S02 Final LANC Combined Specifications -3 of 4.pdf

REPORT COVER PAGE

Geotechnical Engineering Report

LANC Correct FCA Deficiencies – Pavement Reconstruction/Rehabilitation

Los Angeles, California

January 5, 2022

Terracon Project No. 60215157

Prepared for:

Vali Cooper International, LLC

Denver, Colorado

Prepared by:

Terracon Consultants, Inc.

Tustin, California

Terracon Consultants, Inc. 23041 Avenida de la Car lota Laguna Hil ls , Cal iforn ia 92653

P [949] 261 0051 F [949] 261 6110 terracon.com

REPORT COVER LETTER TO SIGN

Vali Cooper International, LLC

18300 East 71st Avenue

Denver, Colorado 80249

Attn: Mr. Jordan Vandermeer, P.E.

Senior Civil Engineer

E: Jordan.Vandermeer@valiint.com

Re: Geotechnical Engineering Report

LANC Correct FCA Deficiencies – Pavement Reconstruction/Rehabilitation

950 South Sepulveda Boulevard

Los Angeles, California

Terracon Project No. 60215157

Dear Mr. Vandermeer:

We have completed the Geotechnical Engineering services for the above referenced project. This study was performed in general accordance with Terracon Proposal No. P60215157 dated June

14, 2021, revised June 28, 2021, and Vali Cooper Contract No. 2021-TCI-P-02 dated October 8, 2021. This report presents the findings of the subsurface exploration and provides geotechnical recommendations concerning earthwork and the design and reconstruction or rehabilitation of pavements and exterior slabs for the proposed project.

We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this report or if we may be of further service, please contact us.

Sincerely, Terracon Consultants, Inc.

Victor V. Nguyen, E.I.T. S. (Raj) Pirathiviraj, P.E., G.E.

Staff Engineer Senior Engineer

APR Review by F. Fred Buhamdan, P.E.

12/31/23 https://na3.documents.adobe.com/verifier?tx=CBJCHBCAABAA7ITGoD-GW5MDW8Huu66kdxp8FnLbuafJ

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REPORT TOPICS

INTRODUCTION

SITE CONDITIONS

PROJECT DESCRIPTION

GEOTECHNICAL CHARACTERIZATION

CORROSIVITY

GEOTECHNICAL OVERVIEW

EARTHWORK

PAVEMENTS

GENERAL COMMENTS

Note: This report was originally delivered in a web-based format. Orange Bold text in the report indicates a referenced section heading. The PDF version also includes hyperlinks which direct the reader to that section and clicking on the GeoReport logo will bring you back to this page. For more interactive features, please view your project online at client.terracon.com.

ATTACHMENTS

EXPLORATION AND TESTING PROCEDURES

SITE LOCATION AND EXPLORATION PLANS

EXPLORATION RESULTS (Summary of Pavement Section Thicknesses, Boring Logs, and Laboratory Data)

SUPPORTING INFORMATION (Photologs, General Notes, and Unified Soil

Classification System)

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INTRODUC TION

Geotechnical Engineering Report

LANC Correct FCA Deficiencies – Pavement

Reconstruction/Rehabilitation

950 South Sepulveda Boulevard

Los Angeles, California Terracon Project No. 60215157

INTRODUCTION

This report presents the results of our subsurface exploration and geotechnical engineering services performed for the proposed FCA Improvements project. The FCA Improvements project consisted of pavement rehabilitation/reconstruction and exterior slab construction along roadways within the Los Angeles National Cemetery (LANC) and Spoils Yard located at 950 South

Sepulveda Boulevard in Los Angeles, California. The purpose of these services is to provide information and geotechnical engineering recommendations relative to:

■ Subsurface soil conditions ■ Pavement design and construction

■ Exterior slab design and construction ■ Site preparation and earthwork

■ Groundwater conditions

The geotechnical engineering Scope of Services for this project consisted of the following:

■ Advanced a total eight (8) borings to an approximate depth of 5 feet below existing site grades (bgs) along Appomattox Drive, Gettysburg Avenue Roundabout, Belleau Wood Drive, and Antietam Avenue Cul-De-Sac

■ Visually accessed multiple roadways and advanced a total of twenty (20) pavement cores through the existing asphalt concrete surface at all other roadways along the LANC.

■ Advanced total of three (3) borings to an approximate depth of 11½ feet bgs at the existing

Spoils Yard.

Maps showing the site and boring locations are shown in the Site Location and Exploration

Plan sections, respectively. A summary table providing the pavement section thicknesses along the roadways is provided in our Exploration Results section. The results of the laboratory testing performed on soil samples obtained from the site during the field exploration are included on the boring logs and as separate graphs in the Exploration Results section.

SITE CONDITIONS

The following description of site conditions is derived from our site visit in association with the field exploration and our review of publicly available geologic and topographic maps.

LANC Correct FCA Deficiencies – Pavement Reconstruction/Rehabilitation ■ Los Angeles, California

January 5, 2022 ■ Terracon Project No. 60215157

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Item Description

Parcel Information

The project is situated within the existing LA National Cemetery located at 950

South Sepulveda Boulevard in Los Angeles, California.

Approximate coordinates for the center of the LANC grave site are 34.0619°N, 118.4539°W

Existing

Improvements

Single story buildings and existing parking lot near the entrance off of 950

South Sepulveda Boulevard and within the maintenance yard

At the Spoils Yard, existing storage containers, dumpsters, and earthen/asphalt paved surfaces.

In addition, existing roadways run throughout the cemetery.

Current Ground

Cover

Asphalt concrete throughout existing roadways.

Earthen cover with light vegetation at Spoils Yard.

Existing Topography

(from Google Earth)

Relatively flat along the roadways. Elevations at the Spoils Yard vary from 391 to 399 feet above mean sea level (MSL) with a gradual slope descending south. To easterly facing bluff resides to the west of the Spoils Yard. The bluff has a top elevation of approximately 410 to 422 and gradually slopes east towards the Spoils Yard at approximate slopes of 6H to 3.5H:1V

PROJECT DESCRIPTION

Item Description

Proposed

Improvements

The project will include site improvements to the Spoils Yard and rehabilitation/reconstruction to the existing roadways. It is our understanding that rehabilitation will generally consist of mill and overlay of existing pavements. However, based on the site visit and assessment of the existing pavement conditions, pavement will be reconstructed along multiple segments of the roads as discussed in this report.

Improvements at the spoils yard and cul-de-sac area will include the following:

■ Asphalt concrete pavement over earthen surface and rehabilitation/reconstruction of existing asphalt concrete paving at southern end.

■ Addition of concrete dumpster pad.

Grading Minimal cut/fill – assumed to be less than one foot

Pavements It is our understanding that new pavements will be constructed and are included in this project.

Traffic Loading

We understand both rigid (concrete) and flexible (asphalt) pavement sections should be considered.

Anticipated Traffic Index Values: 5, 6 and 7 which correspond to equivalent single axis loadings (ESALs) of approximately 7,100, 33,000, and 120,300, respectively. The Civil Designer should verify the design values based on anticipated traffic loading.

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GEOTECHNICAL CHARACTERIZATION

We have developed a general characterization of the subsurface soil and groundwater conditions based upon our review of the data and our understanding of the geologic setting and planned construction. The following table provides our geotechnical characterization.

The geotechnical characterization forms the basis of our geotechnical calculations and evaluation of site preparation, foundation options and pavement options. As noted in General Comments, the characterization is based upon widely spaced exploration points across the site, and variations are likely.

Surface conditions generally consisted of asphalt concrete at the existing roadways and earthen cover at the Spoils Yard. Approximate thicknesses of pavement structural sections have been summarized and provided in the Exploration Results section.

Results of our laboratory testing and field exploration indicates that subsurface soils at the site consists of the following:

■ Sand with varying amounts of silt and gravel along Appomattox Drive and Gettysburg

Avenue Roundabout.

■ Medium stiff to stiff clay with varying amounts of silt and sand and clayey sand along

Belleau Wood Drive and Antietam Avenue Cul-De-Sac

■ Medium dense to very dense sand with varying amounts of silt and clay with a minor interbedded layer of very stiff sandy lean clay at the Spoils Yard.

Conditions encountered at each boring location are indicated on the individual boring logs shown in the Exploration Results section and are attached to this report. Stratification boundaries on the boring logs represent the approximate location of changes in native soil types; in situ, the transition between materials may be gradual.

Lab Results

Laboratory tests were conducted on selected soil samples and the test results are presented in the Exploration Results section and on the boring logs. Atterberg limit test results indicate that the on-site soils generally have low plasticity or are non-plastic. Expansion index testing conducted in B-7 resulted in an expansion index of 32 corresponding to “low” expansion potential as determined by ASTM D4829. Swell testing conducted in boring B-8 indicated that on-site soils within the local vicinity of the Antietam Avenue Cul-De-Sac have low swell potential when saturated under normal loads of 500 pounds per square foot (psf). The following table summarizes results of our R-Value testing:

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Boring Depth (ft, bgs) Laboratory Tested R-Value

B-1, B-2, B-3 Composite 0-5 72

B-5, B-6 Composite 0-5 13

B-8 0-5 14

Groundwater Conditions

Groundwater was not observed in the borings while drilling, or for the short duration the boring remained open. These observations represent groundwater conditions at the time of the field exploration and may not be indicative of other times, or at other locations.

According to data collected from the Los Angeles County Public Works Water Data Library for the

State of California from well number 2535J, located 1.2 miles southwest of the site, the highest groundwater elevation level, between May 15, 2000 and October 22, 2018, was recorded at a depth greater than 100 feet bgs. 1

CORROSIVITY

The results of laboratory sulfides, soluble sulfate, soluble chloride, electrical resistivity, redox potential, total salts, and pH testing are presented in our appendix within the Exploration Results section. The values may be used to estimate potential corrosive characteristics of the on-site soils with respect to contact with the various underground materials which will be used for project construction.

Results of soluble sulfate testing indicate samples of the on-site soils tested possess negligible sulfate concentrations when classified in accordance with Table 19.3.1.1 of the ACI Design

Manual. Concrete should be designed in accordance with the exposure class S0 provisions of the

ACI Design Manual, Section 318, Chapter 19.

1 Groundwater elevation was obtained from a monitoring well (well id: 2535J) located at a distance of approximately 1.2 miles southwest of the project site (www.dpw.lacounty.gov/general/wells#).

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GEOTECHNICAL OVERVIEW

The site appears suitable for the proposed construction based upon geotechnical conditions encountered in the test borings, provided that the recommendations provided in this report are implemented in the design and construction phases of this project.

The recommendations contained in this report are based upon the results of field and laboratory testing (presented in the Exploration Results section), engineering analyses, and our current understanding of the proposed project.

The General Comments section provides an understanding of the report limitations.

EARTHWORK

The following recommendations include site preparation, excavation, subgrade preparation and placement of engineered fills on the project. The recommendations presented for design and construction of earth supported elements including slabs and pavements are contingent upon following the recommendations outlined in this section.

Earthwork on the project should be observed and evaluated by Terracon. The evaluation of earthwork should include observation and testing of engineered fill, subgrade preparation, and other geotechnical conditions exposed during the construction of the project.

Site Preparation

Strip and remove existing vegetation, debris, pavements, and other deleterious materials from proposed exterior slab and pavement areas. Exposed surfaces should be free of mounds and depressions which could prevent uniform compaction. The site should be initially graded to create a relatively level surface to receive fill and provide for a relatively uniform thickness of fill beneath proposed building structures.

Although no evidence of fills, utilities, or underground facilities such as septic tanks, cesspools, basements, and utilities was observed during the site reconnaissance, such features could be encountered during construction. If unexpected fills, utilities, or underground facilities are encountered, such features should be removed and the excavation thoroughly cleaned prior to backfill placement and/or construction.

Subgrade Preparation

Subgrade soils beneath exterior slabs and pavements should be scarified, moisture conditioned, and compacted to a minimum depth of 10 inches. The moisture content and compaction of subgrade soils should be maintained until slab or pavement construction.

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Exposed areas which will receive fill, once properly cleared and benched where necessary, should be scarified to a minimum depth of 10 inches, moisture conditioned, and compacted per the compaction requirements in this report.

Based upon the subsurface conditions determined from the geotechnical exploration, subgrade soils exposed during construction are anticipated to be relatively workable. However, the workability of the subgrade may be affected by precipitation, repetitive construction traffic or other factors. If unworkable conditions develop, workability may be improved by scarifying and drying.

Excavation

It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment.

Individual contractors are responsible for designing and constructing stable, temporary excavations. Excavations should be sloped or shored in the interest of safety following local, and federal regulations, including current OSHA excavation and trench safety standards.

Fill Materials and Placement

All fill materials should be inorganic soils free of vegetation, debris, and fragments larger than 6 inches in size. Pea gravel or other similar non-cementatious, poorly-graded materials should not be used as fill or backfill without the prior approval of the geotechnical engineer.

Clean on-site soils or approved imported materials may be used as fill material for the following:

general site grading exterior slab areas pavement areas

Imported soils for use as fill material within proposed building and structure areas should conform to low volume change materials as indicated in the following specifications:

Percent Finer by Weight

Gradation (ASTM C 136)

3”

No. 4 Sieve ..................................................................................... 50-100

No. 200 Sieve ................................................................................... 10-40

Liquid Limit ....................................................................... 30 (max)

Plasticity Index ................................................................. 15 (max)

Maximum expansion index* .............................................. 20 (max)

*ASTM D 4829

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The contractor shall notify the Geotechnical Engineer of import sources sufficiently ahead of their use so that the sources can be observed and approved as to the physical characteristic of the import material. For all import material, the contractor shall also submit current verified reports from a recognized analytical laboratory indicating that the import has a "not applicable" (Class S0) potential for sulfate attack based upon current ACI criteria and is "mildly corrosive" to ferrous metal and copper. The reports shall be accompanied by a written statement from the contractor that the laboratory test results are representative of all import material that will be brought to the job.

Engineered fill should be placed and compacted in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift.

Fill lifts should not exceed 10 inches loose thickness.

Compaction Requirements

Recommended compaction and moisture content criteria for engineered fill materials are as follows:

Material Type and Location

Per the Modified Proctor Test (ASTM D 1557)

Minimum Compaction Requirement

Range of Moisture Contents for Compaction Above Optimum

Minimum Maximum

On-site soils and low volume change imported fill:

Fill greater than 5 feet in depth 95 0% +3%

Miscellaneous backfill 90 0% +3%

Beneath pavements and exterior slabs: 95 0% +3%

Utility Trenches*: 90 0% +3%

Bottom of excavation receiving fill: 90 0% +3%

Aggregate base (beneath pavements): 95 0% +3%

* Upper 12 inches should be compacted to 95% within pavement areas.

Grading and Drainage

Positive drainage should be provided during construction and maintained throughout the life of the development. Infiltration of water into utility trenches or existing nearby foundations should be prevented during construction. Planters and other surface features which could retain water in areas adjacent to the building or pavements should be sealed or eliminated. In areas where sidewalks or paving do not immediately adjoin the structure, we recommend that protective slopes be provided with a minimum grade of approximately 5 percent for at least 10 feet from perimeter walls. Backfill in utility and sprinkler line trenches should be well compacted and free of all construction debris to reduce the possibility of moisture infiltration.

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Exterior Slab Design and Construction

Compacted subgrade composed of on-site clayey soils will expand with increasing moisture content; therefore, exterior concrete slabs may heave, resulting in cracking or vertical offsets. The potential for damage would be greatest where exterior slabs are constructed adjacent to the building or other structural elements. To reduce the potential for damage caused by movement, we recommend:

exterior slabs should be supported directly on subgrade fill with no, or very low expansion potential;

strict moisture-density control during placement of subgrade fills;

maintain proper subgrade moisture until placement of slabs;

placement of effective control joints on relatively close centers and isolation joints between slabs and other structural elements;

provision for adequate drainage in areas adjoining the slabs;

use of designs which allow vertical movement between the exterior slabs and adjoining structural elements.

Utility Trenches

It is anticipated that the on-site soils will provide suitable support for underground utilities and piping that may be installed. Any soft and/or unsuitable material encountered at the bottom of excavations should be removed and be replaced with an adequate bedding material. A non-expansive granular material with a sand equivalent greater than 30 should be used for bedding and shading of utilities, unless allowed or specified otherwise by the utility manufacturer.

On-site materials are considered suitable for backfill of utility and pipe trenches from one foot above the top of the pipe to the final ground surface, provided the material is free of organic matter and deleterious substances.

Trench backfill should be mechanically placed and compacted as discussed earlier in this report.

Compaction of initial lifts should be accomplished with hand-operated tampers or other lightweight compactors. Where trenches are placed beneath slabs or footings, the backfill should satisfy the gradation and expansion index requirements of engineered fill discussed in this report. Flooding or jetting for placement and compaction of backfill is not recommended.

Construction Considerations

Upon completion of filling and grading, care should be taken to maintain the subgrade moisture content prior to construction of floor slabs and pavements. Construction traffic over the completed subgrade should be avoided to the extent practical. The site should also be graded to prevent ponding of surface water on the prepared subgrades or in excavations. If the subgrade should become desiccated, saturated, or disturbed, the affected material should be removed, or these materials should be scarified, moisture conditioned, and recompacted prior to floor slab and pavement construction.

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On-site clay soils may pump, and unstable subgrade conditions could develop during general construction operations, particularly if the soils are wetted and/or subjected to repetitive construction traffic. The use of light construction equipment would aid in reducing subgrade disturbance. The use of remotely operated equipment, such as a backhoe, would be beneficial to perform cuts and reduce subgrade disturbance.

Should unstable subgrade conditions develop stabilization measures will need to be employed.

Stabilization measures may include placement of aggregate base and multi-axial geogrid. Use of lime, fly ash, kiln dust or cement could also be considered as a stabilization technique. Laboratory evaluation is recommended to determine the effect of chemical stabilization on subgrade soils prior to construction.

We recommend that the earthwork portion of this project be completed during extended periods of dry weather if possible. If earthwork is completed during the wet season (typically November through April) it may be necessary to take extra precautionary measures to protect subgrade soils.

Wet season earthwork operations may require additional mitigative measures beyond that which would be expected during the drier summer and fall months. This could include diversion of surface runoff around exposed soils and draining of ponded water on the site. Once subgrades are established, it may be necessary to protect the exposed subgrade soils from construction traffic.

Construction Observation and Testing

The geotechnical engineer should be retained during the construction phase of the project to observe earthwork and to perform necessary tests and observations during subgrade preparation, proof-rolling, placement and compaction of controlled compacted fills, backfilling of excavations to the completed subgrade.

The exposed subgrade and each lift of compacted fill should be tested, evaluated, and reworked as necessary until approved by the Geotechnical Engineer prior to placement of additional lifts.

Each lift of fill should be tested for density and water content at a frequency of at least one test for every 5,000 square feet in exterior slab and pavement areas. One density and water content test for every 50 linear feet of compacted utility trench backfill.

In the event that unanticipated conditions are encountered, the Geotechnical Engineer should prescribe mitigation options.

In addition to the documentation of the essential parameters necessary for construction, the continuation of the Geotechnical Engineer into the construction phase of the project provides the continuity to maintain the Geotechnical Engineer’s evaluation of subsurface conditions, including assessing variations and associated design changes.

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PAVEMENTS

GENERAL PAVEMENT COMMENTS

Pavement designs are provided for the traffic conditions and pavement life conditions as noted in

Project Description and in the following sections of this report. A critical aspect of pavement performance is site preparation. Pavement designs noted in this section must be applied to the site which has been prepared as recommended in the Earthwork section.

Based on visual assessment of the existing pavement conditions, existing pavement will be reconstructed (removal and replacement) along multiple segments of the roads or existing pavements will be rehabilitated as discussed in this report.

Photographs illustrating existing asphalt concrete pavement conditions are presented in the

Supporting Information section of this report. Based on pavement measurements and our visual observation of the overall condition of the pavement, it is our opinion that the majority of the existing pavements are in fair to poor condition relative to their age. However, some localized areas exhibited significant damage and heaving when compared to other street segments of the

LANC. Rapid deterioration relative to the pavement age was especially observed at the Antietam

Avenue Cul-De-Sac. Heaving was observed along the Antietam Avenue Cul-De-Sac- and along localized areas on Lookout Drive and the Gettysburg Avenue roundabout. Such areas are situated within the remove and replace limits as indicated in the Exploration Plans for these roadways.

It is our understanding that areas of these rapid deterioration may be caused by a combination of poor drainage control, poor quality aggregate, aggregate size control, improper mix design, and poor workmanship coupled with subgrade conditions. Based on laboratory test results and visual observation, we suspect that pavement heaving may be caused by a combination of poor drainage and subsequent swelling of subgrade coupled with potential uplift from roots associated with nearby trees and landscaping. However, it should be noted that our observations are based on limited exploration points. Such root issues cannot be ascertained without removal of the existing asphalt concrete sections and further observation of the subgrade conditions beneath the aforementioned pavement areas.

From a preliminary construction standpoint, Terracon recommends removal of all roots and nearby trees within removal and replacement areas as indicated in the Exploration Plans. We also recommend mixing expansive subgrade with additives such as lime or cement in order to reduce expansion potential of subgrade materials. Laboratory evaluation is recommended to determine the effects of chemical stabilization on subgrade soils during construction.

Furthermore, the subgrade conditions should be observed by a geotechnical engineer during construction and further recommendations, if necessary, should be made based on such observations.

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PAVEMENT RECONSTRUCTION

The following approximate limits of the pavement reconstruction zone are shown in the

Exploration Plan. Within these areas, we recommend that the existing pavements should be removed the replaced with new pavement sections.

■ Gettysburg Avenue (Section between Appomattox Drive and Santiago Drive) – approximately 150 feet segment around roundabout

■ Belleau Wood Drive (Section between Amiens Avenue and San Juan Hills) – 500 feet segment

■ Lookout Drive (Section north of Belleau Wood Drive) – 80 feet segment

■ Antietam Avenue Cul-De-Sac (near Spoils Yard)

Pavement Design Parameters: Estimated and laboratory tested R-values for the site consist of the following:

■ Laboratory tested R-value of 72 along Appomattox Drive and Gettysburg Avenue

Roundabout. A design R-value of 40 was utilized for pavement section design along these roadways.

■ Laboratory tested R-value of 13 along Belleau Wood Drive and R-value of 14 along

Antietam Avenue Cul-De-Sac. A design R-value of 13 was utilized for design of pavement section along Belleau Wood Drive, Antietam Avenue Cul-De-Sac and the Spoils Yard.

R-value testing should be completed prior to pavement construction to verify the design R-value.

Assuming the pavement subgrades will be prepared as recommended within this report, the following pavement sections should be considered minimums for this project for the traffic indices assumed in the table below. As more specific traffic information becomes available, we should be contacted to reevaluate the pavement calculations.

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Pavement Section Thicknesses: The following table provides options for AC and PCC Sections for the following areas of the site:

Gettysburg Avenue Roundabout (Section between Appomattox Drive and Santiago Drive)

Recommended Pavement Section Thickness (inches) 1, 2, 3

Traffic Index (TI) = 5

(~7,100 ESAL)

TI = 6 (~33,000 ESAL)

TI = 7 (~120,300

ESAL)

Section I

Unreinforced Portland Cement Concrete (PCC)

(600 psi Flexural Strength)

5-inches PCC over 4-inches Class II Aggregate Base

5-inches PCC over 4-inches Class II Aggregate Base

6-inches PCC over 4-inches Class II Aggregate Base

Section II

Asphaltic Concrete

3-inches AC over 4-inches Class II Aggregate Base

4-inches AC over 5-inches Class II Aggregate Base

4-inches AC over 7-inches Class II Aggregate Base

1. All materials should meet the CALTRANS Standard Specifications for Highway Construction.

2. Asphalt concrete pavement sections shall be placed in maximum lifts of 2 inches.

3. We recommend pavement areas which are anticipated to be subjected to heavy truck wheel turning movements be constructed with rigid (PCC) pavement sections.

Belleau Wood Drive (Section between Amiens Avenue and San Juan Hills), Lookout Drive (west of Belleau Wood Drive), Antietam Avenue Cul-De-Sac, and Spoils Yard

Recommended Pavement Section Thickness (inches) 1, 2, 3

Traffic Index (TI) = 5

(~7,100 ESAL)

TI = 6 (~33,000 ESAL)

TI = 7 (~120,300

ESAL)

Section I

Unreinforced Portland Cement Concrete

(600 psi Flexural Strength)

5-inches PCC over 4-inches Class II Aggregate Base

5-inches PCC over 4-inches Class II Aggregate Base

6-inches PCC over 4-inches Class II Aggregate Base

Section II

Asphaltic Concrete

3-inches AC over 9-inches Class II Aggregate Base

4-inches AC over 10-inches Class II Aggregate Base

4-inches AC over 15-inches Class II Aggregate Base

1. All materials should meet the CALTRANS Standard Specifications for Highway Construction.

2. Asphalt concrete pavement sections shall be placed in maximum lifts of 2 inches.

3. We recommend pavement areas which are anticipated to be subjected to heavy truck wheel turning movements be constructed with rigid (PCC) pavement sections.

These pavement sections are considered minimal sections based upon the expected traffic and the existing subgrade conditions. However, they are expected to function with periodic maintenance and overlays if good drainage is provided and maintained.

Subsequent to clearing, grubbing, and removal of topsoil, subgrade soils beneath all pavements should be scarified, moisture conditioned, and compacted to a minimum depth of 10 inches. All materials should meet the CALTRANS Standard Specifications for Highway Construction.

Aggregate base materials should meet the gradation and quality requirement of Class 2

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Aggregate Base (¾ inch maximum) in Caltrans Standard Specifications, latest edition, Sections

25 through 29.

All concrete for rigid pavements should have a minimum flexural strength of 600 psi (4,250 psi

Compressive Strength) and be placed with a maximum slump of four inches. Proper joint spacing will also be required to prevent excessive slab curling and shrinkage cracking. All joints should be sealed to prevent entry of foreign material and dowelled where necessary for load transfer.

Preventative maintenance should be planned and provided for through an on-going pavement management program in order to enhance future pavement performance. Preventative maintenance activities are intended to slow the rate of pavement deterioration, and to preserve the pavement investment.

Preventative maintenance consists of both localized maintenance (e.g. crack sealing and patching) and global maintenance (e.g. surface sealing). Preventative maintenance is usually the first priority when implementing a planned pavement maintenance program and provides the highest return on investment for pavements.

Pavement Construction Considerations: Materials and construction of pavements for the project should be in accordance with the requirements and specifications of the State of California

Department of Transportation, or other approved local governing specifications.

Base course or pavement materials should not be placed when the surface is wet. Surface drainage should be provided away from the edge of paved areas to minimize lateral moisture transmission into the subgrade.

PAVEMENT REHABILITATION

It is our understanding that the design team plan to have pavement rehabilitation measures for pavement areas of the LANC graveyard site not covered in the pavement reconstruction sections.

As such, Terracon advanced twenty (20) cores through the existing asphalt concrete sections along roadways throughout the cemetery. A summary table providing the pavement section thicknesses along the roadways is provided in our Exploration Results section. A photolog showing the selected pavement cores are presented in the Supporting Information section.

Based on the existing pavement thicknesses and distress, it is our opinion that the existing pavement areas not covered in the Pavement Reconstruction sections may be rehabilitated by cleaning and sealing the cracks or 1½ inches of mill and overlay along with some sections.

For areas with minor severity cracking and distress, the pavement rehabilitation may consist of milling the existing asphalt concrete surface and overlaying new asphalt concrete. The milling depth and overlay thickness should be verified in the field based on the conditions of the asphalt pavement after milling. In general, the design life expected from the rehabilitated pavement should

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Prior to placement of new asphalt overlay, exposed pavement surface should be inspected for existing cracks. In the event, pavement cracks are still present after cold milling, Terracon should be contacted to evaluate the exposed pavement as further recommendations may be necessary.

In general, exposed cracks should be sealed prior to asphalt overlay.

The following table summarizes our recommended pavement rehabilitation method for the roadways:

Location Core ID Mode of Distress

Rehabilitation Measure

Along the Entire Street

Segment

Gettysburg Ave C-1 Longitudinal, transverse cracking Crack seal

Buena Vista Ave C-2 Weathering, block cracking Mill and Overlay

San Juan Hill Ave C-3 Weathering, block cracking Mill and Overlay

Shiloh Dr C-4 Weathering, transverse cracking, patching Crack seal

Antietam Ave C-5 Weathering, longitudinal cracking Crack seal

Santiago Dr C-6 Weathering, block cracking Crack seal

Meuse Ave C-7 -

Meuse Ave C-8 -

St. Mihiel Ave C-9 -

Constitution Ave C-10 Longitudinal, transverse cracking, weathering Crack seal

Marne Ave C-11 Longitudinal, transverse cracking Crack seal

Chateau Thierry Ave C-12 Weathering Mill and Overlay

Meuse Ave C-13 Alligator cracking Crack seal

Toul Ave C-14 -

Santiago Dr C-15 Weathering, block cracking Crack seal

Appomattox Dr C-16 Weathering, block cracking Crack seal

Appomattox Dr B-1, B-2 Weathering Mill and Overlay

Argonne Ave C-17 -

Soissons Ave C-18 Longitudinal, transverse cracking Crack seal

Amiens Ave C-19 Raised cracking, longitudinal cracking Crack seal

Lookout Dr C-20 Raised cracking Crack seal

1. No rehabilitation measure is necessary

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GENERAL COMMENTS

Our analysis and opinions are based upon our understanding of the project, the geotechnical conditions in the area, and the data obtained from our site exploration. Natural variations will occur between exploration point locations or due to the modifying effects of construction or weather.

The nature and extent of such variations may not become evident until during or after construction.

Terracon should be retained as the Geotechnical Engineer, where noted in this report, to provide observation and testing services during pertinent construction phases. If variations appear, we can provide further evaluation and supplemental recommendations. If variations are noted in the absence of our observation and testing services on-site, we should be immediately notified so that we can provide evaluation and supplemental recommendations.

Our Scope of Services does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken.

Our services and any correspondence or collaboration through this system are intended for the sole benefit and exclusive use of our client for specific application to the project discussed and are accomplished in accordance with generally accepted geotechnical engineering practices with no third-party beneficiaries intended. Any third-party access to services or correspondence is solely for information purposes to support the services provided by Terracon to our client.

Reliance upon the services and any work product is limited to our client and is not intended for third parties. Any use or reliance of the provided information by third parties is done solely at their own risk. No warranties, either express or implied, are intended or made.

Site characteristics as provided are for design purposes and not to estimate excavation cost. Any use of our report in that regard is done at the sole risk of the excavating cost estimator as there may be variations on the site that are not apparent in the data that could significantly impact excavation cost. Any parties charged with estimating excavation costs should seek their own site characterization for specific purposes to obtain the specific level of detail necessary for costing.

Site safety, and cost estimating including, excavation support, and dewatering requirements/design are the responsibility of others. If changes in the nature, design, or location of the project are planned, our conclusions and recommendations shall not be considered valid unless we review the changes and either verify or modify our conclusions in writing.

Responsive ■ Resourceful ■ Reliable

ATTACHMENTS

Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES 1 of 2

EXPLORATION AND TESTING PROCEDURES

Field Exploration

Number of Borings/Corings Boring Depth (feet) Location

2 5 Appomattox Drive

2 3 to 5 Gettysburg Avenue Roundabout

2 5 Belleau Wood Drive

2 5 Antietam Avenue Cul-De-Sac

3 11½ Spoils Yard

20 - All other roadways

1. Only asphalt concrete section was penetrated to determine existing asphalt concrete thicknesses.

Boring Layout and Elevations: Boring layouts were prepared by Terracon and approved by the client. Coordinates were obtained with a handheld GPS unit (estimated horizontal accuracy of about ±10 feet) and approximate elevations were obtained from google earth. If elevations and a more precise boring layout are desired, we recommend borings be surveyed following completion of fieldwork.

Subsurface Exploration Procedures: We advanced the borings with a truck-mounted drill rig using continuous hollow stem flight augers. We advanced the twenty pavement cores with a trailer-mounted core rig. In 5-foot borings, one to two samples were generally obtained. In 11½-foot borings, four samples were generally obtained within the upper 10 feet. Soil sampling was performed using split-barrel sampling procedures. In the split-barrel sampling procedure, a standard 2-inch outer diameter split-barrel sampling spoon is driven into the ground by a

140-pound automatic hammer falling a distance of 30 inches. The number of blows required to advance the sampling spoon the last 12 inches of a normal 18-inch penetration is recorded as the Standard Penetration Test (SPT) resistance value. The SPT resistance values, also referred to as N-values, are indicated on the boring logs at the test depths. A 2.5-inch O.D. split-barrel

Modified California sampling spoon with 2.0-inch I.D. tube lined sampler was also used for sampling. The Modified California split-barrel sampling procedures are similar to standard split spoon sampling procedure; however, blow counts are typically recorded for 6-inch intervals for a total of 12 inches of penetration. The samples were placed in appropriate containers, taken to our soil laboratory for testing, and classified by a geotechnical engineer. In addition, we observed and recorded groundwater levels during drilling and sampling. For safety purposes, all borings were backfilled with auger cuttings after their completion. Pavements were patched with cold-mix asphalt, where appropriate.

Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES 2 of 2

The sampling depths, penetration distances, and other sampling information was recorded on the field boring logs. The samples were placed in appropriate containers and taken to our soil laboratory for testing and classification by a Geotechnical Engineer. Our exploration team prepared field boring logs as part of the drilling operations. These field logs included visual classifications of the materials encountered during drilling and our interpretation of the subsurface conditions between samples. Final boring logs were prepared from the field logs. The final boring logs represent the

Geotechnical Engineer's interpretation of the field logs and include modifications based on observations and tests of the samples in our laboratory.

Laboratory Testing

The project engineer reviewed the field data and assigned laboratory tests to understand the engineering properties of the various soil strata, as necessary, for this project. Procedural standards noted below are for reference to methodology in general. In some cases, variations to methods were applied because of local practice or professional judgment. Standards noted below include reference to other, related standards. Such references are not necessarily applicable to describe the specific test performed.

■ ASTM D2216 Standard Test Methods for Laboratory Determination of Water (Moisture)

Content of Soil and Rock by Mass

■ ASTM D7263 Standard Test Methods for Laboratory Determination of Dry Density (Unit

Weight) of Soil Specimens

■ ASTM D4318 Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of

Soils

■ ASTM D1140 Standard Test Methods for Determining the Amount of Material Finer than

75-µm (No. 200) Sieve in Soils by Washing

■ Caltrans Test Method 301 Method for Determining the Resistance “R” Value of Treated and Untreated Bases, Subbases, and Basement Soils by the Stabilometer

The laboratory testing program included examination of soil samples by an engineer. Based on the material’s texture and plasticity, we described and classified the soil samples in accordance with the Unified Soil Classification System.

SITE LOCATION AND EXPLORATION PLANS

SITE LOCATION

LA National Cemetery – Pavement Reconstruction/Rehabilitation ■ Los Angeles, CA

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT

INTENDED FOR CONSTRUCTION PURPOSES

SITE

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT

INTENDED FOR CONSTRUCTION PURPOSES

AERIAL PHOTOGRAPHY PROVIDED BY

MICROSOFT BING MAPS

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT

INTENDED FOR CONSTRUCTION PURPOSES

LEGEND

C-1: APPROXIMATE CORE

LOCATION

B-1: APPROXIMATE BORING

APPROXIMATE LIMITS OF REMOVE

AND REPLACE

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT

INTENDED FOR CONSTRUCTION PURPOSES

LEGEND

B-1: APPROXIMATE BORING

APPROXIMATE LIMITS OF REMOVE

AND REPLACE

DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT

INTENDED FOR CONSTRUCTION PURPOSES

LEGEND

EXPLORATION RESULTS

Summary of Pavement Section Thicknesses

LA National Cemetery – Pavement Rehabilitation/Reconstruction ■ Los Angeles, California

Core ID Location Pavement Section Thicknesses (in)

B-1 Appomattox Dr.

4 AC over 15 AB

B-2 4 AC over 15 AB

B-3 Gettysburg Ave. Roundabout

4.5 AC over 10 AB

B-4 5 AC over 13 AC

B-5 Belleau Wood Dr.

4 AC over 12 AB

B-6 4 AC over 13 AB

B-7 Antietam Ave. Cul-De-Sac

4 AC over 12 AB

B-8 4 AC over 12 AB

C-1 Gettysburg Ave. 4.75 AC1

C-2 Buena Vista Ave. 3.50 AC1

C-3 San Juan Hill Ave. 2.75 AC1

C-4 Shiloh Dr. 13.50 AC1

C-5 Antietam Ave. 4.25 AC1

C-6 Santiago Dr. 4.75 AC1

C-7 Meuse Ave. 3.75 AC1

C-8 Meuse Ave. 4.00 AC1

C-9 St. Mihiel Ave. 4.25 AC1

C-10 Constitution Ave. 4.00 AC1

C-11 Marne Ave. 4.25 AC1

C-12 Chateau Thierry Ave. 3.50 AC1

C-13 Meuse Ave. 2.25 AC1

C-14 Toul Ave. 4.75 AC1

C-15 Santiago Dr. 2.00 AC1

C-16 Appomattox Dr. 4.50 AC1

C-17 Argonne Ave. 4.25 AC1

C-18 Soissons Ave. 4.00 AC1

C-19 Amiens Ave. 3.75 AC1

C-20 Lookout Dr. 5.50 AC1

AC – Asphalt Concrete AB – Aggregate Base

1. Aggregate base layer, if present, was not measured at these locations.

ASPHALT, 4" Thickness AGGREGATE BASE COURSE, 15" Thickness

POORLY GRADED SAND WITH SILT AND GRAVEL (SP-SM), dark brown

Boring Terminated at 5 Feet

0.3

1.6

5.0

Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.

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LIMITS

LL-PL-PI

LOCATION See Exploration Plan

Latitude: 34.0627° Longitude: -118.4542°

G R

A P

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L O

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DEPTH

Advancement Method:

Hollow Stem Auger

Abandonment Method:

Boring backfilled with Auger Cuttings.

Surface capped with cold-mix asphalt concrete.

Notes:

Project No.: 60215157

Drill Rig: CME-75

BORING LOG NO. B-1

Vali Cooper InternationalCLIENT:

Denver, CO

Driller: 2R Drilling

Boring Completed: 10-28-2021

PROJECT: LA National Cemetary - Pavement Rehabilitation/Reconstruction

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

950 S Sepulveda Blvd.

Los Angeles, CA

SITE:

Boring Started: 10-28-2021

1421 Edinger Ave, Ste C Tustin, CA

WATER LEVEL OBSERVATIONS

Groundwater not encountered

S A

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AGGREGATE BASE COURSE, 15" Thickness

POORLY GRADED SAND WITH SILT AND GRAVEL (SP-SM), dark brown

Boring Terminated at 5 Feet

0.3

1.6

5.0

Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.

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ATTERBERG

LIMITS

LL-PL-PI

LOCATION See Exploration Plan

Latitude: 34.0628° Longitude: -118.4536°

G R

A P

H

IC

L O

G

DEPTH

Advancement Method:

Hollow Stem Auger

Abandonment Method:

Boring backfilled with Auger Cuttings.

Surface capped with cold-mix asphalt concrete.

Notes:

Project No.: 60215157

Drill Rig: CME-75

BORING LOG NO. B-2

Vali Cooper International

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CLIENT:

Denver, CO

Driller: 2R Drilling

Boring Completed: 10-28-2021

PROJECT: LA National Cemetary - Pavement Rehabilitation/Reconstruction

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

950 S Sepulveda Blvd.

Los Angeles, CA

SITE:

Boring Started: 10-28-2021

1421 Edinger Ave, Ste C Tustin, CA

WATER LEVEL OBSERVATIONS

Groundwater not encountered

S A

M P

LE

T

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ASPHALT, 4.5" Thickness AGGREGATE BASE COURSE, 10" Thickness SILTY SAND (SM), trace mica, brown

Auger Refusal at 3 Feet

0.4

1.2

3.0

Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.

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ATTERBERG

LIMITS

LL-PL-PI

LOCATION See Exploration Plan

Latitude: 34.0624° Longitude: -118.4542°

G R

A P

H

IC

L O

G

DEPTH

Advancement Method:

Hollow Stem Auger

Abandonment Method:

Boring backfilled with Auger Cuttings.

Surface capped with cold-mix asphalt concrete.

Notes:

Project No.: 60215157

Drill Rig: CME-75

BORING LOG NO. B-3

Vali Cooper InternationalCLIENT:

Denver, CO

Driller: 2R Drilling

Boring Completed: 10-28-2021

PROJECT: LA National Cemetary - Pavement Rehabilitation/Reconstruction

See Exploration and Testing Procedures for a description of field and laboratory procedures used and additional data (If any).

See Supporting Information for explanation of symbols and abbreviations.

950 S Sepulveda Blvd.

Los Angeles, CA

SITE:

Boring Started: 10-28-2021

1421 Edinger Ave, Ste C Tustin, CA

WATER LEVEL OBSERVATIONS

Groundwater not encountered

S A

M P

LE

T

Y

ASPHALT, 5" Thickness AGGREGATE BASE COURSE, 13" Thickness

SILTY SAND WITH GRAVEL (SM), trace organics, brown

Boring Terminated at 5 Feet

0.4

1.5

5.0

Hammer Type: AutomaticStratification lines are approximate. In-situ, the transition may be gradual.

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ATTERBERG

LIMITS

LL-PL-PI

LOCATION See Exploration Plan

Latitude: 34.0623° Longitude: -118.4540°

G R

A P

H

IC

L O

G

DEPTH

Advancement Method:

Hollow Stem Auger

Abandonment Method:

Boring…