Campo_Road_-_Final_Pavement_Design_Report.pdf

Pavement Design Report San Diego Wildlife Refuge

Campo Road Widening San Diego County, California

September 9, 2019

Submitted To:

Jacobs Engineering

9191 South Jamaica Street Denver, Colorado 80112

By:

Shannon & Wilson, Inc.

1321 Bannock Street, Suite 200 Denver, CO 80204

23-1-01458-040

ALASKA

CALIFORNIA

COLORADO

FLORIDA

MISSOURI

OREGON

WASHINGTON

WASHINGTON DC METRO

WISCONSIN

1321 BANNOCK STREET, SUITE 200

DENVER, COLORADO 80204-4077

303-825-3800 FAX: 303-825-3801

TDD 1-800-833-6388

www.shannonwilson.com 23-1-01458-040

September 9, 2019

Jacobs Engineering 9191 South Jamaica Street Englewood, CO 80112

Attn: Mr. Berwyn Wilbrink

RE: PAVEMENT DESIGN REPORT, SAN DIEGO WILDLIFE REFUGE

CAMPO ROAD WIDENING, SAN DIEGO COUNTY, CALIFORNIA

We are pleased to submit our pavement design report for the above-referenced project. The enclosed report summarizes subsurface conditions encountered in a subsurface exploration program, laboratory tests, and pavement recommendations for the proposed widening of Campo Road.

We appreciate the opportunity to be of service to you on this project. If you have any questions or require further information, please contact me at 303-825-3800.

Sincerely, SHANNON & WILSON, INC.

Gregory R. Fischer, Ph.D.

Senior Vice President

JCG:GRF

Encl: Pavement Design Report

23-1-01458-040_L1.docx

23-1-01458-040_R1 23-1-01458-040 i

TABLE OF CONTENTS

Page

1.0 INTRODUCTION

2.0 SITE AND PROJECT DESCRIPTION

3.0 FIELD EXPLORATIONS AND LABORATORY TEST RESULTS

3.1 Subsurface Explorations

3.2 Laboratory Test Results

4.0 SUBSURFACE CONDITIONS

4.1 Regional Geology

4.2 Subsurface Conditions

4.3 Groundwater

5.0 PAVEMENT DESIGN RECOMMENDATIONS

5.1 Traffic Loading

5.2 Subgrade Soils

5.3 Pavement Sections

6.0 CONSTRUCTION AND MATERIALS SPECIFICATIONS

6.1 Earthwork

6.1.1 Site Preparation

6.1.2 Proof-rolling

6.1.3 Fill Placement and Compaction

6.2 Paving Materials

7.0 CLOSURE

8.0 REFERENCES

TABLE

1 Recommended Materials for Pavements

FIGURES

1 Vicinity Map 2 Site and Exploration Plan ii

APPENDICES

A Subsurface Explorations B Laboratory Test Results C Exploration Photographs D Pavement Design Calculations E Important Information about Your Geotechnical/Environmental Report

PAVEMENT DESIGN REPORT

SAN DIEGO WILDLIFE REFUGE

CAMPO ROAD WIDENING

SAN DIEGO COUNTY, CALIFORNIA

1.0 INTRODUCTION

This pavement design report provides our recommendations for the Campo Road Widening at the San Diego Wildlife Refuge. The report summarizes our subsurface explorations and laboratory testing, and presents our pavement design recommendations and construction considerations. Our services were completed in general accordance with our Subconsulting Agreement No. WVXY4062-S16-0002 with Jacobs Engineering Group, Inc. (Jacobs) dated June 1, 2016.

2.0 SITE AND PROJECT DESCRIPTION

The Campo Road Widening Project is located along State Route (SR) 94 (Campo Road) adjacent to the San Diego Wildlife Refuge, approximately 5 miles east of San Diego, California (refer to Figure 1). The widening project consists of adding a deceleration lane from eastbound Campo Road onto Millar Ranch Road and an acceleration lane from Millar Ranch Road onto eastbound Campo Road. The proposed widening area will require some nominal fills to match the existing roadway grades. In the area of the proposed improvements the Campo Road pavement is asphalt concrete with two travel lanes (a single lane in each direction) and a turn lane for east bound traffic onto Millar Ranch Road. Our scope of work did not include analysis of the existing roadway. It appears that the existing roadway is in good condition and has recently been overlayed, however the details of this rehabilitation are unknown.

3.0 FIELD EXPLORATIONS AND LABORATORY TEST RESULTS

3.1 Subsurface Explorations

Shannon & Wilson implemented a field exploration program to evaluate pavement thickness and subsurface conditions. The exploration program was conducted as night work on August 23 and August 24, 2016 and consisted of drilling 3 borings (designated SW-1 through SW-3). The borings were drilled through the existing asphalt concrete pavement to depths between about 5 and 9 feet. The approximate boring locations are shown on Figure 2. Appendix A describes the procedures used to complete the drilling and sampling of the borings and provides an explanation of the symbols and terminology used, individual boring logs, and asphalt concrete core photos.

Appendix C contains photographs of the boring locations.

3.2 Laboratory Test Results

AP Engineering & Testing, Inc. completed geotechnical laboratory testing to determine index and engineering properties of samples retrieved from the borings. Laboratory tests included natural water content, grain size distribution, Atterberg limits, and Hveem Stabilometer (R-value). Laboratory test results and a discussion of testing procedures for each of the borings are included in Appendix B. The natural water contents, Atterberg limits, and percent fines are also indicated on the individual boring logs in Appendix A.

4.0 SUBSURFACE CONDITIONS

4.1 Regional Geology

The subject section of Campo Road is located within an alluvial valley filled with sediment derived from the sloping terrain that ascends toward the north, south, and east. This hillside terrain is composed of granitoid and gabbro igneous rocks that are Cretaceous in age (Todd et al., 2004). Campo Road runs along the northern side of the valley floor while the active drainage channel is located south of the road. The depth of the artificial fill and alluvial sediments is unknown as our borings were limited to a depth of 9 feet.

4.2 Subsurface Conditions

Based on the borings, the existing pavement asphalt concrete thicknesses was 5.5 inches and

6.75 inches overlying 4.5 inches and 7 inches of aggregate base course in boring SW-1 and SW- 2, respectively. Boring SW-3 encountered 4.5 inches of asphalt concrete overlying 12 inches of concrete. Undocumented fill materials (i.e., fill placed without documentation of placement and moisture-density control) were encountered underlying the pavement in borings SW-1 and SW-2 associated with the roadway embankment. Fill generally consisted of medium dense, silty to clayey sand with varying amounts of gravel. In Boring SW-1 asphalt concrete was encountered throughout the boring and auger refusal was encountered at a depth of 5.5 feet. Underlying the fill, our borings generally encountered alluvium consisting of medium dense to very dense, silty to clayey sand with varying amounts of gravel; however, boring SW-3 encountered hard sandy clay at the bottom of the boring.

Hydrocarbon odors were noted in boring SW-2. If excavation of this material is required special handling and considerations may be required.

Photographs of the recovered pavement core samples are provided in Appendix A. In general, the existing base course consisted of poorly graded gravel with sand and poorly graded sand with gravel.

We assume that the exploratory borings made for this project are representative of the subsurface conditions throughout the project (i.e., the subsurface conditions everywhere are not significantly different from those disclosed by the explorations). If conditions different from those described in this report are observed or appear to be present during construction, we should be advised at once so that we can review these conditions and reconsider our recommendations, where necessary. If there is a substantial lapse of time between submission of our report and the start of work at the site, or if conditions have changed because of natural forces or construction operations at or near the site, it is recommended that this report be reviewed to determine the applicability of the conclusions and recommendations considering the changed conditions and time lapse.

4.3 Groundwater

Groundwater was not encountered in any of our borings, however, fluctuations of groundwater levels at the site are likely and will depend on many factors, including seasonal variations, local precipitation, and flood events. Groundwater is not anticipated to affect the design or construction of the project.

5.0 PAVEMENT DESIGN RECOMMENDATIONS

The performance of a pavement system depends on the type of paving materials and thicknesses, design life, traffic loads and repetitions, and subgrade strength and subgrade drainage characteristics.

The recommended pavement sections were calculated using the methodology described in the California Department of Transportation (CalTrans) Highway Design Manual (Caltrans, 2016a).

This methodology takes into consideration the anticipated traffic loading, type of subgrade soils, and pavement section material properties when calculating a design section. The following sections discuss each of these aspects as they relate to the Campo Road widening pavements.

5.1 Traffic Loading

To estimate a 20-year pavement design life, we used 2014 traffic data accessed from the CalTrans Traffic Census Program (CalTrans, 2016b) to determine the 18-kip Equivalent Single-

Axle Loading (ESAL) values. The traffic index (TI) was calculated from the equivalent single axle loads (ESALs), based on a 20-year design life and traffic data provided by Jacobs and CalTrans. The CalTrans directional annual average daily traffic (AADT) for the roadway is 17,300 with a total truck traffic percentage of 6. The distribution of various truck types (i.e., 2-, 3-, 4-, and 5-axle trucks) measured by CalTrans used for the roadway is listed below:

2-axle trucks = 70.2% 3-axle trucks = 9.3% 4-axle trucks = 4.2% 5-axle trucks = 16.3%

In addition, a linear growth rate of 6.5 percent was assumed for the AADT over the 20-year period, resulting in an ESAL value of approximately 7,790,460 for each traffic lane. The resulting total ESAL was converted to a TI of 11.5. Our estimated ESAL calculations are provided in Appendix D.

5.2 Subgrade Soils

To evaluate existing subgrade strength, a Hveem stabilometer (R-value) test was completed on a bulk sample of representative subgrade materials in accordance with AASHTO T 190. The bulk sample tested of soil encountered in boring SW-1 resulted in an R-value of 36, which we used in our pavement design calculations.

5.3 Pavement Sections

Based on CalTrans pavement design procedures we recommend composite pavement sections consisting of asphalt concrete, base course, and subbase. We recommend the following pavement sections for the proposed project:

Alternative 1: 8.5 inches asphalt concrete over 12 inches base course Alternative 2: 7.5 inches asphalt concrete over 14 inches base course Alternative 3: 6.0 inches asphalt concrete over 6 inches base course over 12 inches subbase

6.0 CONSTRUCTION AND MATERIALS SPECIFICATIONS

The applicability of the design parameters is contingent on good construction practice. Poor construction techniques may alter conditions from those upon which our recommendations are based, and therefore result in poor performance. Our analyses were completed according to CalTrans standards; however, we understand that the project will be constructed according to

Federal Highway Administration (FHWA) Standard Specification for Construction of Roads and Bridges on Federal Highway projects (FP-14) (FHWA, 2014) construction standards. The following sections provide additional construction considerations for this project.

6.1 Earthwork

Site grading and earthwork should be performed in accordance with Sections 200, 250, 300, 400 and 700 of FP-14 and the Project Development and Design Manual (PDDM; FHWA, 2008).

6.1.1 Site Preparation

We recommend that brush and other vegetation be cleared, and roots and stumps be removed from previously undisturbed areas to be graded. Any existing surficial topsoil and soil containing organics should be stripped and removed from areas proposed for new pavement.

The depth of this removal is anticipated to vary, but generally be less than 3 inches. Topsoil and organic-rich soils are not considered suitable for reuse as fill and should be removed from the site or stockpiled for reuse in revegetation.

Undocumented fill was encountered along the alignment and has the potential to contain zones of loose/soft material and deleterious material (e.g., organics). In our opinion placing the pavement sections in areas of undocumented fill could result in poor pavement performance, and if this material is encountered within the pavement widening area it is recommended to remove this material and replace it with properly compacted fill.

6.1.2 Proof-rolling

Prior to filling, the subgrade should be proof-rolled with a fully-loaded, tandem-axle, 10-yard dump truck or equivalent. Areas that are identified as being loose, soft, or yielding during proof-rolling and/or probing should be compacted in place or removed until dense and unyielding subgrade is exposed, then reconditioned or replaced with import fill as described in Section 6.1.3. Care should be taken during proof-rolling and subgrade preparation to avoid disturbing subgrade soils and supporting soils that will remain in place, as they can rut and pump under repeated construction traffic. The final subgrade surface should be sloped to promote positive drainage and kept free of water at all times.

6.1.3 Fill Placement and Compaction

All fill should be compacted to a dense/firm and unyielding condition in accordance with FP-14 Section 204. Import fill should consist of Backfill Material (FP 704.03) with a minimum R-Value of 36. Materials with less fines will be easier to place and compact.

6.2 Paving Materials

The following table summarizes our recommendations for pavement material selection. All specification sections reference the FP-14 U.S. Customary Units (FHWA, 2014) and CalTrans Standard Specifications (CalTrans, 2015).

TABLE 1

RECOMMENDED MATERIALS FOR PAVEMENTS

FP-14

Material CalTrans FP-14

Specification CalTrans

Specification Additional Requirements

Untreated Base Course

(UTBC)

Aggregate Base (AB) Section 301 Division IV

Section 26

• Use FP-14 Gradation C, D, or E

• Minimum R-Value of 78 Aggregate Subbase

(AS) Section 301 Division IV Section 25

• Use FP-14 Gradation A or B

• Minimum R-Value of 40

Hot Asphalt Concrete Pavement

(HACP)

Asphalt Concrete (AC) Section 403 Division V

Section 39

• Aggregate must meet requirements for

ESAL values more than 300,000

Regarding the asphalt binder for HACP, the PDDM requires SuperPave performance grade (PG) binders. The PG binders are chosen based on local weather and anticipated traffic level conditions. Using the PDDM guidelines, 95-percent reliability is required in terms of binder performance. Using a binder within an appropriate temperature and traffic loading range allows for a higher strength and better durability, and improved cohesion will translate into improved long-term performance.

Using the LTPP Bind Program, the minimum required binder for the site is a PG 64-10 (a binder that performs in a temperature range of 64 degrees Celsius to negative 16 degrees Celsius).

Additionally, based on CalTrans, the PG binder typically used in the south coast climatic region is PG 64-10.

7.0 CLOSURE

This report has been prepared for the exclusive use of Jacobs and Central Federal Lands Highway Division for the purpose of providing pavement recommendations for the Campo Road

8.0 REFERENCES

California Department of Transportation (CalTrans), 2016a, Highway Design Manual 6th Edition.

Available from: http://www.dot.ca.gov/hq/oppd/hdm/hdmtoc.htm

California Department of Transportation (CalTrans), 2016b, Traffic Census Program.

http://www.dot.ca.gov/trafficops/census/

California Department of Transportation (CalTrans), 2015, Standard Specifications, State of California Department of Transportation. Available from:

http://www.dot.ca.gov/hq/esc/oe/construction_contract_standards/std_specs/2015_StdSpecs/ 2015_StdSpecs.pdf

Todd, V.R., Alvarez, R.M., and Techni Graphic Systems, Inc., 2004, Preliminary geologic map of the El Cajon 30' X 60' quadrangle, southern California: U.S. Geological Survey, Open-File Report OF-2004-1361, scale 1:100,000.

U.S. Department of Transportation (USDOT), Federal Highway Administration (FHWA), 2008, Federal Lands Highway Project Development and Design Manual (PDDM): U.S.

Department of Transportation and Federal Highway Administration. Available from:

http://flh.fhwa.dot.gov/resources/manuals/pddm/.

U.S. Department of Transportation (USDOT), Federal Highway Administration, 2014, Federal Standard Specifications for Construction of Roads and Bridges on Federal Highway Projects, FP-14 English Units: U.S. Department of Transportation and Federal Highway Administration, available from http://flh.fhwa.dot.gov/resources/pse/specs/.

San Diego

VICINITY MAP

FIG. 1

SHANNON & WILSON, INC.

San Diego Wildlife Refuge

Campo Road Widening

San Diego County, California

Map adapted from aerial imagery provided by

Google Earth Pro, reproduced by permission granted by Google Earth ™ Mapping Service.

NOTE

Approximate Scale in Miles

2 4

September 2019 23-1-01458-040

F i l e n a m e

I E

F

D

E N s

J a c o b s

C

F L

C a m p o

R o a d D r a f t i n g F d w g

D a t e

L o g i n j c g

MT

PROJECT

LOCATION

California

SACRAMENTO

El Centro

San

Diego

Los

Angeles

San

Francisco

Project

Location

SW-3

SW-1

SW-2

Filename: I:\EF\23-1 DEN\01400s\01458 Jacobs CFL\040 Campo Road\Drafting\01458-040_F2.dwg Date: 09-27-2016 Login: jcg

F I G

September 2019 23-1-01458-040

SITE AND

EXPLORATION PLAN

FIG. 2

1. Map adapted from aerial imagery provided by

Google Earth Pro, reproduced by permission granted by Google Earth ™ Mapping Service.

2. The hole location was measured from existing site features and should be considered approximate.

NOTES

Boring Designation and

Approximate Location

LEGEND

SW-1

150 300

Scale in Feet

San Diego Wildlife Refuge

Campo Road Widening

San Diego County, California

M i l l r

R n c h

R o d

APPENDIX A

SUBSURFACE EXPLORATIONS

23-1-01458-040_R1_AA 23-1-01458-040

A-i

A.1 INTRODUCTION .......................................................................................................... A-1

A.2 BORINGS ....................................................................................................................... A-1 A.2.1 Standard Penetration Test ................................................................................. A-1 A.2.2 Soil Classification System ................................................................................ A-2

FIGURES

A-1 Soil Description and Log Key (3 sheets) A-2 Log of Boring SW-1 A-3 Log of Boring SW-2 A-4 Log of Boring SW-3 A-5 Pavement Core Photograph Boring SW-1 A-6 Pavement Core Photograph Boring SW-2 A-7 Pavement Core Photograph Boring SW-3

A-1

A.1 INTRODUCTION

The field exploration program consisted of drilling and sampling three geotechnical borings on August 23 and 24, 2016. The borings were designated SW-1 through SW-3. Locations of the explorations are shown on Figure 2. A representative from Shannon & Wilson observed the drilling and sampling operations, retrieved representative samples for laboratory testing, and prepared descriptive field logs of the explorations. The methods used to conduct the field exploration program are described below.

A.2 BORINGS

The drilling was coordinated (including subcontractor coordination and utility locates) and observed by our field representative. Individual boring logs are presented in Figures A-2 through A-4. These logs represent our interpretation of the subsurface conditions encountered and the results of laboratory testing. The borings were drilled by Pacific Drilling of San Diego, California (under subcontract to Shannon & Wilson) using a truck-mounted drill rig and hollow-stem auger techniques. All borings were backfilled with drill cuttings and patched with cold-patch asphalt per the CalTrans inspector’s recommendations.

A.2.1 Standard Penetration Test

Disturbed samples were obtained in the borings in general accordance with the Standard Penetration Test (SPT) ASTM International (ASTM) Designation: D 1586. The SPT consists of driving a 2-inch outside diameter (O.D.), 1.375-inch inside diameter (I.D.) split-spoon sampler a distance of 18 inches with a 140-pound hammer free-falling a distance of 30 inches. An automatic hammer system was used to advance the samplers. During sampling, the Shannon & Wilson field representative recorded the number of blows for each 6-inch increment of penetration and summed the blow counts for the last two 6-inch increments. This sum is recorded as the penetration resistance number, or N-value. The N-values provide a means for evaluating the relative density or compactness of cohesionless (granular) soils and consistency or stiffness of cohesive (fine-grained) soils (see Figure A-1). The N-values are shown on the individual boring logs.

A-2

A.2.2 Soil Classification System

During drilling, the Shannon & Wilson representative collected soil samples and prepared a field log of each boring. Soil classifications were based on ASTM International (ASTM) Designation: D 2487, Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System), and ASTM Designation: D 2488, Standard Practice for Description and Identification of Soils (Visual-Manual Procedure). The system is referred to as the Unified Soil Classification System and is summarized on Figure A-1.

Campo Road Widening

San Diego County, California

23-1-01458-040September 2019

Geotechnical and Environmental Consultants

Absence of moisture, dusty, dry to the touch

Damp but no visible water

Visible free water, from below water table

FIG. A-1

Shannon & Wilson, Inc. (S&W), uses a soil identification system modified from the Unified Soil Classification System (USCS). Elements of the USCS and other definitions are provided on this and the following pages. Soil descriptions are based on visual-manual procedures (ASTM D2488) and laboratory testing procedures (ASTM D2487), if performed.

STANDARD PENETRATION TEST (SPT)

SPECIFICATIONS

Hammer:

Sampler:

N-Value:

Dry

Moist

Wet

MOISTURE CONTENT TERMS

Modifying (Secondary)

Precedes major constituent

Major

Minor Follows major constituent

1All percentages are by weight of total specimen passing a 3-inch sieve.

2The order of terms is: Modifying Major with Minor.

3Determined based on behavior.

4Determined based on which constituent comprises a larger percentage.

5Whichever is the lesser constituent.

COARSE-GRAINED

SOILS

(less than 50% fines)1

NOTE: Penetration resistances (N-values) shown on boring logs are as recorded in the field and have not been corrected for hammer efficiency, overburden, or other factors.

PARTICLE SIZE DEFINITIONS

RELATIVE DENSITY / CONSISTENCY

Sand or Gravel 4

30% or more coarse-grained:

Sandy or Gravelly 4

More than 12% fine-grained:

Silty or Clayey 3

15% to 30% coarse-grained:

with Sand or with Gravel 4

30% or more total coarse-grained and lesser coarse-grained constituent is 15% or more:

with Sand or with Gravel 5

Very soft Soft Medium stiff Stiff Very stiff Hard

Very loose Loose Medium dense Dense Very dense

RELATIVE

DENSITY

FINE-GRAINED SOILS

(50% or more fines)1

COHESIVE SOILS

< 2 2 - 4 4 - 8

8 - 15 15 - 30

> 30

1Gravel, sand, and fines estimated by mass. Other constituents, such as organics, cobbles, and boulders, estimated by volume.

2Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual-Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428.

A copy of the complete standard may be obtained from ASTM International, www.astm.org.

140 pounds with a 30-inch free fall.

Rope on 6- to 10-inch-diam. cathead 2-1/4 rope turns, > 100 rpm

NOTE: If automatic hammers are used, blow counts shown on boring logs should be adjusted to account for efficiency of hammer.

10 to 30 inches long Shoe I.D. = 1.375 inches Barrel I.D. = 1.5 inches Barrel O.D. = 2 inches

Sum blow counts for second and third 6-inch increments.

Refusal: 50 blows for 6 inches or less; 10 blows for 0 inches.

RELATIVE

CONSISTENCY

N, SPT,

BLOWS/FT.

5% to 12% fine-grained:

with Silt or with Clay 3

15% or more of a second coarse-grained constituent:

with Sand or with Gravel 5

< 5%

5 to 10%

15 to 25%

30 to 45%

50 to 100%

Surface Cement Seal

Asphalt or Cap

Slough

Inclinometer or Non-perforated Casing

Vibrating Wire Piezometer

N, SPT,

BLOWS/FT.

< 4 4 - 10

10 - 30 30 - 50

> 50

DESCRIPTION

< #200 (0.075 mm = 0.003 in.)

#200 to #40 (0.075 to 0.4 mm; 0.003 to 0.02 in.)

#40 to #10 (0.4 to 2 mm; 0.02 to 0.08 in.)

#10 to #4 (2 to 4.75 mm; 0.08 to 0.187 in.)

SIEVE NUMBER AND/OR APPROXIMATE SIZE

#4 to 3/4 in. (4.75 to 19 mm; 0.187 to 0.75 in.)

3/4 to 3 in. (19 to 76 mm)

3 to 12 in. (76 to 305 mm)

> 12 in. (305 mm)

Fine Coarse

Fine Medium Coarse

BOULDERS

COBBLES

GRAVEL

FINES

SAND

Sheet 1 of 3

S&W INORGANIC SOIL CONSTITUENT DEFINITIONS

CONSTITUENT2

COHESIONLESS SOILS

Silt, Lean Clay, Elastic Silt, or

Fat Clay 3

PERCENTAGES TERMS 1, 2

Trace

Few

Little

Some

Mostly

WELL AND BACKFILL SYMBOLS

Bentonite Cement Grout

Bentonite Grout

Bentonite Chips

Silica Sand

Perforated or Screened Casing

SHANNON & WILSON, INC.

SOIL DESCRIPTION

AND LOG KEY

_B O

R

IN

G _C

LA

S

S

3-

1-

8-

C

A M

P O

R D

.G P

J S

W N

E W

.G D

T

/2 6/

Campo Road Widening

San Diego County, California

September 2019

GC

SC

Inorganic

Organic

(more than 50% of coarse fraction retained on No. 4 sieve)

MAJOR DIVISIONS GROUP/GRAPHIC

SYMBOL

CH

OH

ML

CL

TYPICAL IDENTIFICATIONS

Gravel

Sand

Silty Sand; Silty Sand with Gravel

Clayey Sand; Clayey Sand with Gravel

Clayey Gravel; Clayey Gravel with Sand

Sheet 2 of 3

Gravels

Primarily organic matter, dark in color, and organic odor

SW

(more than 12% fines)

Silts and Clays

Silts and Clays

(more than 50% retained on No.

200 sieve)

(50% or more of coarse fraction passes the No. 4 sieve)

(liquid limit less than 50)

(liquid limit 50 or more)

Organic

Inorganic

FINE-GRAINED

SOILS

SM

Sands

Silty or Clayey Gravel

Silt; Silt with Sand or Gravel; Sandy or Gravelly Silt

Organic Silt or Clay; Organic Silt or Clay with Sand or Gravel; Sandy or Gravelly Organic Silt or Clay

HIGHLY-

ORGANIC

SOILS

COARSE-

GRAINED

SOILS

GW

Geotechnical and Environmental Consultants

SHANNON & WILSON, INC.

(less than 5% fines)

PT

(more than 12% fines)

MH

SP

GP

GM

Silty or Clayey Sand

Silty Gravel; Silty Gravel with Sand

(50% or more passes the No.

200 sieve)

SOIL DESCRIPTION

AND LOG KEY

Elastic Silt; Elastic Silt with Sand or Gravel; Sandy or Gravelly Elastic Silt

Fat Clay; Fat Clay with Sand or Gravel;

Sandy or Gravelly Fat Clay

Organic Silt or Clay; Organic Silt or Clay with Sand or Gravel; Sandy or Gravelly Organic Silt or Clay

Poorly Graded Sand; Poorly Graded Sand with Gravel

Well-Graded Sand; Well-Graded Sand with Gravel

Well-Graded Gravel; Well-Graded Gravel with Sand

Poorly Graded Gravel; Poorly Graded Gravel with Sand

Lean Clay; Lean Clay with Sand or Gravel; Sandy or Gravelly Lean Clay

NOTES

1. Dual symbols (symbols separated by a hyphen, i.e., SP-SM, Sand with Silt) are used for soils with between 5% and 12% fines or when the liquid limit and plasticity index values plot in the CL-ML area of the plasticity chart. Graphics shown on the logs for these soil types are a combination of the two graphic symbols (e.g., SP and SM).

2. Borderline symbols (symbols separated by a slash, i.e., CL/ML, Lean Clay to Silt; SP-SM/SM, Sand with Silt to Silty Sand) indicate that the soil properties are close to the defining boundary between two groups.

Peat or other highly organic soils (see

ASTM D4427)

FIG. A-1

OL

(less than 5% fines)

_B O

R

IN

G _C

LA

S

S

3-

1-

8-

C

A M

P O

R D

.G P

J S

W N

E W

.G D

T

/2 6/

NOTE: No. 4 size = 4.75 mm = 0.187 in.; No. 200 size = 0.075 mm = 0.003 in.

UNIFIED SOIL CLASSIFICATION SYSTEM (USCS)

(Modified From USACE Tech Memo 3-357, ASTM D2487, and ASTM D2488)

Campo Road Widening

San Diego County, California

September 2019

Angular

Subangular

Subrounded

Rounded

Flat

Elongated

Sharp edges and unpolished planar surfaces.

Similar to angular, but with rounded edges.

Nearly planar sides with well-rounded edges.

Smoothly curved sides with no edges.

Width/thickness ratio > 3.

Length/width ratio > 3.

Narrow range of grain sizes present or, within the range of grain sizes present, one or more sizes are missing (Gap Graded). Meets criteria in ASTM D2487, if tested.

Full range and even distribution of grain sizes present. Meets criteria in ASTM D2487, if tested.

Crumbles or breaks with handling or slight finger pressure Crumbles or breaks with considerable finger pressure Will not crumble or break with finger pressure

Weak

Moderate

Strong

VISUAL-MANUAL CRITERIA

A 1/8-in. thread cannot be rolled at any water content.

A thread can barely be rolled and a lump cannot be formed when drier than the plastic limit.

A thread is easy to roll and not much time is required to reach the plastic limit. The thread cannot be rerolled after reaching the plastic limit. A lump crumbles when drier than the plastic limit.

It take considerable time rolling and kneading to reach the plastic limit. A thread can be rerolled several times after reaching the plastic limit. A lump can be formed without crumbling when drier than the plastic limit.

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants Sheet 3 of 3

Interbedded

Laminated

Fissured

Slickensided

Blocky

Lensed

Homogeneous

Alternating layers of varying material or color with layers at least 1/4-inch thick; singular: bed.

Alternating layers of varying material or color with layers less than 1/4-inch thick; singular:

lamination.

Breaks along definite planes or fractures with little resistance.

Fracture planes appear polished or glossy;

sometimes striated.

Cohesive soil that can be broken down into small angular lumps that resist further breakdown.

Inclusion of small pockets of different soils, such as small lenses of sand scattered through a mass of clay.

Same color and appearance throughout.

At Time of Drilling Diameter Elevation Feet Iron Oxide Gallons Horizontal Hollow Stem Auger Inside Diameter Inches Pounds Magnesium Oxide Millimeter Manganese Oxide Not Applicable or Not Available Nonplastic Outside Diameter Observation Well Pounds per Cubic Foot Photo-Ionization Detector Pressuremeter Test Parts per Million Pounds per Square Inch Polyvinyl Chloride Rotations per Minute Standard Penetration Test Unified Soil Classification System Unconfined Compressive Strength Vibrating Wire Piezometer Vertical Weight of Hammer Weight of Rods Weight

ATD

Diam.

Elev.

ft.

FeO gal.

Horiz.

HSA

I.D.

in.

lbs.

MgO mm

MnO

NA

NP

O.D.

OW

pcf

PID

PMT

ppm psi

PVC

rpm

SPT

USCS

qu

VWP

Vert.

WOH

WOR

Wt.

STRUCTURE TERMS1

SOIL DESCRIPTION

AND LOG KEY

1Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual-Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM International, www.astm.org.

2Adapted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual-Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM International, www.astm.org.

ACRONYMS AND ABBREVIATIONS

Poorly Graded

Well-Graded

Irregular patches of different colors.

Soil disturbance or mixing by plants or animals.

Nonsorted sediment; sand and gravel in silt and/or clay matrix.

Material brought to surface by drilling.

Material that caved from sides of borehole.

Disturbed texture, mix of strengths.

Mottled

Bioturbated

Diamict

Cuttings

Slough

Sheared

DESCRIPTION

Nonplastic

Low

Medium

High

ADDITIONAL TERMS

PLASTICITY2

CEMENTATION TERMS1

GRADATION TERMS

APPROX.

PLASITICTY

INDEX

RANGE

< 4

4 to 10

10 to 20

> 20

PARTICLE ANGULARITY AND SHAPE TERMS1

FIG. A-1

_B O

R

IN

G _C

LA

S

S

3-

1-

8-

C

A M

P O

R D

.G P

J S

W N

E W

.G D

T

/2 6/

5.5 inches of asphalt concrete.

Aggregate base course.

Medium dense, dark brown, Clayey Sand (SC);

moist; trace to few gravel; pieces of asphalt concrete.

Fill

- Auger refusal at 5.5 feet.

BOTTOM OF BORING

COMPLETED ON 8/23/2016

B-1 S-1

S-2

S-3

G ro un dw at er n ot e nc ou nt er e d du ri ng d ri lli ng

0.5

0.9

5.6

SHANNON & WILSON, INC.

5.5 ft.

REV 3

FIG. A-2

S am pl es

6 in.

AWJ

Automatic

S ym bo l

Refer to the report text for a proper understanding of the subsurface materials and drilling methods. The stratification lines indicated below represent the approximate boundaries between material types, and the transition may be gradual.

SOIL DESCRIPTION

NOTES

1. Refer to Figure A-1 for explanation of symbols, codes, abbreviations and definitions.

2. Groundwater level, if indicated above, is for the date specified and may vary.

3. USCS designation is based on visual-manual classification and selected lab testing.

San Diego Wildlife Refuge Campo Road Widening

San Diego County, California

0 60

Total Depth:

Top Elevation:

Vert. Datum:

Horiz. Datum:

20 40

Geotechnical and Environmental Consultants

23-1-01458-040

Hollow-Stem Auger Pacific Drilling Diedrich D-50

LEGEND

Drilling Method:

Drilling Company:

Drill Rig Equipment:

Other Comments:

LOG OF BORING SW-1

September 2019

Sample Not Recovered

Hole Diam.:

Rod Type.:

Hammer Type:

G ro un d

W at er

D ep th , f t.

Grab Sample

Standard Penetration Test

D ep th , f t.

Latitude:

Longitude:

Station:

Offset:

20 40

M A

S T

E R

_L O

G _E

_P O

C K

E T

P E

N _L

A T

LO

N G

3-

1-

-0

C

A M

P O

R D

.G P

J

/2 8/

PENETRATION RESISTANCE

Hammer Wt. & Drop: 140 lbs / 30 inches

(blows/foot)

Plastic Limit

(<0.075mm)

Liquid Limit Natural Water Content

% Fines % Water Content

67/8"

50/1"

6.75 inches of asphalt concrete.

Aggregate base course.

Medium dense, black, Silty Sand (SM); moist, hydrocarbon odor.

Fill

Medium dense, red-brown, Clayey Sand (SC);

moist, hydrocarbon odor.

Fill

Medium dense, red-brown to yellow-brown, Clayey Sand (SC) to stiff, Sandy Lean Clay (CL); moist.

Alluvium

- Hard drilling encountered at 7.0 feet, color change in cuttings from red-brown to yellow-brown.

BOTTOM OF BORING

COMPLETED ON 8/24/2016

B-1 S-1

S-2

S-3 *

G ro un dw at er n ot e nc ou nt er e d du ri ng d ri lli ng

0.5

1.2

3.0

4.0

9.1

SHANNON & WILSON, INC.

9.1 ft.

REV 3

FIG. A-3

S am pl es

6 in.

AWJ

Automatic

S ym bo l

Refer to the report text for a proper understanding of the subsurface materials and drilling methods. The stratification lines indicated below represent the approximate boundaries between material types, and the transition may be gradual.

SOIL DESCRIPTION

NOTES

1. Refer to Figure A-1 for explanation of symbols, codes, abbreviations and definitions.

2. Groundwater level, if indicated above, is for the date specified and may vary.

3. USCS designation is based on visual-manual classification and selected lab testing.

San Diego Wildlife Refuge Campo Road Widening

San Diego County, California

0 60

Total Depth:

Top Elevation:

Vert. Datum:

Horiz. Datum:

20 40

Geotechnical and Environmental Consultants

23-1-01458-040

Hollow-Stem Auger Pacific Drilling Diedrich D-50

LEGEND

Drilling Method:

Drilling Company:

Drill Rig Equipment:

Other Comments:

LOG OF BORING SW-2

September 2019

Sample Not Recovered

Hole Diam.:

Rod Type.:

Hammer Type:

G ro un d

W at er

D ep th , f t.

Grab Sample

Standard Penetration Test

D ep th , f t.

Latitude:

Longitude:

Station:

Offset:

20 40

M A

S T

E R

_L O

G _E

_P O

C K

E T

P E

N _L

A T

LO

N G

3-

1-

-0

C

A M

P O

R D

.G P

J

/2 8/

PENETRATION RESISTANCE

Hammer Wt. & Drop: 140 lbs / 30 inches

(blows/foot)

Plastic Limit

(<0.075mm)

Liquid Limit Natural Water Content

% Fines % Water Content

50/1"

4.5 inches of asphalt concrete.

12 inches of concrete.

Very dense, light brown to brown, Silty Sand (SM) to Clayey Sand (SC); moist; trace to few gravel.

Alluvium

Very dense, red-yellow, Silty Sand (SM); moist;

trace gravel.

Alluvium

Hard, yellow, Sandy Fat Clay (CH); moist.

Alluvium

BOTTOM OF BORING

COMPLETED ON 8/24/2016

B-1 S-1

S-2

S-3

G ro un dw at er n ot e nc ou nt er e d du ri ng d ri lli ng

0.4

1.4

4.0

8.0

8.5

SHANNON & WILSON, INC.

8.5 ft.

REV 3

FIG. A-4

S am pl es

6 in.

AWJ

Automatic

S ym bo l

Refer to the report text for a proper understanding of the subsurface materials and drilling methods. The stratification lines indicated below represent the approximate boundaries between material types, and the transition may be gradual.

SOIL DESCRIPTION

NOTES

1. Refer to Figure A-1 for explanation of symbols, codes, abbreviations and definitions.

2. Groundwater level, if indicated above, is for the date specified and may vary.

3. USCS designation is based on visual-manual classification and selected lab testing.

San Diego Wildlife Refuge Campo Road Widening

San Diego County, California

0 60

Total Depth:

Top Elevation:

Vert. Datum:

Horiz. Datum:

20 40

Geotechnical and Environmental Consultants

23-1-01458-040

Hollow-Stem Auger Pacific Drilling Diedrich D-50

LEGEND

Drilling Method:

Drilling Company:

Drill Rig Equipment:

Other Comments:

LOG OF BORING SW-3

September 2019

Sample Not Recovered

Hole Diam.:

Rod Type.:

Hammer Type:

G ro un d

W at er

D ep th , f t.

Grab Sample

Standard Penetration Test

D ep th , f t.

Latitude:

Longitude:

Station:

Offset:

20 40

M A

S T

E R

_L O

G _E

_P O

C K

E T

P E

N _L

A T

LO

N G

3-

1-

-0

C

A M

P O

R D

.G P

J

/2 8/

PENETRATION RESISTANCE

Hammer Wt. & Drop: 140 lbs / 30 inches

(blows/foot)

Plastic Limit

(<0.075mm)

Liquid Limit Natural Water Content

% Fines % Water Content

68/11"

Pavement Core at SW-1 Eastbound Lane, 5.5 inches Measured

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

San Diego Wildlife Refuge Campo Road Widening

San Diego County, California

PAVEMENT CORE PHOTOGRAPH

BORING SW-1

September 2019 23-1-01458-040

FIG. A-5

Pavement Core at SW-2 Eastbound Lane, 6.75 inches Measured

San Diego Wildlife Refuge Campo Road Widening

San Diego County, California

PAVEMENT CORE PHOTOGRAPH

BORING SW-2

September 2019 23-1-01458-040

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

FIG. A-6

FIG. A-7

Pavement Core at SW-3 Eastbound Lane, 4.5 inches Measured

San Diego Wildlife Refuge Campo Road Widening

San Diego County, California

PAVEMENT CORE PHOTOGRAPH

BORING SW-3

APPENDIX B

LABORATORY TEST RESULTS

23-1-01458-040_R1_AB.docx 23-1-01458-040 B-i

B.1 INTRODUCTION ...........................................................................................................B-1

B.2 WATER CONTENT ........................................................................................................B-1

B.3 GRADATION ..................................................................................................................B-1

B.4 ATTERBERG LIMITS ....................................................................................................B-1

B.5 R-VALUE ........................................................................................................................B-2

TABLE

B-1 Summary of Laboratory Test Results by Boring

FIGURES

B-1 Grain Size Distribution B-2 Plasticity Chart B-3 R-Value Test Data, Boring SW-1, Bulk Sample, 0.5 to 5.0 ft

B-1

B.1 INTRODUCTION

Laboratory tests were completed on soil samples retrieved from the borings in general accordance with AASHTO testing methods. The laboratory testing program was performed to classify the materials into similar geologic groups and provide data that can be used for design of the project. The laboratory testing was completed by AP Engineering and Testing, Inc. of Pomona, California. The testing program included index tests and geotechnical engineering property tests. A summary of the laboratory test results is presented in Table B-1. The following sections describe the laboratory testing procedures.

B.2 WATER CONTENT

Water content was determined for most of the samples retrieved from the borings in general accordance with AASHTO T 265, Laboratory Determination of Moisture Content of Soils. To perform this test, a sample was weighed before and after oven-drying, and the water content was calculated. Water contents are shown graphically on the boring logs presented in Appendix A and are also summarized in Table B-1.

B.3 GRADATION

The grain size distribution of selected samples was determined in general accordance with AASHTO T 27, Standard Method of Test for Sieve Analysis of Fine and Coarse Aggregates.

Results of these analyses are presented as grain size distribution curves on Figure B-1. The percent fines (silt and clay-sized particles passing the No. 200 sieve) are shown graphically on boring logs in Appendix A and are also summarized in Table B-1.

B.4 ATTERBERG LIMITS

Soil plasticity was determined by performing liquid and plastic Atterberg limits tests on selected samples. The tests were performed in general accordance with AASHTO T 89, Determining the Liquid Limit of Soils and AASHTO T 90, Determining the Plastic Limit and Plasticity Index of Soils. The Atterberg limits include liquid limit (LL), plastic limit (PL), and plasticity index (PI equals LL minus PL) and are generally used to assist in classification of soils, to indicate soil consistency (when compared to natural water content), and to provide correlation to soil properties. The results of the Atterberg limits tests are plotted on plasticity chart on Figure B-2, shown graphically on the boring logs in Appendix A, and summarized in Table B-1.

B-2

B.5 R-VALUE

Hveem Stabilometer (R-value) tests were completed to evaluate the stiffness of soils that may be used in the subgrade of the roadway. Bulk samples collected from the borings were used for the tests. The test was completed in accordance with AASHTO T 190, Standard Test Method for Resistance R-Value and Expansion Pressure of Compacted Soils. The R-value test results are presented as Figure B-3 and summarized in Table B-1.

TABLE B-1

SUMMARY OF LABORATORY TEST RESULTS BY BORING

SHANNON & WILSON, INC.

23-1-01458-040_T1.xlsx/wp/lmr Sheet 1 of 1 23-1-01458-040

G ra ve l

Sa nd

Fi ne s

L iq ui d

L im it

Pl as tic L im it

Pl as tic ity

In de x

R -V al ue

E xu da tio n Pr es su re

Top Bottom (%) (%) (%) (%) (%) (%) (%) (psi) S-1A 2.0 2.7 13.1 S-1C 3.1 3.5 10.8

B-1 0.5 5.0 SC A-2-6 7.1 7 69 24 25 13 12 36 300

S-1B 3.0 3.5 7.9

S-2 4.0 5.5 SC A-6 10.8 0 50 50 24 11 13

S-2 4.0 4.9 9.2 S-3 7.0 8.5 18.7

B-1 1.5 4.0 SC A-2-6 6.2 12 55 33 28 12 16

Notes:

1. Refer to Appendix A, Figure A-1 for definitions.

2. Gravel defined as particles larger than the No. 4 sieve size, Sand as particles between the No. 4 and No. 200 sieve sizes, and Fines as particles passing the No. 200 sieve.

R-Value

SW-1

SW-2

SW-3

Sample Depth (feet)

ATTERBERG LIMITS

N at ur al

M oi st ur e C on te nt

U

SC

S Sy m bo l(1

)SAMPLE DATA

Boring

GRAIN-SIZE ANALYSES(2)

A A

SH

T

O C la ss ifi ca tio n

12 20

.0

NAT.

W.C. %

FINE

GRAIN SIZE IN MILLIMETERS

.0

1/

.0 6.8

.0

LL

.0

.0

.0

2.8

4.8

2.8

DEPTH

(feet) San Diego Wildlife Refuge

Campo Road Widening San Diego County, California

.1

.0

September 2019

.0

COBBLES

.4

1/

GRAIN SIZE DISTRIBUTION

SW-1, B-1

SW-2, S-2

SW-3, B-1

SAMPLE ID

Geotechnical and Environmental Consultants

.6

SHANNON & WILSON, INC.

.0

PI

.0

P E

R C

E N

T C

O A

R S

E R

B Y

W E

IG

H

T

.0

.0

6 4

P E

R C

E N

T F

IN

E

R B

Y W

E

IG

H T

PL

3/

SC

SC

SC

Clayey Sand; few gravel. [A-2-6]

Clayey Sand [A-6]

Clayey Sand; few gravel. [A-2-6]

7.1

10.8

6.2

COARSE MEDIUM

GRAVEL

.3

2 1

5/

HYDROMETER ANALYSIS

3/

U.S.C.S.

SYMBOL

.0

1/

.0

SAND

FINES

Jacobs

SIZE OF MESH OPENING IN INCHES

.0

.0

.0

SIEVE ANALYSIS

.0

.2

.0

GRAIN SIZE IN MILLIMETERS

23-1-01458-040

G S

A _M

A

IN

23-1 -01

458-040 - C A

M P

O R

D .G

P J C

LO

N

E F

R O

M T

H

IS

P R

O

JE

C T

.G P

J 9/27/1

.0

.0

FINES: SILT OR CLAY

NO. OF MESH OPENINGS PER INCH, U.S. STANDARD

FIG. B-1

SAMPLE

DESCRIPTION

COARSE FINE

.0

FIG

. B

-1

0 10 20 30 40 50 60 70 80 90 100 110

LIQUID LIMIT - LL (%)

PI

A T

T _M

A

IN

23-1-01 458-040 - C

A M

P O

R D

.G P

J S H

A N

_W

IL.G

D T

9/2 7/16

PL

LL

Jacobs

Clayey Sand; few gravel. [A-2-6]

Clayey Sand [A-6]

Clayey Sand; few gravel. [A-2-6]

FIG. B-2

CL-ML MH or OH

NAT.

W.C. %

SOIL

CLASSIFICATION

SW-1, B-1

SW-2, S-2

SW-3, B-1

23-1-01458-040September 2019

CL:

CH:

ML or OL:

MH or OH:

CL-ML:

PASS.

#200, %

CHCL

ML or OL

P

LA

S T

IC

IT

Y I

N D

E X

P

I

SC

SC

SC

U.S.C.S.

SYMBOL

LEGEND

Low plasticity inorganic clays; sandy and silty clays

High plasticity inorganic clays

Inorganic and organic silts and clayey silts of low plasticity

Inorganic and organic silts and clayey silts of high plasticity

Silty clays and clayey silts

SAMPLE ID

2.8

4.8

2.8

DEPTH

(feet)

FIG

. B

-2 SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

7.1

10.8

6.2

San Diego Wildlife Refuge Campo Road Widening

San Diego County, California

PLASTICITY CHART

28 33

Project Name: Campo Road Project Number: 23-1-01458-040 Boring No.: SW-1 Sample Type: B-1 Depth: 5.5"-5' Location: N/A Soil Description: Clayey Sand w/gravel

Mold Number G I H Water Added, g 30 15 0 Compact Moisture(%) 10.9 9.3 7.7 Compaction Gage Pressure, psi 70 90 350 Exudation Pressure, psi 120 268 721 Sample Height, Inches 2.4 2.3 2.3 Gross Weight Mold, g 2882 2882 2846 Tare Weight Mold, g 1828 1837 1819 Net Sample Weight, g 1054 1045 1027 Expansion, inchesx10-4 0 1 0 Stability 2,000 (160 psi) 48/120 33/79 10/16 Turns Displacement 4.42 4.34 4.12 R-Value Uncorrected 16 37 85 R-Value Corrected 15 32 84 Dry Density, pcf 120.0 126.0 125.5 Traffic Index 8.0 8.0 8.0 G.E. by Stability 1.62 1.29 0.32 G.E. by Expansion 0.00 0.03 0.00

Gf = 1.34, and 0.0 % Retained on the ¾"

*Not ApplicableR em ar ks

By Exudation:

By Expansion:

R -V

AL

U

E

*N/A

R-VALUE TEST DATA

AASHTO T 190

Tested By:

Computed By: 09/09/16

Date:

Date:

Date:

09/07/16

09/14/16Checked By:

ST

KM

AP

0100200300400500600700800

R -V

A

LU

E

EXUDATION PRESSURE - PSI

0.00

1.00

2.00

3.00

4.00

0.00 1.00 2.00 3.00 4.00

C O

V E

R T

H

IC

K N

E S

S B

Y S

TA

B

IL

O

M E

TE

R

(F T.

COVER THICKNESS BY EXPANSION (FT.)

FIG. B-3

APPENDIX C

EXPLORATION PHOTOGRAPHS

23-1-01458-040_R1_AC.docx 23-1-01458-040 C-i

APPENDIX C

EXPLORATION PHOTOGRAPHS

TABLE OF CONTENTS

FIGURES

C-1 Exploration Photograph Boring SW-1 C-2 Exploration Photograph Boring SW-2 C-3 Exploration Photograph Boring SW-3

San Diego Wildlife Refuge Campo Road Widening

San Diego County, California

EXPLORATION PHOTOGRAPH

BORING SW-1

FIG. C-1

FIG. C-2

San Diego Wildlife Refuge Campo Road Widening

San Diego County, California

EXPLORATION PHOTOGRAPH

BORING SW-2

FIG. C-3

San Diego Wildlife Refuge Campo Road Widening

San Diego County, California

EXPLORATION PHOTOGRAPH

BORING SW-3

APPENDIX D

PAVEMENT DESIGN CALCULATIONS

23-1-01458-040_R1_AD.docx 23-1-01458-040 D-i

APPENDIX D

PAVEMENT DESIGN CALCULATIONS

TABLE OF CONTENTS

ATTACHMENTS

Calc. No. 1 – Campo Road, Pavement Design (15 Pages)

APPENDIX E

IMPORTANT INFORMATION ABOUT YOUR

GEOTECHNICAL/ENVIRONMENTAL REPORT

Page 1 of 2 1/2015

Geotechnical and Environmental Consultants

Attachment to and part of Report 23-1-01458-040

Date: September, 2019

To: Mr. Berwyn Wilbrink Jacobs Engineering Group Inc.

IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL/ENVIRONMENTAL

REPORT

CONSULTING SERVICES ARE PERFORMED FOR SPECIFIC PURPOSES AND FOR SPECIFIC CLIENTS.

Consultants prepare reports to meet the specific needs of specific individuals. A report prepared for a civil engineer may not be adequate for a construction contractor or even another civil engineer. Unless indicated otherwise, your consultant prepared your report expressly for you and expressly for the purposes you indicated. No one other than you should apply this report for its intended purpose without first conferring with the consultant. No party should apply this report for any purpose other than that originally contemplated without first conferring with the consultant.

THE CONSULTANT'S REPORT IS BASED ON PROJECT-SPECIFIC FACTORS.

A geotechnical/environmental report is based on a subsurface exploration plan designed to consider a unique set of project-specific factors. Depending on the project, these may include: the general nature of the structure and property involved; its size and configuration; its historical use and practice; the location of the structure on the site and its orientation; other improvements such as access roads, parking lots, and underground utilities; and the additional risk created by scope-of-service limitations imposed by the client. To help avoid costly problems, ask the consultant to evaluate how any factors that change subsequent to the date of the report may affect the recommendations. Unless your consultant indicates otherwise, your report should not be used: (1) when the nature of the proposed project is changed (for example, if an office building will be erected instead of a parking garage, or if a refrigerated warehouse will be built instead of an unrefrigerated one, or chemicals are discovered on or near the site); (2) when the size, elevation, or configuration of the proposed project is altered; (3) when the location or orientation of the proposed project is modified; (4) when there is a change of ownership; or (5) for application to an adjacent site. Consultants cannot accept responsibility for problems that may occur if they are not consulted after factors which were considered in the development of the report have changed.

SUBSURFACE CONDITIONS CAN CHANGE.

Subsurface conditions may be affected as a result of natural processes or human activity. Because a geotechnical/environmental report is based on conditions that existed at the time of subsurface exploration, construction decisions should not be based on a report whose adequacy may have been affected by time. Ask the consultant to advise if additional tests are desirable before construction starts; for example, groundwater conditions commonly vary seasonally.

Construction operations at or adjacent to the site and natural events such as floods, earthquakes, or groundwater fluctuations may also affect subsurface conditions and, thus, the continuing adequacy of a geotechnical/environmental report. The consultant should be kept apprised of any such events, and should be consulted to determine if additional tests are necessary.

MOST RECOMMENDATIONS ARE PROFESSIONAL JUDGMENTS.

Site exploration and testing identifies actual surface and subsurface conditions only at those points where samples are taken. The data were extrapolated by your consultant, who then applied judgment to render an opinion about overall subsurface conditions. The actual interface between materials may be far more gradual or abrupt than your report indicates. Actual conditions in areas not sampled may differ from those predicted in your report. While nothing can be done to prevent such situations, you and your consultant can work together to help reduce their impacts. Retaining your consultant to observe subsurface construction operations can be particularly beneficial in this respect.

Page 2 of 2 1/2015

A REPORT'S CONCLUSIONS ARE PRELIMINARY.

The conclusions contained in your consultant's report are preliminary because they must be based on the assumption that conditions revealed through selective exploratory sampling are indicative of actual conditions throughout a site. Actual subsurface conditions can be discerned only during earthwork; therefore, you should retain your consultant to observe actual conditions and to provide conclusions.