HomeMy WebLinkAboutPD 2019-0006; ABEDI MOGHADDAM FAMILY RESIDENCE; GEOTECHNICAL INVESTIGATION AND FOUNDATION RECOMMENDATIONS; 2018-10-03
PRELIMINARY GEOTECHNICAL INVESTIGATION AND FOUNDATION RECOMMENDATIONS
PROPOSED NEW RESIDENCE
TO BE LOCATED AT
(APN:215-460-06) ARGONAUTA STREET,
CARLSBAD, CALIFORNIA
EDG Project No. 186021-1
October 3, 2018
PREPARED FOR:
Varoozh Torossian
1823 Bara Road
Glendale, CA. 91208
ENGINEERING
DESIGN GROUP
www.designgroupca.com
2121 Montiel Road, San Marcos, CA 92069
760.839.7302
Date: October 3, 2018
To: Varoozh Torossian
1823 Bara Road
Glendale, California 91208
Re: Proposed new residence to be located at (APN: 215-460-06) Argonauta Street, Carlsbad,
California
Subject: Geotechnical Investigation and Foundation Recommendations Report
In accordance with your request and our signed proposal we have provided this preliminary geotechnical
investigation and foundation recommendations report of the subject site for the proposed new residence.
The findings of the investigation, earthwork recommendations and foundation design parameters are
presented in this report. In general, it is our opinion that the proposed construction, as described herein,
is feasible from a geotechnical standpoint, provided the recommendations of this report and generally
accepted construction practices are followed.
If you have any questions regarding the following report please do not hesitate to contact our office.
Sincerely,
ENGINEERING DESIGN GROUP
Steven Norris Erin E. Rist
California GE#2590 California RCE #65122
ENGINEERING
DESIGN GROUP
www.designgroupca.com
2121 Montiel Road, San Marcos, CA 92069
760.839.7302
Table of Contents
1.0 SCOPE ................................................................................................................................................ 1
2.0 SITE AND PROJECT DESCRIPTION ...................................................................................................... 1
3.0 FIELD INVESTIGATION ....................................................................................................................... 1
4.0 SUBSURFACE CONDITIONS ............................................................................................................... 1
5.0 GEOLOGIC HAZARDS ......................................................................................................................... 2
5.1 FAULTS .......................................................................................................................................... 2
5.2 LIQUEFACTION, LATERAL SETTLEMENT, SUBSIDENCE .................................................................. 2
5.3 TSUNAMI ....................................................................................................................................... 3
5.4 SLOPE STABILITY ............................................................................................................................ 3
6.0 GROUND WATER ............................................................................................................................... 3
7.0 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS ................................................................ 3
8.0 EARTHWORK ..................................................................................................................................... 4
9.0 FOUNDATIONS .................................................................................................................................. 6
10.0 CORROSION AND VAPOR EMISSION ................................................................................................. 8
11.0 CONCRETE SLAB-ON-GRADE ............................................................................................................. 9
12.0 RETAINING WALLS........................................................................................................................... 11
13.0 INFILTRATION .................................................................................................................................. 12
14.0 SURFACE DRAINAGE ........................................................................................................................ 13
15.0 LABORATORY TESTING .................................................................................................................... 14
16.0 CONSTRUCTION OBSERVATION AND TESTING ............................................................................... 14
17.0 MISCELLANEOUS ............................................................................................................................. 15
FIGURES
Site Vicinity Map .......................................................................................................................... Figure No. 1
Site Location Map ........................................................................................................................ Figure No. 2
Site Plan ....................................................................................................................................... Figure No. 3
Test Pit Logs .......................................................................................................................... Test Pit Logs 1-3
APPENDICES
References .................................................................................................................................... Appendix A
General Earthwork and Grading Specifications ............................................................................ Appendix B
Laboratory Results ........................................................................................................................ Appendix C
Retaining Wall Drainage Detail .....................................................................................................Appendix D
VOT Consulting Engineers Page No. 1
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
1.0 SCOPE
This report gives our recommendations for the proposed new residence to be located at Argonauta Street
(APN: 215-460-06), Carlsbad, California. (See Figure No. 1, "Site Vicinity Map", and Figure No. 2, "Site
Location Map"). The scope of our work conducted onsite to date has included a visual reconnaissance of
the property and surrounding areas, review of geologic maps, a limited subsurface investigation of the
subject property, laboratory tests and preparation of this report presenting our findings, conclusions and
recommendations.
2.0 SITE AND PROJECT DESCRIPTION
The subject property is located at Argonauta Street (APN: 215-460-06), Carlsbad, California. For the
purposes of this report the lot is assumed to face south. The property is bordered to the east by an
undeveloped lot, to the west and north by custom-homes and to the south by Argonauta Street.
The general topography of the site area consists of foothill terrain. At the time of this report the lot is
undeveloped. Based upon review of site topography, the lot descends from south (front) to north (rear).
Based upon our review of the proposed preliminary concept site plan, we understand the proposed
development will consist of the construction of a new multi-story residence with subterranean elements,
typical hardscape and landscape improvements. We further understand the proposed residence will
consist of a combination of slab on grade floors as well as structural floors and crawl space elements.
3.0 FIELD INVESTIGATION
Our field investigation of the property consisted of a site reconnaissance, site field measurements,
observation of existing conditions on-site and on adjacent sites and a limited subsurface investigation of
soil conditions. Our subsurface investigation consisted of the visual observation of three exploratory
trenches in the general areas of proposed construction, logging of soil types encountered and sampling
of soils for laboratory testing. The approximate location of the trenches is given in Figure No. 3,
"Approximate Test Trenches Locations".
4.0 SUBSURFACE CONDITIONS
Fill soil and weathered profiles were encountered to an approximate depth of 3 feet below adjacent grade
in our exploratory trenches. Soil types encountered within our trenches are described as follows:
VOT Consulting Engineers Page No. 2
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
4.1 Topsoil / Fill / Weathered
Topsoil, fill and weathered unsuitable materials were encountered to depths up to 3 feet below adjacent
grade in our trenches. It should be noted that deepened fills were visually observed in areas adjacent
to the street. Additionally, we anticipate there may be localized areas of old drainages along portions
of the site. These materials consist of brown to reddish brown to greenish gray, dry to moist, loose to
medium stiff, silty clay and clayey silt with organics. In general, these materials are not considered
suitable for the support of structures and structural improvements in their present state but may be
utilized as re-compacted fill if necessary, provided the recommendations of this report are followed.
Unsuitable soil materials classify as SM-SC per the Unified Soil Classification System, and based on
laboratory testing, possess low potential for expansion.
4.2 Metavolcanic Rock
Metavolcanic rock was found to underlie the fill/weathered profiles material within the exploratory
trenches. The encountered material consists of yellowish brown to reddish brown with traces of white,
dense to hard, fractured, metamorphosed sedimentary rock. These materials are considered suitable for
the support of structures and structural improvements, provided the recommendations of this report
are followed. These materials classify as SM-SC per the Unified Soil Classification System, and based on
visual observation, possess a low potential for expansion.
Detailed logs of our exploratory trenches, as well as a depiction of their locations, please see Figure No.
3, "Site Plan/Location of Trenches", and Test Pit Logs No. 1-3.
5.0 GEOLOGIC HAZARDS
5.1 FAULTS
Our review of geologic literature pertaining to the general site area indicates the subject site is not within
a mapped Alquist-Priolo fault zone. It is our opinion that the site could be subjected to moderate to severe
ground shaking in the event of a major earthquake along any of the faults in the Southern California
region. The seismic risk at this site is similar to that of the surrounding developed area.
5.2 LIQUEFACTION, LATERAL SETTLEMENT, SUBSIDENCE
Liquefaction of cohesionless soils can be caused by strong vibratory motion due to earthquakes.
VOT Consulting Engineers Page No. 3
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
Research and historical data indicate that loose, granular soils underlain by a near-surface ground water
table are most susceptible to liquefaction, while the stability of most silty sands and clays is not adversely
affected by vibratory motion. Because of the dense nature of the soil materials underlying the site and
the lack of near surface water, the potential for lateral spreading, liquefaction, subsidence or seismically-
induced dynamic settlement at the site is considered low. The effects of seismic shaking can be reduced
by adhering to the most recent edition of the California Building Code and current design parameters of
the Structural Engineers Association of California.
5.3 TSUNAMI
Tsunami are sea waves generated by submarine earthquakes, landslides or volcanic activity. Submarine
earthquakes are common along the edge of the Pacific Ocean and coastal areas are subject to potential
inundation by tsunami. Most of the tsunamis recorded on the San Diego Bay tidal gauge have only been
a few tenths of a meter in height. The possibility of a destructive tsunami along the San Diego coastline is
considered low. Tsunami or storm waves (associated with winter storms), even in conjunction with high
tides, do not have the potential for inundations of the site.
5.4 SLOPE STABILITY
As part of the preparation of this report we have reviewed geologic maps of the subject area. Our review
of geologic maps does not indicate landslide deposits at the area in and around the subject site.
6.0 GROUND WATER
Static ground water was not encountered during our limited subsurface investigation. Groundwater is not
anticipated to pose a significant constraint to construction, however based upon our experience, perched
groundwater conditions can develop where no such condition previously existed. Perched groundwater
conditions can develop over time and can have a significant impact on the improvements. Waterproofing
membrane shall be specifically detailed by waterproofing consultant. If groundwater conditions are
encountered during site excavations, a slab underdrain system may be required. Trenches below slab
should be detailed with perimeter and trench cut-off walls keyed into competent material.
7.0 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS
Based upon our review of the preliminary site plan, as referenced in Appendix A, we understand the
VOT Consulting Engineers Page No. 4
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
proposed improvements include a multi-story residence with basement elements, typical hardscape and
landscape improvements. We understand the new residence will be constructed on a combination of
slab-on-grade and raised wood structural floors. In general, it is our opinion that the proposed new
structure and improvements, as discussed and described herein, are feasible from a geotechnical
standpoint, provided the recommendations of this report and all applicable codes are followed.
• In the area of the proposed new residence we anticipate the removal of topsoil/unsuitable
profiles as part of the excavation to proposed building pad elevations.
• We anticipate cut-fill transitions will be generated as part of the preparation of the building pad
as well as the backfill of mid-building retaining walls.
• In consideration of the dense nature of the fractured rock material encountered in our test
trenches and the proposed subterranean building elements, we anticipate grading may require
special excavation equipment and possibly blasting.
• In consideration of the rock nature of the underlying material and the transitions anticipated
based upon the proposed layout we provide the following options:
o Option 1 – Consider structural floors in lieu of concrete slab on grade floors and deepen
footings to competent metavolcanics material.
o Option 2 – Deepen foundations to competent metavolcanic material and design structural
slabs over fill and backfill elements.
o Option 3 – Undercut cut portions of the foundations and slab on grade foundations a
minimum of 1 foot below the proposed foundations.
• Any changes in the proposed design should be reviewed by this office for any revisions to the
recommendations herein.
8.0 EARTHWORK
At the time of this report a site plan and/or a preliminary grading plan was not available for review.
Based upon our review of building elevations, grading is anticipated to include the excavation for the
proposed new below-grade portions of the building, foundations, and creations of driveway/yard
elements. In consideration of the relatively shallow fractured rock material and the anticipated cut/fill
transitions occur, where concrete slabs on grade floors are proposed in lieu of structural floors (i.e.
structural slabs or wood) we anticipate undercutting of portions of slabs and wall foundations. All
grading shall be done in accordance with the recommendations below as well as Appendix B of this report
and the standards of county and state agencies, as applicable.
VOT Consulting Engineers Page No. 5
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
8.1 Site Preparation
Prior to any grading, the areas of proposed improvements should be cleared of surface and subsurface
debris (including organic topsoil, vegetative and construction debris). Removed debris should be properly
disposed of off-site prior to the commencement of any fill operations. Construction debris should not
generally be mixed with fill soils. Holes resulting from the removal of debris, existing structures, or other
improvements, should be filled and compacted.
8.2 Removals
In areas of new proposed structures, topsoil/weathered and fill profiles found to mantle the site, are not
suitable for the structural support of buildings or structural improvements in their present state. We
anticipate unsuitable profiles to be removed as part of grading to pad subgrade. Grading should consist
of the removal of unsuitable soil to competent material, the scarification of subgrade to a minimum depth
of 8-12 inches, placement and re-compaction of fill material, (90 percent minimum relative compaction),
in the area of the proposed slab-on-grade foundations.
8.3 Transitions
All settlement sensitive improvements (including but not limited to building structure, retaining walls,
etc.), should be constructed on a uniform building pad. We anticipate building foundations will be placed
on recompacted fill material. Removal depths should be visually verified by a representative of our firm
prior to placement of fill. Where this condition is not met, undercuts may be necessary.
Undercuts should extend a minimum of 5 feet (or to a distance at least equal to the depth of the fill)
beyond the footprint of the proposed structures (including exterior columns) and settlement sensitive
improvements. Undercuts shall be made a minimum of 18 inches below the foundation, or to a minimum
depth of half the depth of the deepest fill. Undercut bottoms shall be sloped at a minimum of 1% to
daylight and may require a subdrain (see Appendix B). Where this condition cannot be met, it should be
reviewed by Engineering Design Group on a case by case basis.
8.4 Fills/Backfill
All fill/backfill material should be brought to approximately +2% of optimum moisture content and re-
compacted to at least 90 percent relative compaction (based on ASTM D1557). Where concrete slab on
grade floors span between subterranean building walls, they should be designed as structural slabs
VOT Consulting Engineers Page No. 6
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
(Option 3) or the retaining wall foundation should have been undercut (Option 2). Compacted fills
should be cleaned of loose debris and oversize material more than 6 inches in diameter (oversize material
is anticipated), brought to near optimum moisture content, and re-compacted as described above.
Fills should generally be placed in lifts not exceeding 6-8 inches in thickness. Although not anticipated,
imported soils should have a low potential for expansion (EI<50), free of debris and organic matter. Prior
to importing soils, they should be visually observed, sampled and tested at the borrow pit area to evaluate
soil suitability as fill. Onsite excavated fill materials are suitable for re-use as fill material during grading,
provided they are cleaned of debris and oversize material in excess of 6 inches in diameter (oversize
material is anticipated) and free of contamination (including organics). Utility trenches should be properly
backfilled in accordance with the latest edition of Green Book standards.
8.5 Slopes
Where new slopes are constructed permanent slopes may be cut to a face ratio of 2:1 (horizontal to
vertical). Permanent fill slopes shall be placed at a maximum 2:1 slope face ratio. All temporary cut slopes
shall be excavated in accordance with OSHA requirements and shall not undermine adjacent property or
structures without proper shoring of excavation and/or structures. Subsequent to grading, planting or
other acceptable cover should be provided to increase the stability of slopes, especially during the rainy
season (October thru April).
8.6 Flatwork and Driveways
In the area of exterior flatwork and driveways the upper 12 inches of concrete/pavement subgrade shall
be ripped a minimum of 12 inches, moisture conditioned to near optimum moisture content and
compacted to 90% minimum relative compaction (ASTM D1557 – latest edition).
9.0 FOUNDATIONS
The following design parameters may be utilized for new foundations founded on competent material.
9.1 Footings bearing uniformly in competent recompacted material (Option 3) may be designed
utilizing maximum allowable soils pressure of 2,500 psf. Where footings extend into
competent metavolcanics material and footings extend below 5 feet below existing grade an
additional 500 psf may be added to the above bearing capacity for each additional foot of depth
to a maximum bearing capacity of 3,500 psf.
VOT Consulting Engineers Page No. 7
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
9.2 2016 CBC Seismic Design Parameters
Site Class D
Spectral Response Coefficients
SMS (g) 1.122
SM1 (g) 0.640
SDS (g) 0.748
SD1 (g) 0.427
9.3 Bearing values may be increased by 33% when considering wind, seismic, or other short
duration loadings.
9.4 The parameters in the table below should be used as a minimum for designing new footing
width and depth below lowest adjacent grade into competent material. Footing depths are to be
confirmed in the field by a representative of Engineering Design Group prior to the placement of
form boards, steel and removal of excavation equipment.
No. of Floors
Supported
Minimum Footing Width *Minimum Footing Depth Below
Lowest Adjacent Grade
1 15 inches 18 inches
2 15 inches 18 inches
3 18 inches 24 inches
*Footings are anticipated to be deepened to 4+ feet below existing grade.
9.5 All footings founded into competent material should be reinforced with a minimum of two #4
bars at the top and two #4 bars at the bottom (3 inches above the ground). For footings over 30
inches in depth, additional reinforcement, and possibly a stemwall system will be necessary, and
should be reviewed by project structural engineer prior to construction.
9.6 All isolated spread footings should be designed utilizing the above given bearing values and
footing depths, and be reinforced with a minimum of #4 bars at 12 inches o.c. in each direction
(3 inches above the ground). Isolated spread footings should have a minimum width and depth
of 24 inches.
VOT Consulting Engineers Page No. 8
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
9.7 For footings adjacent to slopes a minimum of 10 feet (competent material) horizontal setback in
competent material or properly compacted fill should be maintained. A setback measurement
should be taken at the horizontal distance from the bottom of the footing to slope daylight.
Where this condition cannot be met, it should be brought to the attention of the Engineering
Design Group for review.
9.8 All excavations should be performed in general accordance with the contents of this report,
applicable codes, OSHA requirements and applicable city and/or county standards.
9.9 All foundation subgrade soils and footings shall be pre-moistened to 2% over optimum to a
minimum of 18 inches in depth prior to the pouring of concrete.
10.0 CORROSION AND VAPOR EMISSION
10.1 Resistivity and chloride testing of onsite samples from our subsurface investigation was
conducted to evaluate corrosion potential to proposed improvements. Tests performed
indicate that soils classify according to ACI 318 standard, as category C1, and based upon lab
results considered mild to moderately corrosive to buried metals. Test results are included in
Appendix C of this report. The project structural engineer to note increased concrete
protection requirements for corrosive environments, as applicable.
10.2 Laboratory testing of onsite samples for water soluble sulfates, indicate soils classify, according
to ACI 318 standard, as category S0, mild to moderately corrosive due to sulfate attack to
concrete structures.
10.3 In consideration of the corrosion potential of the onsite soils as indicated above, the
subterranean nature of the structures, and ACI standards we recommend for moisture sensitive
slabs and foundations (i.e. below grade walls/spaces, built interior environments, floor finishes)
the maximum water to cement ratio of 0.45, with a resulting compressive strength of 4,500 psi
minimum (no special inspection required for water to cement ratio purposes, unless otherwise
specified by the structural engineer).
10.4 Buried metals shall be protected and a corrosion engineer should be consulted for appropriate
mitigation recommendations. EDG is not an expert in corrosion protection. Design
recommendations for the protection of improvements from corrosive environment shall be
provided by the corrosion consultant.
VOT Consulting Engineers Page No. 9
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
10.5 Where onsite improvements propose the use of reclaimed water, onsite soils are to be
considered highly corrosive to buried metals. Precautions should be taken to protect all buried
metals.
10.6 Slab Underlayment: We recommend the following beneath proposed slab-on-grade floors.
10.6.a. We recommend a vapor barrier layer (15 mil) placed below the upper one-inch of
sand. The vapor barrier shall meet the following minimum requirements: Permeance
of less than 0.01 perm [grains/(ft²hr in/Hg)] as tested in accordance with ASTM E 1745
Section 7.1 and strength per ASTM 1745 Class A.
10.6.b. In areas of level slab on grade floors, we recommend a one-inch layer of coarse sand
material, Sand Equivalent (S.E.) greater than 50 and washed clean of fine materials,
should be placed beneath the slab in moisture sensitive areas, above the vapor
barrier. There shall be not greater than a 2-inch difference across the sand layer.
10.6.c. The vapor barrier should extend down the interior edge of the footing excavations a
minimum of 6 inches. The vapor barrier should lap a minimum of 8 inches, sealed
along all laps with the manufacturer’s recommended adhesive. Beneath the vapor
barrier a uniform layer of 3 inches of pea gravel is recommended under the slab in
order to more uniformly support the slab, help distribute loads to the soils beneath
the slab, and act as a capillary break.
10.7 The project waterproofing consultant should provide all slab underdrain, slab sealers and
various other details, specifications and recommendations (i.e. Moiststop and Linkseal) at areas
of potential moisture intrusion. Engineering Design Group accepts no responsibility for design or
quality control of waterproofing elements of the building.
11.0 CONCRETE SLAB-ON-GRADE
We anticipate all new concrete slab-on-grade floors will be placed on competent recompacted material.
Where new slabs are proposed, we recommend the following as the minimum design parameters.
11.1 Concrete slab on grade of the proposed new additions should have a minimum thickness of 5
inches and should be reinforced with #4 bars at 18 inches o.c. placed at the midpoint of the slab.
11.1.a. Slump: Between 3 and 4 inches maximum.
11.1.b. Aggregate Size: ¾ - 1 inch.
VOT Consulting Engineers Page No. 10
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
11.2 Adequate control joints should be installed to control the unavoidable cracking of concrete that
takes place when undergoing its natural shrinkage during curing. The control joints should be
well located to direct unavoidable slab cracking to areas that are desirable by the designer.
11.3 All required fills used to support slabs, should be placed in accordance with the grading section
of this report and the attached Appendix B, and compacted to 90 percent Modified Proctor
Density, ASTM D-1557, and as described in the Earthwork section of this report.
11.4 All subgrade soils to receive concrete slabs and flatwork are to be pre-soaked to 2 percent over
optimum moisture content to a depth of 18 inches.
11.5 Exterior concrete flatwork, due to the nature of concrete hydration and minor subgrade soil
movement, are subject to normal minor concrete cracking. To minimize expected concrete
cracking, the following may be implemented:
11.5.a. New flatwork in areas of encountered expansive soil (not anticipated) should be
detailed with 6 inches of base material.
11.5.b. Concrete may be poured with a 10-inch-deep thickened edge. Flatwork adjacent to top
of a slope should be constructed with an outside footing to attain a minimum of 7 feet
distance to daylight.
11.5.c. Concrete slump should not exceed 4 inches.
11.5.d. Concrete should be poured during cool (40 - 65 degrees) weather if possible. If concrete
is poured in hotter weather, a set retarding additive should be included in the mix, and
the slump kept to a minimum.
11.5.e. Concrete subgrade should be pre-soaked prior to the pouring of concrete. The level
of pre-soaking should be a minimum of 2% over optimum moisture to a depth of 18
inches.
11.5.f. Concrete should be constructed with tooled joints creating concrete sections no larger
than 225 square feet. For sidewalks, the maximum run between joints should not
exceed 5 feet. For rectangular shapes of concrete, the ratio of length to width should
generally not exceed 0.6 (i.e., 5 ft. long by 3 ft. wide). Joints should be cut at expected
points of concrete shrinkage (such as male corners), with diagonal reinforcement
placed in accordance with industry standards.
11.5.g. Isolation joints should be installed at exterior concrete where exterior concrete is
poured adjacent to existing foundations.
11.5.h. Drainage adjacent to concrete flatwork should direct water away from the
improvements. Concrete subgrade should be sloped and directed to the collective
drainage system, such that water is not trapped below the flatwork.
VOT Consulting Engineers Page No. 11
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
11.5.i. The recommendations set forth herein are intended to reduce cosmetic nuisance
cracking. The project concrete contractor is ultimately responsible for concrete quality
and performance, and should pursue a cost-benefit analysis of these recommendations,
and other options available in the industry, prior to the pouring of concrete.
12.0 RETAINING WALLS
New retaining walls up to 10 feet may de designed and constructed in accordance with the following
recommendations and minimum design parameters.
12.1 Retaining wall footings should be designed in accordance with the allowable bearing criteria
given in the Foundations section of this report, and should maintain minimum footing depths
outlined in the Foundations section of this report. All retaining wall footings are anticipated to
be placed on competent material. Where cut-fill transitions may occur, alternative detailing may
be provided by the Engineering Design Group on a case by case basis.
12.2 Unrestrained cantilever retaining walls should be designed using an active equivalent fluid
pressure of 35 pcf. This assumes that granular, free draining material with low potential for
expansion (E.I. <50) will be used for backfill, and that the backfill surface will be level. Where
soil with potential for expansion is not low (E.I. >50) a new active fluid pressure will be provided
by the project soils engineer. Backfill materials should be considered prior to the design of the
retaining walls to ensure accurate detailing. We anticipate onsite material may be utilized as
retaining wall backfill (free from oversize material).
12.3 Where the backfill behind the wall is sloped at a maximum slope of 2:1 (H:V) an active
equivalent fluid pressure of 50 pcf, shall be utilized.
12.4 Any other surcharge loadings shall be analyzed in addition to the above values. These surcharge
loads shall include foundations, construction equipment, vehicular traffic, etc.
12.5 If the tops of retaining walls are restrained from movement, they should be designed for a
uniform at-rest soil pressure of 65 psf.
12.6 Retaining walls shall be designed for additional lateral forces due to earthquake, where required
by code, utilizing the following design parameters.
12.6.a. Yielding Walls = PE= (3/8) kAE (ρ) H2 - applied at a distance of 0.6 times the height (H) of
the wall above the base.
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Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
12.6.b. Horizontal ground acceleration value kH = 0.23 g.
12.6.c. Where non-yielding retaining walls are proposed, the specific conditions should be
brought to the attention of Engineering Design Group for alternative design values.
12.6.d. The unit weight of 120 pcf for the onsite soils may be utilized.
12.6.e. The above design parameters assume unsaturated conditions. Retaining wall designs for
sites with a hydrostatic pressure influence (i.e groundwater within depth of retaining wall
or waterfront conditions) will require special design considerations and should be brought
to the attention of Engineering Design Group.
12.6.f. Passive soil resistance may be calculated using an equivalent fluid pressure of 300 pcf. This value
assumes that the soil being utilized to resist passive pressures extends horizontally 2.5 times the
height of the passive pressure wedge of the soil. Where the horizontal distance of the available
passive pressure wedge is less than 2.5 times the height of the soil, the passive pressure value
must be reduced by the percent reduction in available horizontal length.
12.6.g. A coefficient of friction of 0.35 between the soil and concrete footings may be utilized to resist
lateral loads in addition to the passive earth pressures above.
12.6.h. All walls shall be provided with adequate back drainage to relieve hydrostatic pressure, and be
designed in accordance with the minimum standards contained in the "Retaining Wall Drainage
Detail", Appendix D. The waterproofing elements shown on our details are minimums, and are
intended to be supplemented by the waterproofing consultant and/or architect. The
recommendations should be reviewed in consideration of proposed finishes and usage, especially
at anticipated basement levels, performance expectations and budget.
12.6.i. If deemed necessary by the project owner, based on the above analysis, and waterproofing
systems can be upgraded to include slab under drains and enhanced waterproofing elements.
12.6.j. In moisture sensitive areas (i.e. interior living space where vapor emission is a concern; like the
anticipated subterranean portion of the residence), our experience shows, poured-in-place
concrete provides a surface with higher performance-repairability of below grade waterproofing
systems. The developer should consider the cost-benefit of utilizing cast in place building retaining
walls in lieu of masonry as part of the overall construction of the commercial structure.
Waterproofing at basement floors is recommended in areas of moisture sensitive floor finishes.
13.0 INFILTRATION
Bioretention/infiltration facilities shall maintain sufficient horizontal and vertical offset to the future
VOT Consulting Engineers Page No. 13
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
residence to not create a groundwater condition. Infiltration facilities proposed within a 10-foot
horizontal distance to a moisture sensitive structure should be lined with an impervious barrier, within
the 10-foot zone.
Infiltration facilities should be offset from the top and toes of any slopes steeper than a 3:1 or lined with
an impervious barrier. At tops of slopes minimum horizontal distance of 10 feet or a horizontal distance
equal to the height of the slope, measured from the edge of infiltration basin to slope, up to a maximum
of 40 horizontal feet. At the toe of new fill slopes infiltration facilities shall maintain a minimum 10 feet
horizontal offset.
If permeable pavers are proposed in driveway and/or rear patios. Specific paver detailing should be
detailed and constructed per the minimum recommendations of the Interlocking Concrete Paver Institute
and the specific concrete paver manufacturer, including edge restraints, minimum bedding specifications,
base and subgrade requirements, installation tolerances, and drainage, etc. Where runoff and storm
water is directed over permeable pavements and water is anticipated to flow through pavers into an
aggregate base near and adjacent to foundations, detailing shall include systems to control and to prevent
subsurface flow beneath the building. Generally, these systems, detailed as part of the specific building
construction plans, may include the cut-off walls and underdrains.
Proper surface drainage and irrigation practices will play a significant role in the future performance of
the project. Please note in the Corrosion and Vapor Emission section of this report for specific
recommendations regarding water to cement ratio for moisture sensitive areas should be adhered. The
project architect and/or waterproofing consultant shall specifically address waterproofing details.
14.0 SURFACE DRAINAGE
Adequate drainage precautions at this site are imperative and will play a critical role on the future
performance of the proposed residence. Under no circumstances should water be allowed to pond against
or adjacent to tops of slopes and/or foundation walls.
The ground surface surrounding proposed improvements should be relatively impervious in nature, and
slope to drain away from the structure in all directions, with a minimum slope of 2% for a horizontal
distance of 7 feet (where possible). Area drains or surface swales should then be provided in low spots to
accommodate runoff and avoid any ponding of water. Any french drains, backdrains and/or slab
underdrains shall not be tied to surface area drain systems. Roof gutters and downspouts shall be installed
on the new structures and tightlined to the area drain system. All drains should be kept clean and
unclogged, including gutters and downspouts. Area drains should be kept free of debris to allow for
VOT Consulting Engineers Page No. 14
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
proper drainage.
Over watering can adversely affect site improvements and cause perched groundwater conditions.
Irrigation should be limited to only the amount necessary to sustain plant life. Low flow irrigation devices
as well as automatic rain shut-off devices should be installed to reduce over watering. Irrigation practices
and maintenance of irrigation and drainage systems are an important component to the performance of
onsite improvements.
During periods of heavy rain, the performance of all drainage systems should be inspected. Problems
such as gullying or ponding should be corrected as soon as possible. Any leakage from sources such as
water lines should also be repaired as soon as possible. In addition, irrigation of planter areas, lawns, or
other vegetation, located adjacent to the foundation or exterior flat work improvements should be strictly
controlled or avoided.
15.0 LABORATORY TESTING
Laboratory tests were performed on samples of onsite material collected during our subsurface
investigation in the area. Test results are attached as Appendix C.
16.0 CONSTRUCTION OBSERVATION AND TESTING
The recommendations provided in this report are based on subsurface conditions disclosed by the
investigation and our general experience in the project area. Interpolated subsurface conditions should
be verified in the field during construction. The following items shall be conducted prior/during
construction by a representative of Engineering Design Group in order to verify compliance with the
geotechnical and civil engineering recommendations provided herein, as applicable. The project
structural and geotechnical engineers may upgrade any condition as deemed necessary during the
development of the proposed improvement(s).
16.1 Review of final approved grading and structural plans prior to the start of work for compliance
with geotechnical recommendations.
16.2 Attendance of a pre-grade/construction meeting prior to the start of work.
16.3 Observation of any keyways, of subgrade and excavation bottoms.
16.4 Testing of any fill placed, including retaining wall backfill and utility trench backfill.
16.5 Observation of footing excavations prior to steel placement and removal of excavation
equipment.
16.6 Field observation of any "field change" condition involving soils.
VOT Consulting Engineers Page No. 15
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
16.7 Walk through of final drainage detailing prior to final approval.
The project soils engineer may at their discretion deepen footings or locally recommend additional steel
reinforcement to upgrade any condition as deemed necessary during site observations. Engineering
Design Group shall, prior to the issuance of the certificate of occupancy, issue in writing that the above
inspections have been conducted by a representative of their firm, and the design considerations of the
project soils report have been met. The field inspection protocol specified herein is considered the
minimum necessary for Engineering Design Group to have exercised due diligence in the soils engineering
design aspect of this building. Engineering Design Group assumes no liability for structures constructed
utilizing this report not meeting this protocol.
Before commencement of grading the Engineering Design Group will require a separate contract for
quality control observation and testing. Engineering Design Group requires a minimum of 48 hours’ notice
to mobilize onsite for field observation and testing.
17.0 MISCELLANEOUS
It must be noted that no structure or slab should be expected to remain totally free of cracks and minor
signs of cosmetic distress. The flexible nature of wood and steel structures allows them to respond to
movements resulting from minor unavoidable settlement of fill or natural soils, the swelling of clay soils,
or the motions induced from seismic activity. All of the above can induce movement that frequently
results in cosmetic cracking of brittle wall surfaces, such as stucco or interior plaster or interior brittle slab
finishes.
Data for this report was derived from surface and subsurface observations at the site and knowledge of
local conditions. The recommendations in this report are based on our experience in conjunction with the
limited soils exposed at this site. We believe that this information gives an acceptable degree of reliability
for anticipating the behavior of the proposed improvement; however, our recommendations are
professional opinions and cannot control nature, nor can they assure the soils profiles beneath or adjacent
to those observed. Therefore, no warranties of the accuracy of these recommendations, beyond the limits
of the obtained data, is herein expressed or implied. This report is based on the investigation at the
described site and on the specific anticipated construction as stated herein. If either of these conditions
is changed, the results would also most likely change. Man-made or natural changes in the conditions of
a property can occur over a period. In addition, changes in requirements due to state of the art knowledge
VOT Consulting Engineers Page No. 16
Argonauta Street (APN: 215-460-06), Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
and/or legislation are rapidly occurring. As a result, the findings of this report may become invalid due to
these changes. Therefore, this report for the specific site, is subject to review and not considered valid
after a period of one year, or if conditions as stated above are altered.
It is the responsibility of the owner or his/her representative to ensure that the information in this report
be incorporated into the plans and/or specifications and construction of the project. It is advisable that a
contractor familiar with construction details typically used to deal with the local subsoil and seismic
conditions be retained to build the structure.
If you have any questions regarding this report, or if we can be of further service, please do not hesitate
to contact us. We hope the report provides you with necessary information to continue with the
development of the project.
FIGURES
FIGURE 1
Vicinity Map
Site Location
Project: VOT Consulting Engineers
Address: (APN:215-460-06) Argonauta Street, Carlsbad, California
EDG Project No:186021-1
ENGINEERING
DESIGN GROUP
www.designgroupca.com
2121 Montiel Road, San Marcos, CA 92069
760.839.7302
FIGURE 2
Site Map
Site Location
Project: VOT Consulting Engineers
Address: (APN:215-460-06) Argonauta Street, Carlsbad, California
EDG Project No:186021-1
ENGINEERING
DESIGN GROUP 2121 Montiel Road, San Marcos, CA 92069
760.839.7302
FIGURE 3
Site Plan and Approximate
Location of Test Trenches
Not to Scale
1
Project: VOT Consulting Engineers
Address: (APN:215-460-06) Argonauta Street, Carlsbad, California
EDG Project No:186021-1
2
3
ENGINEERING
DESIGN GROUP
www.designgroupca.com
2121 Montiel Road, San Marcos, CA 92069
760.839.7302
Project Name: VOT Consulting Engineers TEST PIT LOG NO. 1
EDG Project 186021-1 Number:
Location: See Figure 3 -Approx. Location of Trenches Sheet 1 of 1
Date(s)
Excavated: 9-13-18 Total Depth: 5'
Groundwater
Level: Not encountered
Logged By: ER-RM Approx. Surface Backfilled
Elev. (date) Same Day
Excavation
Method: Mini Excavator
Soil Type Depth Material Description and Notes ucsc Sample
TOPSOIL, FILL, WEATHERED
A 0'-3' Brown to reddish brown to greenish light grey, dry to slightly moist, loose to SM-SC medium dense/stiff, sandy silts and clayey sands with angular cobbles up to
8-10 inches.
METAVOLCANIC ROCK
B 3'-5' Yellowish brown to reddish brown, dry, hard, highly fractured.
GRAPHIC REPRESENTATION
FT. B.A.G. FG
1 v ·/0/··//~-11
2 1/-: / ®/ -/~1 . ·,.. .. / . . . j
3 i'_t?//-/'.<0)/·_
"X X X .,. " )<.
4 X ?< (';;\, ),, )< )"
>< >-x~,. )<
5 )< It ), "" ,c
6
7
Project Name: VOT Consulting Engineers TEST PIT LOG NO. 2
EDG Project 186021-1 Number:
Location: See Figure 3 -Approx. Location of Trenches Sheet 1 of 1
Date(s)
Excavated: 9-13-18 Total Depth: 5'
Groundwater
Level: Not encountered
Logged By: ER-RM Approx. Surface Backfilled
Elev. (date) Same Day
Excavation
Method: Mini Excavator
Soil Type Depth Material Description and Notes ucsc Sample
TOPSOIL, FILL, WEATHERED
A 0'-3' Light brown to reddish brown, dry to slightly moist, loose to medium dense/
stiff, sandy silts and clayey sands, with angular cobbles up to 6 to 8 inches, SM-SC
roots in upper 24"
METAVOLCANIC ROCK
B 3'-5' Yellowish brown to reddish brown, dry, hard, highly fractured.
GRAPHIC REPRESENTATION
FT. B.A.G. FG
1 -I··/· 4~ : 7
2
y,R)/,,1~
3 I. o/ ./·. "lf?-1/
4 X X ~ r;;-{ ~ ~
X I' ,-, -,c ;<
,X )( ,c \:::_,I _;.: X ,,..
5 ,.. ), ,,,. .,.,. ,,.. -
6
Project Name: VOT Consulting Engineers TEST PIT LOG NO. 3
EDG Project 186021-1 Number:
Location: See Figure 3 -Approx. Location of Trenches Sheet 1 of 1
Date(s)
Excavated: 9/13/18 Total Depth: 7' Groundwater
Level: Not encountered
Logged By: ER-RM Approx. Surface Backfilled
Elev. (date) Same Day
Excavation
Method: Mini Excavator
Soil Type Depth Material Description and Notes ucsc Sample
TOPSOIL, FILL, WEATHERED
A O' -3' Dark brown to reddish brown, dry to slightly moist, loose to medium stiff, silty SM-SC
clays with angular cobbles up to 6 to 8 inches. Roots in upper 24 inches.
COLLUVIUM
B 3'-7' Yellowish brown to reddish brown, moist, very stiff, sandy silts and clayey SM-SC
sands, with angular cobbles up to 6 inches.
GRAPHIC REPRESENTATION
FT. B.A.G. FG
1 ~I JI. -/D ./l
2
ft / ( ,)I . / I --1/G / A -.r
3
1 ,·1w. -1. i 1
4 //;//////;
5 //;1// f..if/.l.
6 V//./·l·I I//
7 ~/,///·/I
APPENDIX A
REFERENCES
1. California Geological Survey, Probabilistic Seismic Hazards Mapping Ground Motion Page.
2. California Department of Conservation, Division of Mines and Geology, Fault Rupture Zones in California, Special
Publication 42, Revised 1990.
3. California Department of Conservation, Division of Mines and Geology, DMG Open-File Report 95-04, Landslide
Hazards in the Northern Part of the San Diego County Metropolitan Area, San Diego County, California –
Landslide Hazard Identification Map No. 35 – Encinitas Quadrangle (Plate D), dated 1995.
4. Day, Robert W. 1999. Geotechnical and Foundation Engineering Design and Construction. McGraw Hill.
5. Rusbourne Design LTD, Project: 2670 Argonauta St. Carlsbad, California, Dated June 12, 2018.
6. Greensfelder, R.W., 1974 Maximum Credible Rock Acceleration from Earthquakes in California Division of Mines
and Geology, Map Sheet 23.
7. Kennedy, Michael P. and Tan Siang S., Geologic Map of the Oceanside 30’x60’ Quadrangle, San Diego County
California. Dated 2002.
8. Lee, L.J., 1977, Potential foundation problems associated with earthquakes in San Diego, in Abbott, P.L. and
Victoria, J.K., eds. Geologic Hazards in San Diego, Earthquakes, Landslides, and Floods: San Diego Society of
Natural History John Porter Dexter Memorial Publication.
9. Ploessel, M.R. and Slossan, J.E., 1974 Repeatable High Ground Acceleration from Earthquakes: California
Geology, Vol. 27, No. 9, P. 195-199.
10. State of California, Fault Map of California, Map No. 1, Dated 1975.
11. State of California, Geologic Map of California, Map No. 1, Dated 1977.
12. Structural Engineers Association of Southern California (SEAOSC) Seismology Committee, Macroseminar
Presentation on Seismically Induced Earth Pressure, June 8, 2006.
13. U.S. Army Corps of Engineers, 1985, Coast of California Storm and Tidal Waves Study, Shoreline Movement Data
Report, Portuguese Point to Mexican Border, dated December
14. U.S. Army Corps of Engineers, 1985, Coast of California Storm and Tidal Waves Study, Coastal Cliff Sediments,
San Diego Region (CCSTWS 87-2), dated June.
15. Van Dorn, W.G., 1979 Theoretical aspects of tsunamis along the San Diego coastline, in Abbott, P.L. and Elliott,
W.J., Earthquakes and Other Perils: Geological Society of America field trip guidebook.
16. Various Aerial Photographs.
APPENDIX B
General Earthwork and Grading Specifications
1.0 General Intent
These specifications are presented as general procedures and recommendations for grading and
earthwork to be utilized in conjunction with the approved grading plans. These general earthwork
and grading specifications are a part of the recommendations contained in the geotechnical report
and shall be superseded by the recommendations in the geotechnical report in the case of conflict.
Evaluations performed by the consultant during the course of grading may result in new
recommendations which could supersede these specifications or the recommendations of the
geotechnical report. It shall be the responsibility of the contractor to read and understand these
specifications, as well as the geotechnical report and approved grading plans.
2.0 Earthwork Observation and Testing
Prior to commencement of grading, a qualified geotechnical consultant should be employed for the
purpose of observing earthwork procedures and testing the fills for conformance with the
recommendations of the geotechnical report and these specifications. It shall be the responsibility
of the contractor to assist the consultant and keep him apprised of work schedules and changes, at
least 24 hours in advance, so that he may schedule his personnel accordingly. No grading
operations should be performed without the knowledge of the geotechnical consultant. The
contractor shall not assume that the geotechnical consultant is aware of all grading operations.
It shall be the sole responsibility of the contractor to provide adequate equipment and methods to
accomplish the work in accordance with the applicable grading codes and agency ordinances,
recommendations in the geotechnical report and the approved grading plans not withstanding the
testing and observation of the geotechnical consultant If, in the opinion of the consultant,
unsatisfactory conditions, such as unsuitable soil, poor moisture condition, inadequate compaction,
adverse weather, etc., are resulting in a quality of work less than recommended in the geotechnical
report and the specifications, the consultant will be empowered to reject the work and recommend
that construction be stopped until the conditions are rectified.
Maximum dry density tests used to evaluate the degree of compaction shouls be performed in
general accordance with the latest version of the American Society for Testing and Materials test
method ASTM D1557.
3.0 Preparations of Areas to be Filled
3.1 Clearing and Grubbing: Sufficient brush, vegetation, roots and all other deleterious material
should be removed or properly disposed of in a method acceptable to the owner, design
engineer, governing agencies and the geotechnical consultant.
The geotechnical consultant should evaluate the extent of these removals depending
on specific site conditions. In general, no more than 1 percent (by volume) of the fill material
should consist of these materials and nesting of these materials should not be allowed.
3.2 Processing: The existing ground which has been evaluated by the geotechnical consultant
to be satisfactory for support of fill, should be scarified to a minimum depth of 6 inches.
Existing ground which is not satisfactory should be overexcavated as specified in the
following section. Scarification should continue until the soils are broken down and free of
large clay lumps or clods and until the working surface is reasonably uniform, flat, and free
of uneven features which would inhibit uniform compaction.
3.3 Overexcavation: Soft, dry, organic-rich, spongy, highly fractured, or otherwise unsuitable
ground, extending to such a depth that surface processing cannot adequately improve the
condition, should be overexcavated down to competent ground, as evaluated by the
geotechnical consultant. For purposes of determining quantities of materials overexcavated,
a licensed land surveyor / civil engineer should be utilized.
3.4 Moisture Conditioning: Overexcavated and processed soils should be watered, dried back,
blended and / or mixed, as necessary to attain a uniform moisture content near optimum.
3.5 Recompaction: Overexcavated and processed soils which have been properly mixed,
screened of deleterious material and moisture-conditioned should be recompacted to a
minimum relative compaction of 90 percent or as otherwise recommended by the
geotechnical consultant.
3.6 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal
to vertical), the ground should be stepped or benched. The lowest bench should be a
minimum of 15 feet wide, at least 2 feet into competent material as evaluated by the
geotechnical consultant. Other benches should be excavated into competent material as
evaluated by the geotechnical consultant. Ground sloping flatter than 5:1 should be benched
or otherwise overexcavated when recommended by the geotechnical consultant.
3.7 Evaluation of Fill Areas: All areas to receive fill, including processed areas, removal areas
and toe-of-fill benches, should be evaluated by the geotechnical consultant prior to fill
placement.
4.0 Fill Material
4.1 General: Material to be placed as fill should be sufficiently free of organic matter and other
deleterious substances, and should be evaluated by the geotechnical consultant prior to
placement. Soils of poor gradation, expansion, or strength characteristics should be placed
as recommended by the geotechnical consultant or mixed with other soils to achieve
satisfactory fill material.
4.2 Oversize: Oversize material, defined as rock or other irreducible material with a maximum
dimension of greater than 6 inches, should not be buried or placed in fills, unless the
location, materials and disposal methods are specifically recommended by the geotechnical
consultant. Oversize disposal operations should be such that nesting of oversize material
does not occur, and such that the oversize material is completely surrounded by compacted
or densified fill. Oversize material should not be placed within 10 feet vertically of finish
grade, within 2 feet of future utilities or underground construction, or within 15 feet
horizontally of slope faces, in accordance with the attached detail.
4.3 Import: If importing of fill material is required for grading, the import material should meet
the requirements of Section 4.1. Sufficient time should be given to allow the geotechnical
consultant to observe (and test, if necessary) the proposed import materials.
5.0 Fill Placement and Compaction
5.1 Fill Lifts: Fill material should be placed in areas prepared and previously evaluated to
receive fill, in near-horizontal layers approximately 6 inches in compacted thickness. Each
layer should be spread evenly and thoroughly mixed to attain uniformity of material and
moisture throughout.
5.2 Moisture Conditioning: Fill soils should be watered, dried-back, blended and/or mixed, as
necessary to attain a uniform moisture content near optimum.
5.3 Compaction of Fill: After each layer has been evenly spread, moisture-conditioned and
mixed, it should be uniformly compacted to no less than 90 percent of maximum dry density
(unless otherwise specified). Compaction equipment should be adequately sized and be
either specifically designed for soil compaction or of proven reliability, to efficiently achieve
the specified degree and uniformity of compaction.
5.4 Fill Slopes: Compacting of slopes should be accomplished in addition to normal
compacting procedures, by backrolling of slopes with sheepsfoot rollers at increments of 3
to 4 feet in fill elevation gain, or by other methods producing satisfactory results. At the
completion of grading, the relative compaction of fill out to the slope face would be at least
90 percent.
5.5 Compaction Testing: Field tests of the moisture content and degree of compaction of the
fill soils should be performed at the consultant’s discretion based on file dconditions
encountered. In general, the tests should be taken at approximate intervals of 2 feet in
vertical rise and/or 1,000 cubic yards of compacted fill soils. In addition to, on slope faces,
as a guideline approximately one test should be taken for every 5,000 square feet of slope
face and /or each 10 feet of vertical height of slope.
6.0 Subdrain Installation
Subdrain systems, if recommended, should be installed in areas previously evaluated for suitability
by the geotechnical consultant, to conform to the approximate alignment and details shown on the
plans or herein. The subdrain location or materials should not be changed or modified unless
recommended by the geotechnical consultant. The consultant however, may recommend changes
in subdrain line or grade depending on conditions encountered. All subdrains should be surveyed
by a licensed land surveyor / civil engineer for line and grade after installation. Sufficient time shall
be allowed for the survey, prior to commencement of filling over the subdrains.
7.0 Excavation
Excavations and cut slopes should be evaluated by a representative of the geotechnical consultant
(as necessary) during grading. If directed by the geotechnical consultant, further excavation,
overexcavation and refilling of cut areas and/or remedial grading of cut slopes (i.e. stability fills or
slope buttresses) may be recommended.
8.0 Quantity Determination
For purposes of determining quantities of materials excavated during grading and/or determining
the limits of overexcavation, a licensed land surveyor / civil engineer should be utilized.
SIDE HILL STABILITY FILL DETAIL
FINISHED SLOPE FACE
PROJECT 1 TO 1 LINE
FROM TOP OF SLOPE TO
OUTSIDE EDGE OF I< EY
OVERBURDEN OR
UNSUITABLE
MATERIAL
EXISTING GROUND --
SURFACE~ --------
,,,...---.,,,,,.
/ ,.,,.,... / .,,...,,.. / .,,...,,.. / __ ,.,,.,...
/ ..,,,--
,,,,,., ✓ / / FINISHED CUT PAO
/ /
-------MP_A_CTeo-:-=
_-:f:f:§:j:j f !J....L_p::--
~ ·-----------I -------------------------PAO OVEREXCAVATION DEPTH
ANO RECOMPACTION MAY BE
RECOMMENDED BY THE
GEOTECHNICAL CONSUL TANT
BASED ON ACTUAL FIELD
CONOIT-IONS-.ENCOUNTERED.
(
COMPETENT BEDROCK OR
MATERIAL AS EVALU~TEO
BY THE GEOTECHNICAL
CONSULTANT
NOTE: Subdrain details and key width recommendations to be provided based
on exposed subsurface conditions
STABILITY FILL / BUTTRESS DETAIL
OUTLET PIPES
,4• ~ NONPERFORATEO PIPE,
100' MAX. O.C. HORIZONTALLY,
30' MAX. O.C. VERTICALLY
-~-=-~
KEY
DEPTH
--::COl,il'A-CI::J
--=---==~~~~==~~~:-~:~~::~=~~=.-.... -. ..----
2 ~\\I
MIN.
f
---------_21'-~~-====~~~~~-
ll~I I
KEY WIDTH j
AS NOTED ON .GRADING PLANS
15' MIN.
e• MIN.
31,4•-1-112·
CLEAN GRAVEL
(3ft~/ft. MIN.
... 9J
NON-PERFORAT
OVERLAP
PIP~::-==--:~~=!ijii~;;,,:Jj --FIL TEA FABRIC
ENVELOPE (MIRAFI
140N OR APPROVED
EQUIVALENT)*
.
see T-CONNECTION
DETAIL
4• ~
PERFORATED
PIPE
4• MIN.
BEDDING
SUBDRAIN TRENCH DETAIL
NOTES:
SEE SUBDRAIN TRENCH
DETAIL
LOWEST SUBDAAIN SHOULD
BE SITUATED AS LOW AS
POSSIBLE TO ALLOW
SUITABLE OUTLET
r-----,. 1 O' MIN.
PERFORATED I t · I EACH SIDE
PIPE~• CAP
NON-PER FORA
OUTLET PIP
T-CO.NNECTION DETAIL
* IF CAL TRANS CLASS 2 PERMEABLE
MATERIAL IS USED IN PLACE OF
314•-1-112• GRAVEL, FILTER FABRIC
MAY BE DELETED
SPECIFICATIONS FOR CALTRANS
CLASS 2 PERMEABLE MATERIAL
U.S. Standard
Sieve Size
l"
3/4"
3/8"
No. 4
No. 8
No. 30
No. SO
No. 200
% Passing
100
90-100
40-100
25-40
18-33
5-15
0-7
0-3
Sand Equiva1ent>7S
For buttress dimensions, see geotechnical report/plans. Actual dimensions of buttress and aubdrain
may be changed by the geotechnical consultant based on field conditions.
SUBDAAIN INSTALLATION-Subdraln pipe should be Installed with perforations down as depicted.
At locatlon, recommended by the geotechnical consultant, nonperforated pipe should be Installed
SUBORAIN TYPE-Subdraln type should be Acrylon trlle Butadlene Styrene (A.B.S.), Polyvinyl Chloride
(PVC) or approved equivalent. Class 125,SDR 32.5 should be used for maximum fill depths of 35 feet.
Claaa 200, SOR 21 1hould be used for maximum fill depth• of 100 feet.
CANYON SUBORAIN DETAILS
...., ____ EX18TIN8
GROUND SUAf'ACI
e• MIN. OVERLAP
-~ . . .
3/-4•-1·112• CLEAN
GRAVEL (9ft.3/ft. MIN.)
Wrlil
SUBORAIN
TRENCH
SEE BELOW
SUBDRAIN TRENCH DETAILS
FILTER FABRIC ENVELOPE /e• MIN. OVERLAP
(MIRAFI 140N OR APPROVED f
EQUIVALENT)*
e• MIN.
COVER
--'---I/, . 3/4•-1 • 112• CLEAN ______ ...i.-------~~-~ -,.;:..._-~ GRAVEL
4• MIN. BEDDING
'----e• .f/J MIN. ___ _,,
PERFORATED
PIPE
(9ft.3 /ft. MIN.)
* IF CAL TRANS CLASS 2 PERMEABLE
MATERIAL IS USEC IN PLACE OF
3/4'-1·1/2' GRAVEL, FlLTER FABRIC
MAY BE DELETED
DETAIL OF CANYON SUBDRAIN TERMINAL
--=-~==~1~ 0 •• O • J • (> ~ -: :• •• : Ve •
0
.:
~ J • -• ..
~
t 15' MIN ., S'MIN1""' PERFORATED ~ . a• J;1 MIN. PIPE ..
NONPERFOAATEO e• 0 MIN.
SPECrFICATIONS FOR CALTRANS
CLASS 2 PERMEABLE MATERIAL
U.S. Standard
Sieve Size % Passing
l" 100
3/4" 90-100
3/8" 40-100
No. 4 25-40
No. 8 18-33
No. 30 5-15
No. SO 0-7
No. 200 0-3
Sand Equiva1ent>7S
Subdraln should be constructed only on competent material as evaluated by the geotechnical
conaultant.
SUBCRAIN INSTALLATION Subdrain pipe should be installed with perforations down as depicted.
At locations recommended by the geotechnical consultant, nonperforated pipe should be Installed.
SUBCRAIN TVPE-Subdrain type should be Acrylonltrlle Butadiene Styrene (A.8.S.), Polyvinyl
Chloride (PVC) or approved equivalent. Class 125, SOR 32.5 should be used for maximum
flll dept ha of 3S feet. Class 200, SOR 21 should be used for maximum flll depths of 100 feet.
KEY AND BENCHING DETAILS
FILL SLOPE ~':.~~~~~ 6~ ~L~:: \\\~~!!!
TO COMPl!TENT MATERI ~:;!.l.~~~::-
EXIST1NG
GROUND SURFAC
2' MIN.L15' MIN~ KEY ILOWEST--7
OEPTH BENCH
(KEY)
BENCH
ACTEO=-:~
FILL-OVER-CUT SLOPE ILL~-----=-
EXISTING ~
GROUND SURF ACE ) ---------
--LO-WEST
...--MIN. BENCH D~~fH (KEY)
CUT SLOPE
(TO BE EXCAVATEO
PRIOR TO FILL
PLACEMENT) //~
CUT-OVER-FILL SLOPE
PROJECT 1 TO 1
LINE FROM TOE
OF SLOPE TO
COMPETENT
MATERIAL
EXISTING / /
GROUND / /
SURFACE~// K
// ~l~.?' / I,, 1.,, .....
/
-::,JI
CUT SLOPE
(TO BE EXCAVATED
PRIOR TO FILL
PLACEMENT)
NOTE: Back drain may be recommended by the geotechnical consultant based on
actual field conditions encountered. Bench dimension recommendations may
also be altered based on field conditions encountered.
ROCK DISPOSAL DETAIL
PIN&aH GRADE
GRANULAR SOIL (S.E.~ 30) TO BE 0ENSIFIED IN PLACE BY FLOODING _ _;;:,,,.-c:::::..._ ___ __
DETAIL
--------------------------------------------
--------------------------------------------
TYPICAL PROFILE ALONG WINDROW
1) Rock with maximum dimensions greater than 6 inches should not be used within 10 feet
vertically of finish grade (or 2 feet below depth of lowest utility whichever is greater),
and 15 feet horizontally of slope faces.
2) Rocks with maximum dimensions greater than 4 feet should not be utilized in fills.
3) Rock placement, flooding of granular soil, and fill placement should be observed by the
geotechnical consultant.
4) Maximum size and spacing of windrows should be in accordance with the above details
Width of windrow should not exceed 4 feet. Windrows should be staggered
vertically (as depicted).
5) Rock should be placed in excavated trenches. Granular soil (S.E. greater than or equal
to 30) should be flooded in the windrow to completely fill voids around and beneath
rocks.
APPENDIX C
VOT Consulting Engineers
(APN: 215-460-06) Argonauta Street, Carlsbad, California Job No. 186021-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CIVIL, STRUCTURAL CONSULTANTS
LABORATORY RESULTS
Method Cal-Trans
Analyte Result Reporting
Limit Units Dilution Method
SULFATE 55.8 n/a ppm 1 CT 417
CHLORIDE 22.5 n/a ppm 1 CT 422
p.H. 6.87 n/a pH units 1 CT 643
RESISTIVITY 13600 n/a ohms.com 1 CT 643
ND=None detected – us/cm = micro Siemens per centimeter - ppm-parts per million
(10,000ppm=1% by weight)
ENGINEERING
DESIGN GROUP
www.designgroupca.com
2121 Montiel Road, San Marcos, CA 92069
760.839.7302
Job Name: Engineering Design Group
Job No: 10-3988L Tested By: JNC
Lab No: 278073 Date Sampled:
Soil Location: N/A Date Tested:
Soil Description: Moderate Reddish Brown SC
LAB WORK SHEET
WET WEIGHT (g)
DRY WEIGHT (g)
% MOISTURE (%)
EXPANSION INDEX TEST
ASTM D 4829
TEST RESULTS
Initial Final
129.3 407.8
115.9 332.9
11.5 22.5
----
----
WEIGHT OF RING & SOIL (Q) 743.0
WEIGHT OF RING (g) 366.3
WEIGHT OF SOIL (lbs.) 0.8305
VOLUME OF RING (ft.~) 0.0073
WET DENSITY (pcf) 114.2
DRY DENSITY (pcf) 102.4
% SATURATION (%) 48.4
EXPANSION READING
DATE TIME: INITIAL READING INCH
NOTES:
I 0.01831 VERY LOW 0-20
LOW 21-50
MEDIUM 51 -90
FINAL READING HIGH 91-130
-1 o-. 03"""""'3.,...o I
EXPANSION INDEX
VERY HIGH 130>
-, _1 __ 5_
El at saturation between 48-52%
Measured El: 14.7
Measured Saturation: 48.4
El at 48-52% Saturation :1 ___ 1_5 ___ 1
APPENDIX D
ENGINEERING DESIGN GROUP
2121 MONTIEL ROAD PHONE: (760) 839-7302
SAN MARCOS, CALIFORNIA 92069 FAX: (760) 480-7477
MINIMUM RETAINING WALL WA TERPROORNG &: DRAINAGE DETAIL
(NOT JO SCALE)
CONC OR CIIU
RET WALL PER
PLAN ct DCTAILS
HYDROTITE WATER-
STOPS AT COLD-
JOINTS PER IIFR
INSTALLATION
INSTRUCTIONS
SLAB ct VAPOR
BARRIER PER
PLAN ct
DCTAILS
IID£ 1HIS DCTAIL REPRESENTS 1HE IIINIIIUII WALL DRAINAGE
AND WATERPROOFING APPLJCA TION 7D SATISFY 1HE STRIJCTIJRAL
DESIGN IN1ENT OF 1HE RETAINING WALL 1HE ARCHITECT OR
DESIGNER OF RECORD FOR THE PRO.ECT SHALL BE RESPONSIBLE
FOR 1HE DESIGN AND SPEaRCA TION OF 1HE WATERPROOFING
ASSEJIBLY.
17\ FOAII UV PROTECTION BOARD PER
\..!.) IIANUFACTIJRER'S SPEaRCA TION --~
(';j\ WATERPROOFING INSTAil.ED PER
\!:/ IIANUFACTIJRER'S SPEaFICATIONS ct
EXTEND BEHIND BACKER BOARD.
/'T\ BACKDRAIN, INSTAil.ED PER
\::!) IIANUFACTIJRER'S SPEaRCATIONS
0~ WATERPROOFING.
ANY PENETRATIONS OF WATERPROOFING
SHALL BE BROUGHT 7D 1HE ATTENTION
OF 1HE WATERPROOFING
CONSULTANT/IIANUFACTIJRER IN
ADVANCE AND SEALED PER
IIANUFACTIJRERS SPEaRCATIONS.
,;"\ TERIIINATION BAR PER
\:!.) IIANUFACTIJRER'S SPEaRCATIONS
@ RLTER FABRIC W/ 6H IIIN LAP
® J/.f" GRA~ <1 SF Im
(j) .f" DIA PERFORATED DRAIN UNE (sal .fO OR
EQUIV.) PERFORATIONS ORIENTED DOWN 1~
IIINIIIUII GRADIENT 7D SUITABLE OUTLET -
EXACT PIPE LOCATION 7D BE DETERIIINED BY
SITE CONS1RAINTS
® .f" TALL CONCRETE CANT O FTG / WALL
CONNECTION (UNDER WATERPROOFING). SLOPE
7D BAac EDGE OF FOOTING.
® COMPACTED BAacFILL 90~ IIIN Rfl.ATIIIE
COMPACTION IN ALL 01HER AREAS U.O.N.
6" IIAX UFTS. ONLY UGHTVEIGHT
HAND-OPERA TED EQUIPMENT SHALL BE USED
Vl1HIN J FEET OF THE BAa< FACE OF WALL
@ CSP ROUGHNESS OF WALL SHALL COIIPL Y Vtf1H
WATERPROOFING IIANUFACTIJRER'S
SPEaRCA TIONS.