HomeMy WebLinkAbout5512; Beech Avenue Sewer Project; Beech Avenue Sewer Project; 2008-12-30nu
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GEOTECHNICAL REPORT
BEECH AVENUE SEWER PROJECT
CARLSBAD, CALIFORNIA
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PREPARED FOR:
Attention: Mark D. Biskup, Associate Engineer
r-| CITY OF CARLSBAD
u Public Works - Engineering
1635 Faraday Avenue
H Carlsbad, California 92008
PREPARED BY:
INLAND FOUNDATION ENGINEERING, INC.
1310 South Santa Fe Avenue
San Jacinto, California 92583
December 30, 2008
Project No. K183-010
December 30, 2008
Project No. K183-010
INLAND FOUNDATION ENGINEERING, INC.
Consulting Geotechnical Engineers
1310 South Santa Fe Avenue
San Jacinto, California 92583
(951) 654-1555
FAX (951) 654-0551
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Attention: Randy Neff, P.E.
KRIEGER AND STEWART, INC.
3602 University Avenue
Riverside, California 92501-3380
Re: Geotechnical Report
Beech Avenue Sewer Project
Carlsbad, California
Dear Mr. Neff:
As requested, we have prepared this Geotechnical Report for the City of Carlsbad for
the City's use in the design of the referenced project. This report was prepared in
general accordance with our proposal dated October 27, 2006.
It is our opinion that the proposed development is feasible from a Geotechnical
Engineering standpoint. Our report includes design recommendations along with the
field and laboratory data.
We appreciate the opportunity of being of service to you on this project. If there are any
questions, please contact our office.
Respectfully,
INLAND FOUNDATION ENGINI
CERTIFIED
ENGINEERING
GEOLOGIST
DRL:LES:kw
Distribution: Addressee (7)
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U TABLE OF CONTENTS
H INTRODUCTION 1
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SCOPE OF SERVICES 1n
U PROJECT DESCRIPTION 3
H GEOLOGIC SETTING 4
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SUBSURFACE CONDITIONS 11
U CONCLUSIONS AND RECOMMENDATIONS 13
Excavatability 13
n Groundwater 14
L-l Trench Wall Stability 14
Pipe Bedding 15
H Embedment 16
^ Compaction Characteristics 17
Lateral Design 17
H Unit Weight 17
^ Protection of Existing Utilities and Storm Drains 17
Recommended Specifications for Placement of Trench Backfill 17
: Pipe Bursting Alternative Considerations 18
Microtunneling Alternative 20
H GENERAL 21
REFERENCES .............................................................................................................. 22
APPENDICES
APPENDIX A -Field Exploration ........................................................................ A-1 -A-6
Explanation of Logs ................................................................................................ A-2
Exploratory Borings ....................................................................................... A-3 - A-5
Site Plan ................................................................................................................. A-6
n APPENDIX B - Laboratory & Soil Mechanic's Testing ........... . ............................ B-1 - B-8
y * Maximum Density-Optimum Moisture Determinations ............................................ B-4
Classification Testing .............................................................................................. B-5
n Direct Shear Testing ............................................................. . ................................ B-6
y Consolidation Testing .......................... . ..................................................... B-7 and B-8
n ANALYTICAL TESTING .............................................................................................. B-3
I GENERAL ................................................................................................................... B-3
INTRODUCTION
This report presents the results of geotechnical exploration and testing conducted for
the City of Carlsbad Beech Avenue Sewer Project. Preliminary project plans prepared
by Krieger & Stewart, Inc. were used as a reference during our study.
SCOPE OF SERVICES
The purpose of the geotechnical investigation was to provide geotechnical parameters
for design and construction of the proposed project. The scope of the geotechnical
investigation included:
• A review of the general geologic conditions and specific subsurface conditions of the
project site.
• An evaluation of the engineering and geologic data collected for the project.
• Preparation of a formal report providing geotechnical conclusions and
recommendations for design and construction.
The tasks performed in order to achieve these objectives included:
• The collection and review of data in order to develop an exploration program.
• Subsurface exploration to determine the nature and stratigraphy of the subsurface
soils and to obtain representative samples for laboratory testing.
• A visual reconnaissance of the site and surrounding area to ascertain the existence
of any unstable or adverse geologic conditions.
• Laboratory testing of representative samples in order to establish the classification
and engineering properties of the soils.
• Analysis of the data collected and the preparation of this report presenting our
geotechnical conclusions and recommendations.
Evaluation of hazardous wastes was not within the scope of services provided. The
evaluation of seismic hazards was based upon field mapping and literature review. The
information in this report represents professional opinions that have been developed
using that degree of care and skill ordinarily exercised, under similar circumstances, by
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Krieger cfi Stewart - Beech A ve. Sewer
Project No. Ki83-010-December 2008 • ': 1 Inland Foundation Engineering, Inc.
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reputable geotechnical consultants practicing in this or similar localities. No other
warranty, either expressed or implied, is made as to the professional advice included in
this report.
Krieger & Stewart - Beech A ve. Sewer
r~] Project No. Kl83-010- December 2008 2 Inland Foundation Engineering, Inc.
PROJECT DESCRIPTION
The Beech Avenue Reach consists of approximately 1,060 lineal feet of proposed
sewer line extending from Ocean Street to the Washington Street Easement in the City
of Carlsbad. This line will replace an existing 8" VCP concrete-encased sewer pipeline.
U.S.G.S. Topographic Map, San Luis Key Quadrangle, and Aerial Photograph (2003)
The depth of the proposed sewer ranges from approximately 13 to 30 feet. We
understand that the proposed sewer line will be constructed using minimum 8-inch
inside diameter gravity sewer. We understand that the new sewer may be constructed
using microtunneling or other trenchless construction methods.
Because the project will occur along an existing paved street, the project may require
the replacement of existing pavement and aggregate base material. We are not aware
if the project will involve the replacement of any existing underground utilities.
Krieger & Stewart - Beech Ave. Sewer
Project No. K183-010 - December 2008 Inland Foundation Engineering, Inc.
GEOLOGIC SETTING
Hu Regional Geology: The project area lies along the coastal portion of the geomorphic
•pj province known as the Peninsular Ranges. The Peninsular Ranges are described as a
lJ series of ranges separated by northwest trending valleys, subparallel to faults branching
from the San Andreas Fault. The trend of the topography is similar to the Coast
H Ranges, but the geology is more like the Sierra Nevada, with granitic rock intruding the
L-' older metamorphic rocks. The Peninsular Ranges extend into lower California and are
n bound on the east by the Colorado Desert. The Los Angeles Basis and the island
jj group (Santa Catalina, Santa Barbara, and the distinctly terraced San Clemente and
San Nicholas islands), together with the surrounding continental shelf (cut by deep
H submarine fault troughs), are included in this province (California Department of
U Conservation, California Geologic Survey, 2002).
Hj Local Geology: More locally, the subject site rests within the Oceanside 30' x 60'
Quadrangle, as mapped by USGS. The area is tectonically and seismically active and
H] is dissected by four major, northwest trending, oblique right slip, Pacific/North American
U Plate boundary fault zones. They include the Elsinore Fault Zone in the northwestern
corner of the quadrangle, the Newport-lnglewood-Rose Canyon Fault Zone in the
: center of the quadrangle (origin of the 1933, M=6.3, Long Beach earthquake), the
Coronado Bank Fault Zone in the southwestern corner of the quadrangle (origin of the
n 1986, ML=5.3, Oceanside earthquake). Landslides are abundant in the western and
,_, offshore parts of the quadrangle. Also, seismic hazards are numerous throughout the
area. A tsunami hazard exists along the coastal margin. The westerly portion of the
^ quadrangle is underlain by a relatively thick (>1000m) succession of Upper Cretaceous,
^ Tertiary, and Quaternary sedimentary and volcanic rocks that unconformably overlie the
.-, older plutonic and basement forearc rock sequence. These rocks consist chiefly of
J beds of marine, paralic and non marine claystone, siltstone, sandstone and
conglomerate and minor flows consisting mostly of Neogene basalt. Many cycles of
rj uplift, erosion, subsidence and deposition since the Late Mesozoic have created the
—I complexity of the existing stratigraphic and structural settings (Kennedy & Tan, 2005).
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: The soils encountered along the proposed alignment consist of marine terrace deposits.
These paralic deposits are defined as deposits laid down on the landward side of a
n coast.
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Based upon our subsurface exploration, the soils are medium dense to dense, weakly
M to strongly cemented, silty sand and sand.u
n Following is a portion of the U.S.G.S. Geologic Map of the Oceanside 30' x 60'
LJ Quadrangle, California (Kennedy & Tan, 2005) depicting the mapped geologic units in
the vicinity of the project alignment:nu
Krieger & Stewart - Beech Ave. Sewer
i—i Project No. Ki 83-010- December 2008 4 Inland Foundation Engineering, Inc.
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Old pantile deposits. Unit 7 (late to middle
Pleistocene)—Mostly poorly sorted, moderntely permeable,
reddish-brown, interfmgered strand line, bench, estuarine
and colluvial deposits composed of siltstone. sandstone and
conglomerate. These deposits rest on the 9-1 I m Bird Rock
terrace (Fig. 3)
Old p:imlic deposits. Unit 6 (late to middle
Pleistocene)—Mostly poorly sorted, moderately permeable,
reddish-brown, interfmgered strandline, beach, estuarine
and colluvial deposits composed of siltstone, sandstone and
conglomerate. These deposits rest on the 22-23 m Nestor
terrace
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Groundwater: The study area is located within the San Diego Hydrologic Region, which
drains west into the Pacific Ocean. The San Diego Hydrologic Region encompasses
approximately 3,900 square miles and is further subdivided into 11 major watersheds.
This project lies within the Carlsbad Watershed. The Carlsbad Watershed occupies
approximately 210 square miles, extending from Lake Wohlford on the east to the
Pacific Ocean on the west and from Vista on the north to Cardiff-by-the-Sea on the
south. This watershed includes the cities of Oceanside, Carlsbad, Encinitas, Vista, and
Escondido. The watershed is drained by Buena Vista, Agua Hedionda, San Marcos
and Escondido creeks and contains four coastal lagoons, including Buena Vista, Agua
Hediona, Batiquitos and San Elijo lagoons (Dudek & Associates, 2003).
Krieger & Stewart - Beech Ave. Sewer
Project No. Kl83-010- December 2008 Inland Foundation Engineering, Inc.
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Groundwater was encountered within one of our exploratory borings (B-03) at a depth
of 25 feet or elevation of 22 feet MSL. This is approximately five feet below the sewer
invert elevation at that location. Oxidation-reduction mottling was encountered within
this boring at a depth of 24 feet. Seasonal fluctuation of groundwater levels is
anticipated and could be a factor during the construction of the sewer.
Groundwater levels in the vicinity reported by Gregg Drilling were reviewed for this
project. Near the intersection of Tamarack Avenue and the 1-5 Freeway, located
approximately 1.2 miles southeast of the site, an approximate depth to groundwater of
45 feet was reported on March 29, 1999. The site is approximately 15 feet higher in
elevation than the project alignment. A second site, located approximately 0.6 miles
east-northeast and approximately 20 feet higher in elevation was drilled on March 8,
2000 and had an approximate groundwater depth of 15 feet (Gregg Drilling, 2006).
This data may be of little relevance to the subject site with the exception that the
groundwater observations indicate a regional gradient toward the southwest within the
portion of Beech Avenue that is the subject of this study. This is illustrated in the
following diagram:
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50
40
30
20
10
Station
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/ Existing Surface
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Exisitng Sewer — .. '
7 -•-
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~--^_
Groundwater
0+00 Station 5+00
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Station 10+00
BEECH AVENUE
The groundwater data indicated for our current exploration is only representative of the
conditions at the time of our exploration and may not reflect the conditions during
construction. Therefore, the local groundwater conditions should be assessed by the
contractor prior to the commencement of work in order to determine if groundwater will
adversely affect the construction process.
Seismicity: The project site does not lie within a State of California Alquist-Priolo
Earthquake Fault Zone, however the proposed alignment is located within a seismically
active region of Southern California. No documented faults are mapped trending
through the alignment; however there are several relatively nearby faults, which are
capable of producing significant ground shaking at the site during major earthquakes.
Krieger & Stewart - Beech Ave. Sewer
Project No. Kl 83-010 - December 2008 Inland Foundation Engineering, Inc.
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The following is a portion of a map and associated legend entitled "Fault Activity Map of
California and Adjacent Areas", compiled by Charles W. Jennings (CDMG, Geologic
Data Map No. 6, 1994) depicts the mapped faults in the site locale of the subject
property.
-••>: ,;± ^j'j^^cf-l \ j_""_~
\-\!-i.' r^^ite «: "X'-^^^^rT
^.^^1^ *'-ygjj$ ^M?'?~T*
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Krieger & Stewart - Beech Ave. Sewer
Project No. K183-010 - December 2008'Inland Foundation Engineering, Inc.
Square on fault indicates where fault .creep slippage has occurred that has been triggered by an
earthquake on some OJterJiUiil-' J;'ti: °f causative earthquake indicated. .Squares to right and Icli of
date indicate terminal points between which triggered creep slippage has occurred (creep cither
continuous or intermittent between these end points). ~ y "—^®i
Holoceiii: fault displacement (during pasi lO.tHHl years) without historic record. Gcoinorphic
evidence for llolocene faulting includes sag ponds; scarps showing liitlecrosion. or ilic following
features in llolocene age deposits: offset stream courses, linear .scarps', shutter ridges, and
triangular faceted spurs. Recency of faulting offshore is based on the interpreted age of the
youngest strain displaced by faulting. Pale orange band S£S2^£2=r* added to cmpiiasi/e
location of Holocene fault displacement.
I .ate Quaternary fault displacement (during past 700.0(10 years). Geoinorphic evidence similar
to thai described for Holoccne faults except features arc less distinct, faulting may he younger.,
but lack of younger overlying deposits precludes more accurate age classification.
Quaternary fault (age undiffcrcmiaied). Most faults of this category show evidence of
displacement sometime during the past 1.6 million years; possible exceptions are faults which
displace rocks of imdiffcrenliaied I'lio-Pieisioccnc age. Unnumbered Quaternary faults were
based on Fault Map of California. 1975. See Bulletin 201. Appendix D for source data.
Late Ceno/oic faults within the Sierra Nevada including, but not restricted to. the Foothills
fault system. Faults show stratigraphic and/or gconiorphic evidence for displacement of laie
Miocene and Pliocene deposits. By analogy, laic Ceno/.oic faults in this system that have been
investigated in detail may have been active in Quaternary time. (Data from RG&F.. I9°3).
Pre-Quaicrnary fault (older than 1.6 million years) or fault without recognized Quaternary
displacement. Some faults are shown in this category because the source of mapping used was
of reconnaissance nature, or was not done with the object of dating fault displacements. Faults
in this category arc not necessarily inactive.
Fault Segment associated with a significant linear trend of accurately located earthquake
epicenters (magnitude 0.2 or greater!. Generally aligned along strike slip faults having
Quaternary displacement, hut not necessarily with historic surface rupture. Ijick ot seismic
activity along any fault is no indication that the fault may not he active in the future (e.g. San
Andreas fault north of San Francisco). Epicenter data arc derived from closely spaced seismic
stations and include cither continuing microseismicily or aftershocks associated with relatively
large earthquakes.
nu According to maps compiled by the California Department of Conservation, Division of
Mines and Geology (DMG) the major faults influencing the site, distances and
maximum earthquake magnitudes are as follows:
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J Fault Zone
Newport-lnglewood (Offshore)
Rose Canyon
Coronado Bank
Elsinore-Temecula
Elsinore-Julian
Distance
(Km)
7.1
7.3
33.3
39.2
39.7
Earthquake
Magnitude (Mw)
6.9
6.9
7.4
6.8
7.1
Slip Rate
(Mm/Yr)
1.50
1.50
3.00
5.00
5.00
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The primary geologic hazard affecting the project is that of ground shaking. Probabilistic
site parameters developed using FRISKSP (Blake, 2000) indicate that there is a 10%
probability that a site acceleration of 0.28g will be exceeded in a 50-year period. The
ground acceleration corresponding to a 10% Probability of Exceedance in 100 years is
Krieger & Stewart — Beech Ave. Sewer
Project No. Kl83-010 - December 2008 8 Inland Foundation Engineering, Inc.
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estimated to be 0.36g. The Modal Magnitude based upon a deaggregation analysis is
7.0.
2001 California Building Code Criteria: On the basis of Standard Penetration
Testing (SPT), it is our opinion that the Soil Profile Type may be assumed to be SD over
the project alignment for the purpose of developing seismic design criteria in
accordance with the 2001 California Building Code. On the basis of the subsurface
conditions and local fault characteristics, the California Building Code provides the
following seismic design parameters:
•;.;., ,^UBC-Chaill%^
li. ;->•••'. fable jsto. ..
16-1
16-J
16-Q
16-R
16-S
16-T
16-U
•;:: ''*%,.' :-V'<'%-^>L, /;/,/. ;>/?
''•r ; Selsmi$ Parameter' r'*;i.
Seismic Zone Factor Z
Soil Profile Type
Seismic Coefficient Ca
Seismic Coefficient Cv
Near Source Factor Na
Near Source Factor Nv
Seismic Source Type
Recommended Value
0.4
SD
0.44
0.71
1.1
1.1
B
2007 California Building Code Criteria: Included for this study was an assessment of
the seismic parameters of the subject site with respect to the 2007 California Building
Code (CBC). The mapped spectral acceleration parameters, coefficients, and other
related seismic parameters were determined by using the Java Ground Motion
Parameter Calculator (U.S.G.S., 2007) and other sources. On these bases, the 2007
California Building Code provides the following seismic design parameters:
/-.' ~CBC3e>iap,'|§j
/£ .-•-•;' R$^*:/J.£Ji-
Table 1613.5.2
Fig. 1613.5(3)
Fig. 1613.5(4)
1613.5.3(1)
1613.5.3(1)
Eq. 16-37
Eq. 16-38
Eq. 16-39
Eq. 16-40
1613.5.6
:. ...-.;" •;.••; -^ Seferhie^arameter;>; > V :;. .
Site Class
Mapped Spectral Acceleration - Ss
Mapped Spectral Acceleration - Si
Site Coefficient - Fa
Site Coefficient - Fv
MCE Spectral Acceleration - SMS
MCE Spectral Acceleration - SMI
Design Spectral Acceleration - SDS
Design Spectral Acceleration - SDi
Seismic Design Category
f- Recommended
jr4.-^ ; :.^ Vgjue " .; ;^;/'/':;;;
D
1.338
0.504
1.0
1.5
1.338
0.756
0.892
0.504
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Krieger & Stewart - Beech Ave. Sewer
Project No. Kl 83-010 - December 2008 Inland Foundation Engineering, Inc.
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It should be noted that these provisions are intended to be the minimum design
H condition for structures and are often used as the maximum level to which structures
^ are designed. The minimum code criteria are designed to allow occupants to safely
n evacuate a structure after an earthquake. The structure may no longer be safe for
jj inhabitants and may ultimately have to be demolished.
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SUBSURFACE CONDITIONS
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The results of our investigation indicate that the site may be characterized as being
underlain by both predominately granular soils consisting of interbedded silty sands and
sands. Larger particles consisting of cobbles or boulders were encountered within our
exploratory boring B-01 at a depth of 26 feet. Due to the nature of the exploratory
borings, it is not possible to estimate the size of particles in the cobble and boulder
range.
The granular materials were generally observed to be in a moderately dense to dense
condition. In borings B-01 and B-02, cementation may be described as weak to
moderate. In Boring B-03, some of the soils were described as being strongly
cemented.
Groundwater was encountered within one of our exploratory borings (B-03) at a depth
of 25 feet. Apparent oxidation-reduction mottling was encountered within this boring at
a depth of 24 feet. A generalized profile indicating the boring locations and ground-
water levels relative to the sewerline and ground surface is presented below:
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Existing Surface
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Exisitng Sewer — ^
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20
10
Station 0+00
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I.I1 , .^- -i NT-
— ^ ^^ Groundwater
Station 5+00
BEECH AVENUE
Station 10+00
Moisture contents of samples retrieved from our borings were variable, depending upon
the soil type and the effects of groundwater. Moisture contents ranged from
approximately three to twenty-four percent. Optimum Moisture Contents ranged from
approximately 9 to 13 percent.
Relative Compactions within the upper 20 feet ranged from approximately 81 to 97
percent. The average Relative Compaction was observed to be approximately 94
percent with a statistical uncertainty of 5 percent. These were computed using
maximum dry densities determined in accordance with ASTM D1557-07. This is useful
in estimating volumetric shrinkage of soil that is excavated and reused as compacted
backfill and in estimating the in-situ strength characteristics of the soil (E1).
Krieger & Stewart - Beech Ave. Sewer
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Consolidation testing indicated that most of the soil is normally- to slightly over-
consolidated. The testing reveals slightly compressible soils.
Sand Equivalent (SE) values ranged from 21 to 35.
Analytical testing indicates sulfates concentrations are less than 0.001 percent.
Chloride concentrations range from 70 to 140 parts per million. Saturated Resistivities
ranged from 3,600 to 10,100 ohm-cm and pH values ranged from 7.4 to 8.4. A
Corrosion Engineering study was not within the scope of services for this project.
Krieger & Stewart - Beech Ave. Sewer
Project No. Ki 83-010 -December 2008 12 Inland Foundation Engineering, Inc.
CONCLUSIONS AND RECOMMENDATIONSnI
On the basis of our exploration and testing, it is our opinion that the feasibility of the
r~| proposed construction will be dependent upon the construction methods used. In
U general, the soils are in a medium dense to dense condition, are weakly to strongly
cemented and are expected to provide a stable environment for the pipeline
construction using the proposed replacement technologies. Although the soil
conditions may be suitable for a variety of construction techniques, the concrete
H] encasement of the existing sewerline may present an obstacle to some of the proposed
L) methodologies such as pipe-bursting and micro-tunneling.
n.1 Caving was not encountered within our exploratory borings. However, hollow-stem
augers were used to case the borings in a specific effort to prevent caving. The borings
H were backfilled with a Bentonite slurry placed through the augers as they were with-
'-' drawn in accordance with the requirements of the County of San Diego. Caving of
r-, open cuts appears to be likely within the sands encountered in Borings B-01 and B-02.
J Although the cementation of the soil encountered in Boring B-03 makes caving less
likely, groundwater on the northeast portion of the project could trigger caving in that
^ area.
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r-i Groundwater was not encountered within the zone of anticipated pipeline excavation
i_j during this study. Groundwater was encountered at a depth of approximately 25 feet
(elevation of 22 feet above MSL) in Boring B-03 located near the eastern end of the
^ propose pipeline alignment. The estimated cover depth at this location is about 19 feet.
u The elevation at the tie-in at the east end of the alignment is approximately 19 feet MSL
n which is approximately 3 feet below the groundwater level observed in Boring B-03
U located approximately 200 feet to the west. Groundwater should be expected within
approximately 65 feet of the tie-in.<~\
All work should be performed in accordance with the specifications of the City of
n Carlsbad. The following sections present more detailed recommendations and
u conclusions regarding excavatability, groundwater, trench wall stability, pipe bedding,
embedment, compaction characteristics, lateral design, protection of existing utilities
and trench backfill:
n 1. Excavatability: Soils along the alignment may be generally characterized as
LJ interbedded silty sands and sands in a medium dense to dense condition.
Although some of these soils were strongly cemented, our subsurface
jj exploration does not indicate that the materials encountered within the proposed
pipeline depths will cause refusal to normal excavating equipment. The
n oversized particles encountered in Boring B-01 were deeper than the planned
Krieger & Stewart - Beech Ave. Sewer
Project No. Ki83-010 - December 2008 13 Inland Foundation Engineering, Inc.
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excavation at that boring location. However, variations in the profile could occur
n and these materials may be encountered. Caving of clean sands that are weakly
L-J cemented could influence the excavation process.
[—\
jj 2. Groundwater: Groundwater was encountered within one of our exploratory
borings (B-03) at a depth of 25 feet or elevation of 22 feet MSL. Apparent
n oxidation-reduction mottling was encountered within this boring at a depth of 24
L-J feet. Groundwater conditions should be expected to fluctuate. The groundwater
data in this report is representative of the conditions at the time of our
I exploration and may not reflect the conditions during construction. Therefore,
the local groundwater conditions should be assessed by the contractor prior to
the commencement of trenching in order to determine if groundwater will
adversely affect the construction process. Should groundwater be indicated
within the planned excavation depths, dewatering should be achieved prior to the
commencement of excavation. Monitoring wells should be installed to confirm
1-1 that dewatering to a depth of at least five feet below the base of the planned
r-i excavation is achieved prior to the commencement of the excavation process.
J The groundwater levels should be maintained to at least five feet below the
planned excavation depth until the backfilling is complete.n
The portions of the pipeline that could be affected by groundwater are estimated
1-1 to be minor unless the regional groundwater levels rise uniformly. Current data
j indicates that groundwater is likely to be encountered in excavations made within
approximately 65 feet of the tie-in at Station 10+64.10. Therefore, dewatering
^ prior to excavating is indicated.
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If groundwater occurs at the base of any excavation, we recommend that the
: excavation process be discontinued to reduce the magnitude of base heave.
The groundwater level should be lowered to at least five feet below the base of
n the excavation before proceeding. If the excavation is not properly dewatered
U and slight base heave occurs, it could result in post-construction settlement of
the pipeline and manholes.n
3. Trench Wall Stability: All excavations should be configured in accordance with
n Cal/OSHA requirements. Our exploration and testing suggests that the soils may
U be classified as being Type C as described in the Excavation Standard of OSHA.
This will not be applicable over any areas affected by saturated soils and/or
n groundwater, which should be anticipated over portions of the pipeline alignment.
The portions of the pipeline that could be affected by groundwater are estimated
r-| to be minor unless the regional groundwater levels rise uniformly. Current data
J indicates that groundwater is most to be encountered in excavations made within
approximately 65 feet of the tie-in at Station 10+64.10.nJ .Krieger & Stewart - Beech A ve. Sewer
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The classification of the soil and the shoring and/or slope configuration should be
the responsibility of the contractor on the basis of the trench depth and the soil
encountered. The contractor should have a "competent person" on-site for the
purpose of assuring safety within and about all construction excavations.
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Temporary shoring may be designed to resist the earth pressure with the effects
of hydrostatic pressures and surcharged loads superimposed. Cantilever
shoring should be based upon a triangular pressure distribution using the active
earth pressure. Shoring, which is braced, may be designed assuming a
rectangular pressure distribution. The following diagrams illustrate these
assumed pressure distributions:
p=32H
BRACED SHORING UNRESTRAINED SHORING
LJ
u
n
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4. Pipe Bedding: Where bedding is necessary to bring the trench bottom up to
grade, we recommend a minimum bedding thickness of 6 inches be placed to
provide uniform and adequate longitudinal support under the pipe. The bedding
material should not be compacted within 6 inches of the bottom of the pipe.
Blocking should not be used to bring the pipe to grade. Bell holes at each joint
should be provided to permit the joint to be assembled properly while
maintaining uniform pipe support.
n
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Krieger & Stewart - Beech Ave. Sewer
Project No. Kl83-010- December 2008 15 Inland Foundation Engineering, Inc.
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Embedment U-TT\i_—-
Haunch
Zone
^ l_Jt^U\JIIIM /-—~~'V (Uncompacted) A \ \r
5. Embedment: Processed native materials should provide suitable support for the
pipe where cover thicknesses are greater than three feet. On-site soils may be
classified silty sands and sands. A Lateral Modulus of Subgrade Reaction (E1) of
2,500 pounds per square inch may be assumed for the entire alignment.
n
U If designs are based upon the use of imported granular embedment materials,
we recommend that a granular free-draining soil be used. The actual thickness
should be determined by the pipeline engineer or manufacturer. We recommend
that if imported granular embedment material is used, it have a minimum Sand
Equivalent (SE) of 30 and be free of particles greater than two inches in
diameter.
To provide protection from particle migration, imported pipe embedment material
should be in accordance with the following criteria:
Di5> 0.75mm and DSO < 7.5mm,
n where D-i5 and DSO represent bedding material particle sizes corresponding to
U 15 and 50 percent passing by weight, respectively. If these criteria cannot be
met, a filter fabric will be required.
The most important factor affecting pipe performance and deflection is the
n haunching material and its density. Material should be placed and consolidated
J under the pipe haunch to provide adequate side support to the pipe while
avoiding both vertical and lateral displacement of the pipe from proper alignment.
H Where coarse material with voids is used for bedding, the same coarse material
^ should also be used for haunching with consideration given to native soil
migration. Haunching is placed up to the pipe springline.
ni i
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Krieger & Stewart — Beech Ave. Sewer
Project No. Ki83-0io - December 2008 16 Inland Foundation Engineering, Inc.
6. Compaction Characteristics: In general, we anticipate that the soils that are
"~l excavated and replaced as controlled compacted backfill will respond to
^ mechanical compaction. Laboratory testing suggests that jetting may not be a
f-| feasible alternative for achieving compaction. As the soils are placed, they
j should be compacted in shallow lifts that are compatible with the strength of the
pipe, the site conditions and the particular compaction methods used. This is the
!~| responsibility of the contractor to determine. We estimate that the shrinkage of
the native soils used in the backfill will be negligible but will vary along the
n alignment.
J
7. Lateral Design: On the basis of laboratory testing, we propose a lateral bearing
H capacity (Passive Earth Pressure) of 250 pounds per square foot per foot of
depth below the lowest adjacent grade. This may be limited to 2,500 pounds per
n square foot per foot of depth. This may be assumed to be applicable for
U resisting jacking forces.
n 8. Unit Weight: For our recommendations, we have assumed a Unit Weight of
133 pounds per cubic foot for backfill compacted to an average of 93 percent at
i near optimum moisture content.
LJ
,_, 9. Protection of Existing Utilities and Storm Drains: Where the pipeline is
constructed beneath existing utility crossings and storm drains, care should be
taken to assure adequate compaction of the backfill beneath the existing utilities.
^ If the existing utilities are rigid or encased in concrete, we recommend that the
^ backfill consist of compacted soil to a depth of not less than one foot beneath the
n utility invert. The remaining backfill should consist of sand-cement slurry poured
J around the existing utility line to assure adequate contact at the base. Protection
of flexible pipes may also require the placement of sand-cement slurry.
n
^ Protection of adjacent utilities will largely depend upon maintaining stable slopes.
j—I Planned vertical excavations should be reviewed to verify that they would not
U remove lateral support from any adjacent flexible utilities.
n • 10. Recommended Specifications for Placement of Trench Backfill:
Trench Excavation: Trenches shall be excavated according to the line and grade
r~| as shown on the drawings. Unless otherwise specified, pipeline trenches shall
U be excavated with the following clear distances:
j • For pipe diameters up to 12-inches, the trench width shall provide 6 to 9-
inches of clearance between the edge of the pipe and the wall of the trench.
n
u Krieger & Stewart — Beech Ave. Sewer
Project No. K183-OW - December 2008 17 Inland Foundation Engineering, Inc.
• For pipe diameters of over 12 inches, the trench width shall provide at least
H 12-inches of clearance between the edge of the pipe and the wall of the
^ trench.
n
ij The sides of the trench shall be parallel to the pipe and shall maintain an equal
distance from the pipe. If the excavation is carried to below the design grade,
H the bottom of the excavation shall be refilled with approved material. Where soft
or otherwise unstable materials are encountered, the excavation shall be carried
r-j to a depth as determined to be necessary by the Engineer and stabilized with
U gravel or other approved bedding material.
i—i The excavations receiving backfill shall be free of trash, debris, or other
unsuitable materials prior to the placement of backfill.
n[
J Pipe Zone Backfill: Except as otherwise required by the project specifications,
contract drawings or manufacturer's recommendations, imported pipe zone
backfill shall consist of clean, cohesionless soil having a Sand Equivalent of
greater than 30 and fewer than 10% particles finer than the No. 200 Sieve. To
n provide protection from particle migration, imported pipe zone material should
uJ also be in accordance with the following criteria:
n
! Di5> 0.75mm and D50 < 7.5mm,> i
1-1 where D15 and D50 represent bedding material particle sizes corresponding to
*-> 15 and 50 percent passing by weight, respectively. If these criteria cannot be
^ met, a filter fabric will be required.
U
This material shall be placed and compacted in a manner that will assure firm
n continuous encasement for the pipe. This may consist of careful flooding oriu jetting combined with vibratory compaction. Jetting should be implemented with
n care to avoid the accumulation of water in the pipe zone. The minimum Relative
iJ Compaction within the pipe zone shall be 90 percent unless otherwise specified.
The pipe zone backfill shall extend to 12 inches above the top of the pipe.n
Trench Backfill: Trench backfill material should be native or approved granular
r-j materials which are free of organic and deleterious materials, rocks or lumps
LJ greater than 3 inches in greatest dimension and other unsuitable materials.
Trench backfill may be compacted at near optimum moisture content by
n mechanical means as necessary for the achievement of satisfactory compaction.
Unless otherwise specified by the drawings, specifications or encroachment
n permits, the minimum acceptable degree of compaction shall be 90 percent of
Krieger & Stewart - Beech Ave. Sewer
^ Project NO. K183-OW - December 2008 18 Inland Foundation Engineering, Inc.
u
the maximum dry density. This is with the exception of the upper 12 inches
0 within roadway areas which shall be compacted to a minimum of 95 percent
'L-J Relative Compaction.
n
u Observations and Compaction Testing: During backfilling, continuous
observations and compaction testing shall be conducted in order to verify
'"I satisfactory compaction. The Maximum Dry Density-Optimum Moisture Content
^ relationship shall be determined by means of the ASTM Standard D1557-07 test
r-| method. The field density shall be determined by either the ASTM Standard
J D1556-07 or ASTM D6938-07b test method. The compaction shall be verified at
maximum intervals of 250 feet for each 2-foot vertical lift or as otherwise
n determined to be necessary by the District Inspector in the field during
backfilling. Some backfill and compaction methodologies will dictate much
r-j shorter test intervals. Compaction testing is required within the pipe zone backfill
U unless gravel is specified and used as backfill material within that zone.
Continuous observations should also be made during the placement of slurry
' around and beneath existing utilities.i )
n Retests: Should testing reveal insufficient compaction, additional testing will be
U necessary in order to define the area requiring recompaction. Without further
testing, it will be assumed that the area between a failing test and a passing test
1 is not properly compacted. As a guideline for evaluation, one test may be taken
at a distance from the failing test equal to 20 percent of the distance to the next
^ passing test. If the test reveals satisfactory compaction, the area between the
L~I failing test and the passing test shall be recompacted. If the test reveals
^ inadequate compaction, the process should be repeated in order to delineate the
.J unsatisfactory area. After recompaction of "failing" areas, retesting should be
conducted in order to confirm satisfactory compaction. At least one retest is
n required for each failing test, even if failing tests are for the purpose of
L-J delineating the area requiring additional work.
n,J 11. Pipe Bursting Alternative Considerations: If pipe bursting is considered as an
alternative for this project, design and installation factors including ground
n conditions, groundwater conditions, degree of upsizing required, construction
^ and depth of the existing pipeline, etc. should be considered. Typically,
PI somewhat less favorable soil conditions for pipe bursting involve densely
(J compacted soils and backfills, soils below the water table and dilatant soils (soils
that expand in volume as they are sheared, e.g. angular sands. Each of these
r"j soil conditions tends to increase the force required for the bursting operation and
to increase the zone of influence of the ground movements (Simicevic & Sterling,
n 2001).
Krieger & Stewart - Beech Ave. Sewer
Project No. K183-OW - December 2008 19 Inland Foundation Engineering, Inc.
LJ
Very dense soils are present along the project alignment. In addition, seasonal
n fluctuations of the groundwater levels could result in portions of the alignment
^ being below the groundwater table. Perhaps the most significant factor for this
n particular project may not be related to soil conditions. The existing pipeline is
jj encased in concrete. Special equipment and methodologies are available to
address concrete encasement. Therefore, a qualified and experienced
H contractor should carefully evaluate these conditions to assess the feasibility and
selection of appropriate pipe bursting system.
r~]
iJ Utilities that interfere with or may be damaged by the burst should be located
exposed prior to the burst. The contractor should take all care in protection of
: existing utilities potentially affected by the pipe bursting operation.u
n 12. Microtunneling Alternative: Another alternative under consideration is
U microtunneling. This is a trenchless technique where pipe-jacking is combined
with horizontal drilling or boring to directly install underground pipelines.
Hydraulic jacks are used to push specially designed pipes through the ground at
the same time the excavation is taking place. The only excavations that are
n necessary for the installation are for jacking and receiving pits that may coincide
L-l with manhole locations. These are typically retained using sheetpiling designed
^ in accordance with the parameters provided in this report. If the alignment is to -
., be collinear with the existing sewer, the presence of existing manholes and
concrete encased sewer line could be problematic.
i—\
^ Conditions will vary along the pipeline alignment. The soils may be assumed to
0 have negligible adhesion but will impose frictional resistance. Our test data
jj suggests a coefficient of friction of up to 0.65.
|~j Our borings indicate soil conditions that are expected to be suitable for this
^ alternative. Seasonal fluctuations of the groundwater levels could result in
r-^ portions of the alignment being below the groundwater table. Dewatering as
LJ previously discussed in this report will be necessary. A qualified and
experienced contractor should carefully evaluate the ground conditions, design
n requirements and the site conditions to assess the overall feasibility and the
^ selection of appropriate excavation methods and earth support systems.
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Krieger & Stewart — Beech Ave. Sewer
Project No. K183-010 - December 2008 20 Inland Foundation Engineering, Inc.
U
GENERALn
The findings and recommendations presented in this report are based upon an
ri interpolation of the soil conditions between boring locations. Should conditions be
U encountered during construction that appears to be different than those indicated by
this report, this office should be notified.
I
At the request of Krieger & Stewart, Inc., the services provided for this project were
P performed for the City of Carlsbad for their use in the design of the Beech Avenue
u Sewer Project. This report may only be used for this purpose. The use of or reliance
upon this report by parties other than Krieger & Stewart, Inc. and the City of Carlsbad or
for other purposes is not authorized without written permission by Inland Foundation
Engineering, Inc. Inland Foundation Engineering, Inc. will not be liable for any projects
H connected with the unauthorized use of this report.U
P-, The recommendations of this report are considered to be preliminary. The final design
i_j parameters may only be determined or confirmed at the completion of project
construction on the basis of observations made during the project construction
'"j operation. To this extent, this report is not considered to be complete until the
u completion of both the design process and project construction.
n
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H
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Krieger & Stewart - Beech Ave. Sewer
^ Project No. KI 83-010 -December 2008 . 21 Inland Foundation Engineering, Inc.
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REFERENCES
ni
LJ Blake, T.F. 1989, EQSEARCH, A computer program for the estimation of peak horizontal
acceleration from Southern California Historical Earthquake Catalog, Version 2.2 (1995).
Blake, T.F. 1989, EQFAULT, A computer program for the deterministic prediction of peak
r~i horizontal acceleration from digitized California faults, Version 2.2 (1995).
U
California Department of Conservation, California Geologic Survey, 2002, California
M Geomorphic Provinces, Note 36.
r-j City of Carlsbad Water Department, Verbal Communications with Joe Adams, Gary
J Goodman, JulyS, 2007.
H Dudek & Assoc, 2003, Carlsbad Water and Sewer Master Plan, Program EIR.
LJ
„ Hart, E.W., 1997, "Fault Rupture Hazard Zones in California," California Division of Mines
, I & Geology Special Publication 42.
H Jennings, C.W., "Fault Activity Map of California and Adjacent Areas", 1994, CDMG,
U Geologic Data Map No. 6.
Krieger & Stewart, Inc., 2007, Preliminary Construction Plans.u
r-i Pipe Jacking Association, "An introduction to pipe jacking and microtunneling design",
ISBN 978-0-9525982-2-0.u
n
U
n
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Simicevic, J, & Sterling, R.L.,2001, "Guidelines for Pipe Bursting", prepared for Army Corp
of Engineers, TTC Technical Report #2001 .02.
n
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u Krieger & Stewart - Beech A ve. Sewer
r~) Project No. K183-010-December 2008 22 Inland Foundation Engineering, Inc.
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LJ
.q APPENDIX A
U
FIELD EXPLORATION
3
For our field investigation, 3 exploratory borings were excavated by means of a
n truck mounted rotary auger rig at the approximate locations shown on Figure A-
L-' 6. The rig utilized 8-inch diameter, hollow-stem augers. Continuous logs of the
n materials encountered were made on the site by a Soil Engineer. These are
J presented on Figures A-3 through A-5.
n Representative undisturbed samples were obtained within our borings by driving
a thin-walled steel penetration sampler with successive 30-inch drops of a 140-
ri pound hammer. The sampler was lowered to the bottom of the boring through
u the hollow-stem auger. The number of blows required to achieve each six
inches of penetration were recorded on our boring logs and used for estimating
the relative consistencies of the subsoils. The sampler type carried brass
sample rings having diameters of 2.41 inches. Undisturbed samples were
f~> removed from the sampler and placed in moisture sealed containers in order to
u preserve the natural soil moisture content. The samples were then transported
^ to our laboratory for further observations and testing.
u
In accordance with the requirements of the County of San Diego, the borings
^ were backfilled using a bentonite slurry that was placed through the auger as the
^ augers were withdrawn.
nJ
nu
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Krieger & Stewart - Beech Ave. Sewer
n Project No. Ki 83-010 - December 2008 A-1 Inland Foundation Engineering, Inc.u
UNIFIED SOIL CLASSIFICATION SYSTEM (ASTM D2487-06)
PRIMARY DIVISIONS GROUP SYMBOLS SECONDARY DIVISIONS
a:LUCDa:
3
CO <?
-J CO LU
Oen
a
LUz
LLI
COcc
§
CJ
—<coa: LU
LU
z£
< <
CLEAN
GRAVELS
(LESS
THAN) 5%
FINES
GW
GP
GRAVEL
WITH
FINES
GM
GC
WELL GRADED GRAVELS, GRAVEL-SAND MIXTURES, LITTLE OR NO FINES
POORLY GRADED GRAVELS OR GRAVEL-SAND MIXTURES, LITTLE OR NO
FINES
SILTY GRAVELS, GRAVEL-SAND-SILT MIXTURES
CLAYEY GRAVELS, GRAVEL-SAND-CLAY MIXTURES
CLEAN
SANDS
(LESS
THAN) 5%
FINES
SW WELL GRADED SANDS, GRAVELLY SANDS, LITTLE OR NO FINES
SP POORLY GRADED SANDS OR GRAVELLY SANDS, LITTLE OR NO FINES
LUa:o
SANDS
WITH
FINES
SM SILTY SANDS, SAND-SILT MIXTURES
SC CLAYEY SANDS, SAND-CLAY MIXTURES
CO
co
2 So 5CO g
QLUZ
ML INORGANIC SILTS, VERY FINE SANDS, ROCK FLOUR, SILTY OR CLAYEY
FINE SANDS
CL INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS,
SANDY CLAYS, SILTY CLAYS, LEAN CLAYS
o
OL ORGANIC SILTS AND ORGANIC SILT-CLAYS OF LOW PLASTICITY
-O a: >
u_ LU LU
xH
LU
<£
O
az co< >
£25•d °CO
MH INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE SANDS OR
SILTS, ELASTIC SILTS
CH INORGANIC CLAYS OF HIGH PLASTICITY, FAT CLAYS
OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTS
HIGHLY ORGANIC SOILS PT PEAT, MUCK AND OTHER HIGHLY ORGANIC SOILS
SANDSTONES SS
g
H CO< —'2 <a: a:O LU
-i< ^o
Q_
SILTSTONES SH
x x
X X
X X
CLAYSTONES CS
LIMESTONES LS
SHALE SL
CONSISTENCY CRITERIA BASES ON FIELD TESTS
RELATIVE DENSITY - COARSE - GRAIN SOIL
RELATIVE
DENSITY
VERY LOOSE
LOOSE
MEDIUM
DENSE
DENSE
VERY DENSE
SPT*
(# BLOWS/FT)
<4
4-10
10-30
30-50
>50
RELATIVE
DENSITY
(%)
0-15
15-35
35-65
65-85
85-100
CONSISTENCY-
FINE-GRAIN SOIL
CONSISTENCY
Very Soft
Soft
Medium Stiff
Stiff
Very Stiff
Hard
SPT*
(# BLOWS/FT)
<2
2-4
4-8
8-15
15-30
>30
TORVANE
UNDRAINED
SHEAR
STRENGTH
(tsf)
<0.13
0.13-0.25
0.25-0.5
0.5-1.0
1.0-2.0
>2.0
POCKET **
PENETROMETER
UNCONFINED
COMPRESSIVE
STRENGTH (tsf)
<0.25
0.25-0.5
0.5-1.0
1.0-2.0
2.0-4.0
>4.0
MOISTURE CONTENT CEMENTATION
* NUMBER OF BLOWS
OF 140 POUND
HAMMER FALLING
30 INCHES TO DRIVE A
2 INCH O.D.
(1 3/8 INCH I.D.) SPLIT
BARREL SAMPLER
(ASTM -1586 STANDARD
PENETRATION TEST)
** UNCONFINED
COMPRESSIVE
STRENGTH IN
TONS/SQ.FT. READ
FROM POCKET
PENETROMETER
DESCRIPTION
DRY
MOIST
WET
FIELD TEST
Absence of moisture, dusty, dry to the touch
Damp but no visible water
Visible free water, usually soil is below water table
DESCRIPTION
Weakly
Moderately
Strongly
FIELD TEST
Crumbled or breaks with handling or slight finger pressure
Crumbles or breaks with considerable finger pressure
Will not crumble or break with finger pressure
EXPLANATION OF LOGS Figure A-2
LOG OF BORING B-01
LJ Elevation:
Drilling Method:
n Drilling Rig:
l_j Boring Diameter:
46.0 Date(s) Drilled:
Rotary Auger
CME-55
8-inches
5/22/07
Sta. 10+95
Logged by:
Hammer Type:
Hammer Weight:
Hammer Drop:
FWC
Auto-Trip
140lb.
30-inches
^^&
H
Q.UJ
0
- 5 -
- 10 -
- 15 -
- 20 -
- 25 -
y
0.
2
O
Tn•
= •' ,~ •
-; i
='.••/.
'':'••*
=='.-11J
&'//.
e;-*
_:'•-*
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!
COoco
SM
SM
SM
SW
SM
rfl
ir
SUMMARY OF SUBSURFACE CONDITIONS
This summary applies only at the location of the boring and at the time of
drilling. Subsurface conditions may differ at other locations and may change at
this location with the passage of time. The data presented is a simplification of
actual conditions encountered and is representative of interpretations made
during drilling. Contrasting data derived from laboratory analysis may not be
reflected in these representations.
AASPHALT CONCRETE (3.5 inches) r~
SILTY SAND. fine to medium grained, dark red brown, moist,
medium dense.
TERRACE DEPOSITS (PARALIC) -
SILTY SAND. fine to medium grained, dark red brown,
moist, medium dense.
_
-
SAND with SILT. fine to coarse grained, red brown, moist,
dense, moderately cemented.
-
_
-
.
-
SILTY SAND, fine to very coarse grained, gray brown,
slightly moist, dense, poorly cemented.-
-
-
BOULDERS and COBBLES in SAND MATRIXfine to
coarse grained, brown, slightly moist, medium dense to
End of boring at 28.25 feet. No groundwater or mottling
encountered. Boring backfill with bentonite (full depth).
SAMPLES
ui . ._J LU UJQ. -J D.
1 * tCO ^ Ul
UJ S CL
K 3 1QJCQ j (f)
m1H
•XH ss1BflXffl ssmJXH ss
JE|ss
JXH ssmk1
XJH SS1
1"nJss
_to
g
3
CD
5
8
11
21
25
34
33
50
21
26
21
29
33
50/4"
50/3"
N.R.
£
UJ
D
fe
0
5
10
7
7
5
5
3
3
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111
116
110
109
105
108
107
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•iBTOmiM Geotechnical Exploration F'9ure No
JyQjNLAND FOUNDATION ENGINEERING, INC. clrisbaTcl
1*1 Project No. K1 83-010 A-3
U
n
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LOG OF BORING B-02
Elevation:
Drilling Method:
Drilling Rig:
Boring Diameter:
54.0 Date(s) Drilled:
Rotary Auger
CME-55
8-inches
5/22/07
Sta. 14+75
Logged by:
Hammer Type:
Hammer Weight:
Hammer Drop:
FWC
Auto-Trip
140 Ib.
30-inches
tHIQ
- 5 -
- 10 -
- 15 -
- 20 -
- 25 -
- 30 -
- 35 -.'.'•.'. '1 GRAPHIC I:>
••..
m
cooco
SM
SM
SM
SUMMARY OF SUBSURFACE CONDITIONS
This summary applies only at the location of the boring and at the time of
drilling. Subsurface conditions may differ at other locations and may change at
this location with the passage of time. The data presented is a simplification of
actual conditions encountered and is representative of interpretations made
during drilling. Contrasting data derived from laboratory analysis may not be
reflected in these representations.
AASPHALT CONCRETE (3.5 inches) r~
SILTY SAND. fine to medium grained, dark red brown, moist,
loose to medium dense.
TERRACE DEPOSITS (PARALIC) - I
SILTY SAND, fine to medium grained, red brown, moist,
medium dense to dense.
-
-
SILTY SAND. fine to medium grained, red brown to gray
brown, moist, medium dense to very dense, slightly to
moderately cemented.
_
-
-
- sand layers throughout -
-
J
-
-
J
-
-i
-
End of boring at 36.33 feet. No groundwater or mottling
encountered. Boring backfilled with cement-bentonite slurry
(full depth).
SAMPLES
DRIVE SAMPLEBULK SAMPLESAMPLE TYPEJ
Jss
J
1
J
1XH ss
I
Jss
I
1X™ ss
18XH ss
IJL BLOWS/6"18
20
19
31
21
36
33
45
28
50
40
50/5"
33
50/4"MOISTURE (%)7
6
2
6
3
4
4 DRY UNIT WT.(pcf)121
111
106
118
109
105
102 RELATIVECOMPACTION (%)•yf"™ Geotechnical Exploration R9ure No
•UL INLAND FOUNDATION ENGINEERING, INC. clrisbaTcl
1 ' 1 Project No. K1 83-010 A-4
n
J
n
u
LOG OF BORING B-03
Elevation:
Drilling Method:
Drilling Rig:
Boring Diameter:
47.0 Date(s) Drilled:
Rotary Auger
CME-55
8-inches
5/22/07
Sta. 18+50
Logged by:
Hammer Type:
Hammer Weight:
Hammer Drop:
FWC
Auto-Trip
140 Ib.
30-inches
^^£ii-
o
Q.co
uj £ co
Q | O | 3
PF
_ K _vJ
- 10 -
- 15 -
- 20 -
- 25 -
- 30 -
•:SM
•'•
SM
SM
SUMMARY OF SUBSURFACE CONDITIONS
This summary applies only at the location of the boring and at the time of
drilling. Subsurface conditions may differ at other locations and may change at
this location with the passage of time. The data presented is a simplification of
actual conditions encountered and is representative of interpretations made
during drilling. Contrasting data derived from laboratory analysis may not be
reflected in these representations.
ASPHALT CONCRETE over AGGREGATE BASE(4 inches
Aover 8 inches) ,
SILTY SAND.fine to medium grained, dark red brown,
slightly moist, dense.
TERRACE DEPOSITS (PARALIC) -
CEMENTED SILTY SAND.fine to medium grained, gray
brown, slightly moist, dense.
2 - mottled gray brown -
SILTY SAND.fine to medium grained, blue gray, wet, dense,
slightly to moderately cemented.
SILTY SAND.fine to coarse grained with clay, light gray, wet
to very moist, dense.
End of boring at 32.5 feet. Perched groundwater encuntered at
25 feet. Mottling encountered at 24 feet. Boring backfilled with
cement-bentonite slurry (full depth).
JUlL INLAND FOUNDATION ENGINEERING, INC.
r~
'.
-
-
;.—
-
--
-
-
-
•
SAMPLES
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Q.5
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<£.
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Geotechnical Exploration R9ure No
Project No. K1 83-010 A-5
SITE PLAN
City of Carlsbad Beech Avenue Sewer Project
Carlsbad, California
ICAKLSBAD BOULI-VARDi i; j
4. i LI IIi !0. eofss oiscI -ii; TAC X5 G329
I ?J&°M.i2 • REMOVE 8° VCP CONCRETE
/ W/ JAC "L5 S4t'l- I
' EtcJ 43.77 I
ENCASED SEWER AND REPLACE
WfTH 8" EXTRA STRENGTH VCP 8 w 4 '1-1 -?. /rn. COPPER SPIKE•* V-' !\ I TV I Tl / *'0 w«sncn• ! / 1 \! , / ="- 1-°*'
-j*-*** \ -^at.\ \ \ \ \ v ,--y .' A'-T n«^^^\\\li[^,./ ^l" *'x '^x'Mi^£:-WiH >C../). „ . -^V:S^:fgg^^ -y yga^^^^^I^^-KJes^zr^l^^T-^^j^v^^-^^^F--^''^ ^-— t—^ <T-—ia*!-^ \-^bp^^- x_v^T^x. \ \\ \ \ N^Vooi: •-., V. • i«-o6'. i W ••1~~li-3S '-, \ o-tao
GRAPHIC SCALE
50 100 200 400 LEGEND
= Approximate Location of Boring
11NCH =100FT
INLAND FOUNDATION ENGINEERING, INC.
1310 South Santa Fe Avenue
San Jacinto, California
(951)654-1555 FAX (951) 654-0551
DRAWN BY: SMG
SCALE: 1"=100'
JOB NO.: K183-010
DATE: 07-09-07 FIGURE NO. A-6
u
n APPENDIX B
I
U
LABORATORY TESTING
[j
Representative bulk soil samples were obtained in the field and returned to our
r~j laboratory for additional observations and testing. Laboratory testing was
U generally performed in two phases. The first phase consisted of testing in order
^ . to determine the compaction of the existing natural soil and the general
: engineering classifications of the soils across the site. This testing was per-
formed in order to estimate the engineering characteristics of the soil and to
H serve as a basis for selecting samples for the second phase of testing. The
U second phase consisted of soil mechanics and analytical testing. This testing
n included direct shear testing and testing to estimate the concentration of water-
jj soluble sulfate. These tests were performed in order to provide a means of
developing specific design recommendations based on the strength
n characteristics of the soil.
u
r-> CLASSIFICATION AND COMPACTION TESTING
LJ
Unit Weight and Moisture Content Determinations: Each undisturbed sample
, was weighed and measured in order to determine its unit weight. A small portion
of each sample was then subjected to testing in order to determine its moisture
n content. This testing was performed in accordance with the ASTM Standards
U D2937-04 and D2216-05. This was used in order to determine the dry density of
the soil in its natural condition. The results of these tests are shown on theni Boring Logs (Figures A-3 through A-5).
n Maximum Density-Optimum Moisture Determinations: Representative soil
LJ types were selected for maximum density determinations. This testing was
performed in accordance with the ASTM Standard D1557-07 test method A.
j The results of these tests are presented graphically on Figures B-4. The
maximum densities are compared to the field densities of the soil in order to
f~] determine the existing relative compaction to the soil.
U
0 Classification Testing: Three soil samples were selected for classification
LJ testing. This testing consists of mechanical grain size analyses, and, Atterberg
Limits determinations. This testing was performed in accordance with the ASTM
n Standards 0422-63(2002) and 04318-05. Sand Equivalent Testing was also
'—' conducted on selected samples. These provide information for developing
r-i classifications for the soil in accordance with the Unified Classification System.
LJ •
Krieger & Stewart - Beech A ve. Sewer
n Project No. Ki83-010 -December 2008 B-l Inland Foundation Engineering, Inc.
LJ
^ This classification system categorizes the soil into groups having similar
j engineering characteristics. The results of these tests are very useful in
detecting variations in the soils and in selecting samples for further testing. The
H results of these tests are presented on Figures B-5.
U
n SOIL MECHANIC'S TESTING
LJ
Direct Shear Testing: One sample was selected for Direct Shear Testing. This
H testing measures the shear strength of the soil under various normal pressures
and is used in developing parameters for foundation design and lateral design.
n Testing was performed using recompacted test specimens, which were saturated
LJ prior to testing. Testing was performed using a strain controlled test apparatus
with normal pressures ranging from 934 to 2230 pounds per square foot. The
results of these tests are shown on Figure B-6.U
n Consolidation Testing: Two samples were selected for consolidation testing.
U This testing was performed in accordance with the ASTM Standard D2435-04.
For this test, relatively undisturbed samples were selected and carefully trimmed
into a one inch thick by 2.41 -inch diameter consolidometer. The consolidometeru . J
was moisture sealed in order to preserve the natural moisture content during the
n initial stages of testing. Loads ranging up to 22,666.1 pounds per square foot
u were applied progressively with the rate of settlement declining to a value of
^ 0.0002 inches per hour prior to the application of each subsequent load. At a
u preselected load, water was introduced into the consolidometer in order to
observe the potential for saturation collapse. The results of this testing are
H presented graphically on Figures B-7 and B-8.
u
U
n
J
LJ '
U
LJ
Krieger & Stewart - Beech Ave. Sewer
Project No. K183-010-December 2008 B-2 Inland Foundation Engineering, Inc.
Lj
U
n
U
n
ANALYTICAL TESTING
Five samples were selected to determine the concentration of soluble sulfates,
chlorides, pH level, and resistivity of and within the on-site soils. The following
table presents the results of this testing:
Sample
Location
B-01
B-02
B-03
Sample
Depth (ft.)
2.5-8.5
10.5-36.33
3.5-26.0
Water-Soluble
Sulfates (%)
<0.001
<0.001
O.001
Chlorides
(ppm)
70
120
140
Minimum
Resistivity
(ohm-cm)
10,100
3,600
5,900
pH
7.4
8.4
8.1
U
U
p
Li
LJ
GENERAL
All laboratory testing has been conducted in conformance with the applicable
ASTM test methods by personnel trained and supervised in conformance with
our QA/QC policy. Our test data only relates to the specific soils tested. Soil
conditions typically vary and any significant variations should be reported to our
laboratory for review and possible testing. The data presented in this report are
for the use of Krieger & Stewart, Inc. and the City of Carlsbad, and may not be
reproduced or used by others without written approval of Inland Foundation
Engineering, Inc.
i — i
U
n
U
Krieger & Stewart — Beech Ave. Sewer
Project No. K183-010 - December 2008 B-3 Inland Foundation Engineering, Inc.
160
155
150
145
140
135
130
u_O
t 1K
wzLU
° 120
a:Q
115
110
105
100
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' MOISTURE CONTENT, %
Specimen Identification Classification Max.Density MC%
• B-01 2.5 SILTY SAND SM 125.0 10.0
IX B-02 10.5 POORLY GRADED SAND SP 113.5 13.0
A B-03 3.5 SILTY SAND SM 132.5 9.0
PROJECT Geotechnical Exploration PROJECT NO. K183-010
Beech Street DATE November 14, 2007
MAXIMUM DENSITY-OPTIMUM MOISTURE CURVES
Inland Foundation Engineering, Inc
L. FIGURE NO. B-4 ^
U
100
p
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N
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B
Y
W
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90
80
70
60
50
40
30
20
10
n
U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS I HYDROMETER
6 4 3 2 1.5 1 3/4 1/23./8 3 4, 6 sl° 141620 30 40 50 70100140200
I I I 1 1 1 1
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100 10 1 0.1 0.01 0.001
GRAIN SIZE IN MILLIMETERS
COBBLES GRAVEL
coarse
Specimen Identification
«
XI
A
B-01 2.5
B-02 10.5
B-03 3.5
Specimen Identification
•
CD
A
B-01 2.5
B-02 10.5
B-03 3.5
fine
SAND
coarse medium fine SILT OR CLAY
Classification S.G.
SILTY SAND SM
POORLY GRADED SAND SP
SILTY SAND SM
D100
4.75
4.75
9.50
D60
0.31
0.47
0.29
D30
0.168
0.249
0.142
LL
NP
22
NP
D10 %Gravel
0.0
0.1585 0.0
0.0
PROJECT Geotechnical Exploration
Beech Street
PL
NP
22
NP
%Sand
81.8
95.5
78.1
PI
NP
NP
NP
Cc
0.83
%Silt
Cu
3.0
%Clay
17.8
4.5
21.9
PROJECT NO. K1 83-010
DATE November 14, 2007
GRADATION CURVES
Inland Foundation Engineering, Inc
, FIGURE NO. B-5 .
2.0
s
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k
s
f
1.5
1.0
0.5
0.0
0.0 0.5 1.0 1.5
NORMAL PRESSURE, ksf
2.0
Specimen Identification Classification Phi Cohesion DD MC%
B-01 2.5 SILTY SAND SM 33 0.134 113 19
PROJECT Geotechnical Exploration
Beech Street
PROJECT NO. K183-010
DATE November 14, 2007
SHEAR TEST DIAGRAM
Inland Foundation Engineering, Inc
FIGURE NO. B-6
0
1
2
3
4
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1,000 10,000 1
STRESS, psf
Specimen Identification
•
PROJECT
B-01 18.5
Classification
SILTY SAND SM
Geotechnical Exploration
Beech Street
DD
105
MC%
2
i
D5
PROJECT NO. K1 83-010
DATE November 14, 2007
CONSOLIDATION TEST
Inland Foundation Engineering, Inc
L FIGURE NO. B-7 ^
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1
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3
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1,000 10,000 1
STRESS, psf
Specimen Identification
0
PROJECT
B-03 22.5
Classification
SILTY SAND SM
Geotechnical Exploration
Beech Street
DD
99
MC%
4
f
PROJECT NO. K1 83-010
DATE November 14, 2007
CONSOLIDATION TEST
Inland Foundation Engineering, Inc
L. FIGURE NO. B-8 ^