A09 - 892CM3036 - BD - Geotech Report.pdf

REPORT C OVER PAGE

Geotechnical Engineering Report

Miramar GS Expansion

Miramar, San Diego County, California

October 29, 2019

Terracon Project No. 60195068

Prepared for:

Engineered With Layton

Chandler, Arizona

Prepared by:

Terracon Consultants, Inc.

Tustin, California

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REPORT TOPICS

INTRODUCTION

SITE CONDITIONS

PROJECT DESCRIPTION

GEOTECHNICAL CHARACTERIZATION

SEISMIC CONSIDERATIONS

LIQUEFACTION

CORROSIVITY

GEOTECHNICAL OVERVIEW

EARTHWORK

PAVEMENTS

GENERAL COMMENTS

ATTACHMENTS

EXPLORATION AND TESTING PROCEDURES

SITE LOCATION AND EXPLORATION PLANS

EXPLORATION RESULTS (Boring Logs and Laboratory Data)

SUPPORTING INFORMATION (General Notes and Unified Soil Classification System)

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INTRODUCTION

Miramar GS Expansion

Miramar National Cemetery

Miramar, San Diego County, California Terracon Project No. 60195068

October 29, 2019

INTRODUCTION

This report presents the results of our subsurface exploration and geotechnical engineering services performed for the proposed improvements to be located within the Miramar National

Cemetery in Miramar, San Diego County, California. The purpose of these services is to provide information and geotechnical engineering recommendations relative to:

■ Subsurface soil conditions ■ Seismic site classification per 2016 CBC

■ Groundwater conditions ■ Pavement design and construction

■ Site preparation and earthwork ■ Foundation design and considerations

■ Soil corrosivity ■ Lateral earth pressure recommendations

The geotechnical engineering Scope of Services for this project included the advancement of fourteen (14) test borings to depths ranging from approximately 0.7 feet to 15.9 feet below existing site grades (bgs).

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

Plan sections, respectively. 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.

Item Description

Parcel Information

The project is located at 5795 Noble Drive San Diego, California within

Miramar National Cemetery in Miramar, San Diego County, California.

Approximate coordinates near the center of the site are 32.872°N, 117.188°W.

Existing

Improvements

The cemetery currently occupies about 313-acres of land and includes in-ground casketed and cremated remains sites with associated facilities, paved parking and drive lanes, and landscaping. The project site is located near the east side of the existing cemetery.

Miramar GS Expansion ■ Miramar, San Diego County, California

October 29, 2019 ■ Terracon Project No. 60195068

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Item Description

Current Ground

Cover Exposed soils and sparse vegetation.

Existing Topography

(from Google Earth)

The site has an approximate elevation ranging between 370 feet and 400 feet above mean sea level.

PROJECT DESCRIPTION

Item Description

Proposed Improvements

The project will include the expansion of the existing cemetery and it will include columbarium niches, inground cremains, committal shelter, roadways, a retaining wall and detention basin.

Proposed construction

Columbarium niches are proposed to be supported on spread footing foundations.

The committal shelter is anticipated to be wood or steel framed structure with concrete slab-on-grade floor and shallow spread footing foundations.

Retaining wall is proposed to be mechanically stabilized embankment (MSE) wall

Maximum loads (assumed)

Columns: 40 to 80 kips

Walls: 1 to 2 klf

Slabs: 150 psf max

Grading

Based on the grading plans, the following grading is anticipated:

◼ Columbarium niches: up to 3 feet of cut and up to 3 feet of fill ◼ Committal shelter: up to 14 feet of fill. An MSE wall is proposed on the south side to retain the planned fill. Additionally, the existing ground will be graded to have a 3H:1V slope face for approximate height of 5 feet.

◼ Detention Basin: up to 12 feet cut

Additionally, up to 3 feet of cuts and 10 feet of fills are anticipated as part of the mass grading operations within the project site to accommodate the roadways, inground cremains, storm drains and other miscellaneous areas

Retaining Walls It is our understanding that a MSE wall with heights on the order of 14 feet will be constructed along the south side of the committal shelter.

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

Traffic Loading

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

Anticipated traffic is as follows:

◼ Driving Lanes: Traffic Index of 5.5

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

Geologic Settings

The site is situated within the southern Peninsular Ranges Geomorphic Province in Southern

California. Geologic structures within this Province trend mostly northwest, in contrast to the prevailing east-west trend in the neighboring Transverse Ranges Geomorphic Province to the north. The Peninsular Range Province extend into lower California and is bounded by the

Colorado Desert to the east, the Pacific Ocean to the west and the San Gabriel and San

Bernardino mountains to the north.1, 2 Surficial geologic units mapped at the site consist of

Pleistocene marine and marine terrace deposits of Quaternary age3.

Site Specific Geology

Auger refusal was encountered in multiple borings at depths varying from 0.7 feet to 15.9 feet bgs. We anticipate refusal materials to be weathered bedrock materials. Based on our review of the geologic literature and maps, the project area is underlain by early Pleistocene paralic deposits. As encountered in our borings, these deposits consist of medium to very dense clayey sands with varying amounts of silt and gravel and hard lean clay with varying amounts of sand to the maximum depth explored of 15.9 feet below ground surface.

Excavation of Paralic deposits are anticipated to be moderate to difficult at shallow depths and difficulty increases as depth increases.

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.

1 Harden, D. R., “California Geology, Second Edition,” Pearson Prentice Hall, 2004.

2 Norris, R. M. and Webb, R. W., “Geology of California, Second Edition,” John Wiley & Sons, Inc., 1990.

State of California – Division of Mines and Geology, Geologic Map of California, Olaf P. Jenkins Edition, San Diego-El Centro Sheet, Compilation by Rudolph G. Strand in 1962, Third Printing 1977

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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 to medium plasticity. A consolidation/collapse test at an approximate depth of 2½ feet below ground surface indicates a slight collapse potential. An R-

Value test indicated the near surface clayey sand/sandy clay soils have an R-Value of 11 and 12.

Expansion Index tests performed in clayey sand materials resulted in an expansion index of 9.

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.

In clayey soils with low permeability, the accurate determination of groundwater level may not be possible without long term observation. Long term observation after drilling could not be performed as borings were backfilled immediately upon completion due to safety concerns. Groundwater levels can best be determined by implementation of a groundwater monitoring plan.

Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff and other factors not evident at the time the borings were performed. Therefore, groundwater levels during construction or at other times in the life of the improvements may be higher or lower than the levels indicated on the boring logs. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project.

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SEISMIC CONSIDERATIONS

The seismic design requirements for buildings and other structures are based on Seismic Design

Category. Site Classification is required to determine the Seismic Design Category for a structure.

The Site Classification is based on the upper 100 feet of the site profile defined by a weighted average value of either shear wave velocity, standard penetration resistance, or undrained shear strength in accordance with Section 20.4 of ASCE 7.

Description Value

2016 California Building Code Site Classification (CBC) C

Site Latitude 32.872°N

Site Longitude -117.188°W

1. Seismic site classification in general accordance with the 2016 California Building Code.

2. The 2016 California Building Code (CBC) requires a site soil profile determination extending to a depth of

100 feet for seismic site classification. The current scope does not include the required 100-foot soil profile determination. Borings were extended to a maximum depth of 15.9 feet, and this seismic site class definition considers that similar or denser soils continue below the maximum depth of the subsurface exploration.

Additional exploration to deeper depths would be required to confirm the conditions below the current depth of exploration.

Faulting and Estimated Ground Motions

The site is located in the southern California, which is a seismically active area. The type and magnitude of seismic hazards affecting the site are dependent on the distance to causative faults, the intensity, and the magnitude of the seismic event. As calculated using the USGS Unified

Hazard Tool, the fault that is considered to have the most significant effect at the site from a design standpoint, has a maximum credible earthquake magnitude of 6.86 and is located approximately 6.54 kilometers from the site.

Based on the USGS Design Maps Summary Report, using the American Society of Civil

Engineers (ASCE 7-10) standard, the peak ground acceleration (PGAM) at the project site is expected to be 0.438g. Based on the USGS Unified Hazard Tool, the project site has a mean magnitude of 6.68.

The project site is not located within an Alquist-Priolo Earthquake Fault Zone based on our review of the State Fault Hazard Maps.4

4 California Department of Conservation Division of Mines and Geology (CDMG), “Digital Images of Official Maps of Alquist-Priolo

Earthquake Fault Zones of California, Southern Region”, CDMG Compact Disc 2000-003, 2000.

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LIQUEFACTION

Liquefaction is a mode of ground failure that results from the generation of high pore water pressures during earthquake ground shaking, causing loss of shear strength. Liquefaction is typically a hazard where loose sandy soils exist below groundwater. The California Geological

Survey (CGS) has designated certain areas as potential liquefaction hazard zones. These are areas considered at a risk of liquefaction-related ground failure during a seismic event, based upon mapped surficial deposits and the presence of a relatively shallow water table.

The project site is not located within a liquefaction hazard zone as designated by the CGS. Based on CGS maps and the encountered subsurface conditions, liquefaction hazard potential at the site is considered low. Other geologic hazards related to liquefaction, such as lateral spreading, are therefore also considered low.

CORROSIVITY

The table below lists the results of laboratory soluble sulfate, soluble chloride, electrical resistivity, and pH testing. 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.

Corrosivity Test Results Summary

Boring

Sample

Depth

(ft)

Soil

Description

Soluble

Sulfate

Sulfides

(ppm)

Chlorides

(ppm)

Red-Ox

Potential

(mV)

Electrical

Resistivity

(Ω-cm)

Total

Salts

(ppm) pH

B-4 0.0-2.5 Sandy Lean

Clay (CL)

0.04 Nil 53 +685 504 1,949 7.78

B-10 0.0-2.5 Clayey Sand

(SC)

0.02 Nil 27 +681 1,795 488 7.42

B-12 0.0-2.5 Clayey Sand

(SC)

0.02 Nil 67 +684 931 1,484 7.56

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.

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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.

Auger refusal was encountered in multiple borings at depths ranging from approximately 0.7 feet to 15.9 feet bgs on weathered bedrock. Excavations penetrating the bedrock materials may require the use of heavy duty machinery to penetrate these materials.

Columbarium niches are planned in areas that will be mass graded and have up to 3 feet of cut and 3 feet fill. The foundation for the Columbarium niches should be supported on a minimum 2 feet of engineered fill materials.

Foundations and floor slab for the committal shelter are proposed to be supported on 6 to 12 feet of engineered fill materials. Additionally, a MSE wall is proposed along the south side of the fill area and the wall will retain up to 14 feet of fill materials.

On site sandy materials are considered suitable to be used as engineered fill materials within committal shelter, MSE wall backfill and Columbarium niches foundations. The onsite sandy soils should be processed to remove all oversized particles (>3 inches in maximum diameter). On site clay materials are not considered suitable to be used as engineered fill materials. These fill materials should be compacted per the compaction requirements presented in this report.

The Site Preparation section addresses the grading recommendations for this project, while the

Shallow Foundation section provides recommendations for the design of foundations of the building. The Floor Slab section addresses slab-on-grade support of the building.

Additionally, up to 3 feet of cuts and 10 feet of fills are anticipated as part of the mass grading operations within the project site to accommodate the roadways, inground cremains, storm drains and other miscellaneous areas. Onsite materials, including clay materials are considered suitable to be used as fill materials in these areas. These fill materials should be compacted per the compaction requirements presented in this report.

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.

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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 foundations, 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, foundation bearing soils, and other geotechnical conditions exposed during the construction of the project.

Site Preparation

Based on the grading plan, up to 11 feet of cut and 14 feet of fill will be required to bring the site to planned construction grade. Prior to the mass grading, the site should be prepared by stripping and removing existing vegetation, roots, debris, and other deleterious materials from proposed cut and fill areas. Exposed surfaces to receive fill should be free of mounds and depressions which could prevent uniform compaction. This should include removal of any loose materials in fill areas.

We recommend stripping topsoil to depths that expose soils with less than 3 percent organics and no roots having a diameter greater than 1/8 inch. While the depth of the unsuitable soils should be expected to vary, the thickness of the top soil layer may be estimated to range between 6 and

12 inches for construction budgeting purposes. The thickness of the top soil layer was not determined during our field exploration. Therefore, the actual depth of stripping should be verified by engineering observations made during the grading operations at the project. Exposed surfaces should be free of mounds and depressions which could prevent uniform compaction.

Stripped materials consisting of vegetation and organic materials should be wasted from the site or used to revegetate landscaped areas or exposed slopes after completion of grading operations.

If it is necessary to dispose of organic materials on site, they should be placed in non-structural areas, and in fill sections not exceeding 5 feet in height.

Evidence of fills or underground facilities such as septic tanks, cesspools, basements, and utilities were observed during the site reconnaissance, and such features could be encountered during construction. If unexpected fills or underground facilities are encountered, such features should be removed, and the excavation thoroughly cleaned prior to backfill placement and/or construction.

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Subgrade Preparation

Mass grading operations for the Columbarium niches should accommodate the placement of a minimum of 2 feet of engineered fill beneath foundations.

Based on the grading plan, up to 12 feet of fill is anticipated in the committal shelter area and up to 14 feet of fill near the MSE wall. Additionally, up to 10 feet of fill will be placed in other areas as part of the mass grading operations. For sloped areas receiving fill, the overexcavation bottom should be benched per the following detail prior to placing the fill materials.

Onsite sandy soils are considered suitable to be used engineered fill materials in the committal shelter, MSE wall and Columbarium niches area. Onsite soils, including clay soils are considered suitable to be used as fill materials in other areas. These onsite materials should be processed to have particle size less than 3 inches and these materials should be compact per the compaction requirements presented in this report.

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.

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Subgrade soils beneath 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.

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. Excavation penetrating the very dense weathered bedrock may require the use of specialized heavy-duty equipment, to facilitate rock break-up and removal.

Consideration should be given to obtaining a unit price for difficult excavation in the contract documents for the project.

The bottom of excavations should be thoroughly cleaned of loose soils and disturbed materials prior to backfill placement and/or construction.

Based on the grading plans, the following excavations are anticipated:

◼ Up to 11 feet for the proposed detention basin and the sides will be sloped

◼ Up to 14 feet for the storm drain trenches

◼ Up to 3 feet in other areas

The sides of excavations may either be sloped or formed with vertical cuts. For vertical sided excavations greater than 5 feet in depth, the excavations will require the use of shoring, bracing or some form of retention to prevent sloughing and caving of the soil into the excavation.

As a safety measure, no equipment should be operated within 5 feet of the edge of the excavation and no materials should be stockpiled within 10 feet of the excavation. Excavations should not approach closer than a distance equal to the depth of excavation from existing structures/facilities without some form of protection for the facilities. Proper berming or ditching should be performed to divert any surface runoff away from the excavation.

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.

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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 sandy soils or approved imported materials may be used as engineered fill material in the structural areas as follows, on-site sandy soils should be processed to have particle size less than 3 inches.

◼ foundation support ◼ interior floor slabs

◼ foundation backfill ◼ retaining wall backfill

On-site soils, including clay soils may be used as fill materials in the following areas:

◼ general site grading ◼ pavement areas

◼ exterior slab areas

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

Percent Finer by Weight

Gradation (ASTM C 136)

1”

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

No. 200 Sieve ................................................................................... 10-35

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

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

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

*ASTM D 4829

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.

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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 or low volume change imported fill:

Beneath shallow foundations: 90% 0% +3%

Beneath slabs: 90% 0% +3%

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

Miscellaneous and retaining wall backfill: 90% 0% +3%

Beneath pavements: 95% 0% +3%

Utility Trenches*: 90% 0% +3%

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

Aggregate base (beneath floor slabs and pavements):

95% 0% +3%

* Upper 12 inches should be compacted to 95% within pavement or structural areas. Low-volume change imported soils should be used in structural 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 excavations should be prevented during construction. Backfill against utility and sprinkler line trenches should be well compacted and free of all construction debris to reduce the possibility of moisture infiltration.

We recommend a minimum horizontal setback distance of 10 feet from the perimeter of any foundations and the high-water elevation of the nearest storm-water retention basin.

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Utility Trenches

It is anticipated that the on-site soils and fill materials 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. Flooding or jetting for placement and compaction of backfill is not recommended.

Shrinkage

For balancing grading on-site, estimated shrink factor of granular soils when used as compacted fill following recommendations in this report ranges between 0.90 and 0.95. Shrinkage factors are based on converting materials in its natural state before disturbance to materials after compaction.

For excavations extending into the weathered bedrock layer, a swell (bulking) factor ranging between 30% and 50% may be used. Swell factors are based on converting materials in its natural state before disturbance to loose materials in stockpiles or on hauling trucks.

Slopes

For permanent slopes in compacted fill areas, recommended maximum configurations for on-site materials are as follows:

Maximum Slope Configuration

Inclination (horizontal:vertical) Slope Treatment

5:1 to 2:1 Re-vegetate

Greater than 2:1 to less steep than 1.5:1 Rip-rap over filter fabric

1.5:1 to 1:1

Grouted rip-rap or 6-inch thick grout with integrated toe-down at base of slope having a minimum depth of 1/5 the total slope height

Steeper than 1:1 Stability analysis or structural retaining wall required

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We expect slopes with this configuration to be resistant to erosion and stable against circular failure. The face of all slopes should be compacted to the minimum specification for fill embankments. Alternately, fill slopes can be over-built with compacted material and trimmed to final configurations.

Placing up to 14 feet of new fill above the existing site soils will result in estimated immediate settlements of less than ½ inches. This settlement will occur over a short period of time during the construction and we anticipate that this settlement will not impact the proposed development.

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.

On-site clayey 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.

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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 2,500 square feet of compacted fill in the building areas and 5,000 square feet in pavement areas. One density and water content test for every 50 linear feet of compacted utility trench backfill.

In areas of foundation excavations, the bearing subgrade should be evaluated under the direction of the Geotechnical Engineer. 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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SHALLOW FOUNDATIONS

Design Parameters

DESCRIPTION RECOMENDATION

Proposed Structure Committal Shelter, Columbarium niches, MSE Wall

Base, and Leveling Pad

Foundation Type Conventional Shallow Spread Footings

Bearing Material

Columbarium niches, MSE wall base and leveling pad: a minimum of 2 feet of engineered fill materials below the bottom footing or MSE wall base.

Committal Shelter: This area will be graded to have 6 to 12 feet of engineered fill materials

Allowable Bearing Pressure 3,000 psf for spread footings

Minimum Dimensions Walls: 18 inches; Columns: 24 inches

Minimum Embedment Depth Below

Finished Grade 18 inches

Total Estimated Settlement 1 inch

Estimated Differential Settlement ½ inch in 50 feet

Foundation Construction Considerations

Finished grade is defined as the lowest adjacent grade within five feet of the foundation for perimeter (or exterior) footings. The allowable foundation bearing pressures apply to dead loads plus design live load conditions. The design bearing pressure may be increased by one-third when considering total loads that include wind or seismic conditions. The weight of the foundation concrete below grade may be neglected in dead load computations.

Foundations should be reinforced as necessary to reduce the potential for distress caused by differential foundation movement. The use of joints at openings or other discontinuities in masonry walls is recommended.

The geotechnical engineer should observe foundation excavations. If the soil conditions encountered differ significantly from those presented in this report, supplemental recommendations will be required.

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FLOOR SLABS

Design Parameters

Item Description

Interior floor system Slab-on-grade concrete for committal shelter

Sub-base 4 inches of Class II aggregate base materials.

Floor slab support This area will be graded to have 6 to 12 feet of engineered fill materials

Modulus of subgrade reaction

200 pounds per square inch per inch (psi/in) (The modulus was obtained based on prepared subgrade beneath floor slabs, and estimates obtained from NAVFAC 7.1 design charts). This value is for a small loaded area (1 Sq. ft or less) such as for forklift wheel loads or point loads and should be adjusted for larger loaded areas.

In areas of exposed concrete, control joints should be saw cut into the slab after concrete placement in accordance with ACI Design Manual, Section 302.1R-37 8.3.12 (tooled control joints are not recommended). Additionally, dowels should be placed at the location of proposed construction joints. To control the width of cracking (should it occur) continuous slab reinforcement should be considered in exposed concrete slabs.

The use of a vapor retarder or barrier should be considered beneath concrete slabs on grade that will be covered with moisture sensitive or impervious coverings, or when the slab will support equipment sensitive to moisture to prevent moisture migration. When conditions warrant the use of a vapor retarder, the slab designer and slab contractor should refer to ACI 302 and ACI 360 for procedures and cautions regarding the use and placement of a vapor retarder/barrier.

Floor Slab Construction Considerations

On most project sites, the site grading is generally accomplished early in the construction phase.

However as construction proceeds, the subgrade may be disturbed due to utility excavations, construction traffic, desiccation, rainfall, etc. As a result, the floor slab subgrade may not be suitable for placement of base rock and concrete, and corrective action will be required.

Terracon should review the condition of the floor slab subgrades immediately prior to placement of the granular leveling course and construction of the slabs. Particular attention should be paid to high traffic areas that were rutted and disturbed earlier and to areas containing backfilled trenches.

Areas where unsuitable conditions are located should be repaired by removing and replacing the affected material with properly compacted fill

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BELOW GRADE STRUCTURES

Lateral Earth Pressures

The lateral earth pressure recommendations are applicable for the design of rigid retaining walls subject to slight rotation, such as cantilever or gravity type concrete walls, and lateral loading against foundation walls.

For soils or fill materials above any free water surface, recommended equivalent fluid pressures for unrestrained foundation elements with level backfill are:

ITEM

Engineered fill comprised of approved Onsite Sandy Soils or Imported Materials

Active Case 33 psf/ft

Passive Case 440 psf/ft a

At-Rest Case 51 psf/ft

Surcharge Pressure 0.30*(Surcharge)

Coefficient of Friction 0.40b a Note: This passive pressure is applicable to the level ground and the passive pressure should be multiplied by a factor of 0.4 for the sloping ground with the orientation up to 2H:1V bNote: Reduce to 0.30 when used in conjunction with passive pressure.

The lateral earth pressures herein do not include any factor of safety and are not applicable for submerged soils/hydrostatic loading. Additional recommendations may be necessary if such conditions are to be included in the design.

Based on the information provided in the civil designers, the MSE wall will be designed by the manufacturer of the proprietary wall system. On-site sandy materials are considered suitable to be used as MSE wall infill soils (reinforced zone), retained soils and foundation soils. We recommend a friction angle of 35 degrees, cohesion value of 100 psf and unit weight of 120 pcf for the onsite materials.

The proposed MSE wall footings should be embedded to a depth such that the setback distance from the edge of the footing to the descending slope is greater than a minimum distance of H/3, where H is the height of the slope.

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The design of retaining structures and shoring systems should consider surcharge loads imposed by the foundations of the proposed building and traffic within a horizontal distance equals to the height of the wall. Surcharge loads acting at the top of the wall should be applied to the wall over the backfill as a uniform pressure over the entire wall height and should be added to the static earth pressures. Surcharge stresses due to point loads, line loads, and those of limited extent, such as compaction equipment, should be evaluated using elastic theory.

Fill against foundation and retaining walls should be compacted to densities specified in the

Earthwork section of our referenced report. Compaction of each lift adjacent to walls should be accomplished with hand-operated tampers or other lightweight compactors. To account for the effect of compaction equipment on the wall during construction, the lateral pressure should not be less than 200 psf, distributed uniformly over the height of the wall.

Adequate drainage should be provided behind the walls to collect water from irrigation, landscaping, surface runoff, or other sources, to achieve a free-draining backfill condition. The wall back drain should consist of Class 2 permeable materials that are placed behind the entire wall height to within 18 inches of ground surface at the top of the wall. As a minimum, the width of Class 2 permeable materials behind the wall should be two feet. Water collected by the back drain should be directed to an appropriate outlet, such as weep holes or perforated pipes, for disposal.

Braced Shoring Recommendations

For the design of braced shoring, we recommend such shoring be designed using a rectangular-shaped distribution of lateral earth pressure of 21H (in psf) (H is the total height of excavation).

The design of the shored excavation should be performed by an engineer knowledgeable and experienced with the on-site soil conditions. The contractor should be aware that slope height, slope inclination or excavation depths should in no case exceed those specified in local, state or federal safety regulations, e.g. OSHA Health and Safety Standards for Excavation, 29 CFR Part

1926, or successor regulations. Such regulations are strictly enforced and, if not followed, the owner or the contractor could be liable for substantial penalties.

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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.

Pavement Design Parameters

A design R-Value, based on laboratory results, was used to calculate the asphalt concrete pavement thickness sections and the Portland cement concrete pavement sections. R-value testing should be completed, after grading but 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.

Pavement Section Thicknesses

The following table provides options for AC and PCC Sections:

Recommended Pavement Section Thickness (inches)

On-site Driveways

TI = 5.5

Section I

Portland Cement Concrete

(600 psi Flexural Strength)

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

Section II

Asphaltic Concrete

3-inches AC over 11-inches Class II Aggregate Base

Or

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

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

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, Responsive ■ Resourceful ■ Reliable 21 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 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.

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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.

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ATTACHMENTS

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

EXPLORATION AND TESTING PROCEDURES

Field Exploration

Number of

Borings

Boring Depth

(feet)

Planned Location Design Elements

3 5.3 to 10.5 Committal Shelter Footprint and

Retaining Wall Alignment Foundations

2 7 and 11 Columbaria Niches Footprint Foundations

2 5 Cortege Lanes (near administration building) Pavements

3 5 “C” Road (Michael Monsoor Ave) Pavements

1 8 “D” Road Pavements and 10 feet Deep

Trench for Storm Drain

2 11 and 15.9 “L” Road and New 18” Storm Drain Pavements and 15 feet Deep

Trench for Storm Drain

1 0.7 Detention Basin Grading and Earthwork for

Detention Basin

1. Below existing ground surface

Boring Layout and Elevations: Unless otherwise noted, Terracon personnel provided the boring layout. Coordinates were obtained with a handheld GPS unit (estimated horizontal accuracy of about ±20 feet) and approximate elevations were obtained by interpolation from the 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 track-mounted drill rig using continuous hollow stem flight augers. Test samples were collected during drilling in general accordance with the appropriate ASTM methods using Standard Penetration Testing (SPT) and sampling using either standard split-spoon or Modified California samplers. A sampling spoon was 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 was recorded as the Standard Penetration Test (SPT) resistance value, also referred to as N-values. The N-values are indicated on the boring logs at the test depths. 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.

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

Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES 2 of 2 for testing and classification by a Geotechnical Engineer. Our exploration team prepared field boring logs as part of the drilling operations.