691-20-150.603.GEOTECHNICAL EVALUATION.pdf

475 Goddard, Suite 200 | Irvine, California 92618 | p. 949.753.7070 | www.ninyoandmoore.com

May 31, 2023 Project No. 209826018

Ms. Michelle Saquilayan Senior Associate, Senior Project Manager Leo A Daly 550 South Hope Street, 27th Floor Los Angeles, California 90071-2627

Subject: Addendum to 2020 Geotechnical Evaluation Boiler Plant Veterans Affairs West Los Angeles Medical Center 11301 Wilshire Boulevard

Los Angeles, California

References: Ninyo & Moore, 2020, Geotechnical Evaluation, Steam Boiler Plant, Veterans Affairs West Los Angeles Medical Center, 11301 Wilshire Boulevard, Los Angeles, California, dated October 16.

Ninyo & Moore, 2022, Proposed Boiler Plant, Methane Mitigation Design, 11301 Wilshire Boulevard, Los Angeles, CA 90073, Submittal Package Issue Date of September 19.

Dear Ms. Saquilayan:

In accordance with your request, we have performed additional geotechnical consulting services for the proposed Boiler Plant located at the Veterans Affairs West Los Angeles Medical Center at 11301

Wilshire Boulevard in Los Angeles, California. We previously prepared our referenced geotechnical evaluation report dated October 16, 2020, which provide our geotechnical design and construction recommendations for the project based on the 2019 California Building Code. However, we understand that the project is being designed according to the 2021 International Building Code

(IBC). We have prepared this addendum to confirm that the geotechnical recommendations provided in our previous report, including seismic design and foundation parameters, remain applicable for the project and meet the requirements of the 2021 IBC. In addition, this letter provides the following additional geotechnical recommendations:

• In our geotechnical evaluation report (Ninyo & Moore, 2020), we recommended that isolated pad footings have a width of 5 feet or more, be founded on compacted fill at a depth of 2 feet below the lowest adjacent grade, and be designed using a net allowable bearing capacity of 4,000 pounds per square foot (psf). Generally, this recommendation remains the same for the project; however, the width of isolated pad footings used to support stairwells and other smaller structural elements can be designed with a width of less than 5 feet using the same allowable bearing capacity of 4,000 psf. These foundations should still be founded on compacted fill at a depth of 2 or more feet below the lowest adjacent grade.

http://www.ninyoandmoore.com/

Ninyo & Moore | VA WLA Boiler Plant, Los Angeles, California | 209826018 | May 31, 2023

• Figure 12 of our report (Ninyo & Moore, 2020) included a triangular distribution for dynamic pressure. Since dynamic pressure does not apply for the restrained wall condition, we have revised the figure by removing this force. In addition, the figure has been revised to show surcharge pressure starting at the bottom of the building foundation. The revised figure is attached herein as Attachment A.

• In Section 12.2.2 of our geotechnical evaluation, we recommended the placement of a vapor retarder and sand layer beneath the Boiler Plant’s interior slab-on-grade. This recommendation is no longer applicable for the project and has been superseded by our recommendation for a subslab methane vapor barrier membrane as presented on Detail 6 of Sheet MMS.8B of the Methane Mitigation Design plans (Ninyo & Moore, 2023).

Ninyo & Moore appreciates the opportunity to continue providing services on this project and working with you.

Respectfully submitted, NINYO & MOORE

Greg M. Corson, PG, CEG Principal, Geologist

Daniel Chu, Ph.D., PE, GE Chief Geotechnical Engineer

GMC/DBC/mlc

Attachment: Attachment A

Ninyo & Moore | VA WLA Boiler Plant, Los Angeles, California | 209826018 | May 31, 2023

ATTACHMENT A

Figure

LATERAL EARTH PRESSURES FOR

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EP

4.

dw g

4/

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JD

P

Geotechnical & Environmental Sciences Consultants

FIGURE 12

NOTE: DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE.

NOT TO SCALE

STEAM BOILER PLANT

VETERAN AFFAIRS WEST LOS ANGELES MEDICAL CENTER

LOS ANGELES, CALIFORNIA

209826018 I 5/23

RESTRAINED RETAINING WALL

pP

D

PASSIVE

PRESSURE

AT-REST

PRESSURE

H/3

RESULTANT

D/3

NOTES:

ASSUMES NO HYDROSTATIC PRESSURE BUILD-UP

BEHIND THE RETAINING WALL

1.

STRUCTURAL, GRANULAR BACKFILL MATERIALS

AS SPECIFIED IN REPORT SHOULD BE USED

2.

FOR RETAINING WALL BACKFILL

BEHIND THE RETAINING WALL

WALL DRAINAGE DETAIL SHOULD BE INSTALLED

DRAINS AS RECOMMENDED IN THE RETAINING3.

RECOMMENDED GEOTECHNICAL DESIGN PARAMETERS

Equivalent Fluid Pressure Psf Lateral Earth

Pressure

Level Backfill with Granular Soils (2)

OP

EP 0

57 H

SLAB

RETAINING

WALL L

q

Ps

0.5q (psf) if L<H; OR 0 IF L>=H

P

RESULTANT

SURCHARGE

PRESSURE

sP

4.

FOUNDATION, MEASURED IN psf.

q IS THE CONTACT PRESSURE FROM BUILDING pP 350 D o

AutoCAD SHX Text

BACKFILL

AutoCAD SHX Text

BUILDING

AutoCAD SHX Text

FOUNDATION

AutoCAD SHX Text

GROUND

AutoCAD SHX Text

SURFACE

September 20, 2023 Project No. 209826018

Ms. Michelle Saquilayan Senior Associate, Senior Project Manager Leo A Daly 550 South Hope Street, 27th Floor Los Angeles, California 90071-2627

Subject: Soil Corrosivity Boiler Plant Veterans Affairs West Los Angeles Medical Center 11301 Wilshire Boulevard

Los Angeles, California

Reference: Ninyo & Moore, 2020, Geotechnical Evaluation, Steam Boiler Plant, Veterans Affairs West Los Angeles Medical Center, 11301 Wilshire Boulevard, Los Angeles, California, dated October 16.

Dear Ms. Saquilayan:

We prepared our referenced geotechnical evaluation report dated October 16, 2020 for the proposed Boiler Plant located at the Veterans Affairs West Los Angeles Medical Center at 11301 Wilshire Boulevard in Los Angeles, California. We have prepared this letter to clarify that the site soils at the boiler plant site should be considered as being “corrosive” per the 2018 Caltrans corrosion criteria and as discussed in Section 12.8, Soil Corrosivity, of our report. The last bullet of the conclusions section of our report (Section 11; page 15) should be ignored as it erroneously indicates that the site soils are non-corrosive.

Ninyo & Moore appreciates the opportunity to continue providing services on this project and working with you.

Respectfully submitted, NINYO & MOORE

Greg M. Corson, PG, CEG Principal, Geologist

Daniel Chu, Ph.D., PE, GE Chief Geotechnical Engineer

GMC/DBC/mlc

Geotechnical Evaluation

Steam Boiler Plant Veterans Affairs West Los Angeles Medical Center

11301 Wilshire Boulevard Los Angeles, California

Leo A. Daly 550 South Hope Street, 27 th Floor | Los Angeles, California 90071-2627

October 16, 2020 | Project No. 209826018

Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness

Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS iamno Typewritten Text

XS-1.0 GEOTECHNICAL EVALUATION, REPORT ADDENDA, AND METHANE GAS SURVEY

Greg M. Corson, PG, CEG Principal Geologist

Daniel Chu, PhD, PE, GE Chief Geotechnical Engineer

GMC/DBC/mlc

Distribution: (1) Addressee (via e-mail)

Geotechnical Evaluation Steam Boiler Plant Veterans Affairs West Los Angeles Medical Center 11301 Wilshire Boulevard Los Angeles, California

Mr. Roy Follmuth Leo A. Daly 550 South Hope Street, 27 th Floor | Los Angeles, California 90071-2627

October 16, 2020 | Project No. 209826018

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 i

CONTENTS

1 INTRODUCTION 1

2 SCOPE OF SERVICES 1

3 SITE DESCRIPTION 2

4 PROPOSED CONSTRUCTION 3

5 PREVIOUS SITE EVALUATIONS 4

6 SUBSURFACE EVALUATION AND LABORATORY TESTING 5

7 GEOLOGY AND SUBSURFACE CONDITIONS 6

7.1 Undocumented Fill 7

7.2 Older Alluvium 7

8 GROUNDWATER 7

9 FLOOD HAZARDS 8

10 FAULTING AND SEISMICITY 8

10.1 Santa Monica Fault 9

10.2 Surface Fault Rupture 10

10.2.1 Alquist-Priolo Earthquake Fault Zoning Act 11

10.3 Seismic Ground Motion 11

10.4 Liquefaction 13

10.5 Tsunami and Seiche Potential 13

10.6 Historical Earthquakes 14

11 CONCLUSIONS 14

12 RECOMMENDATIONS 15

12.1 Earthwork 16

12.1.1 Pre-Construction Conference 16

12.1.2 Site Preparation 16

12.1.3 Excavation Characteristics 16

12.1.4 Treatment of Near Surface Soils 16

12.1.5 New Steam Boiler Plant Building 17

12.1.6 Parking Lots and Driveways, and Other Site Structures 17

12.1.7 Exterior Hardscape 18

12.1.8 Fill Material 18

12.1.9 Fill Placement and Compaction 19

12.1.10 Temporary Excavations 19

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 ii

12.1.11 Shoring 20

12.2 Foundation Design 21

12.2.1 Spread Footings 21

12.2.2 Interior Slabs-On-Grade 22

12.3 Retaining Walls 23

12.4 Site-Specific Seismic Design Considerations 23

12.5 Underground Utilities 24

12.5.1 Pipe Bedding 24

12.5.2 Trench Backfill 24

12.5.3 Modulus of Soil Reaction 25

12.5.4 Lateral Pressures for Thrust Blocks 25

12.6 Sidewalks and Hardscape 25

12.7 Pavement Design 25

14 LIMITATIONS 29

15 REFERENCES 30

TABLES

1 – Principal Active Faults 9

2 – Historical Earthquakes 14

3 – 2019 California Building Code Seismic Design Criteria 23

4 – Pavement Structural Sections 26

FIGURES

1 – Site Location 2 – Site Plan 3 – Proposed Construction 4 – Boring Locations 5 – Regional Geology 6 – Cross Section A-A’ 7 – Fault Locations 8 – Seismic Hazard Zones 9 – Acceleration Response Spectra 10 – Lateral Earth Pressures – Cantilevered Shoring 11 – Lateral Earth Pressures – Braced Excavation 12 – Lateral Earth Pressures - Restrained Retaining Wall

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 iii

13 – Lateral Earth Pressures - Yielding Retaining Walls 14 – Retaining Wall Drainage Detail 15 – Thrust Block Lateral Earth Pressure Diagram

APPENDICES

A – Previous Boring and CPT Logs by Ninyo & Moore (2019) B – Boring Logs C – Laboratory Testing

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 1

1 INTRODUCTION

In accordance with your request, we have performed a geotechnical evaluation for the proposed

Steam Boiler Plant at the Department of Veterans Affairs (VA) West Los Angeles Medical Center

(Facility) located at 11301 Wilshire Boulevard in Los Angeles, California (Figure 1). We understand that the project generally includes the construction of a new steam boiler plant to support the redevelopment of the south campus of the Facility (Figure 2). The purpose of our study was to evaluate the seismic and geotechnical conditions of the site in order to provide geotechnical design and construction recommendations for Schematic Design of the steam boiler plant in general accordance with VA documents PG18-15 (2017) and H18-8 (2016). This report presents our findings, conclusions, and recommendations for the subject project.

Concurrent with this geotechnical evaluation, we also performed a methane gas survey of the steam boiler plant site to evaluate whether methane gas mitigation is required for the new plant building. The results of the methane gas survey are provided under separate cover (Ninyo &

Moore, 2020).

2 SCOPE OF SERVICES

Our scope of services included the following:

• Project planning and coordination with Leo A. Daly (LAD), the VA, and subcontractors.

• Review of readily available background data for the site, including in-house geotechnical data, existing geologic maps, State of California Earthquake Fault Zone (EFZ) maps, State of California Seismic Hazard Zones Maps, City of Los Angeles Safety Element, topographic maps, stereoscopic aerial photographs, and our previous geotechnical evaluation reports prepared for other projects at the Facility (Ninyo & Moore, 2017, 2018 and 2019a).

• Performance of a site reconnaissance to observe the site conditions for drill rig access, to mark the proposed subsurface exploration locations for utility clearance, and to observe and map the site geologic conditions.

• Coordination with Underground Service Alert for underground utility location prior to excavation.

• Subsurface exploration consisting of the drilling, logging and sampling of two hollow-stem-auger (HSA) borings to depths of up to approximately 31½ and 50½ feet. The borings were logged by a representative from our firm, and bulk and relatively undisturbed soil samples were collected at selected depth intervals for geotechnical laboratory testing.

• Geotechnical laboratory testing of collected samples by our laboratory, including tests to evaluate in-situ density and moisture, Atterberg limits, direct shear, consolidation, expansion index, R-value, and soil corrosivity.

• Compilation and geotechnical analysis of the collected field and laboratory data.

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 2

• Preparation of this report presenting our findings, conclusions, and design and construction recommendations for the proposed project.

3 SITE DESCRIPTION

The Facility consists of an approximately 1½-mile-long (north to south) by ½-mile-wide (west to east) rectangular-shaped property located near the southern flank of the Santa Monica

Mountains along the west side of the 405 Freeway (Figure 1). The Facility is divided into north and south campuses by Wilshire Boulevard. The subject project is located within the south campus, which is bounded by Wilshire Boulevard on the north, the 405 Freeway on the east, Federal Avenue and other federal properties on the west, and Ohio Avenue and residential properties on the south. The south campus is developed with multiple medical facility buildings

(Figure 2), including a main hospital building (Building 500) with seven above-grade levels and one below-grade level, a chiller plant for the hospital (Building 501), a three-story eye clinic/polytrauma/employees health building (Building 304), a two-story Administrative & Mental

Health building (Building 401), a two-story medical building (Building 402), a two-story Radiation

Therapy building (Building 345), and an MRI building (Building 507) .The buildings are generally surrounded by pedestrian walkways, landscape areas, vehicle driveways, and paved parking lots. The south campus buildings and parking lots are surrounded by a loop road (Dowlen Drive

West and Dowlen Drive East) that is accessed from Bonsall Avenue on the north and Sawtelle

Boulevard on the south. Other smaller buildings and parking lots are present outside the limits of the loop road. Topographically, the south campus generally slopes downward from north to south with ground elevations ranging from approximately 315 feet (North American Vertical

Datum of 1988 [NAVD88]) at the north end of the campus to approximately 287 feet NAVD88 at the south end of the campus (United States Geological Survey [USGS], 2015 and Michael

Baker International [MBI], 2016). The southern end of the south campus, south of the loop road, is bounded by a moderately steep to steep south-facing slope on the order to 20 to 35 feet in height.

The site of the proposed Steam Boiler Plant is located northeast of the new GLA Kitchen and at the southwest corner of an existing parking lot (Parking Lot No. 43 and the future site of the new

CUP). The site was formerly developed with solar canopies that were removed as part of the

GLA Kitchen construction project, which was being performed at the time of our subsurface exploration. The site is relatively flat, except for the northeast side of the site, which consists of an approximately 12-foot-high, approximately 2:1 (horizontal to vertical) slope that ascends to the adjacent parking lot. The slope face trends to the southeast adjacent to the building but turns to the east southeast of the building. The southwest side of the site is bounded by a second approximately 4 to 5-foot-high, approximately 2:1 (vertical to horizontal) slope that

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 3 descends to an asphalt concrete (AC)-paved driveway. Topographically, the site slopes gently downward from an elevation of approximately 291 feet (NAVD88) at the northwest end of the site to approximately 286 feet (NAVD88) at the southeast end of the site. The elevation of the parking lot adjacent to the site is approximately 300 to 302 feet (NAVD88).

Based on our review of historic aerial photographs and topographic maps (USGS, 1894, 1934, 1950, 1966, 1995, and 2015), we understand that portions of the Facility have been developed since at least 1894 and significant development of the site began in the 1920s. Based on our review of the photos and maps, we understand that multiple phases of construction have occurred, which have included the demolition of many small to relatively large buildings within the limits of the project. Our comparison of the current site elevations (MBI, 2016) and the site elevations shown on the 1934 topographic map (USGS, 1934) suggests that the adjacent

Parking Lot 43 has been raised on the order of 10 to 15 feet with fill. Accordingly, the 2:1 slope beneath the southeast end of the building is a fill slope. Data regarding grading and placement of the fill was not available at the VA for our review.

4 PROPOSED CONSTRUCTION

Based on our review of preliminary plans prepared by Leo A. Daly (LAD, 2020b), we understand that the proposed Steam Boiler Plant will consist of a two-story, rectangular-shaped structure with a footprint measuring approximately 70 feet by 135 feet (Figure 3). The finished floor elevations of the first and second floors will be approximately 286 feet and 304 feet (NAVD88), respectively. We understand that the main level (Level 1) will generally house the boilers, generators, transformers/switchgear and storage area and the second level (Level 2) will mostly consist of open space and catwalks over the boiler areas with some second floor space at the northeast end of the building for an office/conference room, additional storage and an electrical room. Access to Level 1 will be on the southeast and southwest sides of the building. Access to the second-floor space will be via new stairwell and elevator and an outside entry at the northeast corner of the building (elevated grade). The project will also include the installation of two new reserve diesel fuel tanks outside of the building footprint on the southwest side of the building. Other site improvements will include new AC pavement along the southwest and southeast sides of the building and underground utilities. The pavement on the southwest side will be used as parking.

Based on our review of the Basis of Design Grading Plan prepared by Michael Baker

International (MBI, 2019) (Figure 3), we understand that the site is anticipated to be lowered approximately 2 to 4 feet to elevations ranging from of approximately 284 to 285 feet (NAVD88).

The northeast end of the plant building will extend into the existing slope that ascends to the

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 4 adjacent parking lot. Grading of the existing slope and parking lot area during construction of the building and adjacent CUP will result in the northwest wall of the plant retaining a wedge of fill that varies from approximately 14 feet at the north end of the wall to no fill at the south corner of the wall. The northwest side of the building will be bounded by an approximately 2 to 3-foot-high retaining wall that will increase to 14 feet where the building extends into the ascending slope.

An approximately 5 to 7-foot-high, approximately 3:1 (horizontal to vertical slope will ascend from the top of the northwest retaining wall to match existing grade elevations to the northwest.

A third retaining wall will be located at the base of the descending slope along the southwest side of the site, adjacent to the existing driveway, that will be used to extend the site further to the southwest. This third retaining wall will retain approximately 2 to 3 feet of soil.

5 PREVIOUS SITE EVALUATIONS

As a part of our subject geotechnical evaluation, we reviewed readily available geotechnical reports and documents prepared for the WLA Medical Center and/or adjacent sites available from the VA, our previous preliminary geotechnical evaluation report prepared for the subject project (Ninyo & Moore, 2017), and our previous geotechnical evaluations prepared for the GLA

Kitchen and New Tower, Etc. Projects at the WLA Medical Center (Ninyo & Moore, 2018 and

2019a). Documents available from the VA included geotechnical, seismic, and foundation reports prepared for the current hospital building (B500) by L.T. Evans, Inc. (1972), Dames &

Moore (1972), and James E. Slosson & Associates (1972). Brief summaries of our previous reports and the other consultant’s reports are provided below.

L.T. Evans, Inc. (1972) – The consultant performed subsurface exploration during the design of the current hospital building in order to provide geotechnical and foundation design recommendations for the building. They performed fifteen borings to depths ranging from approximately 61 to 101 feet and laboratory testing on collected soil samples to evaluate the subsurface conditions of the site. A boring location map was not included with the report copy we reviewed, so the actual boring locations are unknown to our firm. Their borings generally encountered fill and alluvial deposits to the total depths explored. Recommendations were provided to support the hospital building on CIDH friction piles and smaller structures (“low buildings”) on shallow spread footings

Dames & Moore (1972) – The consultant performed an earthquake hazard study of the proposed hospital site in order to provide an estimate of the maximum level of earthquake-induced ground motion that may be expected at the site and an estimate of the expected site response to the design earthquake (DE) ground motion. Generally, this evaluation included a desk study of available data regarding the seismicity of the region. They generally concluded that the site is representative of “typical” Southern California conditions and risks, the risk for surface ground rupture is remote, and that the site is not considered to be liquefiable

James E. Slosson & Associates (1972) – The consultant performed a geologic and seismic evaluation of the existing hospital site during the design phase of the hospital. Their evaluation included the performance of seismic refraction lines (approximately 4,080 feet in combined length) and two backhoe trenches to depths of up to approximately 10 feet (approximately 1,535

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 5 feet in combined length) to evaluate the site for fault rupture hazard. The seismic lines and trenches did not encounter evidence of surface fault rupture beneath the site.

Ninyo & Moore (2017) – Ninyo & Moore performed a preliminary geotechnical evaluation as part of the Schematic Design (SD-1) phase of the New Tower, Etc. Project in order to provide preliminary geotechnical recommendations for use in the schematic design of the proposed New essential care tower, CUP, garage structure, and site infrastructure. Our evaluation included subsurface exploration within the south campus that included seven borings (B-1 through B-7) up to depths of approximately 101.5 feet, two CPTs (CPT-1 and CPT-2) up to depths of approximately 44 feet, installation and periodic monitoring of one groundwater monitoring well (MW-1) to a depth of approximately 56 feet, and laboratory testing of collected soil samples. Shear wave velocities of the subsurface soils were collected at approximately 5-foot intervals in CPT-1. Based on our geotechnical analyses of the collected background, subsurface, and laboratory data, we prepared preliminary geotechnical recommendations for the project. Our findings, conclusions, and preliminary geotechnical recommendations were provided in our report dated June 7, 2017.

Ninyo & Moore (2018) – Ninyo & Moore prepared a geotechnical data report for the proposed GLA Kitchen to be located at the southeast corner of the south campus. Our report was prepared in order to provide seismic and geotechnical subsurface data as part of Level 2 Request for Proposals Submittal Documents associated with a future design-build contract for the kitchen. Our study included subsurface exploration consisting of six HSA borings (KB-1, KB- 2, KMW-1, KP-1, KM-1, and KM-3) to depths ranging from 12 to 76½ feet, two hand-augered borings (KM-2 and KM-4) to depths of up to approximately 5½ feet, and two CPTs (KCPT-1 and KCPT-2) to depths of approximately 75 feet. Boring KMW-1 was converted to a groundwater monitoring well to a depth of approximately 51½ feet and a percolation test was performed in boring KP-1 at a depth of approximately 12 feet. The percolation test was performed to evaluate the infiltration rate of the site soils for proposed on-site stormwater infiltration. The locations of our previous borings, CPTs, and groundwater monitoring well are shown on Figure 4 of this report.

Ninyo & Moore (2019) – Ninyo & Moore prepared a geotechnical evaluation for the New Tower, Etc. Project located within the South Campus. Our report was prepared in order to provide geotechnical design and construction recommendations for the SD-2 phase of the proposed Essential Care Tower, Central Utility Plant, Garage Structure, and improvements to site infrastructure and underground utilities. Our geotechnical study included subsurface exploration consisting of thirty-five HSA borings (B-1 through B-30 and P-1 through P-5) to depths ranging from approximately 15 to 101½ feet, and nine CPTs (CPT-1 and CPT-9) to depths ranging from approximately 46.2 to 100.6 feet. Boring B-8, B-12, and B-16 were converted to a groundwater monitoring wells MW-2, MW-3, and MW-4, respectively, to depths of approximately 70 feet.

Shear wave velocities of the subsurface soils were collected at approximately 5-foot intervals in CPT-3 and CPT-7. The approximate locations of borings and CPTs located in the vicinity of the proposed Steam Boiler Plant location are shown on Figure 4 of this report. Logs of select borings and CPTs used in the subject evaluation of the Steam Boiler Plant are included in Appendix A.

6 SUBSURFACE EVALUATION AND LABORATORY TESTING

Our subsurface evaluation at the site was conducted on September 15, 2020, and consisted of drilling, logging, and sampling two HSA borings (B-1 and B-2) to depths of approximately 31½ and 50½ feet, respectively. The borings were drilled using a truck-mounted drill rig with 8-inch-diameter augers and were logged in the field by a representative of Ninyo & Moore.

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 6

Representative bulk and relatively undisturbed soil samples were collected from the borings at selected depths for laboratory testing. Logs of the exploratory borings are provided in Appendix

B. The boring locations are shown on Figures 3 and 4. The borings were backfilled with cement-bentonite grout and soil cuttings from the borings spread on-site.

Geotechnical laboratory testing was performed on representative bulk and undisturbed soil samples obtained from the exploratory borings. The geotechnical laboratory testing included tests to evaluate in-situ density and moisture, Atterberg limits, direct shear, consolidation, expansion index, R-value, and soil corrosivity. The geotechnical laboratory test results are presented in Appendix C, and on the borings logs in Appendix B.

7 GEOLOGY AND SUBSURFACE CONDITIONS

The subject site is located in the Los Angeles Basin at the southern end of the Transverse

Ranges geomorphic provinces of southern California (Norris and Webb, 1990). The Los Angeles

Basin has been divided into four structural blocks, which are generally bounded by prominent northwest-trending and west-trending fault systems: the northwestern, southwestern, central, and northeastern blocks. The site is located in the northwestern block, which generally includes the San Fernando Valley and Santa Monica Mountains. The block is bounded by the Santa

Monica-Hollywood-Raymond fault system on the south, the San Gabriel Mountains on the east and northeast, and mountains associated with the Ventura Basin on the north and west. Dibblee

(1991) indicates that the site is underlain by relatively thick sequences of Tertiary-age sedimentary rock (greater than 10,000 feet in thickness) overlain by alluvial deposits. The State of California (1998b) indicates that the site is located on the Santa Monica Plain, which consists of an old dissected alluvial surface located along the southern flank of the Santa Monica

Mountains. The State indicates that the surface was formed by large coalescing alluvial fans that have since been incised by streams draining from the Santa Monica Mountains. The stream channels are generally infilled with younger alluvial deposits.

Based on our review of geologic maps of the site, the site is generally mapped as being underlain by older alluvial fan deposits associated with the Santa Monica Plain that consist of interbedded slightly to moderately consolidated silt, sand, and gravel that has been uplifted and dissected (Campbell, et al., 2014) (Figure 5). The State of California (1998b) describes the older alluvial deposits as medium dense to very dense, sand, clay, and silt with abundant gravel in many layers. Dibblee (1991) describes the older alluvial deposits as gray to light brown, slightly consolidated, pebble-gravel, sand, and silt-clay derived from the Santa Monica Mountains. The south-facing slope along the south side of the south campus is considered to be a fault scarp associated with the north branch of the Santa Monica fault, which is mapped along the base of

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 7 the slope (Dolan, et al., 2000 and Olson, 2018). Further discussion regarding the Santa Monica fault is provided below. The site is located within the mapped limits of the Sawtelle Oil Field

(Dibblee, 1991) and an area mapped by the City of Los Angeles as being a Methane Hazard

Zone (City of Los Angeles [COLA], 2004).

The materials encountered during our subsurface evaluation generally consisted of undocumented fill soils underlain by older alluvium. Detailed descriptions of the materials encountered in our borings are presented on the boring logs in Appendix B. Our interpretations of the subsurface conditions are presented on Cross-Section A-A’ (Figure 6).

7.1 Undocumented Fill

Undocumented fill soils were encountered beneath the ground surface of borings B-1 and B-2 to depths of approximately 3 feet. The fill generally consisted of brown and dark brown, moist, stiff, sandy clay with various amounts of intermixed construction debris (i.e., AC and brick pieces). As discussed above, our comparison of the current site elevations (MBI, 2016) and the site elevations shown on the 1934 topographic map (USGS, 1934) suggests that the adjacent

Parking Lot 43 has been raised on the order of 10 to 15 feet with fill. Our previous borings performed in the parking lot, including B-16 and B-17 (Ninyo & Moore, 2017), support that the parking lot was raised with fill. Undocumented fill was encountered in these borings to depths of approximately 15 to 18 feet, respectively, that consisted of brown and dark brown, moist, firm to hard, clay with variable amounts of silt, sand, gravel and construction debris. Information regarding the placement of existing fills, including ground preparation, remedial excavation, methods of fill placement, and the degree of compaction during placement, is unknown to this firm.

7.2 Older Alluvium

Older alluvium was encountered beneath the fill soils to the total depths explored in our borings.

The older alluvium generally consisted of brown and reddish brown, moist, stiff to hard, clay with variable amounts of sand and gravel, interbedded with brown and reddish brown, stiff to very stiff, clayey to sandy silt and medium dense, silty sand.

8 GROUNDWATER

Groundwater was not encountered in our borings during drilling to the total depth explored of up to approximately 50½ feet below the ground surface. Groundwater monitoring wells installed during our previous work at the Facility, including MW-4 (Ninyo & Moore, 2019) and KMW-1

(Ninyo & Moore, 2018), are located approximately 160 feet north and 190 feet south of the

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 8 proposed building, respectively. The groundwater was measured in these wells at depths of approximately 42 and 66 feet, respectively (i.e., elevations of approximately 239 and 240 feet, respectively). Accordingly, it is anticipated that groundwater is at a similar elevation (el. 239) beneath the site, which is approximately a depth of approximately 49 to 51 feet below the ground surface of the site. The depths and elevations of the groundwater can fluctuate due to variations in ground surface topography, subsurface stratification, rainfall, irrigation practices, groundwater pumping, and other factors which may not have been evident at the time of our field evaluation. The State of California (1998b) indicates that the historic high depth to groundwater at the site is approximately 20 to 25 feet.

9 FLOOD HAZARDS

Based on review of Federal Emergency Management Agency Flood Insurance Rate Map No.

06037C1590F (United States Federal Emergency Management Agency, 2008), the site is mapped within an area considered to be outside of the 0.2 percent annual chance of flood (i.e., 500-year flood). Based on this review, the potential for flooding of the site is considered low.

10 FAULTING AND SEISMICITY

The Facility is located in a seismically active area, as is the majority of southern California, and the potential for strong ground motion in the project area is considered significant during the design life of the proposed project. Figure 7 shows the approximate site location relative to the major faults in the region. According to the Earthquake Zones of Required Investigation Map

(EZRIM) prepared for the Beverly Hills quadrangle (CGS, 2018b), the site is not located within a

State of California EFZ (formerly known as the Alquist-Priolo Special Studies Zone) (Figure 8).

Table 4 lists selected principal known active faults that may affect the subject site and the maximum moment magnitudes (Mmax) as published by the USGS (USGS, 2008). The approximate fault-to-site distances provided in Table 1 were calculated using the USGS fault database (USGS, 2008). The distance to the Santa Monica fault is based on the EZRIM (CGS, 2018b), which indicates that a trace of the north branch of the Santa Monica fault is located approximately 990 feet south of the southern corner of the proposed building. The northern limit of an EFZ designated for this splay is mapped approximately 540 feet south of the proposed building. Additional discussion regarding the Santa Monica fault is provided below.

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 9

Table 1 – Principal Active Faults

Fault Approximate Fault-to-Site Distance1miles (kilometers)

Maximum Moment Magnitude1 (Mmax)

Santa Monica See Discussion Above 7.2 Hollywood 3.5 (5.6) 6.7

Newport-Inglewood (L.A. Basin) 3.5 (5.6) 7.5 Malibu Coast 4.5 (4.2) 7.0

Anacapa-Dume 6.2 (10.0) 7.2 Puente Hills (LA Basin) 6.7 (10.8) 7.0

Palos Verdes 8.2 (13.2) 7.7 Elysian Park (Upper) 9.8 (15.8) 6.7

Verdugo 12.9 (20.8) 6.9 Raymond 13.9 (22.4) 6.8

Sierra Madre 16.8 (27.1) 7.3 Santa Susana 18.1 (29.1) 6.9

Notes:

1 Based on USGS (2008), except for the Santa Monica fault, which is based on CGS (2018).

The principal seismic hazards evaluated at the subject site are surface fault rupture, ground motion, and liquefaction. A brief description of the Santa Monica fault, including previous fault evaluations, the principal seismic hazards, and a summary of historic earthquakes in the region are discussed in the following sections. A brief discussion of the EFZ and Alquist-Priolo

Earthquake Fault Zoning Act is also provided below.

10.1 Santa Monica Fault

The Santa Monica fault is part of the Transverse Ranges Southern Boundary Fault System, which is a system of west-trending reverse, oblique-slip, and left-lateral, strike-slip faults that extends for more than approximately 125 miles along the southern edge of the Transverse

Ranges (Dolan, et al., 2000). The Santa Monica fault is a north-dipping oblique left-lateral reverse fault that extends east-northeast for approximately 21.6 miles from Pacific Palisades through Santa Monica and West Los Angeles. The Santa Monica fault diverges into two major strands (north and south branches) that merge at a depth of approximately 2 kilometers (Dolan, et al., 2000). Locations of the fault branches remain subject to debate and range from well-known where geomorphic evidence (such as, well-defined south-facing scarps are present along portions of the north branch) and where trenching has uncovered fault splays, to moderately and poorly known, where the locations are extrapolated from well and boring data, including abrupt changes in groundwater depths (City of Santa Monica, 1995). The east end of the Santa Monica fault ends at a topographic scarp known as the West Beverly Hills Lineament where strain is thought to be transferred between the Santa Monica and Hollywood faults for a distance of approximately ¾ mile (Treiman, 2000a; Dolan, et al., 2000). According to fault

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 10 studies performed by Dolan, e al. (2000), including fault trenches on the south-facing slope south of the site (an existing fault scarp), the fault has experienced six or more surface fault ruptures within the last approximately 50,000 years, including two or three events since approximately 16,000 to 17,000 years ago. Dolan, et al. (2000), indicates that the north branch has been active within the late Quaternary and has a recurrence interval for surface rupture of approximately 7,000 to 8,000 years. Previous calculations based on regression plots suggested a recurrence interval of approximately 1,900 to 3,300 years (Dolan, et al., 2000). According to

Dolan, et al. (2000), one explanation of the longer recurrence interval based on the trenches suggests infrequent, very large earthquakes of magnitude 7.0 or greater. They conclude that a definite surface rupture occurred approximately 10,000 to 17,000 years ago with a possible event as recent as 1,000 to 3,000 years ago, suggesting that the fault should be considered active (i.e., having experienced rupture within the last approximately 11,700 years). The USGS

Quaternary Fault and Fold Database of the United States suggests the fault was active at some time less than 15,000 years (USGS, 2000). A fault evaluation report prepared by Olson (2018) recommended that the principal traces of the Santa Monica fault, including the splay located south of the site, be established as an EFZ.

10.2 Surface Fault Rupture

Based on our review of the referenced literature and our geologic reconnaissance, no active faults are known to cross the subject alignment; however, as discussed, a mapped splay of the

Santa Monica fault is located along the base of the south-facing slope along the south side of the campus (approximately 990 feet south of the proposed building. During an earthquake event, rupture typically occurs along existing fault planes that act as existing planes of weakness. As discussed by Dolan, et al. (2000), six or more ruptures were observed in their fault trench performed in the fault scarp south of the site. The number and timing of the events, along with the well-defined fault scarp, support the idea that the north branch of the Santa

Monica fault has repeatedly ruptured along the existing splay. The relative steepness of the

Santa Monica fault (dip of approximately 75 degrees to the north) also reduces the risk of deviation from existing fault planes as compared to higher risks of deviation within the hanging wall of low angle thrust faults. Though deviation in the location of surface ground rupture could occur, this is considered to be relatively remote given the recurrence interval of the fault

(approximately 7,000 to 8,000 years [Dolan, et al., 2000]). Based on this information, along with the lack of evidence of faulting through the upper alluvial soils at the site as previously evaluated by James E. Slosson & Associates (undated) and Dames & Moore (1972), the possibility of ground rupture at the site is considered to be relatively low during the design life of the project. However, secondary ground deformation, such as lurching or cracking of the ground

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 11 surface is considered possible within the vicinity of the project site as a result of nearby seismic events.

10.2.1 Alquist-Priolo Earthquake Fault Zoning Act

As presented in the CGS Special Publication 42 (CGS, 2018a), the 1972 Alquist-Priolo

Earthquake Fault Zoning Act requires the State Geologist to delineate EFZs along known active faults in California. The active faults must meet the requirements of being “sufficiently active” (evidence of movement within the last approximate 11,000 years) and “well-defined”

(detectable by a trained geologist). It is known that faults often rupture along a complex zone that may include the movement of multiple splays/strands rather than of a single strand. The EFZs are intended to be sufficiently wide enough on both sides of a known active fault to include these known or unknown splays/strands of the fault. The purpose of the act is generally to prohibit the construction of new structures for human occupancy

(defined as 2,000 or more man hours per year) across the traces of active faults, thus mitigating the hazard of fault rupture. Where new structures, generally for human occupancy, are proposed within an EFZ, additional evaluation is required to confirm that the structure is not underlain by an active fault splay through review of existing data and/or additional subsurface investigation. The law requires structures to be set back from the known trace of active faults. The requirements of this act are generally not applicable to the subject project since the site is not located within the EFZ.

10.3 Seismic Ground Motion

Considering the proximity of the site to active faults capable of producing a maximum moment magnitude of 6.0 or more, the project area has a high potential for experiencing strong ground motion. The 2019 California Building Code (CBC) specifies that the risk-targeted maximum considered earthquake (MCER) ground motion response accelerations be used to evaluate seismic loads for design of buildings and other structures. Per the 2019 CBC, a site-specific ground motion hazard analysis shall be performed for structures on Site Class D with a mapped

MCER, 5 percent damped, spectral response acceleration parameter at a period of 1 second

(S1) greater than or equal to 0.2g in accordance with Sections 21.2 and 21.3 of the American

Society of Civil Engineers (ASCE) Publication 7-16 (2016) for the Minimum Design Loads and

Associated Criteria for Building and Other Structures. We calculated that the S1 for the site is equal to 0.723g using the 2020 Applied Technology Council [ATC] seismic design tool (web-based)]; therefore, a site-specific ground motion hazard analysis was performed for the project area.

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 12

The average shear wave velocity (Vs) for the upper 30 meters of soil (Vs30) utilized in the analysis was 360 meters per second (m/s). This was based on the results of the shear wave velocity measurements collected in CPT-7 (Ninyo & Moore, 2019) located approximately 180 feet west of the site. The shear wave data is presented in Appendix A. Based on our analysis using the California Department of Transportation (Caltrans) Seismic Design Criteria (2019), the depths to Vs = 1,000 m/s and Vs = 2,500 m/s are 264 meters and 3,010 meters, respectively.

The site-specific ground motion hazard analysis consisted of the review of available seismologic information for nearby faults and performance of probabilistic seismic hazard analysis (PSHA) and deterministic seismic hazard analysis (DSHA) to develop acceleration response spectrum

(ARS) curves corresponding to the MCER for 5 percent damping. Prior to the site-specific ground motion hazard analysis, we obtained the mapped seismic ground motion values and developed the general MCER response spectrum for 5 percent damping in accordance with

Section 11.4 of ASCE 7-16 (ATC, 2020).

The 2014 new generation attenuation (NGA) West-2 relationships were used to evaluate the site-specific ground motions. The NGA relationships that we used for developing the probabilistic and deterministic response spectra are by Chiou and Youngs (2014), Campbell and

Bozorgnia (2014), Boore, Stewart, Seyhan, and Atkinson (2014), and Abrahamson, Silva, and

Kamai (2014). The Open Seismic Hazard Analysis software developed by USGS (USGS, 2020a) was used for performing the PSHA. The Calculation of Weighted Average 2014 NGA

Models spreadsheet by the Pacific Earthquake Engineering Research Center was used for performing the DSHA (Seyhan, 2014).

PSHA was performed for earthquake hazards having a 2 percent chance of being exceeded in

50 years multiplied by the risk coefficients per ASCE 7-16. The maximum rotated components of ground motions were considered in PSHA with 5 percent damping. For the DSHA, we analyzed accelerations from characteristic earthquakes on active faults within the region using the

California Department of Transportation (Caltrans) ARS (Caltrans, 2019) seismic design tool

(web-based) and the hazard curves and deaggregation plots at the site using the USGS Unified

Hazard Tool application (USGS, 2020b). A magnitude 7.2 event on the Santa Monica fault with a rupture distance of 0.55 kilometers from the site was evaluated to be the controlling earthquake.

Hence, the deterministic seismic hazard analysis was performed for the site using this event and corrections were made to the spectral accelerations for the 84th percentile of the maximum rotated component of ground motion with 5 percent damping.

The site-specific MCER response spectrum was taken as the lesser of the spectral response acceleration at any period from the PSHA and DSHA, and the site-specific general response

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 13 spectrum was determined by taking two-thirds of the MCER response spectrum with some conditions in accordance with Section 21.3 of ASCE 7-16. Figure 9 presents the site-specific

MCER response spectrum and the site-specific design response spectrum. The general mapped design response spectrum calculated in accordance with Section 11.4 of ASCE 7-16 is also presented on Figure 9 for comparison. The site-specific spectral response acceleration parameters, consistent with the 2019 CBC, are provided in Section 12.5 for the evaluation of seismic loads on buildings and other structures. The site-specific maximum considered earthquake geometric mean (MCEG) peak ground acceleration, PGAM, was calculated as

0.914g.

10.4 Liquefaction

Liquefaction is the phenomenon in which loosely deposited, saturated granular soils (located below the water table) undergo rapid loss of shear strength due to development of excess pore pressure during strong earthquake-induced ground shaking. Ground shaking of sufficient duration results in the loss of grain-to-grain contact due to rapid rise in pore water pressure and it eventually causes the soil to behave as a fluid for a short period of time. Liquefaction is known generally to occur in saturated or near-saturated cohesionless soils at depths shallower than 50 feet below the ground surface. Liquefaction is also known to occur in relatively fine-grained soils

(i.e., sandy silt and clayey silt) with a plasticity index (PI) of less than 7. Factors known to influence liquefaction potential include composition and thickness of soil layers, grain size, relative density, groundwater level, degree of saturation, and both intensity and duration of ground shaking.

Based on our review of EZRIM (CGS, 2018) (Figure 8), the project site is not located in an area mapped as being potentially susceptible to liquefaction. In addition, based on the soil types and densities encountered during our geotechnical evaluation, the potential for liquefaction at the site is considered low and not a design issue. In addition, due to the relative dense nature of the upper sandy on-site soil, the potential for dynamic settlement due to dry sand is low.

10.5 Tsunami and Seiche Potential

Tsunamis are long wavelength seismic sea waves (long compared to ocean depth) generated by the sudden movements of the ocean floor during submarine earthquakes, landslides, or volcanic activity. Seiches are waves generated in a large, enclosed body of water. The nearest enclosed body of water is the Stone Canyon Reservoir located approximately 3.8 miles north of the sites. According to the Los Angeles County Safety Element (County of Los Angeles, 1990), the site is located outside of the anticipated zone of flood inundation associated with Stone

Canyon Reservoir. Due to the distance of the site from these enclosed bodies of water and

Ninyo & Moore | 11301 Wilshire Boulevard, Los Angeles, California | 209826018 | October 16, 2020 14 regional topography, the potential of damage occurring to the sites due to seiches is not considered a risk during the design-life of the project. In addition, the sites are not located within a mapped tsunami inundation area (California Emergency Management Agency, et.al., 2009).

Accordingly, damage due to tsunamis is considered to be low during the design-life of the project.

10.6 Historical Earthquakes

Historical earthquakes, greater than magnitude 6.5 or that caused significant loss of life and property, within…