HomeMy WebLinkAboutCT 11-04; Quarry Creek; Foundation Report; 2014-08-21FOUNDATION REPORT
QUARRY CREEK BRIDGE
CARLSBAD, CALIFORNIA
PREPARED FOR
THE CORKY MCMILLIN COMPANIES
SAN DIEGO, CALIFORNIA
AUGUST 21, 2014
PROJECT NO. 07135-42-04A
GROCON
INCORPORATED
GEOTECHNICAL • ENVIRONMENTAL MATERIALSO
6960 Flanders Drive • San Diego, California 92121-2974 • Telephone 858.558.6900 • Fax 858.558.6159
Project No. 07135-42-04A August 21, 2014
The Corky McMillin Companies 2750 Womble Road, Suite 200 San Diego, California 92106 Attention: Mr. Don Mitchell
Subject: FOUNDATION REPORT QUARRY CREEK BRIDGE CARLSBAD, CALIFORNIA
Dear Mr. Mitchell:
In accordance with your request, we herein submit our Foundation Report (FR) for the proposed Quarry Creek Bridge located in Carlsbad, California. The accompanying report presents the findings
and conclusions from our study.
If you have any questions regarding this FR, or if we may be of further service, please contact the
undersigned at your convenience. Very truly yours,
GEOCON INCORPORATED
Yong Wang GE 2775 Ali Sadr CEG 1778 Rodney C. Mikesell GE 2533
YW:AS:RCM:dmc
(2) Addressee (e-mail) T. Y. Lin International
Attention: Mr. Jay Holombo
TABLE OF CONTENTS
1. INTRODUCTION ................................................................................................................................. 1
2. SCOPE OF WORK ................................................................................................................................ 1
3. PROJECT DESCRIPTION ................................................................................................................... 2 3.1 Background and Site Description ................................................................................................ 2
3.2 Existing Structures ...................................................................................................................... 2
3.3 Proposed Structure ...................................................................................................................... 2 3.4 Pertinent Project Information ...................................................................................................... 3
4. EXCEPTION TO POLICY ................................................................................................................... 3
5. FIELD INVESTIGATION AND TESTING PROGRAM .................................................................... 3
6. LABORATORY TESTING PROGRAM .............................................................................................. 5
7. SITE GEOLOGY AND SUBSURFACE CONDITIONS ..................................................................... 5
7.1 Topography and Geology ............................................................................................................ 5 7.2 Types of Soil and Rock ............................................................................................................... 6
7.2.1 Compacted Fill (Qcf) ..................................................................................................... 6 7.2.2 Alluvium (Qal) ............................................................................................................... 7 7.2.3 Santiago Formation (Ts) ................................................................................................. 7
7.3 Salto Intrusive (Jspi) .................................................................................................................... 7 7.4 Pertinent Soil Conditions or Geologic Hazards .......................................................................... 7
7.3.1 Landslides ...................................................................................................................... 8
7.3.2 Embankment Failures ..................................................................................................... 8 7.3.3 Ground Subsidence ........................................................................................................ 8
7.3.4 Expansive Soils .............................................................................................................. 8
7.3.5 Collapsible Soils ............................................................................................................. 8 7.4 Depth to the Bedrock ................................................................................................................... 9
7.5 Groundwater ................................................................................................................................ 9
8. SCOUR EVALUATION ....................................................................................................................... 9
9. CORROSION EVALUATION ............................................................................................................. 9
10. SEISMIC RECOMMENDATIONS .................................................................................................... 10
10.1 Seismic Ground Motion and Design Response Spectrum ......................................................... 10 10.2 Liquefaction Potential ............................................................................................................... 11
10.3 Surface Fault Rupture Potential ................................................................................................ 12
10.4 Seismic Induced Settlement ...................................................................................................... 12 10.5 Lateral Spreading ...................................................................................................................... 12
10.6 Tsunami ..................................................................................................................................... 12 10.7 Seismic Slope Instability ........................................................................................................... 13
11. AS-BUILT FOUNDATION DATA .................................................................................................... 13
TABLE OF CONTENTS (Continued)
12. FOUNDATION RECOMMENDATIONS .......................................................................................... 13
12.1 Shallow Foundations ................................................................................................................. 15
12.2 Deep Foundations ...................................................................................................................... 16 12.2.1 Special Considerations for Cast-In-Drilled-Hole Piles with Rock Socket ................... 19
12.2.2 Special Considerations for Driven Piles ....................................................................... 19
12.3 Retaining Walls/Wingwalls ....................................................................................................... 19 12.4 Wall Backfill and Approach Fill Earthwork ............................................................................. 20
12.4.1 Additional Considerations ............................................................................................ 20
13. GENERAL NOTES TO DESIGNER .................................................................................................. 21
14. CONSTRUCTION CONSIDERATIONS ........................................................................................... 21
15. DISCLAIMER AND CONTACT INFORMATION........................................................................... 21
16. CLOSURE ........................................................................................................................................... 22 16.1 Foundation and Grading Plan Review ....................................................................................... 22
16.2 Limitations and Uniformity of Conditions ................................................................................ 22
17. REFERENCES .................................................................................................................................... 23
FIGURES Figure 1, Vicinity Map
Figure 2, Site Plan/Geologic Map
Figure 3, Regional Geologic Map Figure 4, Geologic Cross Section A-A′
Figure 5, Geologic Cross Section B-B′
Figure 6, Regional Fault Map Figure 7, Recommended Design Response Spectrum
TABLES Table 5, Summary of Borings ................................................................................................................ 4
Table 7.2, Generalized Stratigraphy and Supporting Characteristics for Bridge ................................... 6
Table 9, Soil Corrosion Test Summary ............................................................................................... 10 Table 10, Fault Information ................................................................................................................. 11
Table 12.1, Foundation Design Data Sheet for CIDH Piles ................................................................ 14 Table 12.2, Foundation Factored Design Loads for CIDH Piles ......................................................... 14 Table 12.3, Foundation Design Data Sheet for Spread Footings ......................................................... 14
Table 12.1.1, Foundation Design Recommendations for Spread Footings ......................................... 15 Table 12.1.2, Recommended Spread Footing Data Table ................................................................... 15 Table 12.2.1, Foundation Recommendations for CIDH Piles ............................................................. 16
Table 12.2.2, Recommended Pile Data Table ..................................................................................... 17 Table 12.2.3, Recommended Soil Parameters For Lpile Analysis (Abut 1) ........................................ 17
Table 12.2.4, Recommended Soil Parameters For Lpile Analysis (Pier 2) ......................................... 18
Table 12.2.5, Recommended Soil Parameters For Lpile Analysis (Abut 1 - Liquefaction) ................ 18 Table 12.2.6, Recommended Soil Parameters For Lpile Analysis (Pier 2 - Liquefaction).................. 18
TABLE OF CONTENTS (Concluded)
APPENDIX A
FIELD INVESTIGATION
Table A-I, Summary of Borings Boring Records
APPENDIX B LABORATORY TESTING
Table B-I, Summary of Laboratory In Situ Moisture Content and Dry Density Table B-II, Summary of Laboratory Grain Size Distribution Test Results Table B-III, Summary of Laboratory Direct Shear Test Results
Table B-IV, Summary of Laboratory Potential of Hydrogen (pH) and Resistivity Test Results Table B-V, Summary of Laboratory Water-Soluble Sulfate Test Results Table B-VI, Summary of Laboratory Chloride Content Test Results
Table B-VII, Summary of Laboratory Sand Equivalent Test Results Table B-VIII, Summary of Laboratory Unconfined Compressive Test Results Table B-IX, Summary of Laboratory Plasticity Index Test Results
Table B-X, Summary of Laboratory Uniaxial Compressive Strength Test Results Figure B-1, Gradation Curve
APPENDIX C LOG OF TEST BORINGS
APPENDIX D ANALYSES AND CALCULATIONS
Project No. 07135-42-04A - 1 - August 21, 2014
FOUNDATION REPORT
1. INTRODUCTION
This Foundation Report (FR) presents the results of a geotechnical investigation for the proposed
Quarry Creek Bridge located in Carlsbad, California. The approximate site location is depicted on the
Vicinity Map, Figure 1. This FR is based on a geotechnical investigation performed by Geocon
Incorporated. The purpose of the investigation was to evaluate general subsurface geologic and
geotechnical conditions along the proposed bridge widening alignment, and to provide geotechnical
recommendations for use in preparing project plans and specifications.
The recommendations presented herein are based on our analyses of the data obtained from exploratory
borings, laboratory test results, engineering analyses, and our experience with similar soil and geologic
conditions. The Boring Records, laboratory test results, Log of Test Borings (LOTB) sheets in Caltrans
format, and analyses and calculations are presented as Appendices A, B, C, and D, respectively.
2. SCOPE OF WORK
Our scope of work included:
Reviewing published geologic maps, aerial photographs, project plans, in-house documents, and other literature pertaining to the site to aid in evaluating geologic conditions and hazards that may be present.
Reviewing currently available project plans and information regarding the bridge foundations and proposed improvements.
Performing a field reconnaissance to note the existing conditions of the project site and surrounding areas.
Drilling/coring 9 small-diameter borings along the proposed bridge alignment to a maximum depth of 66 feet below grade to examine and sample the prevailing soil/rock conditions.
Performing laboratory tests on soil samples to evaluate dry density, moisture content, pH, resistivity, soluble-sulfate content, chloride-ion content, grain size distribution, plasticity, shear strength, sand equivalent, and unconfined compressive strength characteristics of the
prevailing soils. The uniaxial compressive strength tests were also performed on collected rock core samples.
Performing engineering analyses to evaluate liquefaction and lateral spreading potential, seismic design criteria, and foundation design criteria.
Preparing this FR in general accordance with Caltrans’ Foundation Report Preparation for Bridge Foundations, December 2009.
Project No. 07135-42-04A - 2 - August 21, 2014
This FR supersedes the Preliminary Foundation Report (PFR) for the Quarry Creek Bridge, Carlsbad,
California, prepared by Geocon Incorporated, dated March 12, 2014.
3. PROJECT DESCRIPTION
3.1 Background and Site Description
The project site is located within the former Hanson Aggregates Quarry Creek materials plant south
of State Route 78 (SR 78) in Carlsbad, California. Specifically, the location of the site is
approximately 0.2 miles south of SR 78 and 0.5 miles west of College Boulevard as shown on
Figure 1, Vicinity Map. The approximate site coordinates are 33.178772° (latitude) and -117.302637°
(longitude).
Geocon Incorporated has provided geotechnical engineering and compaction testing and observation
services during reclamation grading for the former Hanson aggregate mining quarry. A summary of
observations and compaction test results, as well as an as-graded geologic map are provided in
Geocon’s report titled Final Report of Testing and Observation Services During Site Grading,
Quarry Creek, Carlsbad, California, dated April 4, 2013 (Project No. 07135-42-02). In general, the
approximately 100-acre property was recently sheet graded as part of the reclamation plan for Quarry
Creek Aggregate production plant. In addition to removal and recompaction of the unsuitable soils,
several drop structures were constructed within the Buena Vista Creek drainage and a FEMA Levee
and berm slopes were constructed along the north bank of Buena Vista Creek. Grading has resulted in
construction of large sheet-graded areas or superpads both north and south of Buena Vista Creek.
3.2 Existing Structures
No bridge structure currently exists at the subject site.
3.3 Proposed Structure
Information regarding the proposed bridge is obtained following a review of the currently available
bridge design loads and the preliminary project plan titled: Quarry Creek Bridge Foundation Plan
(65% Unchecked Details), prepared by T. Y. Lin International, received on August 20. 2014. We
understand that the proposed bridge consists of a 3-span structure extending approximately 285 feet
in length and approximately 46 feet in width. Piers will be located outside a 150-foot limit of the
Buena Vista Creek drainage area. The Site Plan/Geologic Map, Figure 2, shows the planned
improvements based on the project plan prepared by T. Y. Lin International together with the
locations of our exploratory borings.
Project No. 07135-42-04A - 3 - August 21, 2014
3.4 Pertinent Project Information
We reviewed the following engineering documents related to the project:
1. Update Geotechnical Investigation, Amended Reclamation Plan, Quarry Creek, Refined
Alternative 3, Carlsbad, California, prepared by Geocon Incorporated, dated September 10, 2009 (Project No. 07135-42-01).
2. Final Report of Testing and Observation Services During Site Grading, Quarry Creek, Carlsbad, California, prepared by Geocon Incorporated, dated April 4, 2013 (Project No. 07135-42-02).
3. Preliminary Geotechnical Investigation, Quarry Creek II, Carlsbad/Oceanside, California,
prepared by Geocon Incorporated, dated May 11, 2012 (Project No. 07135-42-03).
4. Preliminary Foundation Report, Quarry Creek Bridge, prepared by Geocon Incorporated,
dated March 12, 2014 (Project No. 07135-42-04).
5. Preliminary Foundation Plan, Quarry Creek Bridge (65% Unchecked Details), prepared by T.Y. Lin International, received on August 20, 2014.
6. Bridge Design Loads, prepared by T.Y. Lin International, received on August 5 and 20, 2014.
4. EXCEPTION TO POLICY
Unless otherwise stated in this FR, the study performed and preliminary recommendations provided
for the proposed bridge widening are in conformance with Caltrans’ current policy.
5. FIELD INVESTIGATION AND TESTING PROGRAM
The field investigation for the FR was performed between June 18 and July 2, 2014, and consisted of
a site reconnaissance and drilling/coring 9 small-diameter borings near the approximate locations of
proposed foundations as depicted on the Site Plan/Geologic Map, Figure 2. Table 5 is a summary of
the boring information including the proposed structures, boring locations, surface elevations, and
boring depths.
Project No. 07135-42-04A - 4 - August 21, 2014
TABLE 5
SUMMARY OF BORINGS
Boring No.
Approximate Boring Location Boring Depth (feet) Proposed
Structure
Station No.
“Street B” Centerline
Offset
(feet)
Elevation
(feet)
R-14-001 Abut 1 8+27 Lt 24 96 39.5
R-14-002 Abut 1 8+27 Rt 24 96 42
A-14-009 Abut 1 8+04 Rt 8 104 66
A-14-003 Pier 2 8+77.5 Lt 23.5 77 22
A-14-004 Pier 2 8+77.5 Rt 23.5 77 26
A-14-005 Pier 3 10+61.5 Lt 23.5 77 8.5
A-14-006 Pier 3 10+61.5 Rt 23.5 77 16
R-14-007 Abut 4 11+12 Lt 24 95 18
R-14-008 Abut 4 11+12 Rt 24 93 15.5
Borings were advanced to depths ranging from approximately 8.5 to 66 feet below ground surface
using two different drill rigs. Boring A-14-009 was drilled/cored using a truck-mounted drill rig
(Dietrich-120). All other borings were drilled/cored using an all-terrain (ATC) drill rig. These two
drill rigs were both equipped with 8-inch-diameter, continuous hollow-stem augers, a 4-inch diameter
rotary wash tri-cone bit, and approximately 4-inch diamond coring bit. Specifically, R-14-001, R-14-
002, R-14-007, and R-14-008 were rotary wash borings and rock core borings; A-14-009 was
combination of hollow-stem and rock coring; and A-14-003 through A-14-006 were hollow-stem
borings. The average hammer energy efficiencies for ATC and Dietrich-120 rigs are about 78.8 and
80.2 percent, respectively.
In-situ testing and sampling during drilling were performed in general conformance with current
Caltrans’ Soil and Rock Logging, Classification and Presentation Manual. Soil samples were
collected from near the ground surface and at approximately 5-foot intervals to the total depths
explored. Relatively undisturbed samples were obtained by driving an approximately 3-inch outside
diameter (OD) split-spoon sampler (modified California sampler) into the "undisturbed" soil mass
with blows from a 140-pound hammer falling 30 inches. The sampler was equipped with 6-inch-long
by 2½-inch-diameter brass sample tubes to facilitate sample removal and laboratory testing. Standard
Penetration Tests (SPTs) were performed by driving a 2-inch OD split-spoon sampler 18 inches in
general conformance with ASTM D1586. The number of blows required to drive the sampler (blow
counts) the last 12 inches of the 18 sample drive (or portion thereof) are reported on the Boring
Records and the LOTB sheets included in Appendices A and C.
Project No. 07135-42-04A - 5 - August 21, 2014
6. LABORATORY TESTING PROGRAM
We performed laboratory tests in general conformance with California Test Methods (CTM) and
generally accepted test methods of the American Society for Testing and Materials (ASTM). We
performed the following tests:
In-Place Dry Density and Moisture Content: ASTM D 2937 (CTM 226)
Grain Size Distribution/Percent Passing No. 200 Sieve: ASTM D 422 (CTM 202 and 203)
Direct Shear: ASTM D 3080
pH and Resistivity: CTM 643
Sulfate Content: CTM 417
Chloride Content: CTM 422
Plasticity Index: ASTM D 4318 (CTM 204)
Sand Equivalent: ASTM D 2419 (CTM 217)
Unconfined Compressive Strength: ASTM D 2166
Uniaxial Compressive Strength: ASTM D 7012
Test results are presented in Appendix B of this report.
7. SITE GEOLOGY AND SUBSURFACE CONDITIONS
7.1 Topography and Geology
The area surrounding the proposed bridge site generally consists of recently sheet-graded pads to the
north and the south, and Buena Vista Creek to the east and west. North and south facing embankment
slopes were constructed along each side of the creek as part of the grading operation. The slopes have
an inclination of approximately 2.5H:1V (horizontal:vertical). Existing surface elevations in the area
of the planned bridge range from a high of approximately 105 feet above Mean Sea Level (MSL)
near the tops of the embankment slopes to a low of approximately 74 feet above MSL at the Buena
Vista Creek channel.
A Regional Geologic Map is presented as Figure 3. The site and near vicinity are located in an area
underlain by late Holocene alluvial flood plain deposits and middle Eocene Santiago Formation, as
mapped by M. P. Kennedy and S. S. Tan (2005). However, due to extensive mining operations at the
site and subsequent reclamation grading, majority of the Santiago Formation has been removed and
the area is covered with compacted fill.
Based on the results of our field investigation and the referenced grading report, a thickness of up to
approximately 30 feet of compacted fill was placed to achieve finish grades to construct the creek
embankment slopes and graded pads near the bridge alignment.
Project No. 07135-42-04A - 6 - August 21, 2014
7.2 Types of Soil and Rock
Based on the results of our field investigation, the area planned to receive the proposed bridge is
generally underlain by compacted fill, alluvium, Santiago Formation, and igneous rock associated
with the Salto Intrusive. Two geologic cross-sections A-A′ and B-B’ along the proposed bridge
alignment are presented on Figures 4 and 5. The generalized stratigraphy and supporting
characteristics of the subsurface materials near the proposed bridge footings are summarized in
Table 7.2. The soil and rock conditions encountered are described in detail below and on the Boring
Records and the LOTB sheets presented in Appendices A and C, respectively.
TABLE 7.2
GENERALIZED STRATIGRAPHY AND SUPPORTING CHARACTERISTICS FOR BRIDGE
Widening Footing Generalized Stratigraphy Support Characteristics
Abut 1
Compacted fill above approx. El. 76 feet Incompetent
Alluvium between approx. El. 76 feet and 58 feet Incompetent
Salto Intrusive below approx. El. 58 feet Very competent
Pier 2
Compacted fill above approx. El. 76 feet Incompetent
Alluvium between approx. El. 76 feet and 56 feet (left) or 52 feet (right) Incompetent
Salto Intrusive below approx. El. 56 feet (left) or 52 feet (right) Very competent
Pier 3 Compacted fill above approx. El. 69 feet Incompetent
Salto Intrusive below approx. El. 69 feet Very competent
Abut 4 Compacted fill above approx. El. 85 feet (left) or 80 feet (right) Incompetent
Salto Intrusive below approx. El. 85 feet (left) or 80 feet (right) Very competent
7.2.1 Compacted Fill (Qcf)
Compacted fill exists north and south of Buena Vista Creek on the existing embankment slopes and
graded pads. Fill soils derived from on-site excavations or import sources were placed and compacted
in layers until the design elevations were attained. Approximately 8 to 30 feet of compacted fill were
encountered in our borings drilled along the proposed bridge alignment.
As encountered in all borings, the compacted fill generally consist of medium dense, moist, dark
brown silty sand and clayey sand. The bridge abutments were surveyed during grading and the
majority of rock fill was placed outside of bridge abutment areas. However, some rock could exist in
the fill.
For excavation purposes, the compacted fill can be considered a Cal-OSHA Type B soil where water
is not freely seeping and should be considered a Type C soil if water is freely seeping. All
Project No. 07135-42-04A - 7 - August 21, 2014
excavations and trenches should be properly maintained and/or shored in accordance with applicable
OSHA rules and regulations for the safety and stability of adjacent existing improvements.
7.2.2 Alluvium (Qal)
Alluvial deposits exist along the Buena Vista Creek channel bed and underlie the compacted fill north
of the Buena Vista Creek. We expect the thickness of the alluvium to be at least 20 feet, below the
creek channel. Approximately 18 and 24 feet of alluvium were encountered in our Borings drilled at
the proposed Abutment 1 and Pier 2, respectively. The materials generally consist of soft to stiff wet,
dark grayish brown lean clay to sandy lean clay and silty sand.
For excavation purposes, the alluvium can be considered a Cal-OSHA Type C. All excavations and
trenches should be properly maintained and/or shored in accordance with applicable OSHA rules and
regulations for the safety and stability of adjacent existing improvements.
7.2.3 Santiago Formation (Ts)
Adjacent to the proposed Abutment 1, we encountered Santiago Formation in Borings A-14-009,
between alluvium and the bedrock. The Santiago Formation is characterized by very dense, moist
light greenish gray, weakly cemented silty sandstone.
For excavation purposes, the Santiago Formation can be considered a Cal-OSHA Type A soil where
water is not freely seeping and should be considered a Type B soil if water is freely seeping. All
excavations and trenches should be properly maintained and/or shored in accordance with applicable
OSHA rules and regulations for the safety and stability of adjacent existing improvements.
7.3 Salto Intrusive (Jspi)
The Jurassic-aged Salto Intrusive consists of a steeply jointed, light gray, very strong tonalite to very
dark gray gabbro rock considered to be older than the Peninsular Range Batholith and more closely
related to the formation of the Santiago Peak Volcanics. This granitoid bedrock unit is the present
below the surficial soil in all borings and is the predominant geologic unit that has been mined for
aggregate on the property. Exploratory excavations encountered the intrusive rock that exhibited a
variable weathering pattern ranging from intensely weathered and fractured to moderately weathered,
strong crystalline rock.
7.4 Pertinent Soil Conditions or Geologic Hazards
The following sections discuss other potential geologic hazards evaluated for the project including
landslides, embankment failures, ground subsidence, expansive soils, and collapsible soils.
Project No. 07135-42-04A - 8 - August 21, 2014
7.4.1 Landslides
Review of the 1995 published regional landslide maps of the California Geological Survey (formerly
the Division of Mines and Geology) suggested the presence of a suspected landslide west of the
bridge area and in the natural hillside southwest of the bridge. However, observations of intact
outcrops and confirmation of undisturbed slope conditions during our previous field investigation
suggest that the suspected landslides do not exist. Geocon evaluated the landslide areas during a
recent investigation for the overall Quarry Creek II project by geologic mapping and excavation of
exploratory trenches and large diameter borings. The exploratory excavations encountered intact
medium-dense, massive to horizontally-bedded Terrace Deposits. Based on the exploratory
excavation data and exposed outcrops, the previously suspected landslides do not exist and landslides
are not considered to be a hazard to this project.
Several suspicious surficial landslides are mapped along the south bank of the creek several hundred
feet west of the site. These potential landslides should not impact the proposed bridge.
7.4.2 Embankment Failures
No embankment failures were observed during our field investigation.
7.4.3 Ground Subsidence
Ground subsidence occurs where underlying loose geologic units undergo a densification process.
Subsidence can result from the extraction of mineral resources and/or groundwater, as well as the
rapid settlement induced by seismic activity. The potential for ground subsidence is considered very
low at the site.
7.4.4 Expansive Soils
Expansive soils possess a high swelling or shrinking potential due to change in moisture content. The
common materials associated with high expansion potential are clays. Based on laboratory testing
performed during previous grading, portions of the existing fills are considered to have low to high
expansion potential.
Proposed foundations will be supported on bedrock with a very low expansion potential. Thus, the
potential for expansive soils to affect the proposed foundations is considered low.
7.4.5 Collapsible Soils
Collapsing soils are unsaturated soils that undergo a large volume change upon saturation, even
without increase in external loads. Soils that generally display collapsible potential are porous and
Project No. 07135-42-04A - 9 - August 21, 2014
low dry density. Generally no porous or honeycomb structure was encountered in our borings
drilled along the proposed bridge alignment. Thus, the potential for collapsible soils on site is
considered low.
7.5 Depth to the Bedrock
The depth to bedrock is likely to vary along the project alignment, from approximately 13 feet below
the surface south of the creek channel to approximately 46 feet below the graded pad north of the
creek channel.
7.6 Groundwater
Based on the referenced update geotechnical investigation prepared by Geocon Incorporated,
groundwater was encountered in the lower elevation drainage areas of Buena Vista Creek and its
tributaries at depths translating to elevations between 70 and 80 feet MSL in 2003 and 2006.
Groundwater is expected to be near the existing creek flow elevation. Additionally, seepage was
encountered along the bedrock contact along the south side of the creek. Several subsurface drains
were installed in the area east of the proposed bridge to intercept the seepage and outlet it to the
creek.
We encountered groundwater in our Borings A-14-003, A-14-004, A-14-005 and A-14-006 drilled
adjacent to the existing creek channel bed. Specifically, the encountered groundwater levels were at
approximately elevations of 67 and 71 feet (MSL) at the north and south of creek channel,
respectively.
8. SCOUR EVALUATION
The proposed Piers 2 and 3 are likely located within the Buena Vista Creek channel margins. Scour
evaluation of the project site should refer to project hydrology/hydraulic report.
The as-built riprap drop structures may have some influences on the general scour trends within the
creek channel. From a geotechnical standpoint, the appropriate footing elevations of the proposed
piers should be extended below the potential scour elevation.
9. CORROSION EVALUATION
According to Caltrans Corrosion Guidelines (Version 2.0, November 2012), a site is considered
corrosive to foundation elements if chloride concentration is 500 ppm or greater, or sulfate
concentration is 2000 ppm or greater, or the pH is 5.5 or less. The potential of Hydrogen (pH),
resistivity, chlorides content, and soluble-sulfate content tests were performed on 3 samples selected
at random to generally evaluate the corrosion potential to subsurface structures. These tests were
Project No. 07135-42-04A - 10 - August 21, 2014
performed in accordance with California Test Method Nos. 643, 417, and 422. The results are
summarized in Table 9, which indicates that the site is not considered a corrosive environment in
accordance with Caltrans criteria.
TABLE 9
SOIL CORROSION TEST SUMMARY
Boring No./ Sample No. Sample Depth (feet) Resistivity (ohm centimeters) pH Chloride Content (ppm) Sulfate Content (ppm)
R-14-001/B1-1 0 820 7.5 230 420
A-14-004/B4-3 10 900 8.4 150 40
A-14-005/B5-2 5 590 7.8 100 100
Proposed improvements in contact with the ground should be designed and constructed in accordance
with the Caltrans Standard Specifications and good construction practices. Geocon does not practice in
the field of corrosion engineering. If corrosion sensitive improvements are planned, we recommend that
further evaluations by a corrosion engineer be performed to incorporate the necessary precautions to
avoid premature corrosion on corrosion sensitive structures in direct contact with the soils.
10. SEISMIC RECOMMENDATIONS
10.1 Seismic Ground Motion and Design Response Spectrum
Seismic recommendations including seismic ground motion of the site and the design response
spectrum for the bridge widening were developed in accordance with Caltrans’ Methodology for
Developing Design Response Spectrum for Use in Seismic Design Recommendations, November
2012. This procedure is based on Caltrans’ current Seismic Design Criteria (Appendix B), ARS Online
Version 2 Report, 2012 Caltrans Fault Database Report (Version 2a), and USGS probabilistic
seismic hazard analysis and tools. Site-specific information used in the procedure included the
latitude of 33.178772° and the longitude of -117.302637°.
Based on Caltrans’ online fault map and accompanying reports, the site is located approximately
12.2 kilometers (7.6 miles) east of the Newport-Inglewood (Offshore) fault zone, and approximately
12.4 kilometers (7.7 miles) northeast of Rose Canyon fault zone (Oceanside section). Figure 6 is the
Regional Fault Map based on the Caltrans’ online map. Key information of the faults is summarized
in Table 10 below.
Project No. 07135-42-04A - 11 - August 21, 2014
TABLE 10
FAULT INFORMATION
Fault Name Newport-Inglewood (Offshore) Rose Canyon Fault zone (Oceanside section)
Fault ID# 381 396
MMax 6.9 6.8
Fault Type SS SS
Fault Dip 90° 90°
Dip Direction Vertical Vertical
Top of Rupture 0 km (0 mi) 0 km (0 mi)
Bottom of Rupture 10 km (6.2 mi) 11 km (6.8 mi)
RRUP 12.2 km (7.6 mi) 12.4 km (7.7 mi)
Z1.0 N/A N/A
Z2.5 N/A N/A
The site is not located within a deep sedimentary basin in accordance with Caltrans’ Seismic Design
Criteria, Appendix B. Based on the subsurface conditions encountered in our borings, the site is
underlain by fill soils and alluvial soils over igneous rock. A shear wave velocity, Vs30 of 360 m/sec is
considered appropriate for the soil profile (Type D).
Both the deterministic and probabilistic response spectrums of the site were estimated using Caltrans’
Deterministic Response Spectrum Spreadsheet, Probabilistic Response Spectrum Spreadsheet (after
USGS), 2008 Interactive Deaggregation Tool and the ARS Online web tool. The design response
spectrum is the upper envelop of the spectral values of deterministic response spectrum and the
probabilistic response spectrum. The peak horizontal ground acceleration (PGA) at the site is
estimated as 0.37g. The recommended design response spectrum is shown on Figure 7,
Recommended Design Response Spectrum.
10.2 Liquefaction Potential
Liquefaction is a phenomenon in which loose, saturated, and relatively cohesionless soil deposits
located beneath the groundwater table lose strength during strong ground motions. Primary factors
controlling liquefaction include intensity and duration of ground accelerations, characteristics of the
subsurface soil, in situ stress conditions, and depth to groundwater. Our liquefaction assessments
indicate that some layers of the alluvial soils are susceptible to seismic liquefaction.
Project No. 07135-42-04A - 12 - August 21, 2014
10.3 Surface Fault Rupture Potential
The site is not located within an Alquist-Priolo Earthquake Study Zone as established by the State
Geologist around known active faults. Review of available literature and field reconnaissance
revealed no active fault trace through or near the site. The potential for surface fault rupture at the site
is considered very low.
10.4 Seismic Induced Settlement
As a result of strong ground motions, seismic induced settlement may be expected in areas underlain
by liquefiable soils, unconsolidated alluvial deposits, and/or loose granular soils. The potential for
seismic induced settlement at the site proposed for Quarry Creek Bridge was evaluated. The results
indicate that in the area underlain by liquefiable alluvial soils, seismic induced settlement on the order
of 2 to 5 inches could be expected.
10.5 Lateral Spreading
Current understanding within the geotechnical engineering profession is that lateral spreading can be
expected in liquefiable sites adjacent to slopes such as river channels or large bodies of water. The
observed horizontal ground displacement typically decreases with increased distances from the open
face.
The potential of lateral spreading is estimated based on the seismic deformation analysis using
Newmark’s approach in accordance with FHWA guidelines for LRFD Seismic Analysis and Design
of Transportation Geotechnical Features and Structural Foundations (2011). The geometry of
embankment slope, the residual strength characteristics of the subsurface soil, the site acceleration
due to earthquake, as well as the water and groundwater levels are the important parameters in
estimating the potential for lateral spreading. Based on a PGA of 0.37g, the maximum earthquake-
induced horizontal ground displacement is calculated to be about 3½ inches at approximately 50 feet
from the open face of the northern embankment slope. Beyond 50 feet, the calculated horizontal
ground displacement is gradually diminishing. Because the calculated earthquake-induced horizontal
ground displacement is relatively minor, therefore the potential for lateral spreading at the subject site
is considered very low.
10.6 Tsunami
Tsunamis are large sea waves caused by submarine earthquakes, landslides, or volcanic eruptions.
The potential of tsunamis to occur at the site is considered to be very low due to the relatively large
distance from the coastline to the site.
Project No. 07135-42-04A - 13 - August 21, 2014
10.7 Seismic Slope Instability
Planned earthwork may include fill slopes along portions of the approach embankments or abutments
that are similar to the existing slopes. Assuming that new fill materials meet Caltrans’ specifications
for structure backfill, 2H:1V (horizontal:vertical) or flatter fill slopes should have a factor of safety
greater than 1.5 against deep-seated and shallow failures under static loading and a factor of safety
greater than 1.1 under pseudo-static (seismic) loading, where the seismic coefficient of 0.12g that
equals to one third of the horizontal peak ground acceleration and not exceeding 0.2g should was
used in accordance with Caltrans Guidelines for Structures Foundation Reports (Version 2.0).
11. AS-BUILT FOUNDATION DATA
No bridge structure is present at the site. Therefore no as-built foundation data exists for the
project site.
12. FOUNDATION RECOMMENDATIONS
According to current Caltrans’ guidelines, foundation design for abutments and bents are based on
Working Stress Design (WSD) and Load and Resistance Factor Design (LRFD), respectively. Due to
the presence of shallow rock south of creek and liquefiable alluvium north of creek, a foundation
system consisting of both shallow and deep foundations is recommended. Specifically, footings at
Abutment 1 and Pier 2 can be supported on Cast-In-Drilled-Hole (CIDH) piles with rock sockets
embedded in the competent igneous rock. Pier 3 and Abutment 4 can be supported on the competent
igneous rock using spread footings. Dependent upon the final footing location, excavations may
require dewatering. If the limits of disturbance within the creek channel will be jeopardized by the
foundation excavation, temporary shoring to facilitate the footing excavation should be considered.
Alternatively, Pier 3 can be supported by deep foundations consisted of CIDH piles extended into
competent igneous rock. Recommendations for CIDH piles at Pier 3 can be provided if required.
The foundation information from structure design is summarized in Tables 12.1 through 12.3. Our
recommendations are presented in the following sections based on the currently available project
information, and should be considered final unless otherwise stated. All data should be verified if the
final design loads and/or dimensions are modified.
Project No. 07135-42-04A - 14 - August 21, 2014
TABLE 12.1
FOUNDATION DESIGN DATA SHEET FOR CIDH PILES
Support No. Pile Type
Finish Grade Elevation (ft)
Cut-Off Elevation (ft)
Pile Cap Size (ft) Permissible Settlement Under Service Load (in)*
Number of Piles per Support B L
Abut 1 42” CIDH Pile with 30” Rock Socket 97.50 84.00 8.00 46.00 1 6
Pier 2 60” CIDH Pile with 48” Rock Socket 78.00 70.00 7.00 46.00 1 4
*Based on CALTRANS’ current practice, the total permissible settlement is one inch for multi-span structures
with continuous spans or multi-column bents, one inch for single span structures with diaphragm abutments, and two inches for single span structures with seat abutments. Different permissible settlement under service
loads may be allowed if structural analysis verifies that required level of serviceability is met.
TABLE 12.2
FOUNDATION FACTORED DESIGN LOADS FOR CIDH PILES
Support No.
Service-I Limit State (kips) Strength/Construction Limit State (Controlling Group, kips) Extreme Event Limit State (Controlling Group, kips)
Total Load Per Support
Permanent Loads Per Support
Compression Tension Compression Tension
Per Support Max Per Pile Per Support Max Per Pile Per Support Max Per Pile Per Support Max Per Pile
Abut 1 1210 980 1910 320 0 0 980 690 0 360
Pier 2 3740 3050 5210 1310 0 0 3050 2190 0 5670
TABLE 12.3
FOUNDATION DESIGN DATA SHEET FOR SPREAD FOOTINGS
Support No. Finish Grade Elevation (ft) Bottom Of Footing Elevation (ft)
Footing Dimensions (ft) Permissible Settlement Under Service Load (in)* B L
Pier 3 77.00 69.00 10.00 46.00 1
Abut 4 94.00 80.00 8.00 46.00 1
*Based on CALTRANS’ current practice, the total permissible settlement for a shallow footing is one inch for multi-span structures with continuous spans or multi-column bents, one inch for single span structures with diaphragm abutments, and two inches for single span structures with seat abutments. Different permissible
settlement under service loads may be allowed if structural analysis verifies that required level of serviceability is met.
Project No. 07135-42-04A - 15 - August 21, 2014
12.1 Shallow Foundations
Based on the subsurface conditions encountered in our borings, a shallow foundation system is
considered appropriated for the support of the proposed Pier 3 and Abutment 4. Foundation design
recommendations for spread footings and recommended spread footing data table in Caltrans LRFD
format are presented in Tables 12.1.1 and 12.1.2, respectively. Geotechnical recommendations
regarding retaining walls/wingwalls are presented in Section 12.3.
TABLE 12.1.1
FOUNDATION DESIGN RECOMMENDATIONS FOR SPREAD FOOTINGS
Support No
Footing Size (ft) Bottom of Footing Elevation (ft)
Minimum Footing Embedment
Depth (ft)
Total Permissible Support
Settlement (inches)
Service-I Limit State
Strength or
Construction Limit State b=0.45
Extreme Event Limit State b=1.00
B L
Permissible Net Contact Stress2 (ksf)
Factored Gross Nominal Bearing Resistance3 (ksf)
Factored Gross Nominal Bearing Resistance3 (ksf)
Pier 3 10 46 69 4 1 9.4 10.6 23.5
Abut 4 8 46 80 4 1 9.3 10.4 23.2
1. Controlling load combination is the one resulting in the highest ratio of qg,u/qR for foundations on soil, or
qg,max/qR for foundations on rock.
2. For Service-I Limit State, controlling load combination is the one resulting in the highest ratio of qn,u/qpn for
foundations on soil, or qg,max/qR for foundations on rock. Permissible Net Contact Stresses were calculated for controlling load combinations.
3. For Strength, Construction, and Extreme Event Limit State, controlling load combination is the one resulting in the highest ratio of qg,u/qR for foundations on soil, or qg,max/qR for foundations on rock, Factored Gross
Nominal Bearing Resistance were calculated for controlling load combinations.
TABLE 12.1.2
RECOMMENDED SPREAD FOOTING DATA TABLE
Support Location
Service2
Permissible Net Contact Stress (Settlement) (ksf)
Strength/ Construction3 Factored Gross Nominal Bearing Resistance
b=0.45 (ksf)
Extreme Event3
Factored Gross Nominal Bearing Resistance
b=1.00 (ksf)
Pier 3 9.4 10.6 23.5
Abut 4 9.3 10.4 23.2
1. Controlling load combination is the one resulting in the highest ratio of qg,u/qR for foundations on soil, or
qg,max/qR for foundations on rock.
2. Controlling load combination for Service Limit State is the one resulting in the highest ratio of qn,u/qpn for
foundations on soil, or qg,max/qR for foundations on rock.
3. Controlling load combination for Strength, Construction, and Extreme Event is the one resulting in the highest ratio of qg,u/qR for foundations on soil, or qg,max/qR for foundations on rock.
Project No. 07135-42-04A - 16 - August 21, 2014
12.2 Deep Foundations
Deep foundations are considered appropriate foundation types to mitigate the potential settlements
and differential settlements associated with the spread footing in liquefiable alluvial soils north of the
creek channel. Deep foundations consist of drilled shafts with rock sockets are recommended for the
supports at Abutment 1 and Pier 2. The geotechnical capacities of the deep foundations will be
derived from the skin friction on the wall of the rock socket. The rock sockets should have a
minimum diameter of 24 inches and embedded at least 10 feet in competent igneous rock. For the
purposes of WSD, an allowable skin friction of about 10 ksf can be used for the rock socket.
Foundation information and our recommendations are presented in Tables 12.2.1 and 12.2.2 in
accordance with Caltrans’ LRFD procedure for bridge foundations.
TABLE 12.2.1
FOUNDATION RECOMMENDATIONS FOR CIDH PILES
Support Location Pile Type
Cut-off Elevation (ft)
Service-I Limit State Load per Support (kips)
Total Permissible Support Settlement (inches)
Required Factored Nominal Resistance (kips) Design Tip Elevations (ft)
Specified Tip Elevation (ft)
Strength/Construction Extreme Limit
Total Permanent Comp. (φ=0.7) Tension (φ =0.7) Comp. (φ =1.0) Tension (φ =1.0)
Abut 1
42” CIDH Pile with
30” Rock Socket
84 1210 980 1 320 0 690 360
48 (a-I) 48 (a-II) 52 (b-II) 48 (c) --- (d)
48 or (d)
Pier 2
60” CIDH Pile with 48” Rock Socket
70 3740 3050 1 1310 0 2190 670
42 (a-I) 42 (a-II) 47 (b-II) 42 (c) --- (d)
42 or (d)
Notes:
1. Design tip elevations are controlled by: (a-I) Compression (Strength Limit), (b-I) Tension (Strength Limit),
(a-II) Compression (Extreme Event), (b-II) Tension (Extreme Event), (c) Settlement, (d) Lateral Load.
2. The CIDH Specified Tip Elevation shall not be raised above the design tip elevations for tension, lateral, and tolerable
settlement.
3. Design tip elevation for Lateral Load is provided by the Structure Designer (SD).
4. Unsuitable soil layers (liquefiable), that do not contribute to the design nominal resistance exist at Abutment 1 and Pier
2 extending to elevations of 58 ft and 52 ft, respectively.
Project No. 07135-42-04A - 17 - August 21, 2014
TABLE 12.2.2
RECOMMENDED PILE DATA TABLE
Support No Pile Type
Nominal Resistance (kips) Design Tip Elevations (feet) Specified Tip Elevation (feet) Compression Tension
Abut 1 42” CIDH Pile with
30” Rock Socket 690 360 48 (a), 52 (b), 48 (c), -- (d) 48 or (d)
Pier 2 60” CIDH Pile with 48” Rock Socket 2190 670 42 (a), 47 (b), 42 (c), -- (d) 42 or (d)
Notes:
1. Design tip elevations are controlled by: (a) Compression, (b) Tension, (c) Settlement, (d) Lateral Load.
2. The CIDH Specified Tip Elevation shall not be raised above the design tip elevations for tension, lateral, and tolerable settlement.
3. Design tip elevation for Lateral Load is provided by the Structure Designer (SD).
4. Unsuitable soil layers (liquefiable), that do not contribute to the design nominal resistance exist at Abutment 1
and Pier 2 extending to elevations of 58 ft and 52 ft, respectively.
We understand that the specified pile length should not be less than the critical length for which
greater lengths do not results in a significant reduction in deflection at the pile top. Our recommended
soil parameters for LPILE analyses including the unit weights, friction angles, modulus, compressive
strength, and strain value are provided in Tables 12.2.3 through 12.2.6 below.
TABLE 12.2.3
RECOMMENDED SOIL PARAMETERS FOR LPILE ANALYSIS (ABUT 1)
Soil Layer
Soil Model (LPILE)
Elevation (feet) Unit Weight (pci)
Friction Angle (°)
K (pci)
Young’s Mod. (psi)
Uniaxial Comp. Strength
(psi)
RQD (%) k_rm Top Bottom
1 Sand 84 76 0.0723 35 90 -- -- -- --
2 Sand 76 67 0.0723 30 50 -- -- -- --
3 Sand 67 58 0.0362 30 20 -- -- -- --
4 Weak
Rock 58 35 0.0810 -- -- 1.0E+06 750 30 0.0001
Project No. 07135-42-04A - 18 - August 21, 2014
TABLE 12.2.4
RECOMMENDED SOIL PARAMETERS FOR LPILE ANALYSIS (PIER 2)
Soil
Layer
Soil Model (LPILE)
Elevation (feet) Unit Weight (pci)
Friction Angle (°)
K
(pci)
Young’s Mod. (psi)
Uniaxial Comp.
Strength (psi)
RQD
(%) k_rm Top Bottom
1 Sand 70 67 0.0723 30 50 -- -- -- --
2 Sand 67 52 0.0362 30 20 -- -- -- --
3 Weak
Rock 52 30 0.0810 -- -- 1.0E+06 750 30 0.0001
TABLE 12.2.5
RECOMMENDED SOIL PARAMETERS FOR LPILE ANALYSIS (ABUT 1 - LIQUEFACTION)
Soil Layer
Soil Model
(LPILE)
Elevation (feet) Unit Weight
(pci)
Friction Angle
(°)
K (pci)
Young’s Mod.
(psi)
Uniaxial Comp. Strength (psi)
RQD (%) k_rm Top Bottom
1 Sand 84 76 0.0723 18 45 -- -- -- --
2 Sand 76 67 0.0723 15 25 -- -- -- --
3 Sand 67 58 0.0362 15 10 -- -- -- --
4 Weak
Rock 58 35 0.0810 -- -- 1.0E+06 750 30 0.0001
TABLE 12.2.6
RECOMMENDED SOIL PARAMETERS FOR LPILE ANALYSIS (PIER 2 - LIQUEFACTION)
Soil Layer
Soil Model (LPILE)
Elevation (feet) Unit Weight (pci)
Friction Angle (°)
K (pci)
Young’s Mod. (psi)
Uniaxial Comp. Strength (psi)
RQD (%) k_rm Top Bottom
1 Sand 70 67 0.0723 15 25 -- -- -- --
2 Sand 67 52 0.0362 15 10 -- -- -- --
3 Weak
Rock 52 30 0.0810 -- -- 1.0E+06 750 30 0.0001
We understand that the design tip elevations for lateral loads are provided by structure design. If
multiple rows of pile are planned at support locations with a center-to-center spacing of 2- to 7-pile
diameters, p-multipliers should be applied to account for reduced lateral resistance due to pile-soil-
pile interaction per current Caltrans Amendments to AASHTO LRFD Bridge Design Specifications.
Project No. 07135-42-04A - 19 - August 21, 2014
Geotechnical recommendation regarding shallow foundations and retaining walls/wingwalls are
presented in Sections 12.1 and 12.3, respectively.
12.2.1 Special Considerations for Cast-In-Drilled-Hole Piles with Rock Socket
CIDH piles with rock sockets are drilled shafts that require drilling and excavation into rock. Drilling
the igneous bedrock is very difficult. The contractor should have appropriate excavating and/or rock
coring tools for very hard and/or fresh rock. Casing and/or wet method may be considered to
facilitate the excavation of overburden materials and prevent borehole from caving of loose layers.
Because the shafts will develop support in socket length, therefore field inspection by a representative
of project geotechnical engineer should be performed to verify that the desired rock socket length and
rock conditions are as anticipated.
12.2.2 Special Considerations for Driven Piles
Deep foundations with driven piles are not selected by current design. Geocon Incorporated should be
contacted for special considerations if driven piles are selected during final design.
12.3 Retaining Walls/Wingwalls
Abutments and wingwalls are typically unrestrained retaining walls that are allowed to rotate more
than 0.001H (where H equals the height of the retaining wall portion of the wall) at the top of the
wall. Retaining walls not restrained at the top and having a level backfill surface should be designed
for an active soil pressure equivalent to the pressure exerted by a fluid density of 36 pcf. Walls
supporting 2H:1V backfill should be designed for an equivalent fluid pressure of 50 pcf. For retaining
walls subject to vehicular loads within a horizontal distance equal to two-thirds the wall height, a
surcharge equivalent of 2 feet of fill soil (unit weight of 125 pcf) should be added. Soil placed for
retaining wall backfill should meet the requirements outlined in Section 12.4 of this report.
Resistance to lateral loads will be provided by friction along the base of the wall foundation or by
passive earth pressure against the side of the footing. Passive earth pressure may be taken as 150 pcf for
walls founded on a 2H:1V slope, and 340 pcf for horizontal ground in front of the wall. The
approximate value of relative movement required to reach the recommended passive earth pressure is
about 2 percent. An allowable coefficient of friction of 0.35 is recommended for footings in properly
compacted fill. An allowable coefficient of friction of 0.40 is recommended for footings in Salto
Intrusive. This friction coefficient may be combined with the allowable passive earth pressure when
determining resistance to lateral loads. The upper 12 inches of soil in front of the wall should not be
relied on for passive resistance unless the ground surface is covered with asphalt or concrete.
Project No. 07135-42-04A - 20 - August 21, 2014
Footings located within 7 feet of the top of slopes are not recommended. Footings that must be
located within this zone should be extended in depth such that the outer bottom edge of the footing is
at least 7 feet horizontally inside the face of the slope.
If Caltrans Standard Plans retaining walls, the net bearing stresses and/or the gross uniform bearing
stresses listed in Caltrans 2010 Revised Standard Plans for retaining walls can be considered for the
foundation soils provided that the maximum wall height does not exceed 14 feet.
All grading should be performed in conformance with Sections 6-3, 19-3, 19-5, and 19-6 of the
Caltrans Standard Specifications or equivalent.
All retaining walls should be provided with a drainage system adequate to prevent the buildup of
hydrostatic forces. The drainage system should consist of weepholes or backdrains. The above
recommendations assume a properly compacted granular backfill material with no hydrostatic forces.
If conditions different than those described are anticipated, or if specific drainage details are desired,
Geocon should be contacted for additional recommendations.
Foundation excavations should be observed by the Engineer, or a representative of Geocon
Consultants Incorporated prior to the placement of reinforcing steel and concrete to verify that the
exposed soil conditions are consistent with those anticipated. If unanticipated soil conditions are
encountered, foundation modifications may be required.
12.4 Wall Backfill and Approach Fill Earthwork
All grading with properly compacted fill should be performed in conformance with Sections 6-3, 19-
3, 19-5, and 19-6 of the Caltrans Standard Specifications or equivalent. Backfill placed behind
abutment walls, retaining walls and wing walls should have a Sand Equivalent of 20 or greater.
Ponding or jetting of backfill should not be permitted.
If new fill will be placed over existing slopes at some locations to bring the ground surface to final
planned grades, they should be keyed and benched into the existing slopes in accordance with Section
19-6.03A of the Caltrans Standard Specifications.
12.4.1 Additional Considerations
Consideration should be given to the use of surface treatments to minimize surficial erosion until
adequate erosion-resistant vegetation can become established. All roadway drainage should be
directed to appropriate collection and discharge facilities to prevent run-off from flowing over the
tops of slopes. Surface paving is recommended for slopes steeper than 2H:1V.
Project No. 07135-42-04A - 21 - August 21, 2014
13. GENERAL NOTES TO DESIGNER
This report is prepared based on the currently available project information including the proposed
structures and foundations described in Sections 3.3 and 12, respectively. Geocon Incorporated must
be contacted for further recommendations if the proposed structures and foundations are changed.
14. CONSTRUCTION CONSIDERATIONS
Areas to be developed should be cleared and stripped of obstructions, trees, bushes, grass, roots, and
the upper few inches of soil containing organic debris. Soils/organics removed by stripping can be
transported off-site or stockpiled for use in landscaping. Existing drainage and utility lines or other
existing subsurface structures that are not to be utilized, if any, should be removed, destroyed or
abandoned in compliance with applicable regulations.
Excavation of the onsite materials can be accomplished using conventional heavy-duty excavation
equipment. Excavation difficulty should be expected within the very dense and/or hard layers. Heavy
ripping will generate oversize materials not suitable for backfill. All excavations and trenches should
be properly maintained and/or shored in accordance with applicable OSHA rules and regulations for
the safety and stability of adjacent existing improvements.
Perched groundwater may be present near areas where heavy irrigation has occurred. Generally,
perched groundwater will result in nuisance seepage. Dewatering should be considered if excavation
extending below the groundwater table.
Foundation excavations should be observed by a representative of the project geotechnical engineer
of record. CIDH pile and rock socket drilling should also be observed by a representative of the
project geotechnical engineer of record. The observation should be performed to evaluate whether the
exposed soil and/or rock conditions are consistent with those anticipated. If unanticipated soil
conditions are encountered, foundation modifications may be required.
15. DISCLAIMER AND CONTACT INFORMATION
The recommendations contained in this report are based on specific project information regarding
structure type, location, and design loads that have been provided by T.Y. Lin International. If any
changes are made during final project design, Geocon should review those changes to determine if
these foundation recommendations are still applicable. Any questions regarding the above
recommendations should be directed to the attention of Mr. Yong Wang, 858-558-6900, at the San
Diego Office of Geocon.
Project No. 07135-42-04A - 22 - August 21, 2014
16. CLOSURE
16.1 Foundation and Grading Plan Review
Geocon should review the grading plans and foundation plans prior to final design submittal to
determine whether additional analysis and/or recommendations are required.
16.2 Limitations and Uniformity of Conditions
The firm that performed the geotechnical investigation for the project should be retained to provide
testing and observation services during construction to provide continuity of geotechnical
interpretation and to check that the recommendations presented for geotechnical aspects of site
development are incorporated during site grading, construction of improvements, and excavation of
foundations. If another geotechnical firm is selected to perform the testing and observation services
during construction operations, that firm should prepare a letter indicating their intent to assume the
responsibilities of project geotechnical engineer of record. A copy of the letter should be provided to
the regulatory agency for their records. In addition, that firm should provide revised
recommendations concerning the geotechnical aspects of the proposed development, or a written
acknowledgement of their concurrence with the recommendations presented in our report. They
should also perform additional analyses deemed necessary to assume the role of Geotechnical
Engineer of Record.
The recommendations of this report pertain only to the site investigated and are based upon the
assumption that the soil conditions do not deviate from those disclosed in the investigation. If any
variations or undesirable conditions are encountered during construction, or if the proposed
construction will differ from that anticipated herein, Geocon Incorporated should be notified so that
supplemental recommendations can be given. The evaluation or identification of the potential
presence of hazardous was not part of the scope of services provided by Geocon Incorporated.
The findings of this report are valid as of the present date. However, changes in the conditions of a
property can occur with the passage of time, whether they be due to natural processes or the works of
man on this or adjacent properties. In addition, changes in applicable or appropriate standards may
occur, whether they result from legislation or the broadening of knowledge. Accordingly, the findings
of this report may be invalidated wholly or partially by changes outside our control. Therefore,
this report is subject to review and should not be relied upon after a period of three years.
Project No. 07135-42-04A - 23 - August 21, 2014
17. REFERENCES
1. California Department of Transportation, 2011, California Amendments to AASHTO LRFD Bridge Design Specifications, Fourth Edition.
2. --------, 2012, Corrosion Guidelines, Version 2.0.
3. --------, 2009, Foundation Report Preparation for Bridge Foundations.
4. --------, 2014, Memos To Designers 3-1 and 4-1.
5. --------, 2009, Seismic Design Procedure.
6. --------, 2010, Standard Specifications.
7. FHWA, LRFD Seismic Analysis and Design of Transportation Geotechnical Features and
Structural Foundations, Reference Manual, FHWA-NHI-11-032, GEC No. 3, August 2011 (Rev. 1).
8. Geocon Incorporated, Update Geotechnical Investigation, Amended Reclamation Plan,
Quarry Creek, Refined Alternative 3, Carlsbad, California, dated September 10, 2009 (Project No. 07135-42-01).
9. --------, Final Report of Testing and Observation Services During Site Grading, Quarry
Creek, Carlsbad, California, dated April 4, 2013 (Project No. 07135-42-02).
10. --------, Preliminary Foundation Report, Quarry Creek Bridge, Carlsbad, California, dated March 12, 2014 (Project No. 07135-42-04).
11. --------, Preliminary Geotechnical Investigation, Quarry Creek II, Carlsbad/Oceanside, California, dated May 11, 2012 (Project No. 07135-42-03).
12. Larsen, E. S., 1948, Batholith and Associated Rocks of Corona, Elsinore and San Luis Rey Quadrangle Southern California, Geological Society of America, Memoir 29.
13. M. P. Kennedy and S. S. Tan, 2005,Geologic Map of the Oceanside 30’ X 60’ Quadrangle,
California.
14. Tan, S. S. and D. G. Giffen, 1995, Landslide Hazards in the Northern Part of the San Diego County, California, California Division of Mines and Geology, Open-File Report 95-04.
15. Unpublished reports, aerial photographs, and maps on file with Geocon Incorporated.
16. Youd, L. T., I. M. Idriss, et al., October 2001, Liquefaction Resistance of Soils: Summary Report from 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction
Resistance of Soils, Journal of Geotechnical and Geoenvironmental Engineering.
APPENDIX A
Project No. 07135-42-04A - A-1 - August 21, 2014
APPENDIX A
FIELD INVESTIGATION
The field investigation for this Foundation Report (FR) was performed between June 18 and July 2,
2014, and consisted of a site reconnaissance and drilling/coring 9 small-diameter borings near the
approximate locations of new foundations as depicted on the Site Plan/Geologic Map (Figure 2). Table A-
I is a summary of the boring information including the proposed structures, boring locations, surface
elevations, and boring depths.
TABLE A-I
SUMMARY OF BORINGS
Boring No.
Approximate Boring Location Boring Depth (feet) Proposed Structure Station No. “Street B” Centerline Offset (feet) Elevation (feet)
R-14-001 Abut 1 8+27 Lt 24 96 39.5
R-14-002 Abut 1 8+27 Rt 24 96 42
A-14-009 Abut 1 8+04 Rt 8 104 66
A-14-003 Pier 2 8+77.5 Lt 23.5 77 22
A-14-004 Pier 2 8+77.5 Rt 23.5 77 26
A-14-005 Pier 3 10+61.5 Lt 23.5 77 8.5
A-14-006 Pier 3 10+61.5 Rt 23.5 77 16
R-14-007 Abut 4 11+12 Lt 24 95 18
R-14-008 Abut 4 11+12 Rt 24 93 15.5
Borings were advanced to depths ranging from approximately 8.5 to 66 feet below ground surface using
two different drill rigs. Boring A-14-009 was drilled/cored using a truck-mounted drill rig (Dietrich-120).
All other borings were drilled/cored using an all-terrain (ATC) drill rig. These two drill rigs were both
equipped with 8-inch-diameter, continuous hollow-stem augers, a 4-inch diameter rotary wash tri-cone
bit, and approximately 4-inch diamond coring bit. Specifically, R-14-001, R-14-002, R-14-007, and R-14-
008 were rotary wash borings and rock core borings; A-14-009 was combination of hollow-stem and rock
coring; and A-14-003 through A-14-006 were hollow-stem borings. The average hammer energy
efficiencies for ATC and Dietrich-120 rigs are about 78.8 and 80.2 percent, respectively.
In-situ testing and sampling during drilling were performed in general conformance with current Caltrans’
Soil and Rock Logging, Classification and Presentation Manual. Soil samples were collected from near
the ground surface and at approximately 5-foot intervals to the total depths explored. Relatively
undisturbed were obtained by driving an approximately 3-inch outside diameter (OD) split-spoon sampler
Project No. 07135-42-04A - A-2 - August 21, 2014
(modified California sampler) into the "undisturbed" soil mass with blows from a 140-pound hammer
falling 30 inches. The sampler was equipped with 6-inch-long by 2½-inch-diameter brass sample tubes to
facilitate sample removal and laboratory testing. Standard Penetration Tests (SPTs) were performed by
driving a 2-inch OD split-spoon sampler 18 inches in general conformance with ASTM D1586. The
number of blows required to drive the samplers (blow counts) the last 12 inches of the 18 sample drive (or
portion thereof) are reported on the Boring Records and the Log of Test Borings (LOTB) sheets included
in Appendices A and C.
Soils encountered in exploratory borings were classified in accordance with ASTM Practice for
Description and Identification of Soils (Visual-Manual Procedure D 2488-00) and Caltrans’ Soil and Rock
Logging, Classification, and Presentation Manual (2010 Edition).
All Boring Records are included in Appendix A. The LOTB sheets in Caltrans format are presented in
Appendix C.
SILTY SAND (SM); medium dense; light olive-grayish brown; moist; fine to
medium grained. (COMPACTED FILL)
-Dark grayish brown; medium grained with trace angular coarse SAND; little
gravel.
-Grinding on hard rock.
-Boulder; refusal; drilling stopped and resumed on 6/27/2014 by coring
through the boulder approximately 12".
-Continued with Tri-cone rotary.
-Becomes gravelly from 11 to 13 feet.
-Dense; dark grayish brown; moist; medium sand; little gravel.
SANDY lean CLAY (CL); medium soft; very dark gray; wet, light gray spots.
(ALLUVIUM)
pp=1.0 tsf.
SM
CL
B1-1
B1-2
B1-3
B1-4
B1-5
B1-6
11.6
9.3
21.3
34
CORE
16
56
8
10
114.7
129.4
104.7
07135-42-04A.GPJ
MATERIAL DESCRIPTIONLITHOLOGY
... STANDARD PENETRATION TEST
SOIL
CLASS
(USCS)
... DISTURBED OR BAG SAMPLE
GEOCON
06-26-2014
SAMPLE SYMBOLS
... WATER TABLE OR SEEPAGE
DEPTH
IN
FEET
Limited Access Rig Rotary Wash PENETRATIONRESISTANCE(BLOWS/FT.)Figure A-1,
Log of Boring R-14-001, Page 1 of 2
... CHUNK SAMPLEGROUNDWATER A. Sadr
SAMPLE
NO.CONTENT (%)(P.C.F.)DATE COMPLETED
DRY DENSITYEQUIPMENT
ELEV. (MSL.)96'MOISTUREBY:
BORING R-14-001
... CORE SAMPLE ... DRIVE SAMPLE (UNDISTURBED)
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
07135-42-04A
SILTY SAND (SM); medium dense; grayish brown; wet; fine to medium.
IGNEOUS ROCK (Salto Intrusive); massive; gray, moderately weathered;
very hard; moderately fractured.
BORING TERMINATED AT 39.5 FEET.
Groundwater was not encountered.
Backfilled with bentonite slurry on 06/27/2014
ERi=79%
SMB1-7
B1-8
11
12
CORE
07135-42-04A.GPJ
MATERIAL DESCRIPTIONLITHOLOGY
... STANDARD PENETRATION TEST
SOIL
CLASS
(USCS)
... DISTURBED OR BAG SAMPLE
GEOCON
06-26-2014
SAMPLE SYMBOLS
... WATER TABLE OR SEEPAGE
DEPTH
IN
FEET
Limited Access Rig Rotary Wash PENETRATIONRESISTANCE(BLOWS/FT.)Figure A-1,
Log of Boring R-14-001, Page 2 of 2
... CHUNK SAMPLEGROUNDWATER A. Sadr
SAMPLE
NO.CONTENT (%)(P.C.F.)DATE COMPLETED
DRY DENSITYEQUIPMENT
ELEV. (MSL.)96'MOISTUREBY:
BORING R-14-001
... CORE SAMPLE ... DRIVE SAMPLE (UNDISTURBED)
30
32
34
36
38
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
07135-42-04A
SILTY SAND (SM); medium dense; dark grayish brown; moist; fine to
medium grained. (COMPACTED FILL)
SILTY to CLAYEY SAND (SM-SC); medium dense; dark brown; moist; fine
to medium grained.
-Becomes GRAVELLY from 8 feet.
-BOULDER; change to rock coring; cored through BOULDER 12" thick.
Poorly-graded SAND (SP); medium dense; dark gray; fine and coarse SAND;
some gravel.
CLAYEY SAND (SC); medium dense; dark greenish gray; moist; fine to
medium gravel; chunks of asphalt.
SILTY SAND (SM); medium dense; dark gray; wet; fine grained; very thin
layer of SILT interbeds. (ALLUVIUM)
SANDY CLAY (CL); soft; very dark gray; wet; mottled light gray.
SM
SM-SC
SP
SC
SM
CL
B2-1
B2-2
B2-3
B2-4
B2-5
17.0
10
CORE
23
19
35
8
111.3
07135-42-04A.GPJ
MATERIAL DESCRIPTIONLITHOLOGY
... STANDARD PENETRATION TEST
SOIL
CLASS
(USCS)
... DISTURBED OR BAG SAMPLE
GEOCON
06-30-2014
SAMPLE SYMBOLS
... WATER TABLE OR SEEPAGE
DEPTH
IN
FEET
Limited Access Rig Rotary Wash PENETRATIONRESISTANCE(BLOWS/FT.)Figure A-2,
Log of Boring R-14-002, Page 1 of 2
... CHUNK SAMPLEGROUNDWATER A. Sadr
SAMPLE
NO.CONTENT (%)(P.C.F.)DATE COMPLETED
DRY DENSITYEQUIPMENT
ELEV. (MSL.)96'MOISTUREBY:
BORING R-14-002
... CORE SAMPLE ... DRIVE SAMPLE (UNDISTURBED)
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
07135-42-04A
CLAYEY SAND (SC); medium dense; dark gray; wet; fine to medium gravel.
-Boulder (drilling stopped and resumed on 06/30/2014).
-06/30/2014 cored through the BOULDER; approximately 15".
-Dense; dark gray; wet; fine to medium grained with angular GRAVEL.
IGNEOUS ROCK (Salto Intrusive); massive; gray; highly weathered; hard;
fractured; medium grained; reddish orange iron oxide staining.
-Run 1 from 38' to 42'; recovery 100%; RQD 31%
-Becomes moderately weathered.
BORING TERMINATED AT 42 FEET.
Groundwater was not encountered.
Backfilled with bentonite slurry on 06/30/2014
ERi=79%
SCB2-6
B2-7
B2-8
B2-9
18.417
CORE
30
CORE
113.1
07135-42-04A.GPJ
MATERIAL DESCRIPTIONLITHOLOGY
... STANDARD PENETRATION TEST
SOIL
CLASS
(USCS)
... DISTURBED OR BAG SAMPLE
GEOCON
06-30-2014
SAMPLE SYMBOLS
... WATER TABLE OR SEEPAGE
DEPTH
IN
FEET
Limited Access Rig Rotary Wash PENETRATIONRESISTANCE(BLOWS/FT.)Figure A-2,
Log of Boring R-14-002, Page 2 of 2
... CHUNK SAMPLEGROUNDWATER A. Sadr
SAMPLE
NO.CONTENT (%)(P.C.F.)DATE COMPLETED
DRY DENSITYEQUIPMENT
ELEV. (MSL.)96'MOISTUREBY:
BORING R-14-002
... CORE SAMPLE ... DRIVE SAMPLE (UNDISTURBED)
30
32
34
36
38
40
42
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
07135-42-04A
SILTY SAND (SM); dense; brown; dry; fine to medium grained. (FILL)
SANDY lean CLAY (CL); soft; dark gray; moist; slightly plastic.
(ALLUVIUM)
Lean CLAY (CL); stiff; dark gray; moist; plastic.
pp=1.5 tsf.
-Groundwater at 10' below ground surface (no sample recovery).
-No sample recovery.
SANDY lean CLAY (CL); soft; gray; moist; medium plasticity.
IGNEOUS ROCK (Salto Intrusive); gray; moderately weathered; hard;
moderately fractured.
REFUSAL AT 22 FEET.
Groundwater encountered at 10 feet.
Backfilled with bentonite slurry on 06/30/2014
ERi=79%
SP
CL
CL
B3-1
B3-2
B3-3
B3-4
B3-5
22.114
10
14
50/5"
106.5
07135-42-04A.GPJ
MATERIAL DESCRIPTIONLITHOLOGY
... STANDARD PENETRATION TEST
SOIL
CLASS
(USCS)
... DISTURBED OR BAG SAMPLE
GEOCON
06-30-2014
SAMPLE SYMBOLS
... WATER TABLE OR SEEPAGE
DEPTH
IN
FEET
Limited Access Rig Rotary HSA PENETRATIONRESISTANCE(BLOWS/FT.)Figure A-3,
Log of Boring A-14-003, Page 1 of 1
... CHUNK SAMPLEGROUNDWATER M. Mehta
SAMPLE
NO.CONTENT (%)(P.C.F.)DATE COMPLETED
DRY DENSITYEQUIPMENT
ELEV. (MSL.)77'MOISTUREBY:
BORING A-14-003
... CORE SAMPLE ... DRIVE SAMPLE (UNDISTURBED)
0
2
4
6
8
10
12
14
16
18
20
22
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
07135-42-04A
SILTY SAND (SM); medium dense; light brown; moist; fine to medium
grained. (COMPACTED FILL)
SANDY lean CLAY; soft; dark brown; moist; medium plasticity.
(ALLUVIUM)
CLAYEY SAND (SC); medium dense; dark brown; moist; fine grained.
pp=1.5 tsf.
-Groundwater measured at 10 feet (when augers removed, not static level).
SANDY lean CLAY (CL); soff; light gray; moist; medium plasticity.
pp=0.5 tsf.
SILTY SAND (SM); Medium dense; light gray; wet; fine grained.
-Rod getting stuck due to sands.
-Becomes medium to coarse.
pp=1.0 tsf.
IGNEOUS ROCK (Salto Intrusive); gray; massive; moderately weathered;
hard; moderately fractured.
REFUSAL AT 26 FEET.
Groundwater encountered at 10 feet.
Backfilled with bentonite slurry on 06/30/2014
ERi=79%
SM
CL
SC
CL
SM
B4-1
B4-2
B4-3
B4-4
B4-5
B4-6
20.4
15
9
17
19
107.0
07135-42-04A.GPJ
MATERIAL DESCRIPTIONLITHOLOGY
... STANDARD PENETRATION TEST
SOIL
CLASS
(USCS)
... DISTURBED OR BAG SAMPLE
GEOCON
06-30-2014
SAMPLE SYMBOLS
... WATER TABLE OR SEEPAGE
DEPTH
IN
FEET
Limited Access Rig Rotary HSA PENETRATIONRESISTANCE(BLOWS/FT.)Figure A-4,
Log of Boring A-14-004, Page 1 of 1
... CHUNK SAMPLEGROUNDWATER M. Mehta
SAMPLE
NO.CONTENT (%)(P.C.F.)DATE COMPLETED
DRY DENSITYEQUIPMENT
ELEV. (MSL.)77'MOISTUREBY:
BORING A-14-004
... CORE SAMPLE ... DRIVE SAMPLE (UNDISTURBED)
0
2
4
6
8
10
12
14
16
18
20
22
24
26
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
07135-42-04A
SILTY SAND (SM); medium dense; brown; moist; fine to medium grained.
(FILL)
SANDY lean CLAY (CL); stiff; dark brown; moist; trace angular coarse
SAND and GRAVEL maximum size ½".
CLAYEY SAND (SC); loose; light brown; moist; fine to medium grained
SAND.
pp=1.5 tsf.
-Hard grinding noises - rig shaking - driller indicated bedrock.
IGNEOUS ROCK (Salto Intrusive); gray to light reddish; moderately
weathered; hard; fractured; trace reddish orange iron oxide mottling.
REFUSAL AT 8.5 FEET.
Groundwater encountered at 6 feet.
Backfilled with bentonite slurry 0n 07/01/2014
ERi=79%
SM
CL
SC
B5-1
B5-2 26.715 94.0
07135-42-04A.GPJ
MATERIAL DESCRIPTIONLITHOLOGY
... STANDARD PENETRATION TEST
SOIL
CLASS
(USCS)
... DISTURBED OR BAG SAMPLE
GEOCON
07-01-2014
SAMPLE SYMBOLS
... WATER TABLE OR SEEPAGE
DEPTH
IN
FEET
Limited Access Rig Rotary HSA PENETRATIONRESISTANCE(BLOWS/FT.)Figure A-5,
Log of Boring A-14-005, Page 1 of 1
... CHUNK SAMPLEGROUNDWATER M. Mehta
SAMPLE
NO.CONTENT (%)(P.C.F.)DATE COMPLETED
DRY DENSITYEQUIPMENT
ELEV. (MSL.)77'MOISTUREBY:
BORING A-14-005
... CORE SAMPLE ... DRIVE SAMPLE (UNDISTURBED)
0
2
4
6
8
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
07135-42-04A
SILTY SAND (SM); medium dense; light brown; damp; fine to medium
grained. (COMPACTED FILL)
SANDY CLAY (CL); firm; dark brown; moist; medium plasticity.
-Groundwater 5.5 feet measured on 07-02-2014.
LEAN CLAY (CL); stiff; light brown; moist; plastic.
pp=1.5 tsf.
IGNEOUS ROCK (Salto Intrusive); dark greenish gray; decomposed; soft;
intensely fractured COBBLE size; moderately weathered corestones.
-No recovery
-Highly to moderately weathered; dark gray with abundant iron oxide
mottling; hard; slightly fractured; in-filled with iron oxide.
REFUSAL AT 16 FEET.
Groundwater encountered at 5.5 feet.
Backfilled with bentonite slurry on 07/01/2014
ERi=79%
SM
CL
CL
B6-1
B6-2
B6-3
B6-4
B6-5
B6-6
35
9
67
50/6"
50/3"
07135-42-04A.GPJ
MATERIAL DESCRIPTIONLITHOLOGY
... STANDARD PENETRATION TEST
SOIL
CLASS
(USCS)
... DISTURBED OR BAG SAMPLE
GEOCON
07-01-2014
SAMPLE SYMBOLS
... WATER TABLE OR SEEPAGE
DEPTH
IN
FEET
Limited Access Rig Rotary HSA PENETRATIONRESISTANCE(BLOWS/FT.)Figure A-6,
Log of Boring A-14-006, Page 1 of 1
... CHUNK SAMPLEGROUNDWATER M. Mehta
SAMPLE
NO.CONTENT (%)(P.C.F.)DATE COMPLETED
DRY DENSITYEQUIPMENT
ELEV. (MSL.)77'MOISTUREBY:
BORING A-14-006
... CORE SAMPLE ... DRIVE SAMPLE (UNDISTURBED)
0
2
4
6
8
10
12
14
16
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
07135-42-04A
SILTY SAND (SM); medium dense; light brown; moist; fine to medium
grained SAND; with angular GRAVEL COBBLE maximum size 12".
(COMPACTED FILL)
CLAYEY SAND (SC); medium dense; brown to dark brown; moist; fine to
medium grained SAND; trace angular GRAVEL.
pp=4.5 tsf.
IGNEOUS ROCK (Salto Intrusive); soft; orangish brown; intensely
weathered; intensely fractured.
-Driller indicated very hard drilling; change to coring
Cored 15'-18' to confirm.
-Becomes gray; very hard; slightly fractured; moderately weathered.
REFUSAL AT 18 FEET.
Groundwater was not encountered.
Backfilled with bentonite slurry on 07/01/2014
ERi=79%
SM
SC
B7-1
B7-2
B7-3
B7-4
27
72/11"
CORE
07135-42-04A.GPJ
MATERIAL DESCRIPTIONLITHOLOGY
... STANDARD PENETRATION TEST
SOIL
CLASS
(USCS)
... DISTURBED OR BAG SAMPLE
GEOCON
07-01- 2014
SAMPLE SYMBOLS
... WATER TABLE OR SEEPAGE
DEPTH
IN
FEET
Limited Access Rig Rotary Wash PENETRATIONRESISTANCE(BLOWS/FT.)Figure A-7,
Log of Boring R-14-007, Page 1 of 1
... CHUNK SAMPLEGROUNDWATER M. Mehta
SAMPLE
NO.CONTENT (%)(P.C.F.)DATE COMPLETED
DRY DENSITYEQUIPMENT
ELEV. (MSL.)95'MOISTUREBY:
BORING R-14-007
... CORE SAMPLE ... DRIVE SAMPLE (UNDISTURBED)
0
2
4
6
8
10
12
14
16
18
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
07135-42-04A
SILTY SAND (SM); medium dense; light brown; moist fine to medium
grained with angular GRAVEL; some COBBLES maximum size 12".
(COMPACTED FILL)
CLAYEY SAND (SC); very dense; dark brown; moist; medium to coarse
grained with angular GRAVEL maximum size 2".
-Switch to coring due to large boulder.
SANDY lean CLAY; very stiff; olive to olive brown; moist; slightly plastic.
IGNEOUS ROCK (Salto Intrusive); gray; moderately weathered; hard
intensity; intensely fractured.
-Run 1 from 13' t0 15½'; recovery ?%; RQD 10%
-Very hard below 15 feet.
REFUSAL AT 15.5 FEET.
Groundwater was not encountered.
Backfilled with bentonite slurry on 07/01/2014
ERi=79%
SM
SC
CL
B8-1
B8-2
B8-3
B8-4
B8-5
18.854
CORE
22
CORE
07135-42-04A.GPJ
MATERIAL DESCRIPTIONLITHOLOGY
... STANDARD PENETRATION TEST
SOIL
CLASS
(USCS)
... DISTURBED OR BAG SAMPLE
GEOCON
07-01- 2014
SAMPLE SYMBOLS
... WATER TABLE OR SEEPAGE
DEPTH
IN
FEET
Limited Access Rig Rotary Wash PENETRATIONRESISTANCE(BLOWS/FT.)Figure A-8,
Log of Boring R-14-008, Page 1 of 1
... CHUNK SAMPLEGROUNDWATER M. Mehta
SAMPLE
NO.CONTENT (%)(P.C.F.)DATE COMPLETED
DRY DENSITYEQUIPMENT
ELEV. (MSL.)93'MOISTUREBY:
BORING R-14-008
... CORE SAMPLE ... DRIVE SAMPLE (UNDISTURBED)
0
2
4
6
8
10
12
14
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
07135-42-04A
SILTY SAND (SM); medium dense; light gray to white; moist; fine to
medium grained. (COMPACTED FILL)
CLAYEY SAND (SC); dense; dark brown to dark gray; fine grained.
-Loose; wet; dark grayish brown.
SILTY SAND (SM); medium dense; moist; light brown; fine to medium
grained.
-Becomes GRAVELLY from 20 o 23 feet.
SILTY to CLAYEY SAND (SM-SC); medium dense; moist; dark graysih
brown; fine to medium grained.
pp= 3 tsf.
SM
SC
SM
SM-SC
B9-1
B9-2
B9-3
B9-4
B9-5
42
9
27
38
26
07135-42-04A.GPJ
MATERIAL DESCRIPTIONLITHOLOGY
... STANDARD PENETRATION TEST
SOIL
CLASS
(USCS)
... DISTURBED OR BAG SAMPLE
GEOCON
06-18-2014
SAMPLE SYMBOLS
... WATER TABLE OR SEEPAGE
DEPTH
IN
FEET
D-120 Hollow Stem PENETRATIONRESISTANCE(BLOWS/FT.)Figure A-9,
Log of Boring A-14-009, Page 1 of 3
... CHUNK SAMPLEGROUNDWATER A. Sadr
SAMPLE
NO.CONTENT (%)(P.C.F.)DATE COMPLETED
DRY DENSITYEQUIPMENT
ELEV. (MSL.)104'MOISTUREBY:
BORING A-14-009
... CORE SAMPLE ... DRIVE SAMPLE (UNDISTURBED)
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
07135-42-04A
SANDY lean CLAY (CL); medium soft; dark grayish brown; mottled; light
gray; wet; little fine grained. (ALLUVIUM)
pp=0.5 tsf.
CLAYEY SAND (SC); loose to medium dense; dark grayish brown; wet; fine
to medium grained.
SEDIMENTARY ROCK (Poorly indurated SANDSTONE); moderately
bedded; light greenish gray; moderately weathered; soft. (SANTIAGO
FORMATION); [SILY SAND (SM); dense; moist, fine to medium grained,
weakly cemented]
-Switched to coring
IGNEOUS ROCK (Salto Intrusive); massive; bluish gray; moderately
weathered; very hard; moderately fractured; strong; fractures range from
approximately 45º to near vertical.
-Run 1 from 46' t0 50'; recovery 69%; RQD 46%
-Run 2 from 50' t0 54'; recovery 87%; RQD 23%
-Run 3 from 54' t0 56'; recovery 96%; RQD 92%
-Run 4 from 56' t0 61'; recovery 98%; RQD 39%
CL
SC
SC
B9-6
B9-7
B9-8
B9-9
9
15
30
50/5.5"
CORE
CORE
CORE
CORE
07135-42-04A.GPJ
MATERIAL DESCRIPTIONLITHOLOGY
... STANDARD PENETRATION TEST
SOIL
CLASS
(USCS)
... DISTURBED OR BAG SAMPLE
GEOCON
06-18-2014
SAMPLE SYMBOLS
... WATER TABLE OR SEEPAGE
DEPTH
IN
FEET
D-120 Hollow Stem PENETRATIONRESISTANCE(BLOWS/FT.)Figure A-9,
Log of Boring A-14-009, Page 2 of 3
... CHUNK SAMPLEGROUNDWATER A. Sadr
SAMPLE
NO.CONTENT (%)(P.C.F.)DATE COMPLETED
DRY DENSITYEQUIPMENT
ELEV. (MSL.)104'MOISTUREBY:
BORING A-14-009
... CORE SAMPLE ... DRIVE SAMPLE (UNDISTURBED)
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
07135-42-04A
-Strong iron staining along fractures
-Moderately fractured.
-Run 5 from 61' t0 64'; recovery 100%; RQD 20%
-Run 6 from 64' t0 66'; recovery 100%; RQD 0%
-Intensely fractured.
REFUSAL AT 66 FEET.
No groundwater.
Backfilled with bentonite slurry
ERi=80%
CORE
CORE
07135-42-04A.GPJ
MATERIAL DESCRIPTIONLITHOLOGY
... STANDARD PENETRATION TEST
SOIL
CLASS
(USCS)
... DISTURBED OR BAG SAMPLE
GEOCON
06-18-2014
SAMPLE SYMBOLS
... WATER TABLE OR SEEPAGE
DEPTH
IN
FEET
D-120 Hollow Stem PENETRATIONRESISTANCE(BLOWS/FT.)Figure A-9,
Log of Boring A-14-009, Page 3 of 3
... CHUNK SAMPLEGROUNDWATER A. Sadr
SAMPLE
NO.CONTENT (%)(P.C.F.)DATE COMPLETED
DRY DENSITYEQUIPMENT
ELEV. (MSL.)104'MOISTUREBY:
BORING A-14-009
... CORE SAMPLE ... DRIVE SAMPLE (UNDISTURBED)
60
62
64
66
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
07135-42-04A
APPENDIX B
Project No. 07135-42-04A - B-1 - August 21, 2014
APPENDIX B
LABORATORY TESTING
We performed laboratory tests in general accordance with California Test Methods (CTM) and generally
accepted test methods of the American Society for Testing and Materials (ASTM). We performed the
following tests:
In-Place Dry Density and Moisture Content: ASTM D2937 (CTM 226) – 5 tests
Grain Size Distribution/Percent Passing No. 200 Sieve: ASTM D 422 – 3 tests
Direct Shear: ASTM D 3080 – 2 tests
pH and Resistivity: CTM 643 – 3 tests
Sulfate Content: CTM 417 – 3 tests
Chloride Content: CTM 422 – 3 tests
Sand Equivalent: ASTM D 2419 – 3 tests
Unconfined Compression: ASTM D 2166 – 4 tests
Plasticity Index: ASTM D 4318 – 2 tests
Uniaxial Compressive Strength: ASTM D 7012 – 2 tests
Test results are presented on the following tables and figures. Brief descriptions of the laboratory testing
conditions and procedures are presented below:
In situ moisture content and dry density tests were performed on five selected tube samples. Tests were performed in general accordance with ASTM D 2937 (CTM 226). Results are presented in
Table B-I and on the Boring Records in Appendix A.
Grain size distribution and percent passing the No. 200 sieve (200-wash) tests were performed on three selected soil samples in accordance with ASTM D 422. Tests results are summarized in
Table B-II. Grain size distribution curves are depicted on Figure B-1.
Direct shear tests were performed on two selected soil samples in accordance with ASTM D
3080. Test results are summarized in Table B-III.
Soil corrosion parameters (pH, resistivity, sulfate and chloride content) tests were performed on
three combined soil samples in accordance with CTM 643, 417 and 422. Test results are
summarized in Tables B-IV, B-V, and B-VI.
Five soil samples were tested for their Sand Equivalent in accordance with ASTM D 2419. The
results are presented in Table B-VII.
Unconfined Compressive Strength tests were performed on two soil samples in accordance with
ASTM D 2166. The test results are summarized in Table VIII.
Project No. 07135-42-04A - B-2 - August 21, 2014
Plasticity Index tests were performed on two soil samples in accordance with ASTM D 4318. The results are presented in Table B-IX.
Uniaxial Compressive Strength tests were performed on two rock cores in accordance with
ASTM D 7012. The results are presented in Table B-X.
The remaining soil samples are now stored in our laboratory for future reference and analysis if needed.
All soil and rock samples will be kept in Geocon laboratory for an additional 6 months following
completion of the final report.
TABLE B-I
SUMMARY OF LABORATORY IN SITU MOISTURE CONTENT AND DRY DENSITY
TEST RESULTS (ASTM D 2937/CALIFORNIA TEST METHOD 226)
Boring/ Sample No. Sample Depth (feet) Dry Density (pcf) Moisture Content (% dry wt.)
R-14-001/ B1-2 5 114.7 11.6
R-14-001/ B1-4 15 129.4 9.3
R-14-002/ B2-6 30 113.1 18.4
A-14-005/B5-2 5 94.0 26.7
R-14-008/B8-2 5 - 18.8
TABLE B-II
SUMMARY OF LABORATORY GRAIN SIZE DISTRIBUTION TEST RESULTS
(ASTM D 422)
Boring/ Sample No. Sample Depth (feet) % Gravel % Sand % fines USCS Classification
R-14-001/ B1-7 30 8 64 28 SM
A-14-002/ B2-6 30 0 68 32 SM
A-14-004/B4-4 15 0 79 21 SM
TABLE B-III
SUMMARY OF LABORATORY DIRECT SHEAR TEST RESULTS
(ASTM D 3080)
Boring/ Sample No. Sample Depth (feet) Dry Density (pcf) Moisture Content (%) Cohesion (psf) Angle of Shear Resistance
(degrees)
R-14-002/B2-4 20 111.3 17.0 860 22
A-14-004/B4-4 15 107.0 20.4 660 27
Project No. 07135-42-04A - B-3 - August 21, 2014
TABLE B-IV
SUMMARY OF LABORATORY POTENTIAL OF HYDROGEN (PH) AND RESISTIVITY TEST RESULTS
(CALIFORNIA TEST METHOD 643)
Boring/Sample No. Sample Depth (feet) pH Resistivity (ohm centimeters)
R-14-001/B1-1 0 7.5 820
A-14-004/B4-3 10 8.4 900
A-14-005/B5-2 5 7.8 590
TABLE B-V
SUMMARY OF LABORATORY WATER-SOLUBLE SULFATE TEST RESULTS
(CALIFORNIA TEST METHOD 417)
Boring/Sample No. Sample Depth (feet) Water-Soluble Sulfate, ppm
R-14-001/B1-1 0 420
A-14-004/B4-3 10 40
A-14-005/B5-2 5 100
TABLE B-VI
SUMMARY OF LABORATORY CHLORIDE CONTENT TEST RESULTS
(CALIFORNIA TEST METHOD 422)
Boring/Sample No. Sample Depth (feet) Chloride Ion Content, ppm
R-14-001/B1-1 0 230
A-14-004/B4-3 10 150
A-14-005/B5-2 5 100
TABLE B-VII
SUMMARY OF LABORATORY SAND EQUIVALENT TEST RESULTS
(ASTM D 2419)
Boring No. Sample No. Sample Depth (feet) Sand Equivalent
R-14-001 B1-2 5 14
R-14-001 B1-4 15 33
A-14-003 B3-1 2 12
A-14-004 B4-4 15 19
A-14-007 B7-4 0 16
Project No. 07135-42-04A - B-4 - August 21, 2014
TABLE B-VIII
SUMMARY OF LABORATORY UNCONFINED COMPRESSIVE STRENGTH TEST RESULTS
(ASTM D 2166)
Boring No. Sample No. Unconfined Compressive Strength (psi)
R-14-001 B1-6 9.2
A-14-003 B3-2 16.3
TABLE B-IX
SUMMARY OF LABORATORY PLASTICITY INDEX TEST RESULTS
(ASTM D 4318)
Boring No. Sample No. Liquid Limit (%) Plastic Limit (%) Plasticity Index (%) Soil Classification
R-14-001 B1-6 33 17 16 CL
R-14-002 B2-6 30 19 11 CL
TABLE B-X
SUMMARY OF LABORATORY UNIAXIAL COMPRESSIVE STRENGTH TEST RESULTS
(ASTM D 7012)
Boring No. Sample No. Uniaxial Compressive Strength (psi)
A-14-009 B9-10A 23,050
A-14-009 B9-10B 20,700
0
10
20
30
40
50
60
70
80
90
100
0.0010.010.1110
3/8" 4
30.0
PROJECT NO. 07135-42-04A
U. S. STANDARD SIEVE SIZE
COARSE
3"3/4"1-1/2"8 16 20 30 40
PL
FINE
NAT WCPERCENT FINER BY WEIGHT30.0
(SM) Silty SAND15.0
PI
COARSE
GRAVEL
07135-42-04A.GPJ
A-14-004
CARLSBAD, CALIFORNIA
(SM) Silty SAND
SAND
MEDIUM
5060 100 200
SAMPLE
GEOCON
SILT OR CLAYFINE
GRAIN SIZE IN MILLIMETERS
CLASSIFICATION
R-14-001
R-14-002
LL
(SM) Silty SAND
10
DEPTH (ft)
QUARRY CREEK BRIDGE
GRADATION CURVE
Figure B-1
APPENDIX C
APPENDIX C
LOG OF TEST BORINGS
FOR
QUARRY CREEK BRIDGE
CARLSBAD, CALIFORNIA
PROJECT NO. 07135-42-04A
APPENDIX D
APPENDIX D
ANALYSES AND CALCULATIONS
FOR
QUARRY CREEK BRIDGE
CARLSBAD, CALIFORNIA
PROJECT NO. 07135-42-04A