HomeMy WebLinkAboutCT 05-12; Ocean Street Residences; SOILS REPORT OF OCEAN STREET RESIDENCES; 2013-02-19WNCED GEOTECHNICAL SOLUTIONS. INC.
9707 Waples StreeL Suite 150
Diego, California 92121
ephone: (6 i 9) 708-1649 Fax; (714) 409-3287
Zephyr Partnere -luly ! 6,2013
I 1750 Sorrento Valley Road, Suite 1,30 P/W 1205-06
San Diego, C A 92121 Report 1205-06-B-8
Attention: Mr. Jim McMena,min
Subject: Geoteclmical Review of Proposed Ocean Street Residences Litjuefaction
Mitigation and Response to Esgil Review Cominents (Carlsbad PC134M>3tt),
City of Carlsbad, Cmiifornia
Gentlemen:
In accordance to your request .Advanced Geotechnical Solutions, Inc. (A(JS) has reviewed the propesed
ground improvement design prepared by Hayward Baker Geotechnical Construction (2013) and prepared
a response to Esgil Review comment (52) regarding design and constii.iCiion procedures for iiquefiictiori
mitigation measures forthe northern portion ofthe project.
The following is AGS's response to the reviewer's comments:
AGS has reviewed the referenced Stone Column Submittal at Ocean Street Residences (I IB 2013). leased
upon our review the proposed design and methodology is consistent with the current standard of care and
generally meets the liquefaction mitigation recommended in our referenced reports. As is typical for
these types of ground improvement mitigation measures the initial design methodology will be veritled
during the con.struction process by additional field testing (Cone Penetrometer Soundings (CPT")) and
analysis of the data by both AGS and the General Contractors (HB) Licensed Geotechnical Engineer.
Typically the procedure for approval will consist ofthe following;
1. Install initial series of production stone columns by the general Contractor.
2. histallatioii ofthe stone columns is performance based and can be modified during construction to
meet the design criteria. For this project the performance criteria consists of: mitigation of surface
manifestation (loss of bearing, sand boils, and ground cracking); and micig.-ition of dynamically
induced settlement to I inch or less utilizing the design earthquake (M=6.9 with site acceleration
of a=0.4g). Shoukl testing (CPT) and liquefaction analysis indicate that these design measures are
not being met then the depth, spacing, and or diameter ofthe stone columns will be modified to
meet the design criteria.. Subsequent CPT testing aod analysis would then be conducted to verity
ttiat the modification ofthe stone coliimirs (i.e. depth, spacing, a,nd diameter) has been met.
3. A final letter report would be prepared by HB and reviewed by AGS that would summarize the
actual construction (location, spacing, mtd diameter of the stone columns). As part, of this final
submittal a liquefaction and theoretical dyD,aniic settlement analysis would be included.
During construction it is thc responsibility ofthe specialty contractor (HB) to insure that the installation
ofthe stone colum,ns is not adversely affecting adjacent properties and i.mprovements. Accordingly, it is
incumbent upon the contractor to develop a monitoring plan prior to construction. On similar projects
ORANGE AND L.A, COUNTIES INLAND EMPIRE SAN DIEGO AND IMPERIAL COUNTIES
(71T) 786-5661 (619)708-1649 (619)850-3980
Page 3 .luly 16,2013
Report 1205-06-B-8 P/W 1205-06
REFE,R,ENCES
Hayward Baker Geotechmca! Construction, Inc. (HB 2013). Stom Column Construction Submittal Soil
Improvement Ocean Street Residences (CD 12-09), City ofCarhbad, California, .luly 15, 2013.
Esgil Corporation, Plan Clwck Review Comments, Multi Family Condominium (implex and Parking
Garage, 2303Ocean Street, Carlshad Calijarnki, dated .Jiify 3, 2013.
Advanced Geotechnical Solutions, Inc. (2013d). Geoiechnical Review of Struetura! Plans Ocean Sireel
Residences (CD 12-09), City ofCarlsbad, California. P/W 120.5-06. Report P/W12054)6-8-7, June
19, 2013.
Advanced Geotechnical Solutions, Inc. (2013c). Supplemental Geotechnical Recommendations Ocean
Street Residences (CD 12-09). Ciiy ofCarlsbad Califbmia, P/W 1205-06. Report P/W1205-06-8-6,
May 22, 2013.
Advanced Geoiechnical Solutions. Inc. (20I3h). Preliminary Geotechnical Recommendations for
PernKahle Pavers and "Grass Pave", Ocean Street Residences (CD 12-09), City qf Carlsbad,
California, P/W 1205-06, Report P/WI205-06-B-5, April 12, 2013.
Advanced Geotechnical Solutions, Inc. (2013a). Grading Plan Review, Ocean Street Residences (CD 12-
09), City of Carlsbad, California (CD 12-09), City of Carlshad Caiifbrnia P/W 1205-06, Report
P/W1205-06-B-3, March 19, 2013.
Advanced Geotechnical Solutions, Inc. (2012). Response to Cycle Review Comments Ocean Street
Residences (CD 12-09). City of Carlsbad California, P/W 1205-06, Report P/W1205-06-B-2, October
30, 2012.
Geocon Inc., Geotechnical Investigation, Ocean Street Condominiums, Ocean Street and Mountain View
Drive, Carlsbad, California, dated September 3, 2004 (project no. 07353-22-01).
RBF Consulting, A Baker Company, Ocean Street Residences, Tentative Tract Map, dated October 8,
2012, Sheets 1 through 8.
City of Carlsbad, Memorandum CDI2-09-Ocean Street Residences 2'"' Review, dated October 25, 2012.
ADVANCED GEOIECHNICAL SOLUTIONS, INC.
Hayward Baker Inc.
10303 Channel Road
Ukeside.CA 92040
Tel: 619-956-0850
Fax: 619-956-0863
HAYWARD
BAKER
Geotechnical Construction
Stone Column Submittal
Ground Improvement at Ocean Street Residences
Carlsbad, California
CT C?5 'IZ , OP 12-^?^
THINI^SAFE
California • Colorado • Florida • Georgia • Illinois • Maiyland • Minnesota • Missouri
New jersey • New Yoilc • North Carolina • Pennsylvania • Rhode Island
Tennessee • Texas • Utah • Washington • Albeita • Br itish Columbia • Ontario
www.HaywardBaker.com
Equal Opponunily Ewployei
Stone Column ConstiTiction
Table of Contents:
1.
2.
3.
4.
5.
Introduction
Method Statement
Vibro-Stone Columns
Equipment
Schedule
Quality Assurance and Verification
Testing
Material Test Data
Shop Drawings
Design Basis
Analytical Approach
References
Pg.2
Pg.2
Pg.2
Pg-
Pg.
Pg.
Pg.4
Pg.4
Pg.4
Pg.5
Pg.7
Appendix A Drawing - HBI-1 - Stone Column Layout
Appendix B Design Calculations
Appendix C Sieve analysis of % inch crushed rock
Appendix D Vibro Log
HAYWARD
BAKER
Geotechnical Construclion
Hayward Baker Inc.
10303 Channel Road
Lakeside, CA 92040
Tel:
Fax:
619-956-0850
619-956-0863
HAYWARD
BAKER
Geotechnical Construction
July 15,2013
MKG Consulting
20857 Parkridge
Lake Forest, CA 92630
Attention: Mr. Michael Gaddie
Subject: Stone Column Construction Submittal
Soil Improvement at Ocean Street Residences
Carlsbad, Califomia
Dear Mr. Gaddie:
Hayward Baker Inc. (HBI) is pleased to submit the enclosed ground improvement design
and associated layout drawings for the above referenced project. This submittal,
including any engineering and/or designs incorporated herein, was prepared and is
fumished by HBI. We performed this evaluation in a manner consistent with the standard
of care ordinarily exercised by members of the geotechnical engineering community
practicing in the site area.
The following sections outline our equipment, material requirements, design basis,
analytical approach, scope of work, and acceptance criteria design to mitigate the
liquefaction potential.
We appreciate the opportunity to be of service. Plei
have any questions.
Sincerely,
HAYWARD BAKER INC.
Rommel Mallari
Project Manager
idersigned if you
Sunil Arora, PE
Project Manager
THINI^SAFE
California • Colorado • Florida • Georgia • Illinois • Maiyland • Minnesota • Missoui i
New Jereey • New Yoit • Noith Carolina • Pennsylvania • Rhode Island
Tennessee • Texas • Utah . V\/ashington • Alberta • British Columbia • Ontario
www.HaywardBaker.com
Equal Opporturoly Emp/oyei
Stone Columns Submittal
Ocean Street Residences
Page 2 of8
INTRODUCTION:
An approximate 3 acres site is being developed along Ocean Street in the City of
Carlsbad. The proposed construction consists of 35 residential stmctures comprised of
two story duplexes.
1. METHOD STATEMENT
Our shop drawing in Appendix A depicts our soil improvement plans of stone column for
the proposed expansion. The stone column treatment program will address liquefaction.
Confirmation of improvement effectiveness will be evaluated by performing a series of
CPTs after the stone column construction.
Following stone column installation, anticipated heave material shall be removed by
others. A minimum of the top 24 inches (61 cm) shall be excavated and backfilled with
cohesionless Engineered fill to at least 90% relative compaction according to ASTM
D1557,
A brief description of the proposed techniques is as follows:
Vibro-Stone Columns: This ground improvement technique uses specialty purpose-built
depth vibrators to densify and reinforce the soils while constmcting a stone coltimn of an
average 3 feet (0.9 m) diameter. HBI may predrill the top 7 feet (2 m) with a 24 inch (0.6
m) (approximate) continuous flight augers to enable the vibrator to penetrate through the
stiffer crust. HBI may choose to predrill deeper as site conditions dictate. Please refer to
drawing in Appendix A for layout spacing.
The installation process consists of imparting energy by means of vibrations that are
generated close to the tip of the vibrator and are produced by rotating eccentric weights
mounted on a shaft. An electric motor tums the eccentric weights. Follower tubes are
added to achieve the varying design depth (up to 35 ft (10.7 m)). To install a stone
column, the vibrator is suspended from a crane/excavator. The vibrator is lowered into
the ground under the action of its own weight, vibrations, and air jetting. Upon reaching
the design depth, the vibrator is lifted in stages as the stone is fed through a side pipe and
expelled at the tip of the vibrator. Cohesionless soils are densified while cohesive soils
are reinforced by the installation of the column. The program would consist of a grid
pattern of stone columns designed to achieve allowable deformations in the slab areas
while minimizing the liquefaction potential. Pre-augering may be performed to a depth of
approximately 7 feet or more below the working surface.
Installation of stone columns by the dry bottom feed method displaces the ground. Some
heave may occur across the areas worked. Any vibration and/or movement monitoring of
HAYWARD
BAKER
Geotechnical Construction
Stone Colunms Submittal
Ocean Street Residences
Page 3 of8
adjacent stmctures or improvement shall be performed by others. Verification of
improvement shall be undertaken by others using cone penetration testing (CPT) after
stone column installation. Acceptance of the work will be in accordance with the
acceptance criteria outlined in this document.
Equipment: Major support equipment anticipated to be utilized for stone column
construction consists of:
• 100 ton or bigger crawler crane/excavator
• Excavator mounted drill for pre-drilling approximately top 10 feet of soil
• Generator to power the vibrator
• Air Compressor to push gravel through the follower tube
• Loader to move gravel from stock pile to skip bucket (hanging from
crane) or Gradall
Schedule: Based on estimated quantities and depending on the work hours allowed by
the Contractor and Owner, HBI anticipates Stone Column Constmction to take
approximately 7 to 8 weeks utilizing 10 hour shift working five days a week. This
duration excludes mobilization, demobilization and any testing/wait times. Work area
will be divided into sectors; HBI will complete one sector at a time, allowing testing to be
performed while work is proceeding in other sectors.
Quality Assurance and Verification Testing:
Quality control will be performed by the Site Superintendent ensuring that all production
data is present in the vibro-logs and is in accordance with the drawings. Attention is
required to ensure that HBI is getting adequate amperage (in excess of 160 A) while
constmcting the columns and maintenance of the average theoretical diameter of 3 feet.
Average diameter of the column is calculated from the stone volume utilized for the
respective column. One loader bucket holds approximately 2 cubic yard of material.
Depth of the column will be checked with the markings on the vibrator.
These logs will be reviewed by HBI's Project Manager on a weekly basis (more
frequently, if needed). Appropriate changes will be made as field conditions dictate in
order to meet the design intent. Any changes to the design shall be proposed by HBI and
shall be reviewed and approved by the Engineer.
The acceptance criteria of stone column treatment will be based on verifying the design
described below by means of CPT tests, complemented by SPT tests, if necessary.
Post stone column installation CPTs are to be located at a point indicative of the average
conditions achieved by the ground improvement program. HBI suggests performing post
constmction CPTs close to the pre-constmction CPTs, but shall have at least two rows of
stone columns in all directions. The treatment site will be divided into sectors. Each
HAYWARD
BAKER
Geotechnical Corstruction
Stone Columns Submittal
Ocean Street Residences
Page 4 of8
sector will be evaluated with a CPT and if necessary complemented with an SPT to
obtain samples, verify classification of the soil, and match against the Chinese
liquefaction criteria (NCEER, 1997; SCEC, 1999). HBI suggests at least 10 days pass
after installation of stone columns before CPT testing is conducted. This will allow the
dissipation of the excess pore water pressure induced by our vibrator.
The CPTs will be digitally analyzed by HBI in general agreement with procedures used
in this document for the evaluation of pre-improvement conditions. Additionally, the
effect ofthe stone column presence and reinforcement will account for a reduction factor.
At footing locations, the results of the CPT liquefaction settlement will be combined with
expected resuhs for the post constmction amovmts of static settlement. The static
settlement reduction factor will be calculated in accordance with Priebe (1976).
In the event that dynamic settlements appear to exceed the total or differential
settlements, HBI may proceed to investigate the nature of the soil by using the SPT
allowed for by the Contractor/Owner together with relevant laboratory testing,
Altematively, HBI could install additional stone columns or use other means of
improving the groimd to achieve the performance specification.
2. MATERIAL TEST DATA:
HBI proposes to utilize aggregate for stone column constraction. Attached as Appendix C
is the sieve analyses from Vulcan Material (supplier).
3. SHOP DRAWINGS:
Our shop drawing in Appendix A depicts our soil improvement plans of stone column for
the proposed expansion.
4. DESIGN BASIS:
We have based oiu" feasibility and design on information obtained from Advanced
Geotechnical Solutions, Inc. (AGS) Grading Plan Review report dated on March 19,
2013. In accordance with HBI's analyses, existing soil to the depths of to 35 feet from the
existing ground surface is contributing to most of the liquefaction induced settlement.
By constmcting a stone column approximately up to 35 feet from existing grade, HBI
expects to reduce hazards (induced by liquefaction) related to the following issues with
the proposed stone column plan:
• Liquefaction Induced Settlement
• Surface Manifestation
• Differential Settlement
HliAM^lMUfVRD BAKER
Geotcchnknl Corwtfuction
Stone Columns Submittal
Ocean Street Residences
Page 5 of8
Input Parameters for the design are as follows:
• Design groundwater level: +7 ft (+2.4m) MSL
• Design earthquake magnitude, Mw: 6.9
• Design peak ground acceleration: 0.4g
ANALYTICAL APPROACH
a. Generalized soil profile and pre-improvement deformations:
The report by AGS indicates that "the site is underlain by old paralic deposits. The old
paralic deposits are subsequently overlain by undocumented engineered fill and alluvial
soils of variable depths. In general, the artificial fill consists of clayey to silty sands,
sand are slightly moist to saturated, loose to dense. The alluvium generally consists of
sands, silty sand to sandy silts and clays. The deeper deposits are poorly consolidated.
The paralic deposits can be described as two distinct subunits; a coarse grained sub unit
characterized hy dense to medium dense silty sands to san and fine grained sub units
characterized by medium firm to hard sandy silts and clays.
According to AGS, the site is underlain by potentially liquefiable soils. Liquefaction is a
phenomenon where loose, saturated coarse-grained soils lose their strength and acquire
some mobility from strong ground motion induced by earthquakes. However, soil
improvement can be utilized to mitigate liquefaction potential.
b. Dynamic Settlement Analysis and Improvement Program:
Liquefaction analyses were undertaken in general accordance with procedures outlined
by Youd and Iddriss NCEER 1997, and Martin and Lew SCEC, 1999 with modifications
for calculation of fmes content in accordance with Baez, Martin, and Youd (2000). Given
the earthquake parameters outlined in Section 1, liquefaction evaluations shall be
performed at post CPT locations, based on following design assumptions:
Design highest groundwater depth: 8 feet (2.4 m)
Ground water table depth during CPT tests 8 feet (2.4 m)
Design earthquake magnitude, Mw: 6.9
Design peak ground acceleration: 0.4g
Dynamic settlement analyses shall be performed in general accordance with Tokimatsu
and Seed, 1984 procedures. The stated procedures were developed as a function of
penetration resistance in terms of a CPT tip resistance. The thin layer correction may be
used for post constmction dynamic settlement analysis.
Gcote<hnical Comtruction
Stone Columns Submittal
Ocean Street Residences
Page 6 of 8
The ground improvement program has been designed to address liquefaction settlement.
To accomplish the liquefaction mitigation the soil must be densified, drained, reinforced,
or replaced in part or in total. In general, procedures for the liquefaction design with
vibro-stone columns were followed in accordance with methods presented by Baez and
Martin (1993) and Baez (1995). The degree of densification resulting from the
installation of vibro-stone columns is a fiinction of many factors, including: soil type, silt
and clay content, uniformity of soil gradation, plasticity of the soils, initial penetration
resistance, energy input, backfill material, and area replacement ratios (relationship
between area of stone to tributary area per stone column). Based on past experience we
have determined that a vibro-stone column program consisting of a spacing of
approximate 9 feet center-to-center would achieve the intended performance criteria
within the ground improvement area, as shown in HBI soil improvement shop drawing in
Appendix A. Effectiveness of stone column layout plan will be confirmed by post
constmction CPTs.
The area replacement ratio of 8.7% for 3.0 ft diameter stone columns in the planned grid
will provide a dynamic settlement improvement reduction value of 1.6. This
improvement factor is to be applied to the calculated free field settlements obtained from
the CPT.
HBI has not performed FLAC analysis for this specific site. However, a copy of a
numerical analysis performed for HBI's previous project is attached (Appendix B). The
analysis evaluates the dynamic settlement of a liquefiable soil profile with and without
stone columns. Analyses were performed using the finite difference computer program
FLAC. The attached analyses were performed for a case where the stone colurrm spacing
was 10 feet (squared grid) and the stone column diameter was 3 ft in sand layers. This
combination of stone column parameters equates to an area replacement ratio of 7.1%. In
this case the dynamic settlement improvement factor, when compared to computations of
free field settlements, was 1.5; in other words, by installing the stone columns the free
field settlements are reduced by 33%. An outline ofthe analytical steps is also attached.
We anticipate that average post treatment liquefaction settlements will be below 1.0 inch
in the stone column treated area.
HAYWARD
Geocechmcd ConstrucUon
Stone Columns Submittal
Ocean Street Residences
Page 7 of8
REFERENCES
Baez, J.I. and G.R. Martin (1993) "Advances in the Design of Vibro Systems for the
Improvement of Liquefaction Resistance," Symposium of Ground Improvement,
Vancouver Geotechnical Society, Vancouver, B.C.
Baez J.I. (1995) "A Design Model for the Reduction of Soil Liquefaction by Vibro-
Stone Columns," Ph.D. Dissertation, University of Southem Califomia.
Baez, J.L, Martin G.R., and T.L. Youd (2000) "Comparison of SPT-CPT
Liquefaction Evaluations and CPT Interpretations," GSP No. 97, Innovations and
Applications in Geotechnical Site Characterization, Proceedings of Sessions of Geo-
Denver 2000.
Christian Wheeler Engineering (CWE), 2008, Preliminary Geotechnical
Investigation, Proposed Holiday Irm Building Expansion, San Diego, Califomia,
Prepared August 14,2008 (Project No. CWE 2070455.01)
Gilstrap, S.D., and T.L. Youd (1998) "CPT Based Liquefaction Resistance Analyses
Evaluated Using Case Histories," Master of Science Thesis, Technical Report CEG-
98-01, Department of Civil and Environmental Engineering, Brigham Yoimg
University, Provo, Utah.
Martin, G.R. and M. Lew (1999) "Recommended Procedures for Implementation of
DMG Special Publication 117 -Guidelines for Analyzing and Mitigating
Liquefaction in California-" Southern California Earthquake Center.
Priebe, H.J. (1976) "Abschatzung des Setzungsverhaltens eines durch
Stopfverdichtung verbesserten Baugmndes," Die Bautechnik, 53 (H.5)
Priebe, H.J. (1995), "The design of Vibro Replacement", Ground Engineering,
December, 31-37.
Robertson and Woeller (2005), "Geotechnical Site Investigation Using the Cone
Penetration Test" Short course sponsored by Gregg.
Schmertmann (1970) "Static Cone to Compute Static Settiement Over Sand," Journal
of Soil Mechanics and Foundations, Div ASCE, Vol. 96, No. SM3, May, pp. 1011-
1043
Tokimatsu, K., and H.B. Seed (1984) "Simplified Procedures for the Evaluation of
Settiements in Clean Sands," Report No. UCB/GT-84/16, Earthquake Engineering
Research Center, University of Califomia, Berkeley.
HAYWARD
Geotechnical ConstnicUon
Stone Columns Submittal
Ocean Street Residences
Page 8 of 8
Youd, T.L. and I.M. Idriss (1997) "Proceedings ofthe NCEER Workshop on
Evaluation of Liquefaction Resistance of Soils," NCEER Technical Publication 97-
0022.
HAYWARD
BAKER
Geotechnical Comtruction
Appendix A
HAYWARD
Geotechnical Construction
OCEAN STREET RESIDENCES
Cailsbnd, Callfuriila
Appendix B
HAYWARD
BAKER
Geotechnical Construction
ANALYSIS PROCEDURES
1, Detennining jnodiiliis of liquefied sand in FLAC
• Use the soil profile without stone column
• Determine initial stress distribution under 2000 psf surface load before liquefaction
• Change the modulus of the liquefied sand to achieve 3% (or I %) volumetric strain
• Output liquefied sand modulus as a function of depth
2, Calculating bulk modulus and shear modulus in EXCEL program
• Afler the sand liquefied, assuming Estone=3Br, |t=0.4 at each depth
• Output modulus of stone column as a function of depth
3, Computing seltlement of the soil profile with stone column in FLAC
• Determine initial stress distribution under 2000 psf surface load with stone column
before liquefaction, assuming Ko=0.575
• The soil properties of clay layers and stone column in clay layers remain the .same
during earthquake
• Change the modulus of the liquefied sand obtained from step I
Change the modulus of the stone column obtained from step 2
• Calculate deformation and stress distribution
• Post-process weighted average vertical strain at each depth
.>w>S . nv
ml
• Output vertical displacement and verlical stress contours
4. Calculating settlement infiuence ratio and plotting in EXCEL file.
HAYWARD
BAKER
Geotechnical Constructton
Analysis ofScttlcnicnt Rediicllon by Slone Column in Liquefied Sand
!• LAC MODEL
2-D Axial Synimelric: represenling lO'xIO" grid
Coiistiliitive Model: Mohi-Coiilomb 2000 psf
lililli
Stone Column
(t)=42.5°
... I
Stone Column
(|)=42.5°
tr
f:
Stone Column
((.=37.5°
Eslono=3Er
Elev. 0
Stiff Clay
Su=2000 psf
E=3e5 psf, 1.1=0.4
Elev. 5
Medium Clay
Su=1000 psf
E=2e5 psf, 1.1=0.4
4
Elev. 16
Loose Sand
Before LQ:
(t.=32°, n=0.37
E=3e5 psf
After LQ:
Su=300 psf
fi=0.4
Svoi=3%, or 1%
Er calculated
-J Elev. 26'
a: 5.56'
HAYWARD
Geotechnica I Con&tt uction
SUMMARY OF RESULTS
Table I. Settlement of groimd surface with stone column
File
Name
LQ Depth
(ft)
Vol. Strain in
LQ Sand
(%)
Ground Surface
Settlement without
Stone Column (ft)
Ground Surface
Settlement with
Stone column (ft)
N
Iq14e 16-26 3 0.3 0.22 1.4
lq16 16-26 1 0.1 0,07 1.5
Iq17 26-36 3 0,3 0.20 1,5
Iq18 36-46 3 0.3 0.20 1.5
The settlement ofthe ground suiface due to the liquefaction of the loose sand layer is a
function of the sand layer thickness, depth, volumetric strain of the liquefied sand, the
modulus ofthe stone column, Poission's ratio, and the initial stress distribution. The 16
ft thick ciay cap minimizes the differential settlement on the ground surface. Due to the
local effect, the strain reduction factor increases near the interface between the liquefied
sand layer and the clay cap. The average seUlemenl reduction is about 1.5.
This analysis is conservative. The residual strength of liquefied sand was estimated as
300 psf, without any improvement due to the vibro-densification of stone column
installations. The lateral stress in the sand layer was assumed as 0.575 Ov . It was found
in the analysis that the lateral stress had significant effect on the settlement.
HAYWARD
BAKER
Geotechnical Construction
Appendix C
HAYWARD
BAKER
Geotechnical Construction
VULCAN MATERIALS COMPANY- Westem Division
Contractor: Hayward Baker
Project: Ocena Sf Apts
Plant: Vuican Matenals / Carroll Canyon
Material: 3/4" Washed Crushed Rock
July 12.2013
This is to certify that Vulcan Materials Company, Western Division, Carroll Canyon,
will supply 3/4" washed crushed rock to the above listed project.
No specifications reviewed for this material
Percent
Sieve Size Passing
37.5 mm (1 1/2") 100
25 mm d") 100
19 mm (3/4") 92
12.5 mm (1/2") 27
9.5 mm (3/8") 7
4.75 mm (No. 4) 2
2.36 mm (No. 8) 1
Submitted by:
Wes Jacobs
Technical Services Supervisor
Wj/SB
c Please Note: ** NOT VALID IF ALTERED
If you should have any questions regarding this submittal please contact the
San Diego Regional Laboratory at (858) 547-4981
10051 Black Mountain Road • San Diego, Califomia 92126* FAX (858) 547-9056
HAYWARD
BAKER
Geotechnical Construction
Appendix D
Geotechmcal Construction
* HAYWARD BAKER INC.
GC:
Job Nairn;
Job No.:
Geotechnical Engkieer:
Project Mmsgir:
vibro Dally Report No.
Pg.1 of 1
Date:
Pfobe
No.
Point
No.
Time Convkte
lir./min.
Stilt Stop Total
Surfece
Elivetion
Column
Bottom
Elevelloa
Lengtfi OT
Treatnwnt
Fl
Avg.
LW Tliichnece
ft.
Stone
Atfded
Avg.
DIamgter
tnclMi
Mu
Amp.
Pre
llllll to-
ttomSfc.
REMARKS
Pfobe
No.
Point
No.
Time Convkte
lir./min.
Stilt Stop Total
Surfece
Elivetion
Column
Bottom
Elevelloa
Lengtfi OT
Treatnwnt
Fl
Avg.
LW Tliichnece
ft. Biicliets Tone Cu.Varils.
Avg.
DIamgter
tnclMi
Mu
Amp.
Pre
llllll to-
ttomSfc.
REMARKS
1
2
3
«
S
6
?
8
9
10
11
12
13
H
15
ie
17
IS
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
3S
37
38
39
40
41
42
43
44
Total Rig
OaiV produdion Ln. Ft.:
Prav. acc. Production
Total production Ln. Ft.
Total daily rock tons.:
Prev. acc. Tons.:
Total tons.:
Hayward Biker :
HAYWARD
Geoiechnical Constructton
Zephyr Partners
11750 Sorrento Valley Road, Suite 130
SanDiego, CA92121
ADVANCED GEOTECHNiCAL SOLUTIONS, INC.
25109 Jefferson Avenue, Suite 200
Murrieta, Califomia 92562
Telephone: (619) 708-1649 Fax: (714) 409-3287
May 22, 2013
PAV 1205-06
Report 1205-06-B-6
Attention: Mr. Jim McMenamin
Subject: Supplemental Geotechnical Recommendations Ocean Street Residences (CD
12-09), City of Carlsbad, California
Gentlemen;
In accordance with your request. Advanced Geotechnical Solutions, Inc.'s (AGS) has prepared this letter
with supplemental geotechnical recommendations regarding remedial grading and design parameters for
proposed soldier beam wall along the westerly property line for the Ocean Street Residences (CD 12-09),
City of Carlsbad.
1.0 Revised Remedial Grading Recommendations
For all settlement-sensitive structures (where feasible) complete removal of unsuitable soils should be
conducted below and extending on a 1: 1 (horizontal to vertical) downward projection to bedrock. For the
northerly portion ofthe site (Units 15 -35) where the proposed ground modification with Stone Columns
are proposed removal and recompaction should extend to a depth of approximately 2 feet above existing
ground water. Once these removals and recompaction is completed the proposed Stone Columns can be
constructed and the remaining design fill and retaining walls can then be constructed.
2.0 Design Parameters for Proposed Soldier Beam Wall Western Property Line
It is our understanding that the retaining wall along the westerly property line will be as high as 11 feet
and will be within a foot or two from the property line. Given the proximity to the adjacent improvements
this wall has been modified to a Soldier Beam permanent shoring wall. For the design of this wall the
following design parameters are presented:
Static Case
LevelBackfill
Rankine Equivalent Fluid
Coefficients Pressure (psf/lin.ft.)
Coefficient of Active Pressure: Ka = 0.41 51
Coefficient of Passive Pressure: Kp = 2.46 307
Y = soil density = 125 pounds per cubic foot (pcf)
Seismic Case
In addition to the above static pressures, unrestrained retaining walls should be designed to
resist seismic loading. In order to be considered unrestrained, retaining walls should be
allowed to rotate a minimum of roughly 0.004 times the wall height. The seismic load can
ORANGE AND L.A. COUNTIES
(714)786-5661
INLAND EMPIRE
(619) 708-1649
SAN DIEGO AND IMPERIAL COUNTIES
(619) 850-3980
'asit J.
Report t205-06-B-6
May 22, 201 3
P/W i205"(!6
be modeled as a thnsst load applied at a jjoinl 0.6H above the base of the wall, where I I is
equal to the height ofthe wall. This seismic load (in pounds per llsieal fool, of wall) is
represented by the following eqoaiiori:
Wliere:
H = Height ofthe wall (feet)
y = soil density = 125 pounds per cubic foot (pcf)
k], = seismic pseudostatic coefficienl, = 0,4 peak horizonla! ground acceleration / g
Walls .shouid be designed lo resist tlie combined effects of adjacent siruciores, static
pressures and the above seisoiic thrust load,
Waterproatlag autl Prajnage
Adequate waterproofing should be installed to minimize water marks on fhe face of the
wall. Drainage should also be provided behind the Soldier Beam permanent shoring wall
to minimize the build-itp of hydro-static pressures behirsd l:lie wall. Suitable drainage
outlets should 'oe installed through the wall face and directed to drainage devices io
miniiriize the potential for nuisarice water to accumulate at the toe of the wall. Final
design of the waterproofing and drainage should be determined by the Owner and
Specialty Conlractor designing and con.structing the wall.
Advaticed Geotechnical Solution.s, Inc. appreciates the opportunity to provide you with geotechnical
consulting .services and profes.sional opinions. If you have any questions, please contact the undersigned
at (619) 708-1649.
Respectfu 1 ly Subn:iitted,
Advanced Geotechnical Solutiims, Inc.
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Page 3 May 22, 2013
Report 1205-06-6-6 P/W 1205-06
fiiliilMIll
Advanced (Jeoiecknicai Sobdkms, Inc. (20J3h). Preliminary Geotechmca! Recomimndaiiom for
Permeahte Pavers ami "Grms Pave", Ocean Street Residences (CD 12-09), Cily of Carkhail
Calif friiia, iVW .1205-06, Report P^WJ2(^j-i)6-!/ 5, April i2. lid3.
Advanced (Jeoievlmicai Saiulians, Inv. (201 ja). Grading Pian Review, Ocean Street Residence.^ (I'D .12 -
09), City of Carlsbad, California (CD 12-09), Cily of Carlsbad, Califorma, P/W 1205-06, Reporl
P/W12Q5-06-B-3, March 3.^2013.
Advanced Geotechmcal Solutions, Inc. (2010). Response io Cycle Review Coinments Ocean Sireel
Residences (CD 12-09), Citv <}f Carlshad, CaUfornia. P/W 1205-06. Repori P/W1205d)6-B-2, October
30, 2012.
Geocon Inc.. Geotechnical Invesligation, Ocean Street Condomimums, Ocean Street and hdoutstain View
Drive, Carlshad, Califomia, dated September 3, 2004 (projecl no, 0/353-22-01)
RBF Ctmstilling, A Baker Company, Ocean Sireel Residences, Tentative Tract Map, dated October d',
2012, Sheets 1 through 8
City ofCarlshad, Memorandum CD12-09-Ocean Street Residences 2'"' Review, dated October 25. 2012
ADVANCED flEOTECHNiCAL SOLlJUOiS, INC.
1^/ ckjuck^
AGS
Zephyr Partners
11750 Sorrento Valley Road, Suite 130
San Dieao, CA 92121
Attention:
Subject:
References:
ADVANCED GEOTECHNICAL SOLUTIONS, INC.
9707 Waples Street. Suite 150
San Dietio. Caiifomia 92121
Telephone; (61Q) 708-1649 Fax: f7]4i 409-.1287
^'^^EjVjB^bniary 19. 2013
I^BB2??nio PW 1205-06
LAND DPI T^^on No. 1205-06-B-4
Grading Plan Review Ocean Street Residences (CD 12-09). City of Carlsbad.
Califomia
1) Precise Grading Plans for Ocean Street Residences, prepared by RBF Consulting,
undated, droM'ingNo. 476-9A (sheets 5-9,).
2) Geoteclmical Investigation. Ocean Street Condominimns, Ocean Street and
Mountain Vie^v Drive, Carhhad, California, prepared by Geocon Inc., dated
September 3, 2004 (projecf rio. 07353-22-01)
Mr. Jim McMenamin
Gentlemen:
In accordance with your request, presented herein are the results of Advanced Geotechnical
Solutions, Inc.'s (AGS) grading plan review for the undated Ocean Street Residences Drawing No.
476-9A (sheets 5-9), City ofCarlsbad, California. Specifically. AGS has reviewed sheets 5 and 9 for
confonnance to the recommendations presented in the Geoteclmical Investigation prepared by
Geocon (ref 2). Based upon our review it is AGS's opinion that the proposed Precise Grading Plans
were prepared in general accordance with tlie recommendations presented in the referenced report
and are suitable for the proposed construction.
Advanced Geotechnical Solutions, Inc. appreciates the opportunity to provide you with geotechnical
consulting services and professional opinions. If you have any questions, please contact the
undersigned at (619) 708-1649.
Respectfully Submitted,
Ad^'-anced Oeotechnlcal Solutions, Inc.
'J&^sh.^/<- ^^^:i'<^v:^ President
RCE 46544 / RGE 2314. Reg. Exp. 6-30-1:
Distri iiulion; {4i Addressee
ORANGE AND L.A. COUNTIES
(714)786-5661
INLAND EMPIRE
(619) 708-1649
SAN DIEGO .AND IMPERIAL COUNTIES
(619) 850-3980
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CONSULTAM
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GEOTECHNICAL INVESTIGATION
OCEAN STREET CONDOMINIUMS
OCEAN STREET AND
MOUNTAIN VIEW DRIVE
CARLSBAD, CALIFORNIA
^ 0 2005
PREPARED FOR
2303 INVESTORS LP
LA JOLLA, CALIFORNIA
SEPTEMBER 3, 2004
GEOTECHNICAL CONSULTANTS
GEOCON
INCORPORATED
Project No. 07353-22-01
September 3,2004
2303 Investors LP
1020 Prospect Street, Suite 314
La Jolla, Califomia 92037
Attention: Ms. Christine Stanley
Subject: OCEAN STREET CONDOMINIUMS
OCEAN STREET AND MOUNTAIN VIEW DiUVE
CARLSBAD, CALIFORNIA
GEOTECHNICAL INVESTIGATION
Dear Ms. Stanley:
In accordance with your authorization of our Proposal No. LG-04289 dated June 24, 2004, we are
submitting the results of our Geotechnical Investigation for the subject site. The accompanying report
presents the fmdings and conclusions from our study. Based on the results of our study, it is our
opinion that the subject site can be developed as proposed, provided the recommendations of this
report are followed.
Should you have any questions regarding this investigation, or if we may be of further service, please
contact the undersigned at your convenience.
Very truly yours,
GEOCON INCORPORATED
Kenneth E. Cox
RCE 65804
KEC:JrV:GWC:dmc
(6) Addressee
6960 Flonders Drive a Son Diego, California 92121-2974 E Telephone (858) 558^5900 e Fax (858) 558-6159
TABLE OF CONTENTS
1. PURPOSE AND SCOPE ^
2. SITE AND PROJECT DESCRIPTION 1
3. SOIL AND GEOLOGIC CONDITIONS 2
3.1 Undocumented Fill and Alluvium, Undifferentiated (Qudf/Qal) .."."1*."..."...'2
3.2 Terrace Deposits (Qt) ^ ' " '2
4. GROUNDWATER 3
5. GEOLOGIC HAZARDS 3
5.1 Faulting and Seismicity "3
5.2 Soil Liquefaction Potential 4
5.3 Landslides ^
5.4 Tsunamis and Seiches 2
6. CONCLUSIONS AND RECOMMENDATIONS 6
6.1 General ^
6.2 Soil and Excavation Characteristics ''g
6.3 Seismic Design Criteria ^
6.4 Mitigation of Liquefaction ....Z........"'7
6.5 Grading g
6.6 Excavation Slopes, Shoring, and Tiebacks .....'"......Z.""^..."...".10
6.7 Permanent Slopes
6.8 Foundation Recommendations p
6.9 Deep Foundations ^3
6.10 Concrete Slabs ,
6.11 Retaining Walls and Lateral Loads L"..........15
6.12 Preliminary Pavement Section "Z. ."17
6.13 Drainage
6.14 Grading and Foundation Plan Review .19
LIMITATIONS AND UNLFORMITY OF CONDITIONS
MAPS AND ILLUSTRATIONS
Figure 1, Vicinity Map
Figure 2, Geologic Map
Figures 3-5, Geologic Cross-Sections
Figure 6, Wall/Column Footing Detail
Figure 7, Retaining Wall Drainage Detail
APPENDIX A
FIELD INVESTIGATION
Figures A-l - A-10, Logs of Borings
TABLE OF CONTENTS (Continued)
APPENDIX B
LABORATORY TESTING
Table B-I, Summary of Laboratory Direct Shear Test Results
Table B-II, Summary of Laboratory Expansion Index Test Results
Table B-IU, Summaiy of Laboratoiy Maximum Dry Density and Optimum Moisture Content Tests Results
Table B-IV, Summary of Laboratory Resistance Value Test Results
Table B-V, Summary of Laboratory pH and Resistivity Test Results
Table B-VI, Summary of Laboratory Water-Soluble Sulfate Test Results
Figure B-l, Gradation Curves
Figures B-2 and B-3, Consolidation Curves
APPENDIX C
RECOMMENDED GRADING SPECIFICATIONS
LIST OF REFERENCES
GEOTECHNICAL INVESTIGATION
1. PURPOSE AND SCOPE
This report has been prepared for the proposed condominiums to be located on the north side of
Ocean Street, west of Mountain View Drive in Carlsbad, Califomia (see Vicinity Map, Figure 1). The
purpose ofthis investigation was to evaluate the surface and subsurface soil conditions, map general
site geology, identify geotechnical constraints (if any) to the project, and provide recommendations
relative to the geotechnical engineering aspects of proposed development.
The scope of our investigation included a site reconnaissance, geologic mapping, review of aerial
photographs, field investigation, laboratorj' testing, engineering analyses, and preparation of this
report. Our scope also included a review of published geologic literature pertinent to the site.
Our field investigation was perfonned on July 16 and 26 and August 27, 2004 and consisted of
drilling and logging ten small-diameter borings. These borings were drilled to examine the soil and
geologic units and locate geologic contacts and features within areas of proposed development. Logs
of the exploratory borings are presented in Appendix A.
The approximate locations of the exploratory borings and site geology are plotted on Figure 2,
Geologic Map. The geologic units encountered are also represented on the Geologic Cross-Sections,
Figures 3 through 5.
Laboratory tests were performed on selected soil samples obtained from the borings to determine
pertinent physical properties for engineering analyses. Test results and a discussion pertaining to the
laboratory testing are presented in Appendix B.
The conclusions and recommendations presented herein are based on an analysis ofthe data obtained
from the exploratory borings, laboratory tests, and our experience with similar soi] and geologic
conditions.
2. SITE AND PROJECT DESCRiPTiON
The subject site consists of developed land with apartment buildings and appurtenances located on
the north side of Ocean Street and south of Buena Vista Lagoon. The property is bounded by a
private drive to the east, apartments to the west, and Ocean Street to the south. Aerial photographs
from 1953 indicate that the Buena Vista Lagoon once extended into the northem portion of the site. It
is assumed that this land was reclaimed by placing hydraulic fill.
Project No. 07353-22-01 September 3. 2004
Surface elevations range from a low of approximately 12 feet above Mean Sea Level (MSL) on the
northem side to a high of approximately 40 feet MSL at Ocean Street.
Proposed development consists of the demolition of the existing apartments and mass grading of the
site to enable construction of new condominiums with partially depressed parking stmcmre. Final
grading project plans are currently being developed; however, based on the existing topography, it is
expected that cuts and fills of up to 15 and 10 feet, respectively, will likely be required to achieve
finish grade on the pads.
The above locations, descriptions and proposed development are based on a site reconnaissance and
information provided by you. If development plans differ significantly from those described herein.
Geocon Incorporated should be contacted for review and possible revision to this report.
3. SOIL AND GEOLOGIC CONDITIONS
Soil conditions encountered during the field investigation included undocumented fill soil, alluvium,
and Terrace Deposits. Each of these soil t)'pes is discussed below.
3.1 Undocumented Fill and Alluvium, Undifferentiated (Qudf/Qal)
Undocumented fill soil and alluvium were encountered in Borings B3 and B5 through BIO. The fill
consists of silty sand and sandy silt. The portion of the fiU below the water table was likely placed
with hydraulic fill methods. Shallow unmapped fills associated with the previous development are
likely across the site. The fill is considered unsuitable in its present condition for the support of fiil
and/or structures and will require remediation as recommended in this report.
Alluvium consists of silty and clayey sand and sandy silt. The alluvium is considered unsuitable in its
present condition for the support of fill and/or stmctures and will require complete removal.
The undocumented fill and alluvium are not differentiated on the Geologic Map and the Geologic
Cross-Sections.
3.2 Terrace Deposits (Qt)
Terrace Deposits were encountered in all of the borings, except boring B9, beneath the undocumented
fill and the alluvium. This geologic unit is characterized as medium to very dense silty and clean sand
and fum to hard clay and sandy silt. This unit should provide adequate support characteristics for
proposed project development.
Project No. 07353-22-01 TT. September 3.2004
4. GROUNDWATER
Groundwater was encountered at a depth of 7 to 11.5 feet in borings B5 through B8 and BIO. This
corresponds to an elevation of approximately 1 foot above Mean Sea Level (MSL). However, areas
adjacent to the ocean generally have groundwater elevations of approximately 3 feet MSL. Any
excavation that extends to approximately 3 feet MSL should expect to encounter groundwater.
Groundwater is not expected to otherwise affect constmction as presently proposed; however, it is not
uncommon for groundwater or seepage conditions to develop where none previously existed.
Therefore, proper surface drainage of rainfall and irrigation water will be important to future
performance of the project.
5. GEOLOGIC HAZARDS
5.1 Faulting and Seismicity
No active faults are known to exist at the site or in the immediate vicinity and none were encountered
during our field investigation. The nearest knovm active fault is the Newport-Inglewood Fault located
approximately 4.3 miles west ofthe site.
The computer program EQFAULT (Blake, 1989, updated 2000) was used to calculate the distances of
known faults from the site. References used "vwthin the program in selecting faults to be included
were Jennings (1975), Anderson (1984), and Wesnousky (1986). In addition to fault location,
EQFAULT estimated peak ground accelerations at the site for maximum magnitude earthquakes.
Attenuation relationships presented by Sadigh, et al, (1997) were used to estimate peak site
accelerations. Presented on Table 5.1 are the faults determined by the analysis to be most likely to
subject the site to ground accelerations.
Project No. 07353-22-01 . 3 . September 3, 2004
TABLE 5.1
MAXIWIUM EARTHQUAKE MAGNITUDE AND PEAK SITE ACCELERATIONS*
Fault Name
Approximate
Distance From
Site (miles)
Estimated Maximum
Earthquake Magnitude
(Mw)
Estimated Peak Site
Acceleration (g)
Newport-Inglewood (Offshore) 4 7.1 0.39 Rose Canyon Fault Zone 5 7.2 0.39
Coronado Bank 21 7.6 0.18
Elsinore-Temecula 24 6.8 0.10
Elsinore-Julian 25 7.1 0.12
Elsinore-Glen Ivy 33 6.8 0.07
Palos Verdes 35 7.3 0.09
Earthquake Valley 45 6.5 0.04
Newport-Inglewood (L.A. Basin) 45 7.1 0.06
Chino-Central Avenue 47 6.7 0.05
San Jacinto-San Jacinto Valley 47 6.9 0.05
The site could be subjected to moderate to severe ground shaking in the event of an earthquake on
any of the above-referenced faults or other faults within the southem Califomia and northem Baja
Califomia region. With respect to this hazard, the site is considered comparable to others in the
general vicinity. While listing peak accelerations is useful for comparison of potential effects of fault
activity in a region, other considerations are important in seismic design, including frequency and
duration of motion and the soil conditions underiying the site. We recommend that seismic design of
the stmctures be perfonned in accordance with the Uniform Building Code (UBC) guidelines that are
currently adopted by the City of Carisbad.
5.2 Soil Liquefaction Potential
Soil liquefaction occurs within relatively loose, cohesionless sands located below the water table that
are subjected to ground accelerations from earthquakes. The methodology of Youd, et al., (2001) was
used to evaluate the potential for liquefaction. Based on the analysis, there is a high potential for
liquefaction of an approximately 10 foot thick layer of silty sand and sandy silt within the
undocumented fill and alluvium in the northem portion ofthe site. This layer of liquefiable material
was observed in Borings B7, B8, and BIO.
Manifestation of liquefaction at the ground surface is expected to consist of approximately 3.5 inches
of total settlement. Differential settlement is expected to be approximately half of the total settlement,
but may occur over relatively short distances. County topography maps indicate very little elevation
difference between the northem portion of the site and the lagoon. Therefore, the potential for lateral
Project No. 07353-22-01 September 3,2004
spreading and flow slides is considered low. Mitigation of liquefaction settlement should consist of
deep foundations or stone columns as discussed in subsequent sections of this report.
5.3 Landslides
Examination of aerial photographs in our files indicates that no landslides are present on the property
or at a location that could impact the subject site.
5.4 Tsunamis and Seiches
The site is located approximately 400 feet fi-om the ocean and adjacent to the Buena Vista Lagoon
with a minimum elevation at the site of approximately 12 feet Mean Sea Level (MSL). Therefore,
there is a moderate potential of a tsunamis or seiche inundating the site.
Project No. 07353-22-01 -5-September 3, 2004
6. CONCLUSIONS AND RECOMMENDATIONS
6.1 General
6.1.1 It is our opinion that no soil or geologic conditions were encountered during the
investigation that would preclude development of the property as planned, provided that
the recommendations of this report are followed.
6.1.2 The northem portion of the site is underiain by up to 24 feet of undocumented fill and
alluvium over dense Terrace Deposits. The southem portion of the site is underiain by
dense Terrace Deposits with localized areas of shallow, undocumented fill.
6.1.3 Undocumented fill and alluvium are not considered suitable for the support of fill and/or
stmctural loading in its present condition and will require remediation as outlined in this
report.
6.1.4 Groundwater was encountered in Borings B5 through B7 at an elevation of approximately
1 foot MSL, but is generally encountered at approximately 3 feet MSL near the ocean.
Groundwater and/or seepage-related problems are not expected. Surface drainage should be
directed into properly designed drainage stmctures and away from pavement edges,
building pads, and other moisture-sensitive improvements.
6.1.5 Following remedial grading, stmctures can be supported on conventional shallow
foundation systems with slab-on-grade floors founded on dense Tenace Deposits or
properiy compacted fill within the southem portion of the site. Highly expansive clays
within the Terrace Deposits were encountered at finish floor elevations near Buildings 1
through 5. Deep footings and thick concrete slabs-on-grade will be required, or these clays
should be removed and replaced with low expansive compacted fill. Remedial grading will
not fae possible where fill/alluvium extends below the water table in the northem portion of
the site. Stmctures located in these areas will need to be supported on deep foundations
with structural slabs or stone columns.
6.2 Soil and Excavation Characteristics
6.2.1 Laboratory test results indicate that clay layers withm the Terrace Deposits possess "very
High" expansion potential (Expansion hidex [EI] greater than 130) as defined by Uniform
Building Code Table 18-I-B. The sandy portions of the Terrace Deposits have a low
expansion potential. Recommendations presented herein assume either that the highly
expansive soils will be left in place or the site will be graded such that soils with an EI of
50 or less will be present at finish grade.
Project No. 07353-22-01 -6- September 3.2004
6.2.2 We expect that the on-site soils can be excavated with moderate to heavy effort with
conventional heavy-duty grading equipment.
6.2.3 A near-surface soil sample was subjected to pH, resistivity, and water-soluble sulfate
content tests. The results are summarized in Appendix B and indicate a corrosive
environment with respect to buried metals. The soluble-sulfate test results indicate that
concrete structures exposed to soils at the location tested have a "negligible" water-soluble
sulfate exposure as defined by UBC Table 19-A-4. Geocon Incorporated does not practice
in the field of corrosion engineering. Therefore, if improvements that could be susceptible
to corrosion are planned, it is recommended that further evaluation by a corrosion engineer
be performed.
6.3
6.3.1
Seismic Design Criteria
For seismic design, the southera portion of the site is characterized as soil type Sc. Because
the northem portion has a potential for liquefaction, Sp is appropriate. The following table
summarizes site design criteria. The values listed on Table 6.3 are for the offshore segment
of the Newport-Inglewood Fault, which is identified as a Type B fault and is more
dominant than the nearest Type A fault due to its proximity to the site. The offshore
segment of the Newport-Inglewood Fault is located approximately 4.3 miles west of the
site.
TABLE 6.3
SEISMIC DESIGN PARAMETERS
Parameter Southern Northern UBC Reference
Seismic Zone Factor 0.40 0.40 Table 16-1
Soil Profile Sc SF Table 16-J
Seismic Coefficient, C, 0.40 0.44 Table 16-Q
Seismic Coefficient, Cv 0.63 1.08 Table 16-R
Near-Source Factor, 1.00 1.00 Table 16-S
Near-Source Factor, Nv 1.10 1.10 Table 16-T
Seismic Source B B Table 16-U
6.4
6.4.1.
Mitigation of Liquefaction
Mitigation of liquefaction within the northern portion of the site is expected to consist of
either deep foundation systems for the buildings or soil improvement by installation of
stone columns.
Project No. 07353-22-01 •7-September 3, 2004
6.4.2 If deep foundations are used, the upper 3 feet of existing fill and alluvium should be
removed and recompacted to provide uniform support for proposed parking areas and
flatwork. These improvements could experience settlement in a liquefaction event, but it is
generally not cost effective to mitigate hquefaction for such improvements.
6.4.3 Stone columns under construction consist of inserting a vibratory probe into the dense
Tenace Deposits and releasing gravel into the hole created by the probe. This is continued
to the surface creating a column of stone that densifies the loose sands. Following stone
column constmction, a minimum Cone Penetration Tip resistance of 120 tons per square
foot (tsf) in clean sand and 100 tsf in silty sands should be obtained. We expect that the
stone columns will be approximately 30 inches in diameter and spaced approximately 8
feet, center to center.
6.4.4 Following stone column construction, the upper 3 feet of existing fill and alluvium will be
highly disturbed because of the stone column operation and should be removed and
recompacted in accordance with the Grading section of this report.
6.5 Grading
6.5.1 All grading should be perfonned in accordance with the Grading Ordinance of the City of
Carisbad and the Recommended Grading Specifications in Appendix C. Where the
recommendations ofthis section conflict with those of Appendix C, the recommendations
of this section take precedence.
6.5.2 All earthwork should be observed and all fills tested for proper compaction by Geocon
Incorporated.
6.5.3 Prior to commencing grading, a preconstraction conference should be held at the site with
the owner or developer, grading contractor, civil engineer, and geotechnical engineer in
attendance. Special soil handling and/or the grading plans can be discussed at that time.
6.5.4 Site preparation should begin with the removal of all deleterious material, refuse,
construction debris, and vegetadon. The depth of removal should be such that material
exposed in cut areas and soil to be used as fill is relatively free of organic matter. Material
generated during stripping and/or site demolition should be exported from the site.
6.5.5 Undocumented fiiyalluvium in the southem portion of the site should be removed to finn
Ten-ace Deposits and replaced with properiy compacted fill. Localized areas of
Project No. 07353-22-01 September 3,2004
undocumented fill, such as the location of former building footings in the southem portion
of the site, are expected to be approximately 2 feet in thickness.
6.5.6 If deep foundations are used witiiin the northern portion of the site, the upper 3 feet of
existing fill and alluvium should be removed and recompacted prior to installation of the
foundations to provide uniform support for paridng and flatwork areas. If stone columns
are planned, the upper 3 feet of fill and alluvium will be highly disturbed by the stone
column operation and should be removed and recompacted.
6.5.7 After unsuitable soil has been removed as described above, the site may be brought to final
subgrade elevations with structural fill compacted in layers. All areas planned to receive fill
should be scarified to a depth of approximately 8 inches, moisture conditioned to slightly
above optimum moisture content, and compacted to at least 90 percent relative compaction.
Excavated soils generated during grading, except for the highly expansive clays, should be
placed and compacted in layers to the design finish grade elevations. All fill and baclcfill
soil should be placed in loose, horizontal layers approximately 8 inches thick, moisture
conditioned to 1 to 3 percent above optimum, and compacted to at least 90 percent relative
compaction as determined by ASTM Test Method D 1557-02. Fill areas with test results
indicating a soil moisture content below optimum may require additional moisture
conditioning prior to placing additional fill.
6.5.8 Highly expansive clays were encountered nearly finish floor elevation near Buildings 1
through 5. Deep footings and thick slabs-on-grade are recommended if these clays are left
in place. Altematively, the highly expansive clays can be removed to a depth of 5 five
below finish grade and replaced with low expansive compacted fill.
6.5.9 The upper 24 inches of soil in streets and parking areas should also consist of low
expansive materials.
6.5.10 To reduce the potential for differential settlement, it is recommended that the cut portion of
cut/fill transition building pads be undercut to an elevation that is at least 3 feet below the
rough grade elevation.
6.5.11 Oversize materials (hard lumps or rock greater than 12 inches in dimension), if
encountered, should be placed in accordance with the recommendations for oversize rock
placement mcluded in the Recommended Grading Specifications in Appendix C.
Project No. 07353-22-01 .9 . September 3, 2004
6.6 Excavation Slopes, Shoring, and Tiebacks
6.6.1 Deep excavations and cuts can often result in settlement of the surrounding ground surface.
This settlement may be sufficient to cause damage or distress to buildings, retaining walls,
utilities, services, or other stmctures located near the excavation.
6.6.2 The Terrace Deposits can be considered Type A soils, in accordance with OSHA
guidelines. The undocumented fill and alluvium can be considered Type B soils.
Temporary slopes in the Tenace Deposits may be excavated no steeper than M:l
(horizontalrvertical) to a height of 20 feet without shoring. Slopes in existing fill and
alluvium should be no steeper than 1:1. Loose cobble should be cleaned from the face of
slopes. The top of the excavation should be a minimum of 15 feet from the edge of existing
improvements. Excavations steeper than those recommended or closer than 15 feet from an
existing improvement may require shoring in accordance with applicable OSHA codes and
regulations.
6.6.3 The design of temporary shoring is govemed by soil and groundwater conditions, and by
the depth and width of the excavated area. Continuous support of the e;xcavation face
should be provided by a system of soldier piles and wood lagging. Excavations exceeding
15 feet may require tieback anchors to provide additional wall restraint.
6.6.4 Temporary cantilevered shoring should be designed for an active soil pressure equivalent to
the pressure exerted by a fluid density of 25 pounds per cubic foot (pcf). Additionally,
lateral earth pressure due to the surchargmg effects of adjacent stmctures and/or traffic
loads should be considered, where appropriate, during design ofthe shoring system.
6.6.5 Passive soil pressure resistance for embedded portions of soldier piles can be based upon
an equivalent passive soil fluid weight of 350 pcf The passive resistance can be assumed to
act over a width of three pile diameters. Typically, soldier piles should be embedded a
minimum of 0.5 times the maximum height of the excavation (this depth is to include
footing excavations). The project stmctural engineer should determine the actual
embedment depth.
6.6.6 It is essential that the soldier pile and lagging system allow very limited amounts of lateral
displacement. Earth pressures acting on a lagging wall can result in the movement of the
shoring toward the excavation and result in ground subsidence outside of the excavation.
Therefore, we recommend that horizontal movements of the shoring waU be accurately
monitored and recorded during excavation and anchor construction. Survey points should
be established at both the top and at least one intermediate point between the top of the pile
Project No. 07353-22-01 . 10-September 3,2004
6.6.7
6.6.8
6.7.2
6.7.3
6.7.4
and the base of the excavation on 20 percent of die soldier piles. These points should be
monitored on a regular basis during excavation work. The shoring system should be
designed to limit horizontal soldier pile movement to less than 1 inch.
Lagging should keep pace with excavation and anchor constmction. We recommend that
the excavation not be advanced deeper than 3 feet below the bottom of lagging at any time.
These unlagged gaps of up to 3 feet should only be allowed to stand for short periods of
time in order to decrease the probability of soil sloughing and caving. Backfilling should be
conducted when necessary between the back of lagging and excavation sidewalls to reduce
sloughing in this zone. Furthennore. the excavation should not be advanced more than 4
feet below a row of tiebacks prior to those tiebacks being proof tested and locked off
If tieback anchors are employed, Geocon should be contacted for additional
recommendations.
6.7 Permanent Slopes
6.7.1 Permanent cut and fill slopes will likely be part of site development. Fill and cut slopes
with mclinations of 2:1 (horizontahvertical) should have adequate factors of safety against
• both deep-seated and surficial instability.
The outer 15 feet of fill slopes, measured horizontal to the slope face, should be composed
of properiy compacted granular soil fill to reduce the potential for surficial slouching
Consideration should be given to the use of jute mesh or other surface treatment to
minimize transport by mnoff until adequate vegetation can be established.
All fill slopes should be overbuilt at least 3 feet horizontally and cut back to the desi^^n
fimsh gr^de. As an altemative, fill slopes may be compacted by back-rolling at vertical
intervals not to exceed 4 feet and then track-walked with a Caterpillar D8 tractor (or
equivalent) upon completion such that the fill soils are uniformly compacted to at least 90
percent relative compaction to the face ofthe finished slope.
Drainage devices should be provided to prevent the discharge of water over the tops of all
slopes. All slopes should be planted, drained and properiy maintained to reduce erosion.
Project No. 07353-22-01 ""HT September 3,2004
6.8 Foundation Recommendations
6.8.1 The following foundation recommendations are based on the assumption that the
prevaihng soil within 5 feet of finish grade beneath building pads will consist of compacted
fill or tenace deposits with an Expansion Index (EI) less than 50.
6.8.2 Continuous strip footings should be at least 12 inches wide and should extend at least
18 inches below lowest adjacent pad grade. Steel reinforcement for continuous footings
should consist of four No. 4 steel-reinforcing bars placed horizontally in the footings, t Jo
near the top and two near the bottom. The project structural engineer should design steel
reinforcement for spread footings. Figure 6 presents a typical footing dimension detail
depicting the depth to lowest adjacent grade.
6.8.3 Isolated spread footings that are a minimum of 2 feet square and founded 18 inches below
lowest adjacent pad grade in properiy compacted fill or formational soils may be designed
for the allowable soil bearing pressures recommended below.
6.8.4
6.8.5
6.8.6
6.8.7
If highly expansive clays are left in place, the following foundation recommendations
should be used. Continuous strip footings should be at least 12 inches wide and should
extend at least 36 inches below lowest adjacent pad grade. Steel reinforcement for
contmuous footings should consist of four No. 5 steel-reinforcing bars placed horizontally
in the fooungs; two near the top and two near the bottom. Isolated spread footings should
be a minimum of 2 feet square and founded 24 inches below lowest adjacent pad grade in
the highly expansive Terrace Deposits.
Foundations may be designed for an allowable soil bearing pressure of 2,500 pounds per
square foot (psf) (dead plus live load) for footings founded in properiy compacted fill or
firm Tenace Deposits. These soil-bearing pressures may be increased by 200 psf and
400 psf for each additional foot of foundation width and depth respectively, up to a
maximum allowable soil pressure of 3,500 psf
The allowable bearing pressures recommended above may be increased by up to one-third
for transient loads such as those due to wind or seismic forces.
The minimum foundation dimensions and steel reinforcement recommendations presented
above are based on soil characteristics only and are not intended to replace reinforcement
requu-ed for structural considerations.
Project No. 07353-22-01 ~~ .
September 3,2004
6.8.8 FoundaticMi excavations should be observed by a representative of Geocon Incorporated
prior to the placement of reinforcing steel or concrete to detennine whether the exposed
soil conditions are consistent witii those anticipated. If unanticipated soil conditions are
encountered, foundation modifications may be required.
6.8.9 No special subgrade presaturation is deemed necessary prior to placing concrete; however,
die exposed foundation and slab subgrade soils should be sprinkled, as necessary, to
maintain a moist condition as would be expected in any such concrete placement.
6.8.10 Where buildings or other improvements are planned near the top of a slope steeper than 3:1
(horizontalrvertical), special foundations and/or design considerations are recommended
due to the tendency for lateral soil movement to occur. Building footings should be
deepened such that the bottom outside edge of the footing is at least 7 feet horizontally
inside the face of the slope. Although other improvements that are relatively rigid or brittie
(such as concrete flatwork or masonry walls) may experience some distress if located near
the top of a slope, it is generally not economical to mitigate this potential. It may be
possible, however, to incorporate design measures that would pennit some lateral soil
movement without causing extensive distress. Geocon Incorporated should be consulted for
specific recommendations.
6.9 Deep Foundations
6.9.1 Undocumented fiiyalluvium was encountered along the northem edge of the property. In
areas were these soil types extend below the water table, there is the potential for
liquefaction. Deep foundations can be used for support of buildings. A structural slab also
supported by the deep foundation system is recommended. Due to noise limitations, we
expect the driven pile cannot be used. Therefore, recommendations for drilled piers and
auger-cast piles are provided below.
6.9.2 Drilled piers will develop support by both friction and end bearing in the Terrace Deposits
at depth. Drilled piers should be at least 24-inches in diameter and should extend at least 5
feet into competent Tenace Deposits. Auger-cast piles are generally 14-inches or 16-inches
in diameter and should also extend at least 5 feet into competent Tenace Deposits.
6.9.3 An allowable end bearing capacity of 20,000 pounds per square foot (psf) can be used for
design of drilled piers and auger-cast piles. An allowable skin friction of 600 psf may be
used for the portion of the drilled pier within the Tenace Deposits. No skin friction is
pennitted within the undocumented fill or alluvium/slopewash soil. For preliminary design
purposes, the top of die competent Tenace Deposits can be assumed to be at Elevation -10
Project No. 07353-22-01 . 13 . September 3,2004
feet MSL although it is actually variable across the site. The maximum tip elevation would
therefore be approximately -5 feet MSL. Allowable uplift capacities can be taken as die
allowable friction resistance over the entire drilled pier/auger-cast pile length, including the
fill/alluvium. The uplift capacity may also be limited by stmctural considerations and
should be checked by the structural engineer. Downdrag loads due to liquefaction have
been incorporated into the design.
6.9.4 If pile spacing is at least four times the maximum dimension of the pile, no reduction in
axial capacity for group effects is considered necessary.
6.9.5 The lateral loads at the ground surface that produce a defiection of Vi inch at the pile cap
under both hquefied and non-liquefied conditions are presented on Table 6.8. These
capacities can be increased proportionately widi deflection to a maximum deflection of 1
inch. If greater capacities flian those shown on Table 6.8 are needed, Geocon should be
contacted to develop specific lateral capacity-deflection curves on a case-by-case basis.
TABLE 6.9
LATERAL LOAD/DEFLECTION FOR DRILLED PIERS/ACP
Pile Type Lateral Load in kips Pile Type
Fixed Head Free Head
14-inch ACP (nonliquefied) 16.5 kips 7.0 kips
16-inch ACP (nonliquefied) 21.0 kips 9.3 kips
24-inch drilled pier (nonliquefied) 43.8 kips 20.7 kips
14-inch ACP (liquefied) 14.8 kips 6.5 kips
16-inch ACP (liquefied) 17.4 kips 8.9 kips
24-inch drilled pier (liquefied) 29.8 kips 18.8 kips
6.9.6
6.9.7
Pile settlement is expected to be on the order of i4-inch for drilled piers and auger cast
piles. Settlements should be essentially complete shortiy after completion of the structure.
Drilled piers will have to be consfructed using a water or slurry displacement method of
construction. Because a portion of the drilled pier capacity will be developed by end
bearing, the bottom of the borehole should be cleaned of all loose cuttings prior to the
placement of steel and concrete. Concrete should be placed within die pier excavation as
soon as possible after the auger/cleanout plate is wididrawn to reduce the potential for
discontinuities or caving. Concrete should be placed with a tremie and the bottom of the
tremie should be maintained below the level of the concrete at all times. Because concrete
Project No. 07353-22-01 -14-September 3, 2004
will be placed below groundwater, PVC pipes should be attached to the reinforcing cage to
provide a method of perfonning non-destructive testing of the drilled piers in the event that
questions arise regarding the structural integrity of the drilled piers. Initial set of the
concrete should occur prior to drilling adjacent piles within 5 pile diameters.
6.9.8 Auger-cast piles may be may be used in lieu of drilled piers. The quality of auger cast piles
is highly dependent on die contractor's experience and constraction observation. The
contractor should supply equipment to accurately measure concrete grout volumes and a
mud balance to evaluate specific gravity. The volume of grout pumped should exceed die
theoretical volume of the pile by 15 to 20 percent. The specific gravity of die concrete
grout should be 1.8 to 1.9 which corresponds to a water/cement ratio of approximately 0.45
to 0.5. The withdrawal rate of the auger should be such that the bottom of the auger is
always maintained at least 3 feet below the top of the upward rising concrete grout column.
Initial set of the concrete grout should occur prior to drilling adjacent piles widiin 5 pile
diameters.
6.9.9 Based on laboratory testing, the on-site soils are conosive with respect to steel. The
groundwater is expected to be saltwater. The structural engineer should take diis data into
account when selecting cement quantities and types for piles. Adequate concrete cover over
reinforcing steel should be provided in accordance with good construction practices and
design standards.
6.10 Concrete Slabs
6.10.1 If structures in the northem portion of the site are supported on piles, structural slabs
should be used. Concrete slabs-on-grade for the soudiem portion of the site should be at
least 5 inches thick. Minimum slab reinforcement should consist of No. 3 steel reinforcing
bars placed IS inches on center in botii horizontal directions and positioned within the
upper one-third of the slab. The concrete slabs-on-grade should be underiain by at least 4
inches of clean sand and, where moisture-sensitive floor coverings are planned, a visqueen
moisture barrier placed at die midpoint of the sand cushion should be provided. The
concrete slabs-on-grade should also be provided with isolation or expansion joints to
permit vertical movement between the slabs, footings and walls.
6.10.2 Crack-contirol joints should be spaced at intervals not greater than 12 feet and should be
constmcted using sawcuts or odier methods as soon as practically possible following
concrete placement. Crack-control joints should extend a minimum depth of one-fourth the
slab thickness.
Project No. 07353-22-01 .15 . September 3,2004
6.10.3 Exterior slabs not subject to vehicular loads should be at least 4 inches diick and reinforced
with 6x6-W2.9AV2.9 (6x6-6/6) welded wire mesh. The mesh should be placed widiin the
upper one-third of the slab. Proper mesh positioning is critical to future performance of the
slab. It has been our experience diat the mesh must be physically pulled up into the slab
after concrete placement. The contractor should take extra measures to provide proper
mesh placement. Prior to construction of slabs, die subgrade should be moisture
conditioned to at least optimum moisture content and compacted to at least 90 percent
relative compaction. The subgrade soils should not be allowed to dry prior to placing
concrete.
6.10.4 The recommendations of diis report are intended to reduce the potential for slabs to crack
due to differential settiement of fill soils. However, even with the incorporation of the
recommendations presented herein, foundations, stucco walls and slabs-on-grade placed on
such soil conditions may exhibit some cracking due to soil movement and/or shrinkage.
The occunence of concrete shrinkage cracks is independent of die supporting soil
characteristics. Their occunence may be reduced and/or controlled by limiting die slump of
the concrete, proper concrete placement and curing, and the placement of crack-control
joints at periodic intervals, particularly where re-entrant slab comers occur.
6.11 Retaining Walls and Lateral Loads
6.11.1 Retaining walls that are aUowed to rotate more than O.OOIH (where H equals the height of
the retaining wall portion of die wall in feet) at the top of the wall and having a level
backfill surface should be designed for an active soil pressure equivalent to the pressure
exerted by a fluid density of 35 pounds per cubic foot (pcf). Where the backfdl will be
inclined at no steeper than 2:1, an active soil pressure of 50 pcf is recommended. These soil
pressure recommendations are provided with the assumption diat the backfill soil within an
area bounded by the wall and a 1:1 plane extending upward from die base of the wall
possess an Expansion Index of less than 50.
6.11.2 Where walls are restrained from movement at the top, an additional uniform pressure of 7H
psf should be added to the above active soil pressure.
6.11.3 All retaining walls should be provided with a drainage system adequate to prevent the
buildup of hydrostatic forces and should be waterproofed as requu-ed by the project
architect. The use of drainage openings through the base of the wall (weep holes) is not
recommended where the seepage could be a nuisance or otherwise adversely impact the
property adjacent to the base of the wall. A typical retaining wall drainage detail is
presented on Figure 7. The above recommendations assume a properiy compacted backfill
Project No. 07353-22-01 - ] 6 -September 3,2004
material with no hydrostatic forces or imposed surcharge load. If conditions different than
those described are anticipated, or if specific drainage details are desired, Geocon
Incorporated should be contacted for additional recommendations.
6.11.4 Wall foundations should extend 12 inches and 24 inches below adjacent grade for walls
founded in low expansive granular fill and highly expansive Terrace Deposits, respectively.
An allowable bearing capacity of 2,500 psf can be used for retaining walls. The proximity
of the foundation to the top of a slope steeper than 3:1 could impact the allowable soil
bearing pressure. Therefore, Geocon Incorporated should be consulted where such a
condition is anticipated.
6.11.5 For resistance to lateral loads, an allowable passive earth pressure equivalent to a fluid
density of 350 pcf is recommended for footings or shear keys poured neat against properiy
compacted granular fill soils or undisturbed natural soils. The allowable passive pressure
assumes a horizontal surface extending away from the base of the wall at least 5 feet or
three times the height of the surface generating the passive pressure, whichever is greater.
The upper 12 inches of material not protected by floor slabs or pavement should not be
included in the design for lateral resistance.
6.11.6 An allowable friction coefficient of 0.35 may be used for resistance to sliding between soil
and concrete. This friction coefficient may be combined with the allowable passive earth
pressure when determining resistance to lateral loads.
6.11.7 The recommendations presented above are generally applicable to the design of rigid
concrete or masonry retaining walls having a maximum height of 12 feet, hi the event that
walls higher than 12 feet or odier types of walls (such as crib-type walls) are planned,
Geocon Incorporated should be consulted for additional recommendations.
6.12 Preliminary Pavement Section
6.12.1 The following pavement sections are preliminary and assume that granular fill will be
present at subgrade elevation. Actual pavement sections should be determined once
subgrade elevations are attained at die end of grading and additional R-value testing is
performed on subgrade soil samples. Utilizing the laboratory determined R-value and
procedures outlined in the Caltrans Highway Design Maixual, Section 600, pavement
sections were evaluated and are presented on Table 6.12.
Project No. 07353-22-01 - 17- September 3,2004
TABLE 6.12
PRELIMINARY PAVEMENT SECTIONS
Location Assumed
Traffic Index
Asphalt Concrete
(inches)
Class Z Aggregate
Base (inches)
Auto Parking and Driveways 5.0 3.0 4.0
Truck Traffic/Fire Lane 7.0 4.0 4.5
6.12.2 Prior to placing aggregate base materials, pavement area subgrade soil should be scarified
to a depth of 12 inches compacted to a minimum of 95 percent relative compaction.
6.12.3
6.12.4
6.12.5
6.13
6.13.1
Class 2 base should conform to Section 26-1.02A of the Standard Specifications for the
State ofCalifomia Depaitment of Transportation (Caltrans) and should be compacted to a
minimum of 95 percent of die maximum dry density at near-optimum moisturel content.
Asphalt concrete should confonn to Section 203-6 of die Standard Specifications for
Public Works Construction (Greenbook).
mere trash bin enclosures are planned within asphalt paved areas, we recommend that die
pavement section consist of 6 inches of Portland Cement concrete (minimum Modulus of
Rupture of 600 psi) reinforced with No. 3 bars spaced at 18 inches in each horizontal
direction. The concrete should extend into the roadway sufficiently so that die entire truck
is on the concrete when loading and unloading.
The performance of asphalt concrete pavements and Portland Cement concrete pavement is
highly dependent upon providing positive surface dramage away from die edge of the
pavement. Ponding of water on or adjacent to pavement will likely result in premature
pavement distress and subgrade failure. If planter islands are proposed, the perimeter curb
should extend at least 12 inches below the aggregate base of the adjacent pavement. In
addition, surface drainage within the planter should be such that ponding will not occur.
Drainage
Establishing proper drainage is necessary to reduce the potential for differential soil
movement, erosion, and subsurface seepage. Positive measures should be taken to properiy
finish grade die building pads after stmctures and odier improvements are m place, so diat
drainage water from the building pads and adjacent properties is directed to streets and
away from foundations and tops of slopes. Experience has showoi diat even with these
provisions, a shallow groundwater or subsurface condition can and may develop in areas
where no such condition existed prior to site development. This is particularly tme where a
Project No. 07353-22-01 • 18-September 3,2004
substantial increase in surface water infiltration results from an increase in landscape
irrigation.
6.14 Grading and Foundation Plan Review
6.14.1 The geotechnical engineer and engineering geologist should review the grading and
foundation plans prior to fmalization to verify then- compliance widi die recommendltions
of diis report and detennine the necessity for additional comments, recommendations
and/or analysis.
Project No. 07353-22-01 '
September 3,2O04
1.
3.
LIMITATIONS AND UNIFORMITY OF CONDITIONS
The recommendations of this report pertain only to tlie site investigated and are based upon
the assumption that the soil conditions do not deviate from those disclosed in the
investigation. Ifany variations or undesirable conditions are encountered during constmction
or If the proposed constiiiction will differ fi-om that anticipated herein. Geocon Incoiporated
should be notified so that supplemental recommendations can be given. The evaluation or
Identification of die potential presence of hazardous or corrosive materials was not part of die
scope of services provided by Geocon Incorporated.
This report is issued with the understanding that it is die responsibility of die owner or his
representative to ensure that the information and recommendations contained herein are
brought to die attention of die architect and engineer for the project and incoiporated into the
plans, and that the necessary steps are taken to see that the contractor and subcontractors
cany out such recommendations in the field.
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, whedier due to natural processes
or the works of man on this or adjacem properties. In addition, changes in applicable or
appropnate standards may occur, whether a result of legislation or die broadenin^^ of
knowledge. Acconiingly, die fmdings of this report may be invalidated wholly or partially by
changes outside our control. Therefore, diis report is subject to review and should not be
rehed upon after a period of du-ee years.
Project No. 07353-22-01
Septembers, 2004
INCORPORATED
GEOTECHNICAL CONSULTANTS OCEAN STREET CONDOMINIUMS
CARLSBAD, CALIFORNIA
DATE 09-03-2004 PROJECTNO. 07353-22-01 FIG, 1
CHANG
ARCHXrECTURE
OCEAN STREET CONDOMINIUMS
CARLSBAD, CALIFORNIA
SCALE: r = 60'
GEOCON LEGEND
Qudf/Sl UNDOCUMENTED FILL, AND ALLUVIUM
(Undifferentiated)
Qt ..TERRACE DEPOSITS (Datteii Where Buried)
5? APPROX. LOCATION OF GEOTECHNICAL
BORING
APPROX LOCATION OF GEOLOGIC CONTACT
(Querried W/here Uncertain)
E'
' APPROX. LOCATION OF GEOLOGIC
CROSS - SECTION
GEOCON
INCORPORATED
OlDoamtim cnsf Satlinoj/Droftino 4/07353 OCEAN SmS! OOO/DWG.
GEOLOGIC MAP
GEOTECHNIC4.L CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159
PROJECT NO. 07353 - 22 - 01
FIGURE 2
DATE 09-03-2005
90 '
60 •
I-UJ Ui LL
Z 30'
o
>
UJ
111
0 —
-30-
EXISTING
GRADE
-PROPOSED BUILDING
-PROPOSED BUILDING—•
EXISTING BUILDING
B-3
m m 90 I
120 150 180 210 240
DISTANCE. FEET
GEOLOGIC CROSS - SECTION
SCALE: 1" = 30' (HORE. = VERT.)
GEOCON LEGEND
Qudf/sS UNDOCUMENTED FILL, AND ALLUVIUM (Undifferentiated)
Qf TERRACE DEPOSITS
/— APPROX. LOCATION OF GEOLOGIC CONTACT (Querried Where Uncertain)
."2 ^ APPROX. LOCATION OF GROUNDWATER TABLE (Querried Where Uncertain)
O/Documenn end Ssitinsi^relring .4/07353 OCEAN STRET COMXD/DWG.
OCEAN STREET CONDOMINIUMS
CARLSBAD, CALIFORNIA
Cl
r- 90
— 60
30
w S
h-
UJ
UJ
I—-30
265
GEOO
INCORPORATED
GEOTECHNICAL CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CAUFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159
PROJECT NO. 07353 - 22 - 01
FIGURE 3
DATE 09-03-2004
90 —1
60 •
f-UJ LU LL
LU
30 —
0 —
-30—J
OCEAN STREET CONDOMINIUMS
CARLSBAD, CALIFORNIA
EXISTING
GRADE
EXISTING
BUILDING \
.7.. ..9..
Qt
30 60 90 120 150 180 210
DISTANCE, FEET
i
240
1
270 300 330 360
GEOLOGIC CROSS - SECTION
SCALE: 1" = 30' (HORIZ. = VERT)
GEOCON LEGEND
Qudf/Sl UNDOCUMENTED FILL, AND AUUVIUM (Undifferentiated)
Qt TERRACE DEPOSITS
/•— APPROX. LOCATION OF GEOLOGIC CONTACT (Quemed Wtiere Uncertain)
.?. 2- APPROX LOCATION OF GROUNDWATER TABLE (Querried Where Uncertain)
INCORPORATED
- 60
go
CO
UJ UJ
30 z
g
i
UJ
-0
»--30
420
GEOTECHNICAL CONSULTANTS
6960 FLANDERS DRIVE • SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159
PROJECT NO. 07353 - 22 - 01
FIGURE 4
DATE 09-03-2004
C/DaiuTOW. ml S»H»,B«jT>riillm3 4/07353 OCEAN Slim CONDO/DWa
90 •
50 -
UJ
u. Z 30' O
Ul
-30-
OCEAN STREET CONDOMINIUMS
CARLSBAD, CALIFORNIA
Qudf/al
Qt
90
60
J m
us UJ u.
30 z' O
UJ
— 0
ii—30
30 60 90 120 150 180 210
DISTANCE. FEET
300 330 %0 n—I
390 400
GEOLOGIC CROSS - SECTION
SCALE: 1" = 30' (HORIZ. = VERT) "
GEOCON LEGEND
Qudf/S! UNDOCUMENTED FILL, AND ALLUVIUM (Undifferentiated)
Qf TERRACE DEPOSITS
APPROX. LOCATION OF GEOLOGIC COtvPrACT (Querried Where Uncertain)
2 S- APPROX. LOCATION OF GROUNDWATER TABLE (Quemed Where Uncertain)
INCORPORATED
GEOTECHNICAL CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159
PROJECT NO. 07353-22-01
FIGURE 5
DATE 09-03-2004
O/Docurwnti ond SslUnsi/Dfoflino 4/073S3 OCEAN STSSICONOO/DWG.
WALL FOOTING
CONCRETE SLAB
SAND
VISQUEEN
PAD GRADE
FOOTING-
WIDTH
^ I-- S oa
.. O 1=1
COLUMN FOOTING
CONCRETE SLAB
SANO ' • •. ... •. -.•• •«'-. > .: .:v *.•*• ; ' •
VISQUEEN
II -rv
• FOOTING WIDTH'
....SEE REPORT FOR FOUNDATION WITDH AND DEPTH RECOMMENDATION
NO SCALE
WALL / COLUMN FOOTING DIMENSION DETAIL
INCORPORATED
GEOTECHNICAL CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CALIRDRNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159
KC/RA
COlKJOrZOWG/RA
DSK/EOOOO
OCEAN STREET CONDOMINIUMS
CARLSBAD, CALIFORNIA
DATE 09-03-2004 PROJECT NO. 07353 - 22 - 01 FIG. 6
GROUND SURFACE
RETAINING WALL
3M" CRUSHED
GRAVEL
MIRAFI MON
FILTER FABRIC
OR EQUIVALENT
4" DIA. PERFORATED
SCHEDULE 40 PVC PIPE
NOTES:
'yly'Ifp^,^^^^^^ ''^'^^LS. SUCH AS MIRADRAIN 7000 XL OR EQUIVALENT
MAYBE USED IN LIEU OF PLACING GRAVEL TO HEIGHT OF 2/3 THE TOTAL WALL HEIGHT
2 SHOULD BE UNIFORMLY SLOPED AND MUST LEAD TO A POSmVE GRAVITY OUTLET
'AC^=^E'SIL°SSI^^^^^^^^
NO SCALE
RETAINING WALL DRAINAGE DETAIL
GEOTECHNICAL CONSULTANTS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159
KC/RA
«EIWAlt4.[)WG/I!A
DSK/EOOOO
J
OCEAN STREET CONDOMINIUMS
CARLSBAD, CALIFORNIA
DATE 09-03-2004 PROJECTNO. 07353-22-01 FIG. 7
APPENDIX
APPENDIX A
FIELD INVESTIGATION
The field investigation was performed on July 16 and 26 and August 27, 2004, and consisted ofa site
reconnaissance and drilling ten exploratory small-diameter borings at the approximate locations
shown on Figure 2. The small-diameter borings were drilled to depths varying from 16 to 3014.
Borings Bl through B3 were drilled with a CME 55 drill rig equipped with hollow-stem auger.
Borings B4 through BIO were drilled with a mud rotary drill rig. Relatively undisturbed samples were
obtained by driving a Califomia Modified Sampler 12 inches with blows fi-om a 140-pound hammer
falling 30 inches. This split-tube sampler was equipped with 1-inch-high by 2V8-inch-diameter brass
sampler rings to facilitate sample removal and testing. Disturbed bulk samples were obtained from
the boring's cuttings.
The soil conditions encountered in the borings were visually examined, classified and logged in
general accordance widi the American Society for Testing and Materials (ASTM) Practice for
Description and Identification of Soils (Visual-Manual Procedure D 2488). The logs of the
exploratory borings are presented on Figures A-l through A-10. The logs depict the various soil types
encountered and indicate the depths at which samples were obtained.
Project No. 07353-22-01 Septeinber 3.2004
PROJECTNO. 07353-22-01
BORING B 1
ELEV. (MSL)
EQUIPMENT
-38 DATE COMPLETED 07-16-2004
CME 55
2 o »-
I- Z LL CO -7-
z u.
go
Q
UJ
MATERIAL DESCRIPTION
4" ASPHALT CONCRETE
TERRACE DEPOSITS
Medium dense, moist, brown, Silty, fine to medium SAND
Hard, moist, tan-brown, CLAV
-Becomes very stiff and brown at 13 feet
Medium dense, moist, brown. Silt)', fine to medium SAND
15 104.8
23 102.1
52 114.5
94.1
96.0
BORING TERMINATED AT 20 FEET
No groundwater
Hole filled with cuttings mixed with 1 bag ponland cement
Figure A-1, 7363-22-01.GPJ
Log of Boring B 1, Pagelofl
SAMPLE SYMBOLS ° • ^-"-"^^ "^SUCCESSFUL Ij ... STANDARD PENETRATION TEST 1 .. DRIVE SAMPLE (UND1STUR3ED)
^ .. DISTURBED OR BAG SAMPLE ii] ... CHUNK SAMPLE Y. ... WATER TABLE OR SEEPAGE
NOTE. 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.
PROJECT NO. 07353-22-01
BORING B 2
ELEV. (MSL) -35
EQUIPMENT
DATE COMPLETED 07-16-2004
CME 55
2 o 1-
h- ZU.
I- to S
UJ
00
o: o
us S\
o z s o o
MATERIAL DESCRiPTiON
4" ASPHALT CONCRETE
TERRACE DEPOSITS
Medium dense, moist, red-brown, Silt}', fine to medium SAND
Very stiff, moist, brown, CLAY
Dense, moist, tan, fine to coarse SAND
50/6"
46
118.4
108.3
21 96.2
46 102.1
96.8
5.7
9,5
26.2
4.4
BORING TERMINATED AT 20 FEET
No groundwater
Hole filled with cuttings mixed with 1 bag ponland cement
Figure A-2, 7353-22-DVGPJ
Log of Boring B 2, Page 1 of 1
SAMPLE SYMBOLS ° - '"^'^'"^ UNSUCCESSFUL ID ... STANDARD PENETRATION TEST B ... DRIVE SAMPLE (UNDISTURBED)
^ ... DISTURBED OR BAG SAMPLE B .. CHUNK SAMPLE 2; ... WATER TABLE OR SEEPAGE
NOTE. 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.
PROJECTNO. 07353-22-01
BORING B 3
ELEV. (MSL.) -32
EQUIPMENT
DATE COMPLETED 07-16-2004
CME 55
S LU 2 o ^-t 2 LL
I- w > >• \— LU SS
2 U-OlSTU YDB (P.C. OlSTU D: 5 O Q O
MATERIAL DESCRIPTION
UNDOCUMENTED FILL/ALLUVIUM
Medium dense, moisi, dark-brown, Silty, fine lo medium SAND
TERRACE DEPOSITS
Firm, moist, brown, Sandy SILT 11
Firm, moist, brown, CLAY
-Gravel at 7 feet
Dense, moist, gray-brown, fine to coarse SAND
12
37
113.8
107.8
46 110.2
-Gravel laver at 17 feet
Hard, moist, grav-brown. CLAYSTONE*
BORING TERMINATED AT 20 FEET
Hole filled with cuttings mixed with 1 bag portland cement
49
Figure A-3,
Log of Boring B 3, Page 1 of 1
88.5
6.8
5.1
;).9
7353-22.01 ,GPJ
SAMPLE SYMBOLS Q ... SAMPUNG UNSUCCESSFUL c. . STANDARD PENETRATION TEST 1. DRIVE SAMPLE (UNDISTURBED)
^ ... DISTURBED OR BAG SAMPLE s. . CHUNK SAMPLE
% •
WATER TABLE OR SEEPAGE
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS ANO TIMES : INDICATED. IT
PROJECT NO. 07353-22-01
DEPTH
IN
FEET
SAMPLE
NO.
CC Ll I-
1 SOIL
Q Z CLASS GROU (USCS)
BORING B 4
ELEV, (MSL)
EQUIPMENT
-38 DATE COMPLETED 07-26-2004
MUD ROTARY
2 O F-b 2
I- w >
LU ;n o ' CO '
05 -^
CC
UJ o
OT Iff
O £ s o o
MATERIAL DESCRIPTION
B4-1 I
- 4
B4-2
10
- 12 -
14 -
16 -
IB -
B4-3 I
I-. I
B4-4
B4-5
20
SM
TERRACE DEPOSIT
Very dense, moist, red-brown, Silty, fine to medium SAND
-Becomes tan -brown at 10 feet
50/6" 119.2
65 110.9
65
63 109.4
78 106.7
11.9
5.2
I5.I
16.4
BORING TERNtlNATED AT 20 FEET
No groundwater encountered
Hole filled wilh 15 gallons of bentonite slurry
Figure A-4, -353-22-01,G?J
Log of Boring B 4, Page 1 of 1
SAMPLE SYMBOLS ° - UNSUCCESSFUL |] ... STANDARD PENETRATION TEST M ... DRIVE SAMPLE (UNDISTURBED)
^ ... DISTURBED OR BAG SAMPLE C .. CHUNK SAMPLE J!; .. WATER TABLE OR SEEPAGE
NOTE; THS LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICAT=D IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
PROJECTNO. 07353-22-01
DEPTH
IN
FEET
SAMPLE
NO.
>-o o
cc UJ F-
1 SOIL
o CWSS
z (USCS)
o cc CD
BORING B 5
ELEV. (MSL.) _
EQUIPMENT
-15 DATE COMPLETED 07-26-2004
MUD ROTARY
2 o H
I- Z LL
h- CO >
CL ~
Z u-ft a: a
ii
81
SQ
- 0
- 2
MATERIAL DESCRIPTION
B5-1 I SM
- 4 -
- 6
B5-2
10 -
12 -
14 -
16
18 -
B5-3
B5-4
B5-5
SC
ML
UNDOCUMENTED FILL/ALLUVIUM
Loose, moist, tan and brown, Silty, fine to coarse SAND
Loose to medium dense, moist, brown. Clayey, fine to coarse SANT*
-Becomes saturated at 11 feet
-I foot layer of gravel al 13 feet
TERRACE DEPOSITS
Hard, saturated, gray-green, Sandy SLIT
-No recoven'
BORING TERMINATED AT 19.5 FEET
Groundwater encountered ai 11 feet
Hole filled with 15 gallons of bentonite slurry
11 111.5
19
110.9
74/10"
50/6"
113.4
14.1
17.^
15.3
Figure A-5,
Log of Boring B 5, Page 1 of 1
7353-22-01 .GPJ
SAMPLE SYMBOLS D ... SAMPLING UNSUCCESSFUL c. . STANDARD PENETRATION TEST 1 DRIVE SAMPLE (UNDISTURBED)
^ ... DISTURBED OR BAG SAMPLE B. . CHUNK SAMPLE . WATER TABLE OR SEEPAGE
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES : DATE INDICATED. IT
PROJECTNO. 07353-22-01
DEPTH
IN
FEET
SAMPLE
NO.
>-o o
—I o r f-
SOIL
CLASS
(USCS)
BORING B 6
ELEV. (MSL.) -16
EQUIPMENT
DATE COMPLETED 07-26-2004
MUD ROTARY
2 CJ H
b 2 LL
S S ^
I- W g
z w2
a.
cc ^
>- =-cc a
Ul
o z 5 O o
MATERIAL DESCRIPTION
. •! B6-1
:
6 -
8 -
10
12
14 -
B6-2 .iJi
m
•i-' 1
B6-3 I'
B6-4 [
UNDOCUMENTED FILL/ALLUVIUM
Medium dense, moist, brown, Silrj', fine to coarse SAND
SM
ML
SM
Stiff, moist, gray-green, Sandy SILT
Medium dense, moist, red-brown, Silt); fine to coarse SAND'
SM
ML
TERRACE DEPOSITS
Very dense, pale gray, Siity, fine to coarse SAND
20 106.0 S.O
12
Hard, saturated, tan, Sandy SILT
88/9" 106.4 179
50/3"
BORING TERMINATED AT 15.75 FEET
Groundwater encountered al 11.5 feet
Hole filled with 7 gallons of bemonite slurry
Figure A-6,
Log of Boring B 6, Page 1 of 1 7353-22-01. SPJ
SAMPLE SYMBOLS U ... SAMPLING UNSUCCESSFUL f} . . STANDARD PENETRATION TEST • .. DRIVE SAMPLE (UNDISTURBED)
^ .. DISTURBED OR BAG SAMPLE B . . CHUNK SAMPLE , WATER TABLE OR SEEPAGE
IS NOT WARRANTED ToirRi^RSATl'^ioFT^^^^^^^^^
PROJECT NO. 07353-22-01
r
DEPTH
IN
FEET
SAMPLE
NO.
>-CD O
_j O I
SOIL
CLASS
(USCS)
BORING B 7
ELEV. (MSL.)
EQUIPMENT
-14 DATE COMPLETED
MUD ROTARY
07-26-2004
LU — O K Z LL
< W
«^
OT — Z u-
EC Q
UJ ^
WLU
Oz
5 O
u
- 0
10
12
14
16
18
20
22
24
B7-1
I- I
B7-2
SM
B7-3
A
I- I 'I
i- ,1
I
I I-
B7-4
B7-5
ML
SM
MATERIAL DESCRIPTION
UNDOCUMENTED FILL/ALLUVIUM
Medium dense, moist, orange-brown, Silty, fine to coarse SAND
11
-Becomes gray
-Layer of asphalt concrete at 9 feet
Soft, wet, dark gray, Sandy SILT; organic~odor
-Becomes saturated at 11.5 feet
25 112.5
SM
Medium dense, saturaled, dark gray, Silty, fine to coarse SAND'
16.6
-1 foot gravel layer at 23 feet
Figure A-7,
Log of Boring B 7, Page 1 of 2
TERR.ACE DEPOSITS
Veniclense. ?ei. light lan .Silty, fine to coarse SAND
15
105.2 14.9
7353.22-01.GPJ
SAMPLE SYMBOLS [Zl ... SAMPLING UNSUCCESSFUL u. . STANDARD PENETRATION TEST 1 . DRIVE SAMPLE (UNDISTURBED)
NOTF TWP 1 nr^ nr Cl loci iD=A»^e r.
^ ... DISTURBED OR BAG SAMPLE B. . CHUNK SAMPLE . WATER TABLE OR SEEPAGE
ISNOT WARRANTEDToiirerRESENTATIVETsUB^^^^^^^
PROJECTNO. 07353-22-01
- 30
DEPTH
IN
FEET
- 26 -
28
SAMPLE
NO.
B7-6
B7-7
i I- i
r ' ! I-I I
I 1 I
SOIL
CLASS
(USCS)
BORING B 7
ELEV. (MSL.) -14
EQUIPMENT
DATE COMPLETED 07-26-2004
MUD ROTARY
2 U H-I- Z LL
F- OT S
z w2
0. u: —
MATERIAL DESCRIPTION
SM
50/6"
>-
OT -> Z U.
IC
Q
UJ
ii
o z s o o
113.1
-:
15.6
BORING TERMINATED AT 30.5 FEET
Groundwater encountered at 11.5 feet
Hole filled with 25 gallons of bentonite slurry
Figure A-7,
Log of Boring B 7, Page 2 of 2 7353-22-01 GPJ
SAMPLE SYM BOLS ^ • UNSUCCESSFUL B ,.. STANDARD PENETRATION TEST B ... DRIVE SAMPLE (UNDISTURBED)
^ ... DISTURBED OR BAG SAMPLE
NOTF THC ( nr^ nir ei isei IBCA Of! .--^.ii...-.-.^
B ... CHUNK SAMPLE ^ ... WATER TABLE OR SEEPAGE
ISNOTWARRANTEDTOBERipRyrE^A^IvToFS^^^^^^^^^^^ .
PROJECTNO. 07353-22-01
DEPTH
IN
FEET
SAMPLE
NO.
>-
CO o
_l o X
SOIL
CLASS
(USCS)
BORINGS 8
ELEV. (MSL)
EQUIPMENT
-10 DATE COMPLETED 08-27-2004
MUD ROTARY
I- OT S TY UJ ?
OT Z U. OlSTU YDB (P.C. OlSTU IC S O a o
MATERIAL DESCRIPTION
2 -
4 -
BS-I
10 -
12 -
14 -
B8-2
B8-3
16
18 -
BS-4
20
22
24 -
BS-5
ff
SC
SM
fy
SM
SP
UNDOCUMENTED FILL/ALLUVIU.M
Very dense, moist, brown. Clayey, fine to coarse SAND
53
Loose, moist, brown, Silty, fine to coarse SAND, some gravef
Loose, saturated, black. Silly, fine to coarse SAND and GRAVEL '
Loose, saturated, gray, fine to medium SAND"
-Becomes medium dense, some concrete in sampler
-Gravel layer at 24 feet
Figure A-8,
7353-22-01 .GPJ Log of Boring B 8, Page 1 of 2 7353-22-01 .GPJ
SAMPLE SYMBOLS ^ - UNSUCCESSFUL C ... STANDARD PENETRATION TEST B ... DRIVE SAMPLE (UNDISTURBED)
^ ... DISTURBED OR BAG SAMPLE B .. CHUNK SAMPLE 2 .. WATER TABLE OR SEEPAGE
• REPRESENTATIVE OF SUBSURFACE CONDrriONS AT OTHER LOCATIONS AND TIMES
PROJECT NO, 07353-22-01
DEPTH
IN
FEET
SAMPLE
NO.
SOIL
CLASS
(USCS)
BORING B 8
ELEV. (MSL.) -10
EQUIPMENT
DATE COMPLETED 08-27-2004
MUD ROTARY
2 o K
H- Z LL
1- w >
^OTO
OT
Z U.
cc
Q
lU s-
O Z
so o
- 26 -
- 28 -
- 30 -
- 32 -
34 -
MATERIAL DESCRIPTION
BS-6 Medium dense, saturated, gray, Silty, fine to medium SAND, some shells 25
B8-7
SM
r-
36
38 -
40 -
B8-8
K
B8-9
TERRACE DEPOSITS
Very dense, saturaled, gray. Clayey, fine to coarse SANDSTONE
-NO recovery 50/4"
SC
98/10'
-No recovery 60/6"
BORING TERMINATED AT 41 FEET
Groundwater encountered at 8 feet
Hole filled wilh 40 gal. of benionile slurry
Figure A-8,
Log of Boring B 8, Page 2 of 2
7353-2201.GPJ
SAMPLE SYMBOLS ° ... SAMPLING UNSUCCESSFUL IJ ... STANDARD PENETRATION TEST S ... DRIVE SAMPLE (UNDISTURBED)
^ ... DISTURBED OR BAG SAMPLE B ... CHUNK SAMPLE 51 ... WATER TABLE OR SEEPAGE
IS NOT WARRANTED TOBER EPRESENTATI VE OF SUBSURFACE CONDmONS AT OTHER LOCATIONS AND TIMES. • DATE INDICATED IT
PROJECTNO. 07353-22-01
DEPTH
IN
FEET
SAMPLE
NO.
>-a o
-3 o X f-
SOIL
CLASS
(USCS)
BORING B 9
ELEV. (MSL.) -12
EQUIPMENT
DATE COMPLETED 08-27-2004
MUD ROTARY
n UJ 2 O h-
t Z LL
LL h- 2-
I- OT >
cc —
>-
OT -^ Z U.
CC Q
ii
w u/ o z s o u
- 0 MATERIAL DESCRIPTION
UNDOCUMENTED FILL/ALLU\ IUM
Loose, moist, brown. Clayey, fine to coarse SAND
SC
B9-1
Dense, moist, red-brown, Silty, fine lo coarse SAND, boulders and debris
SM 47
BORING TERMINATED AT 6 FEET
No groundwater encountered
Hole filled with cuttings mixed with bentonite
Figure A-9,
735S-22-01.GPJ Log of Boring B 9, Page 1 of 1 735S-22-01.GPJ
SAMPLE SYMBOLS ^ UNSUCCESSFUL B ... STANDARD PENETRATION TEST 1 ... DRIVE SAMPLE (UNDISTURBED)
B ... DISTURBED OR BAG SAMPLE Q ... CHUNK SAMPLE X .- WATER TABLE OR SEEPAGE
ISNOTWARRANTEOToFEFErRErENTrTIVE^^^^^^^^^^ IT
PROJECT NO. 07353-22-01
BORING B 10
ELEV. (MSL.) -13
EQUIPMENT
DATE COMPLETED 08-27-2004
MUD ROTARY
2 o h-t: 2: LL
I- OT > ^550
> .... 1-
OT -r
LU 5? QH
Z u. OlSTU IN 1 CI>i 1 YDB (P.C. OlSTU IN 1 CI>i 1 OH 5 0 a 0
MATERIAL DESCRIPTION
UNDOCU.MENTED FILL/ALLUVIU.M
Dense, moist, red-brown, Clayey, fine to coarse SAND
46
-Becomes verj' loose at 5 feet
-Becomes saturated at 7 feel
Loose, saturated, dark gray 10 black, Clayey, fine to coarse SAND, slight
organic odor ^
-Becomes medium dense
Medium dense, saturated, light-tan, Silty, fine SAND
12
39
Figure A-10,
Log Of Boring B 10, Page 1 of 2
TERRACE DEPOSITS ~ '
Y^n j^atuiated. oale-grav. Clavev, fip^ |n T^f/(j(,m SAND.STnNTf
7353-22-01 GPJ
SAMPLE SYMBOLS U ... SAMPLING UNSUCCESSFUL
^ ... DISTURBED OR BAG SAMPLE
B STANDARD PENETRATION TEST
B ... CHUNK SAMPLE
• ... DRIVE SAMPLE (UNDISTURBED)
S. .. WATER TABLE OR SEEPAGE
PROJECT NO. 07353-22-01
DEPTH
IN
FEET
SAMPLE
NO.
>-
CD O
o I
SOIL
CLASS
(USCS)
BORING B 10
ELEV. (MSL.) -13
EQUIPMENT
DATE COMPLETED 08-27-2004
MUD ROTARY
UJ
t 2: LL
gf i
I- OT >
Z«2
OT
Z LL g^
a: o
UJ g.
or r-^
?2
OTUJ
Oz s o o
MATERIAL DESCRIPTION
BlO-6
- 26
- 28
- 30 BlO-7
y
SC
BORING TERMINATED AT 31 FEET
Groundwater encountered at 7 feel
Hole filled wilh 40 gal. of bentonite slurry
60
85
Figure A-10, 73S3.22-01.GPJ
Log of Boring BIO, Page 2 of 2
SAMPLE SYMBOLS ° - ^^""^SSFUL C .. STANDARD PENETRATION TEST H ... DRIVE SAMPLE (UNDISTURBED)
M ... DISTURBED OR BAG SAMPLE B ... CHUNK SAMPLE I ... WATER TABLE OR SEEPAGE
NOTE. THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES OM.Y AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT TM= DATE INDICATED IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES INDICATED. IT
r
A .
APPENDIX
APPENDIX B
LABORATORY TESTING
Laboratory tests were performed in accordance with generally accepted test mediods of die American
Society for Testing and Materials (ASTM) or other suggested procedures. Samples were subjected to
drained direct shear, grain-size analysis, consolidation, expansion index, R-value, and laboratorj'
maximum dry density and optimum moisture content tests. One sample was tested for its corxosivitj'
characteristics. Results ofthe grain-size analysis and consolidation tests are presented on Figures Bl
through B3. Results of the other laboratory tests are presented on Tables B-l through B-VI. In situ
moisture and dry density tests are presented on the boring logs (Appendix A).
TABLE B-l
SUMMARY OF LABORATORY DIRECT SHEAR TEST RESULTS
ASTM D 3080-98
Sample
No.
Dry Density
(pcf)
Moisture Content
(%)
Unit Cohesion
(psf)
Angle of Shear
Resistance (degrees)
Bl-4 114.5 14.5 630 33
B6-1 105.0 8.0 370 36
TABLE B-ll
SUMMARY OF LABORATORY EXPANSION INDEX TEST RESULTS
ASTM D 4829-95
Sample
No.
Moisture Content Dry
Density (pcf)
Expansion
Index
Sample
No. Before Test (%) After Test (%)
Dry
Density (pcf)
Expansion
Index
B2-5 13.8 36.8 99.7 181
Project No. 07353-22-01 B-l -September 3, 2004
TABLE B-III
SUMMARY OF LABORATORY MAXIMUM DRY DENSITY
AND OPTIMUM MOISTURE CONTENT TEST RESULTS
ASTM D 1557-02
Sample No. Description
Maximura
Dry Density
(pcf)
Optimum
Moisture Content
{% dry wt.)
B3-1 Dark brown Silty, fine to coarse SAND 134.0 8.1
TABLE B-IV
SUMMARY OF LABORATORY RESISTANCE VALUE TEST RESULTS
ASTM D 2844-99
Sample No. Description R-Value
Bl-1 Reddish brown Silty, fine to medium SAND
with a trace of gravel 65
TABLE B-V
SUMMARY OF LABORATORY pH AND RESISTIVITY TEST RESULTS
CALIFORNIA TEST METHOD NO. 643
Sample No. pH Minimum Resistivity
(ohm-centimeters)
B3-3 6.4 210
TABLE B-VI
SUMMARY OF LABORATORY WATER-SOLUBLE SULFATE TEST RESULTS
CALIFORNIA TEST METHOD NO. 417
Sample No. Water-Soluble Sulfate (%)
B3-3 0.050
Project No. 07353-22-01 . B-2-September 3,2004
PROJECTNO. 07353-22-01
GRAVEL SAND
SILT OR CLAY COARSE FINE COARSE MEDIUM FINE SILT OR CLAY
100
3" 1-1/2" 3/4" 3/8'
U. S. STANDARD SIEVE SIZE
200
90
80
70
O
LU
60
>-CD
a: UJ 50 •z. 50
LL
H
Z 40 LU 40
O £r LU
a. 30
20
10
0
ITl
GRAIN SIZE IN MILLIMETERS
"OTOOll
SAMPLE DEPTH (ft) CLASSIFICATION NATWC LL PL PI
B5-3 10.0 Sandy SILT (ML)
B7-3 10.0 Clayey SAND (SC)
GRADATION CURVE
OCEAN STREET CONDOMINIUM
CARLSBAD, CALIFORNIA
7353-22.01.GPJ
Figure B-1
PROJECTNO. 07353-22-01
SAMPLE NO. B7-4
z o I
_J o OT 2 O o
h-z
UI o cn UJ Q.
APPLIED PRESSURE (ksf)
Initial Dry Density (pcf) 105.2
Initial Water Content (%) 14.9
TOO
Initial Saturation (%) 68.6
Sample Saturated at (ksf) 2.0
CONSOLIDATION CURVE
OCEAN STREET CONDOMINIUM
CARLSBAD, CALIFORNIA
7353-22-01, GPJ
Figure B-2
PROJECTNO. 07353-22-01
SAMPLE NO. B5-2
2
O
H-< O _r O
OT
2 O O \-
z
UJ o a: UJ CL
10
TIT
APPLIED PRESSURE (ksf)
Initial Dry Density (pcf) 110.9
Initial Water Content {%) 17.4
IDO
Initial Saturation (%) 93.2
Sample Saturated at (ksf) 2.Q
CONSOLIDATION CURVE
OCEAN STREET CONDOMINIUM
CARLSBAD, CALIFORNIA
7353.22-01,GPJ
Figure B-1
APPENDIX
It.
APPENDIX C
RECOMMENDED GRADING SPECIFICATIONS
FOR
OCEAN STREET CONDOMINIUMS
OCEAN STREET AND MOUNTAIN VIEW DRIVE
CARLSBAD, CALIFORNIA
PROJECT NO. 07353-22-01
RECOIVUVIENDED GRADING SPECIFICATIONS
1. GENERAL
1.1. These Reconamended Grading Specifications shall be used in conjunction with the
Geotechnical Report for the project prepared by Geocon Incorporated. The
recommendations contained in the text of the Geotechnical Report are a part of the
earthwork and grading specifications and shall supersede die provisions contained
hereinafter in the case of conflict.
1.2. Prior to die commencement of grading, a geotechnical consultant (Consultant) shall be
employed for die purpose of observing earthwork procedures and testing the fills for
substantial conformance with the recommendations of the Geotechnical Report and diese
specifications. It will be necessary diat the Consultant provide adequate testing and
observation services so that he may determine that, in his opinion, the work was performed
in substantial conformance with these specifications. It shall be the responsibility of the
Contractor to assist the Consultant and keep him apprised of work schedules and changes
so that personnel may be schedided accordingly.
1.3. It shall be the sole responsibility of the Contractor to provide adequate equipment and
methods to accomplish the work in accordance with applicable grading codes or agency
ordinances, diese specifications and die approved grading plans. If, in the opinion of die
Consultant, unsatisfactory conditions such as questionable soil materials, poor moisture
condition, inadequate compaction, adverse weather, and so forth, result in a quality of work
not in conformance with these specifications, the Consultant will be empowered to reject
the work and recommend to the Owner that construction be stopped until the unacceptable
conditions are corrected.
2. DEFINITIONS
2.1. Owner shall refer to the owner of die property or the entity on whose behalf the grading
work is being performed and who has contracted with the Contractor to have grading
performed.
2.2. Contractor shall refer to the Contractor performing the site grading work.
2.3. Civil Engineer or Engineer of Work shall refer to the Califomia licensed Civil Engineer
or consulting firm responsible for preparation of the grading plans, surveying and verifying
as-graded topography.
GI rev. 07/02
2.4. Consultant shall refer to the soil engineering and engineering geology consulting firm
retained to provide geotechnical services for die project.
2.5. Soil Engineer shall refer to a Califomia licensed Civil Engineer retained by die Owner,
who is experienced in the practice of geotechnical engineering. The Soil Engmeer shall be
responsible for having qualified representatives on-site to observe and test die Contractor's
work for conformance with these specifications.
2.6. Engineering Geologist shall refer to a Califomia licensed Engineering Geologist retained
by die Owner to provide geologic observations and recommendations during the site
grading.
2.7. Geotechnical Report shall refer to a soil report (including all addenda) which may include
a geologic reconnaissance or geologic investigation diat was prepared specifically for the
development of the project for which these Recommended Grading Specifications are
intended to apply.
3. MATERIALS
3.1. Materials for compacted fill shall consist of any soil excavated from die cut areas or
imported to the site that, in the opinion of the Consultant, is suitable for use in constmction
of fdls. In general, fill materials can be classified as soil fills, soil-rock fills or rock fills, as
defined below.
3.1.1. Soil fills are defined as fills containing no rocks or hard lumps greater than 12
inches in maximum dimension and containing at least 40 percent by weight of
material smaller than 3/4 inch in size.
3.1.2. Soil-rock fills are defmed as fills containmg no rocks or hard lumps larger than 4
feet in maximum dimension and containing a sufficient matrix of soil fill to allow
for proper compaction of soil fill around the rock fragments or hard lumps as
specified in Paragraph 6.2. Oversize rock is defined as material greater dian 12
inches.
3.1.3. Rock fills are defmed as fills containing no rocks or hard lumps larger than 3 feet
in maximum dimension and containing Uttie or no fines. Fines are defmed as
material smaUer than 3/4 inch in maximum dimension. The quantity of fines shall
be less than approximately 20 percent ofthe rock fill quantity.
GI rev. 07/02
3.2. Material of a perishable, spongy, or otherwise unsuitable nature as determined by the
Consultant shall not be used in fills.
3.3. Materials used for fill, either imported or on-site, shall not contaui hazardous materials as
defined by die Califomia Code of Regulations, Title 22, Division 4, Chapter 30, Articles 9
and 10; 40CFR; and any other applicable local, state or federal laws. The Consultant shall
not be responsible for the identification or analysis of the potential presence of hazardous
materials. However, if observations, odors or soil discoloration cause Consultant to suspect
the presence of hazardous materials, the Consultant may request fi-om the Owner the
termination of grading operations within the affected area. Prior to resuming grading
operations, the Owner shall provide a written report to the Consultant indicating that the
suspected materials are not hazardous as defined by applicable laws and regulations.
3.4. The outer 15 feet of soil-rock fill slopes, measured horizontally, should be composed of
properiy compacted soil fill materials approved by the Consultant. Rock fill may extend to
the slope face, provided that the slope is not steeper than 2:1 (horizontahvertical) and a soil
layer no thicker dian 12 inches is track-walked onto the face for landscaping purposes. This
procedure may be utilized, provided it is acceptable to the goveming agency. Owner and
Consultant.
3.5. Representative samples of soil materials to be used for fill shall be tested in the laboratory
by the Consultant to determine the maximum density, optimum moisture content, and,
where appropriate, shear strength, expansion, and gradation characteristics of the soil.
3.6. During grading, soil or groundwater conditions other than those identified in the
Geotechnical Report may be encountered by the Contractor. The Consultant shall be
notified immediately to evaluate the significance of the unanticipated condition
4. CLEARING AND PREPARING AREAS TO BE FILLED
4.1. Areas to be excavated and filled shall be cleared and grubbed. Clearing shall consist of
complete removal above the ground surface of trees, stumps, brush, vegetation, man-made
structures and similar debris. Grubbing shall consist of removal of stumps, roots, buried
logs and other unsuitable material and shall be performed in areas to be graded. Roots and
other projections exceeding 1-1/2 inches in diameter shall be removed to a depth of 3 feet
below the surface of the ground. Borrow areas shall be grubbed to the extent necessary to
provide suitable fill materials.
GI rev. 07/02
4.2. Any asphalt pavement material removed during clearing operations should be properiy
disposed at an approved off-site facility. Concrete fragments which are free of reinforcing
steel may be placed in fills, provided diey are placed in accordance with Section 6.2 or 6.3
ofthis document
4.3. After clearing and grubbing of organic matter or other unsuitable material, loose or porous
soils shall be removed to the depth recommended in die Geotechnical Report. The depth of
removal and compaction shall be obser\'ed and approved by a representative of the
Consultant. The exposed surface shall then be plowed or scarified to a minimum depth of 6
inches and until die surface is firee from uneven features diat would tend to prevent unifonn
compaction by the equipment to be used.
4.4. Where the slope ratio of die original ground is steeper tiian 6:1 (horizontahvertical), or
where recommended by the Consultant, the original ground should be benched in
accordance widi the following illustration.
TYPICAL BENCHING DETAIL
Finish Grade
Remove
Unsuitable Material
As Recommended By
Soil Engineer
Original Ground
Finish Slope Surface
Slope To Be Such That
Sloughing Or Sliding
Does Not Occur
"B"
See Note 1 See Note 2
No Scale
DETAIL NOTES: (1) Key width "B" should be a minimum of 10 feet wide, or sufficiently wide to
pemut complete coverage with the compaction equipment used. The base of the
key should be graded horizontal, or inclined slighdy into die natural slope.
(2) The outside of the bottom key should be below the topsoil or unsuitable surficial
material and at least 2 feet into dense formational material. Where hard rock is
exposed in the bottom ofthe key, die depth and configuration ofthe key may be
modified as approved by the Consultant.
GI rev. 07/02
4.5. After areas to receive fill have been cleared, plowed or scarified, die surface should be
disced or bladed by the Contractor until it is uniform and free fi-om large clods. The area
should then be moisture conditioned to achieve die proper moisture content, and compacted
as recommended in Section 6.0 of these specifications.
5. COMPACTION EQUIPMENT
5.1. Compaction of soil or soil-rock fdl shall be accomplished by sheepsfoot or segmented-steel
wheeled rollers, vibratory rollers, multiple-wheel pneumatic-tired rollers, or odier types of
acceptable compaction equipment. Equipment shall be of such a design diat it will be
capable of compacting the soil or soil-rock fill to the specified relative compaction at the
specified moisture content.
5.2. Compaction of rock fills shall be performed in accordance with Section 6.3.
6. PLACING, SPREADING AND COMPACTION OF FILL MATERIAL
6.1. Soil fill, as defined in Paragraph 3.1.1, shall be placed by the Contractor in accordance with
the following recommendations:
6.1.1. Soil fill shall be placed by the Contractor in layers that, when compacted, should
generally not exceed 8 inches. Each layer shall be spread evenly and shall be
dioroughly mixed during spreading to obtain uniformity of material and moisture
in each layer. The entire fill shall be constmcted as a unit in neariy level lifts. Rock
materials greater than 12 niches in maximum dimension shall be placed in
accordance with Section 6.2 or 6.3 of these specifications.
6.1.2. In general, the soil fill shall be compacted at a moisture content at or above the
optimum moisture content as detennined by ASTM D1557-00.
6.1.3. When the moisture content of soil fill is below that specified by die Consultant,
water shall be added by the Contractor until the moisture content is in the range
specified.
6.1.4. When the moisture content of the soil fill is above the range specified by the
Consultant or too wet to achieve proper compaction, the soil fill shall be aerated by
the Contractor by blading/mixing, or odier satisfactory methods until die moisture
content is within the range specified.
GIrev. 07/02
6.1.5. After each layer has been placed, mixed, and spread evenly, it shall be thoroughly
compacted by the Contractor to a relative compaction of at least 90 percent
Relative compaction is defined as the ratio (expressed in percent) of the in-place
dry density of the compacted fill to the maximum laboratory dry density as
determined in accordance with ASTM D1557-00. Compaction shall be continuous
over the entire area, and compaction equipment shall make sufficient passes so that
the specified minimum relative compaction has been achieved throughout the
entire fill.
6.1.6. Soils having an Expansion Index of greater than 50 may be used in fills if placed at
least 3 feet below finish pad grade and should be compacted at a moisture content
generally 2 to 4 percent greater than die optimum moisture content for the material.
6.1.7. Properly compacted soil fill shall extend to the design surface of fill slopes. To
achieve proper compaction, it is recommended that fdl slopes be over-built by at
least 3 feet and then cut to the design grade. This procedure is considered
preferable to track-walking of slopes, as described in the following paragraph.
6.1.8. As an altemative to over-buildmg of slopes, slope faces may be back-rolled with a
heavy-duty loaded sheepsfoot or vibratory roller at maximum 4-foot fill height
intervals. Upon completion, slopes should then be track-walked with a D-8 dozer
or similar equipment, such that a dozer track covers all slope surfaces at least
twice.
6.2. Soil-rock fill, as defmed in Paragraph 3.1.2, shall be placed by the Contractor in accordance
with the following recommendations:
6.2.1. Rocks larger than 12 inches but less than 4 feet in maximum dimension may be
incorporated into the compacted soil fill, but shall be limited to the area measured
15 feet minimum horizontally from the slope face and 5 feet below finish grade or
3 feet below the deepest utility, whichever is deeper.
6.2.2. Rocks or rock fragments up to 4 feet in maximum dimension may either be
individually placed or placed in windrows. Under certain conditions, rocks or rock
fragments up to 10 feet in maximum dimension may be placed using similar
methods. The acceptability of placing rock materials greater than 4 feet in
maximum dimension shall be evaluated during grading as specific cases arise and
shall be approved by the Consultant prior to placement.
GI rev. 07/02
6.2.3. For individual placement, sufficient space shall be provided between rocks to allow
for passage of compaction equipment.
6.2.4. For windrow placement, the rocks should be placed in trenches excavated in
properiy compacted soil fill. Trenches should be approximately 5 feet wide and 4
feet deep in maximum dimension. The voids around and beneath rocks should be
filled widi approved granular soil having a Sand Equivalent of 30 or greater and
should be compacted by flooding. Windrows may also be placed utilizing an
"open-face" method ui lieu of the trench procedure, however, diis method should
first be approved by the Consultant.
6.2.5. Windrows should generally be parallel to each other and may be placed eidier
parallel to or perpendicular to the face of die slope depending on die site geometry.
The minimum horizontal spacing for windrows shall be 12 feet center-to-center
widi a 5-foot stagger or offset from lower courses to next overlying course. The
minimum vertical spacing between windrow courses shall be 2 feet from the top of
a lower windrow to the bottom of the next higher windrow.
6.2.6. All rock placement, fill placement and flooding of approved granular soil in the
windrows must be continuously observed by the Consultant or his representative.
6.3. Rock fills, as defined in Section 3.1.3., shall be placed by the Contractor in accordance with
the following recommendations:
6.3.1. The base of the rock fill shall be placed on a sloping surface (minimum slope of 2
percent, maximum slope of 5 percent). The surface shall slope toward suitable
subdrainage outiet facilities. The rock fills shall be provided with subdrams during
construction so diat a hydrostatic pressure buildup does not develop. The subdrains
shall be permanently connected to controlled drainage facilities to control post-
construction infiltration of water.
6.3.2. Rock fills shall be placed m lifts not exceeding 3 feeL Placement shall be by rock
trucks traversing previously placed lifts and dumping at the edge of the currentiy
placed lift. Spreading of the rock fill shall be by dozer to facilitate seating of the
rock. The rock fill shall be watered heavily during placement. Watering shall
consist of water trucks traversing in fi-ont of the cunent rock lift face and spraying
water continuously during rock placement. Compaction equipment widi
compactive energy comparable to or greater than diat of a 20-ton steel vibratory
roller or other compaction equipment providing suitable energy to achieve the
required compaction or deflection as recommended in Paragraph 6.3.3 shall be
GIrev. 07/02
utilized. The number of passes to be made will be determined as described in
Paragraph 6.3.3. Once a rock fill lift has been covered with soil fill, no additional
rock fill lifts will be permitted over the soil fill.
6.3.3. Plate bearing tests, in accordance with ASTM Dl 196-93, may be performed in
both the compacted soil fill and in the rock fill to aid in determining the number of
passes of the compaction equipment to be performed. If performed, a minimum of
three plate bearing tests shall be performed in the properiy compacted soil fill
(minimum relative compaction of 90 percent). Plate bearing tests shall then be
performed on areas of rock fill having two passes, four passes and six passes of the
compaction equipment, respectively. The number of passes required for the rock
fill shall be determined by comparing die results of die plate bearmg tests for the
soil fill and the rock fill and by evaluating the deflection variation widi number of
passes. The requued number of passes of die compaction equipment will be
performed as necessary until die plate bearing deflections are equal to or less than
that determined for the properiy compacted soil fill. In no case will the required
number of passes fae less than two.
6.3.4. A representative of the Consultant shall be present during rock fill operations to
verify diat the minimum number of "passes" have been obtained, that water is
being properiy applied and that specified procedures are being followed. The actual
number of plate bearing tests will be determined by the Consultant during grading.
In general, at least one test should be performed for each approximately 5,000 to
10,000 cubic yards of rock fdl placed.
6.3.5. Test pits shall be excavated by the Contractor so that die Consultant can state that,
in his opinion, sufficient water is present and that voids between large rocks are
properiy filled with smaller rock material. In-place density testing will not be
required in the rock fills.
6.3.6. To reduce the potential for "piping" of fines into the rock fill fi-om overiying soil
fill material, a 2-foot layer of graded filter material shall be placed above the
uppermost Uft of rock fill. The need to place graded filter material below the rock
should be detennined by die Consultant prior to commencing grading. The
gradation of the graded filter material will be detennined at die time die rock fill is
being excavated. Materials typical of the rock fill should be submitted to the
Consultant in a timely manner, to allow design of the graded filter prior to the
commencement of rock fill placement.
GI rev. 07/02
6.3.7. All rock fill placement shall be continuously observed during placement by
representatives of the Consultant.
7. OBSERVATION AND TESTING
7.1. The Consultant shall be the Owners representative to observe and perform tests during
clearing, grubbing, fillmg and compaction operations. In general, no more dian 2 feet in
vertical elevation of soil or soil-rock fill shall be placed witiiout at least one field density
test being performed widiin that interval. In addition, a minimum of one field density test
shall be perfomied for every 2,000 cubic yards of soil or soil-rock fdl placed and
compacted.
7.2. The Consultant shall perform random field density tests of the compacted soil or soil-rock
fdl to provide a basis for expressing an opinion as to whether the fill material is compacted
as specified. Density tests shall be performed in the compacted materials below any
disturbed surface. When diese tests indicate that die density of any layer of fdl or portion
thereof is below diat specified, the particular layer or areas represented by die test shall be
reworked until the specified density has been achieved.
7.3. During placement of rock fill, the Consultant shall verify diat the minimum number of
passes have been obtained per die criteria discussed in Section 6.3.3. The Consultant shall
request the excavation of observation pits and may perfonn plate bearing tests on the
placed rock fills. The observation pits will be excavated to provide a basis for expressing
an opinion as to whether the rock fill is properiy seated and sufficient moisture has been
applied to the material. If performed, plate bearing tests will be performed randomly on the
surface of the most-recendy placed lift. Plate bearing tests will be performed to pro\dde a
basis for expressing an opinion as to whether the rock fill is adequately seated. The
maximum deflection in the rock fill determined in Section 6.3.3 shall be less than the
maximum deflection of the properiy compacted soil fill. When any of the above criteria
indicate diat a layer of rock fill or any portion thereof is below that specified, the affected
layer or area shall be reworked until the rock fill has been adequately seated and sufficient
moisture applied.
7.4. A settiement monitoring program designed by the Consultant may be conducted in areas of
rock fill placement. The specific design of the monitoring program shall be as
recommended in the Conclusions and Recommendations section of die project
Geotechnical Report or in the fmal report of testing and observation services performed
during grading.
GIrev. 07/02
7.5. The Consultant shall observe the placement of subdrams, to verify that die drainage devices
have been placed and constructed in substantial conformance with project specifications.
7.6. Testing procedures shall conform to the following Standards as appropriate:
7.6.1. Soil and Soil-Rock Fills:
7.6.1.1. Field Density Test, ASTM D1556-00, Density of Soil In-Place By the
Sand-Cone Method.
7.6.1.2. Field Density Test, Nuclear Method, ASTM D2922-96, Density of Soil and
Soil-Aggregate In-Place by Nuclear Methods (Shallow Depth).
7.6.1.3. Laboratory Compaction Test, ASTM D1557-00, Moisture-Density
Relations of Soils and Soil-Aggregate Mixtures Using 10-Pound Hammer
and 18-Inch Drop.
7.6.1.4. Expansion Index Test, ASTM D4829-95, Expansion Index Test.
7.6.2. Rock Fills
7.6.2.1. Field Plate Bearing Test, ASTM D1196-93 (Reapproved 1997) Standard
Method for Nonreparative Static Plate Load Tests of Soils and Flexible
Pavement Components, For Use in Evaluation arui Design of Airport arui
Highway Pavements.
8. PROTECTION OF WORK
8.1. During construction, the Contractor shall properiy grade all excavated surfaces to provide
positive drainage and prevent ponding of water. Drainage of surface water shall be
cond-olled to avoid damage to adjoining properties or to fmished work on the site. The
Contractor shall take remedial measures to prevent erosion of freshly graded areas until
such time as permanent drainage and erosion control features have been installed. Areas
subjected to erosion or sedimentation shall be properly prepared in accordance with the
Specifications prior to placing additional fill or structures.
8.2. After completion of grading as observed and tested by die Consultant, no further
excavation or filling shall be conducted except in conjunction with die services of die
ConsultanL
GI rev. 07/02
9. CERTIFICATIONS AND FINAL REPORTS
9.1. Upon completion of the work. Contractor shall fumish Owner a certification by the Civil
Engineer stating that the lots and/or building pads are graded to within 0.1 foot vertically of
elevations shown on the grading plan and that all tops and toes of slopes are within 0.5 foot
horizontally of the positions shown on the grading plans. After installation of a section of
subdrain, the project Civil Engineer should survey its location and prepare an as-built plan
of the subdrain location. The project Civil Engineer should verify the proper oudet for the
subdrains and the Contractor should ensure that the drain system is free of obstructions.
9.2. The Owner is responsible for fumishing a final as-graded soil and geologic report
satisfactory to the appropriate goveming or accepting agencies. The as-graded report
should be prepared and signed by a Califomia licensed Civil Engineer experienced in
geotechnical engineering and by a Califomia Certified Engineering Geologist, indicating
that the geotechnical aspects of the grading were performed in substantial conformance
with the Specifications or approved changes to the Specifications.
GI rev. 07/02
LIST OF REFERENCES
1. Blake, T. F., EQFAULT, A Computer Program for the Detemiinistic Prediction of Peak
Horizontal Acceleration fi-om Digitized California Faults, Users Manual, 1989a, p. 79
(Revised 1997 and 2000).
2. County of San Diego Topographic Survey, Ortho-photo, Sheet No. 362-1659, PhototTaphv
dated 1975. ^
3. Geologic Maps of the Northwestem Part of San Diego County, California. Califomia
Division of Mines and Geology Open-file Report 96-02, 1996.
4. United States Department of Agriculture, 1953 Stereoscopic Aerial Photographs, Flight
AXN-I4M, Photo Nos. 20 and 21.
5. United States Geological Survey, 7.5 minute Quadrangle Series, San Luis Rey Quadrangle
1968, Photorevised 1975.
6. Unpublished reports, aerial photographs and maps on file with Geocon Incorporated.
Project No. 07353-22-01 Septeinber 3,2004
10S Engineering, lac. DRAFT
neittcamlTranspertamn
6342 Fen-is Square, San Diego, CA 92121
Phone 619-890-1253, Fax 619-374-7247
May 2,2005
Prospect Point Development
c/o Tim Clark
1020 Prospect Ave, Suite 314
La Jolla, CA 92037
SUBJECT: Traffic Generation Letter Report for the Ocean Street Residences
Redevelopment Project fi'om 50 Apartments to 35 Condominiums
Dear Mr. Clark:
The foiiowing traffic generation letter report has been prepared to document why a traffic study
does not appear necessary for this project due to the net decrease in traffic through the
redevelopment of 50 apartment units to 35 condominitun units.
PROJECT LOCATION, DESCRIPTION, AND TRAFFIC GENERATION
The project site is located in the northwest quadrant of the City, north of Ocean Street, west of
tiie AT&SF Railroad, south of the Buena Vista Lagoon and east of the Rue Des Chateaux
development. The 3.05 acre project site is currently developed with 50 apartments units in
three separate buildings (16.4 units per acre) as shown in Figure 1. Access to the existing
apartments is provided from Ocean Street via two residential driveways located along the
westem and eastem property lines.
The project applicant is proposing to demolish the existing apartment buildings on-site and
construct 35 new stacked-flat condominium units (11.5 units per acre). Access for the project
is proposed to be located at the southwest comer from Ocean Street. A two driveway system
will create a vehicular entry court that provides queuing and tum around area for the future
residents and their guests as shown in Figure 2. The project is proposing a gated entry along
the westem property line that will include the required emergency system for access
(KNOX/Opticon).
Usmg the San Diego Association of Govemments (SANDAG) trip rates from the Brief Guide
of Vehicular Traffic Generation Rates for the San Diego Region, April 2002, this
redevelopment project is calculated to have a net change of-120 Average Daily Traffic (i\DT),
-10 AM peak hom: trips (-2 inboimd and -8 outbound), and -12 PM peak hour trips (-8 inbound
and -4 outbound) over the existing use as shown in Table 1.
USingSMOng, la§. ocean street Redevelopment Project DRAFT Traffic Letter Report
TraWsannTrattsnortatiett Mr. ciark - May 2,2005