (d) 63.0 48.0 N/A

Abut 3 HP 14x89 143.72 360 50

(a) 89.5 (b) 122.5 (c) 120.0

(d) 123.0

89.5 360

Design Tip Elevations For Abutments Are Controlled By: (a) Compression, (b) Tension, (c) Settlement, (d) Lateral Load.

Note: Lateral pile analysis was performed by the designer (Mark Thomas) and lateral tip elevation was provided by the designer.

12.2.2 Lateral Pile Capacity

We understand that lateral pile analysis will be performed by the designer (Mark

Thomas). In addition, since the structure will be founded in Class S2 soil, lateral stability analysis of the CIDH at the bent will be performed per SDC 6.2.6 (Oct 2019 interim revision). Lateral load analysis will be performed using LPILE Program. We have developed generalized soil profile and summarized in the following table.

PARIKH Project No.: 2022-110-GEO

Table 10– Generalized Soil Profile - Abut -1 (Based on R-23-009) Approximate Elevation

(ft)

Generalized

Soil Profile

LPILE Soil Type Soil

Strength

Effective Unit Weight

(pcf)

145 to 138 Lean Clay (CL) (fill) Stiff Clay w/o Free Water, Reese c = 1000 psf 120

138 to 124 Lean Clay (CL) Stiff Clay w/o Free Water, Reese c = 750 psf 120

124 to 121 Silt (ML) Stiff Clay w/o Free Water, Reese c = 1000 psf 120

121 to 119.5 Silt (ML) Stiff Clay w/o Free Water, Reese c = 1000 psf 62.5

119.5 to 110 Silty Sand (SM) Sand, Reese φ = 34 degrees 62.5

110 to 95 Silty Sand (SM) Sand, Reese φ = 32 degrees 62.5

95 to 84.5 Silty Sand (SM) Sand, Reese φ = 36 degrees 62.5

84.5 to 74.5 Silt (ML) Stiff Clay w/o Free Water, Reese c = 3,000 psf 62.5

74.5 to 63.5 Silty Sand (SM) and Clayey Sand

(SC)

Sand, Reese φ = 32 degrees 62.5

63.5 to 18 Silty Sand (SM), Silty Gravel (GM) and Clayey Gravel (GC) Sand, Reese φ = 38 degrees 62.5

*Default values can be used for ε50 and K.

Table 11 – Generalized Soil Profile – Bent 2 & Abut -3 (Based on R-25-011 & R-23-012) Approximate Elevation

(ft)

Generalized

Soil Profile

LPILE Soil Type Soil

Strength

Effective Unit Weight

(pcf)

145 to 138 Lean Clay (CL) (fill) Stiff Clay w/o Free Water, Reese c = 1000 psf 120

138 to 134.5 Clayey Gravel (GC) Sand, Reese φ = 30 degrees 120

134.5 to 126.5 Lean to fat Clay (CL/CH) and

Elastic Silt (MH) Stiff Clay w/o Free Water, Reese c = 1,500 psf 120

126.5 to 121 Elastic Silt (MH) Stiff Clay w/o Free Water, Reese c = 3,000 psf 120

121 to 114 Elastic Silt (MH) Stiff Clay w/o Free Water, Reese c = 3,000 psf 62.5

114 to 104.5 Elastic Silt (MH) and Sandy Lean

Clay (CL) Stiff Clay w/o Free Water, Reese c = 3,000 psf 62.5

104.5 to 99.5 Silty Sand (SM) Sand, Reese φ = 30 degrees 62.5

99.5 to 64.5 Elastic Silt (MH) and Sandy Silt

(ML)

Stiff Clay w/o Free Water, Reese c = 3,500 psf 62.5

64.5 to 38 Silty Sand (SM) and Silty Gravel with Sand (GM) Sand, Reese φ = 38 degrees 62.5

*Default values can be used for ε50 and K.

12.2.3 Lateral Earth Pressure Capacity

Walls that are free to rotate at least 0.004 radians may be assumed flexible for the active condition. Walls that are not capable of this movement should be assumed rigid and designed for the at-rest condition.

The proposed abutments should be designed to resist an active earth pressure of 36 pcf equivalent fluid pressure (EFP, based on an active earth pressure coefficient, ka, of 0.283 and a unit weight of 125 pcf) and live load. This value assumes no hydrostatic pore

PARIKH Project No.: 2022-110-GEO pressure buildup behind the wall and is based on well-drained, well-compacted Structure

Backfill per Section 19-3.02C of the Caltrans Standard Specifications behind the abutment walls.

For the longitudinal stiffness and passive resistance, the abutment walls should be designed based on the bilinear model per Section 6.3.1 of the Caltrans Seismic Design

Criteria (SDC, version 2.0, dated April 2019). The bilinear model is based on experimental and calibrated analytical models using engineered structural backfill to a relative compaction of at least 95%.

Seismic Design: Per AASHTO LRFD Specification (8th Edition), Chapter 11, the horizontal seismic acceleration coefficient (kh) is calculated as half of horizontal peak acceleration

(PGA). Based on our analysis PGA at this wall location is 0.18g. Therefore, a seismic factor

(kh) of 0.09 is recommended. It is noted that kh is used in the Mononobe-Okabe equation to calculate the total seismic active earth pressure coefficient (KAE) per AASHTO LRFD

Specification (8th Edition), Chapter 11. Total seismic active earth pressure coefficient (KAE) of 0.31 and incremental seismic earth pressure coefficient (∆KAE) of 0.03 are recommended per Figure A11.3.2-2 & A11.3.2-3 of AASHTO LRFD Specification (8th

Edition).

12.3 Approach Fills

Based on the General Plan, provided by the designer, we understand that about 23- and 21-feet fills are planned at abutment 1 & 3 locations, respectively.

12.3.1 Settlement Under Embankment

As discussed in Section 6.3, both fine grained and coarse-grained soils were encountered at abutment locations. Consolidation and immediate settlement are anticipated due to the proposed embankment fills at abutment 1 and 3 locations.

We have reviewed and adopted correlations from various references with revision to the site-specific laboratory test results for estimating the indexes for settlement calculation.

The estimation of pre-consolidation pressure is based Su/p per Skempton (1957) and

NAVFAC D.M. 7.1. The modified compression index (Cc/(1+e0)) and the recompression index (Cr/(1+e0)) were estimated based on the correlation with natural moisture content based on Lambe and Whitman (1969). Immediate settlement of sand layers was calculated using Hough’s (1969) Method.

PARIKH Project No.: 2022-110-GEO

Considering the proposed backfill embankment configuration, the estimated ground settlements may be on the order of 5 inches and 5.5 inches at abutment 1 and 3, respectively. Settlement calculations are attached in Appendix V. Estimated immediate and consolidation settlement amount are shown in the following table.

Table 12 – Estimated Immediate and Consolidation Settlement

Location

Estimated

Immediate

Settlement

(inches)

Estimated Consolidation Settlement (inches)

Over-

Consolidated

(OC)

Normally

Consolidated (NC)

Abut 1

Embankment

1.8 2.9 0.4

Abut 3

Embankment

1.3 4 -

Over Consolidation Ration (OCR) is calculated by dividing in-situ effective stress to Pc. The analysis results (attached in appendix V) indicate that most of the anticipated consolidation settlement at both abutments are in the over-consolidated (OC). Per Section C10.6.2.4.3, AASHTO LRFD BDS, settlement of over-consolidated clay/silt usually occur one order of magnitude faster than soil without pre-consolidation, and it is reasonable to assume that they take as rapidly as the loads are applied. Immediate settlement will take as rapidly as the embankment fill is placed. For practical design purposes and to account for potential variation in the ground conditions, a waiting period of 30 days is recommended prior to the construction of piles and pavement. The settlement monitoring is recommended and should be performed as per Caltrans Standard Test Method 112.

12.3.2 Slope Stability

As discussed in Section 6.3, the subsoils generally consist of medium stiff to hard lean clay, silt and medium dense to very dense granular materials including gravels and cobbles. In our opinion, the slope stability of the embankment should be satisfactory. This is supported by the results of the slope stability analyses performed at the abutments of the

OC structure. The results are presented in Appendix V and summarized in the following table.

PARIKH Project No.: 2022-110-GEO

Table 13 – Slope Stability Analysis Results

Location

Static Condition Seismic Condition

(Pseudo-Static Analysis))

Factor of

Safety

Resistance

Factor

Factor of

Safety

Resistance

Factor

Abutment 1 1.89 0.53 1.57 0.63

Abutment 3 2.41 0.41 2.07 0.48

13.0 NOTES FOR SPECIFICATIONS

Before using the information provided below in this section, please review the report to comprehend the contents and intent of the geotechnical design. The Standard Special

Provisions (SSPs) in this section will be revisited when the Project features are finalized.

49-1.03 Expected Difficult Pile Installation

The expected difficult pile installation conditions are summarized in the following table.

Table 14– Expected Difficult Pile Installation

Pile Location

Conditions Structure

Number

Support Location

Br. No.

24-0168

Abutment 1 & 3 Very dense gravels, cobbles, potential boulders, hard driving may be expected. Should difficult driving be encountered where the vertical compression requirement is met (per Gates formula), pile driving should be allowed to terminate short of the specified tip elevation provided that either one of the following conditions are satisfied:

- Other requirements including tension, settlement, and lateral demands are met;

- Any practical pile refusal within 5 feet above the specified tip elevation, which may be considered acceptable and cut off at the option of the contractor.

Bent 2 Very dense gravels, cobbles, occasional boulders, hard drilling, caving soils, potential groundwater, temporary and permanent casing, noise control, and traffic control.

49-2.01C (3) Drilling for Driven Piles

If necessary to attain specified tip elevation, the contractor should drill holes with a diameter not greater than 9 inches for the proposed HP 14x89 steel piles before pile driving.

PARIKH Project No.: 2022-110-GEO

49-2.01C (4) Predrilling for Driven Piles in Proposed Embankment is Required

Predrilling is required in the proposed approach embankment. According to Standard

Specifications, a predrilled hole must be at least 6 inches larger than the greatest dimension of the pile cross section.

Table 15– Predrilling for Driven Piles

Structure Number Support Location Bottom of Hole Elevation, feet

Br. No. 24-0168 Abutment 1 OG Elevation, Approximate Elev. 136

Abutment 3 OG Elevation, Approximate Elev. 136

49-2.01C (5) Pile Set Period is Allowed

If the piles do not attain the nominal driving resistance at the specified tip elevation, the piles may be allowed to stand for a “set period” of minimum 24 hours without driving. If the nominal driving resistance is attained for each pile designated to be re-driven, the remaining piles in that footing are considered acceptable.

49-3.02B(6)(c): List of Synthetic Slurry for CIDH piles at least 24” in diameter

This SSP will be used in its entirety unedited because the CIDH piles are at least 24 inches in diameter and 5 feet in length.

49-3.02C (6): Permanent Steel Casing Installation

Fill voids in the annular space between the casing and the soil with grout per Section 49-3.02B

(5) and 49-3.02C (6).

49-3.02C (7): Permanent Casing for Type II CIDH Piling with Optional Construction Joint Shown

Section 49-3.02C (7) applies to CIDH concrete piles because a construction joint is shown on the plans.

It is recommended that the casings be corrugated metal pipe and placed in a drilled hole.

Casings placed in a drilled hole must comply with section 49-3.02C (7).

PARIKH Project No.: 2022-110-GEO

14.0 NOTES FOR CONSTRUCTION (CIDH CONCRETE PILES)

The calculated “Nominal Resistance” of the CIDH concrete piles was based on side resistance only. Tip resistance was not used. The zones used to calculate the side resistance of the CIDH concrete piles are shown in the table below.

TABLE 16 – Zones Used to Calculate Side Resistances

Support

Location

Top of Side Resistance

Zone Elevation

(feet)

Bottom of Side Resistance

Zone Elevation

(feet)

Specified

Tip Elevation

(feet)

Bent 2 119 51.0 49.0

Due to limitations inherent in the geotechnical investigation, it is neither uncommon to encounter unforeseen variations in the subsurface conditions during construction, nor is it practical to determine all such variations in an acceptable exploration program.

Therefore, the contractor should expect the following conditions for the pile construction:

• The concrete placement for the CIDH concrete piles may occur below the groundwater surface, which may necessitate the slurry displacement method and use of temporary casings.

• Difficult installation may be anticipated according to the boring data (i.e., potential very dense cobbles, sand and gravel with occasional boulders). In addition, caving should also be expected within granular materials. Such caving condition may require additional drilling and cleaning effort and may increase the concrete volume for the piles. The contractors should be aware of these conditions so that they can take appropriate steps to comply with the standards and maintain the integrity of the piles. Due to gravels and cobbles in the substrata, standard drilling slurry method may only not be able to prevent caving and sloughing. We also suggest casing oscillation construction method due to caving concerns of gravels and cobbles, if needed.

• Pile excavations should not be allowed to stand open overnight without full-length casing, and excavations should be poured as soon as practical.

• The bottom of the bent excavations should be free of debris and loose materials and properly cleaned. Access tubes should be provided to allow for pile integrity testing and construction QA/QC (gamma-gamma logging or cross-hole sonic logging) procedures except

PARIKH Project No.: 2022-110-GEO for piles constructed in dry holes or holes dewatered without the use of temporary casing to control groundwater.

• All pile excavations should be observed by the Project geotechnical engineer or the owner’s representatives during drilling and prior to the placement of reinforcement and concrete so that if conditions differ from those anticipated, appropriate recommendations can be made.

Since earthwork activities and pile installation will be performed close to adjacent structures, we recommend that a comprehensive pre-construction survey and monitoring program be implemented. This should include, but not limited to, pre-construction, during construction, and post-construction conditions of the surrounding structures. This should also serve as a basis to developing appropriate mitigation options for restoration of these structures.

15.0 REPORTS COPY LIST

This report is prepared for Mark Thomas (Designer) for Hazel Avenue OC (Widen) which is part of Hazel Avenue Interchange Project in the County of Sacramento, California. A copy of this report will be submitted to the designer. The report should be distributed to those listed under

Report Distribution in the Communications and Reporting section of Offices of Geotechnical

Design – Quality Management Plan. A geotechnical report distribution list is provided below as reference.

Table 17– Geotechnical Report Distribution List Addressee Report Title(s) District 1 District 4 District 5

District Project Manager All N/A N/A Alex Biaheza

Project Liaison Engineer

(Structures)

SPGR N/A N/A Minh Vo

Structures Construction R.E.

Pending File

FR No longer needed.

Structures Office Engineer FR To Be Determined

District Materials Engineer All N/A N/A To Be Determined

Geotechnical Archive All http://svgcgeodog.dot.ca.gov

16.0 INVESTIGATION LIMITATIONS

Our services consist of professional opinions and recommendations made in accordance with generally accepted geotechnical engineering principles and practices and are based on our site reconnaissance and the assumption that the subsurface conditions do not deviate from observed conditions. All work done is in accordance with generally accepted geotechnical engineering principles and practices. No warranty, expressed or implied, of merchantability or

PARIKH Project No.: 2022-110-GEO fitness, is made or intended in connection with our work or by the furnishing of oral or written reports or findings.

The scope of our services did not include any environmental assessment or investigation for the presence or absence of hazardous or toxic materials in structures, soil, surface water, groundwater or air, below or around this site. Unanticipated soil conditions are commonly encountered and cannot be fully determined by taking soil samples and excavating test borings;

different soil conditions may require that additional expenditures be made during construction to attain a properly constructed project. Some contingency fund is thus recommended to accommodate these possible extra costs.

This report has been prepared for the proposed project as described earlier, to assist the engineer in the design of this project. In the event any changes in the design or location of the facilities are planned, or if any variations or undesirable conditions are encountered during construction, our conclusions and recommendations shall not be considered valid unless the changes or variations are reviewed, and our recommendations modified or approved by us in writing.

This report is issued with the understanding that it is the designer's responsibility to ensure that the information and recommendations contained herein are incorporated into the project and that necessary steps are also taken to see that the recommendations are carried out in the field.

The findings in this report are valid as of the present date. However, changes in the subsurface conditions can occur with the passage of time, whether they are due to natural processes or to the works of man, on this or adjacent properties. In addition, changes in applicable or appropriate standards occur, whether they result from legislation or from the broadening of knowledge. Accordingly, the findings in this report might be invalidated, wholly or partially, by changes outside of our control.

Respectfully submitted, PARIKH CONSULTANTS, INC.

Kandeep Saravanapavan, P.E., G.E. 3040 Y. David Wang, Ph.D., P.E.52911

Senior Project Engineer Project Manager

12/31/1612/31/26

12/31/27

PARIKH Project No.: 2022-110-GEO

17.0 REFERENCES

American Association of State Highway and Transportation Officials, 2017, “AASHTO LRFD

Bridge Design Specifications”, 8th Edition.

California Department of Transportation, “Caltrans ARS Online, v3.0.2”

(https://arsonline.dot.ca.gov/)

California Department of Transportation, “Caltrans Fault Data Base (V2b)”

California Department of Transportation, “Caltrans Test Methods”

California Department of Transportation, 2018, “Corrosion Guidelines, Version 3.0”, Division of

Engineering Services, Materials Engineering and Testing Services, Corrosion and Structural

Concrete Field Investigation Branch.

California Department of Transportation, “Geotechnical Manual”

(https://dot.ca.gov/programs/engineering-services/manuals/geotechnical-manual)

California Department of Transportation, “Memo To Designers”

(https://dot.ca.gov/programs/engineering-services/manuals/memo-to-designers)

California Department of Transportation, 2012, “Methodology for Developing Design Response

Spectrum for Use in Seismic Design Recommendations.”

California Department of Transportation, 2022, “Standard Plans”

California Department of Transportation, 2022, “Standard Specifications”

Gutierrez, C.I., (compiler) 2011, Preliminary Geologic Map of the Sacramento 30´ by 60´

Quadrangle, California. California Department of Conservation, California Geological Survey.

U.S Geological Survey and California Geological Survey, Quaternary fault and fold database for the United States, Accessed April 28, 2022, at: http//earthquake.usgs.gov/hazards/qfaults/.

Parikh Consultants, Inc, Preliminary Foundation Report, Hazel Avenue OC (Widen), dated April

17, 2023.

APPENDIX I

SITE MAP

HAZEL AVENUE OVERCROSSING (WIDEN) PROJECT

SACRAMENTO COUNTY, CALIFORNIA

PLATE NO.: 1

PROJECT VICINITY MAP

Approximate Project Location

Scale 0 2 Miles

JOB NO.:2022-110-GEO

Ame rica n R iver

Go ld Po in te Ln

E3

Fo lso m Blv d

Ae roj et Rd

Bir km on t D r

Ak ron

St

N im b u s R d

F lo ri d a R d

Hazel A ve

Nimbus

Water

Water t Pl t t t t t t t t t t Qr

Qm

MPm

MPm

MPm

Pl t

Qtl

Qhc

Qhc af af af

0 2,000

Feet GEOLOGIC MAP

Scale: 1:10,000

El Dorado Hills

Citrus Heights Folsom

Carmichael

Rancho Cordova

Holocene, San Francisco Bay Mud

Map Location

Legend

Geologic Data Source:

Gutierrez, C.I., (compiler) 2011, Preliminary Geologic Map of the Sacramento 30´ by 60´ Quadrangle, California. CGS.

Miocene, Mehrten Fm - undivided

Pliocene, Laguna Fm

Pleistocene, Turlock Fm

Pleistocene, Riverbank Fm, undivided

Pleistocene, Modesto Fm, undivided

Latest Holocene, stream channel deposits

Historic, dredge tailings

Artificial fill

MPm

Pl

Qtl

Qr

Qm

Qhc t af

HAZEL AVENUE OVERCROSSING (WIDEN)

SACRAMENTO COUNTY, CALIFORNIA

JOB NO.: 2022-110-GEO PLATE NO.: 3

Approximate Project Location

FAULT MAP

0 30

Miles

Scale: 1:1,100,000

MAP LOCATION

California

Fault data source:

Legend

60 mile radius m ile ra di us m ile ra diu s

Project Location

D unnigan H ills

F oothills - Lone flt

G reat V

. 01 G reat V . 02

G reat V. 03

G reat V. 03a

M idland

H ayw ard N th

G reat V. 04a

R io

V is ta

G reenville-M arsh C k

G reen V.

C oncord

C ordelia

G reen V.

Foothills

F oothills -

R escue flt

F oothills - P oorm an G ulch

F oothills -

S pencerville flt

F oothills -

C leveland H ill flt

Foothills -

D ew itt flt Foothills -

H w y 49 flt

V aca

Fault trace Fault name

CascadeHistoric <150 yrs

Latest Quaternary <15,000 yrs

Quaternary <1.6 million yrs

USGS & CGS. Quaternary Fault and Fold Database for the United States. Accessed 4/28/2022.

HAZEL AVENUE OVERCROSSING (WIDEN)

JOB NO.: 2022-110-GEO PLATE NO.: 4

APPENDIX II

GROUND MOTION DATA SHEET

Site Information Recommended Response Spectrum

Latitude: 38.6307

Longitude -121.2172

VS30 (m/s) = 393 0.0 0.18 1.000 1 0.180

0.1 0.34 1.000 1 0.340

6.72 0.2…

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