HomeMy WebLinkAboutPD 2019-0009; 2700 ARGONAUTA RESIDENCE; PRELIMINARY GEOTECHNICAL INVESTIGATION AND FOUNDATION RECOMMENDATIONS; 2019-01-04ENGINEERING 2121 Montiel Road, San Marcos, CA 92069
' 1DESIGN GROUP 760.839.7302
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PRELIMINARY GEO TECHNICAL INVESTIGATION AND FOUNDATION RECOMMENDATIONS
PROPOSED NEW RESIDENCE
TO BE LOCATED AT
(APN:215-460-05) ARGONAUTA STREET,
CARLSBAD, CALIFORNIA
4 EDG Project No. 175864-1
January 41h, 2019
RECORD COPY
PREPARED FOR: Initial Date
Keith Webster
1460 Orpheus Avenue
Encinitas, CA 92024
w
ENGINEERING
1111111 DESIGN GROUP San Marcos, CA 92069
wwwdesigngroupca.m
Date: January 4, 2019
To: Keith Webster
1460 Orpheus Avenue
Encinitas, CA 92024
Re: Proposed new residence to be located at (APN: 215-460-05) 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
E.
(((C C 65122
cmt-
CA% IQ~ D C
Steven Norris
California GE#2590
Erin E. Rist
California RCE #65122
RECEIVED
JUL 02 2019
LAND DEVELOPMENT
ENGINEERING
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..................................................................................................................................7
10.0 CORROSION AND VAPOR EMISSION.................................................................................................8
11.0 CONCRETE SLAB-ON-GRADE ........................................................................................................... 10
12.0 RETAINING WALLS...........................................................................................................................11
13.0 INFILTRATION ............................................................................................. ..................................... 13
14.0 SURFACE DRAINAGE........................................................................................................................14
15.0 LABORATORY TESTING ................................... .................................................................................15
16.0 CONSTRUCTION OBSERVATION AND TESTING ............................ ...................................................15
17.0 MISCELLANEOUS.............................................................................................................................16
FIGURES
SiteVicinity Map ..........................................................................................................................Figure No. 1
SiteLocation Map ........................................................................................................................Figure No. 2
SitePlan .......................................................................................................................................Figure No. 3
TestPit Logs ..........................................................................................................................Test Pit Logs 1-3
APPENDICES
References....................................................................................................................................Appendix A
General Earthwork and Grading Specifications............................................................................Appendix B
LaboratoryResults ........................................................................................................................Appendix C
Retaining Wall Drainage Detail .....................................................................................................Appendix D
1.0 SCOPE
This report gives our recommendations for the proposed new residence to be located at Argonauta Street
(APN: 215-460-05), 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: 215-460-05), Carlsbad, California. For the
purposes of this report the lot is assumed to face south. The property is bordered to the east and west by
undeveloped lots, to the north by a single-family residence 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. The lot descends generally 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 be constructed utilizing slab-on-grade
floors.
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 2 feet below adjacent grade
in our exploratory trenches. Soil types encountered within our trenches are described as follows:
Webster Residence Page No. 1
Argonauta Street (APN: 215460-05), Carlsbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
G(O1aCKN,CAI. cM,. S1RUC1URAtONSULTAN15
4.1 Topsoil / Fill / Weathered
Topsoil, fill and weathered unsuitable materials were encountered to depths up to 2 feet below adjacent
grade in our trenches. It should be noted that deepened fills were visually observed in areas adjacent to
the street. These materials consist of brown to reddish brown to greenish gray, dry to moist, loose to
medium stiff, silty clays and clayey silts 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 to medium 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 and Approximate 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.
Research and historical data indicate that loose, granular soils underlain by a near-surface ground water
Webster Residence Page No. 2
Argonauta Street (APN: 215-460-05), Carlsbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
GEO1SCHNICA. CIVIL STRUCTURAL CONSULTANTS
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
proposed improvements include a multi-story residence with basement elements, typical hardscape and
landscape improvements. We understand the new residence will be constructed with slab-on-grade
floors. In general, it is our opinion that the proposed new structure and improvements, as discussed and
Webster Residence Page No. 3
Argonauta Street (APN: 215-460-05), Carlsbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
G(OT1cHNICALCIVL STRUCTURAL CONSULTANTS
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 basement pad subgrade elevation
(anticipated to be on the order of 10 to 15 feet)
In consideration of the dense nature of the fractured rock material encountered in our test pits
and the proposed subterranean building elements, we anticipate grading may require special
heavy excavation equipment and possibly blasting.
Upper level foundations areanticipated to span lower level foundations and therefore span across
retaining wall backfill zones.
Second level foundations are anticipated to be partially founded in competent rock material.
We anticipate basement foundations will be founded on competent underlying rock material.
Where second level foundations span retaining wall backfill of lower level basement retaining
walls, we recommend 95 percent relative compaction (based on ASTM D1557 - latest edition) of
the upper 3 feet.
Third level foundations are anticipated to span over fill material. Upper 3 feet to be compacted
to 95% relative compaction in building footprint.
Based upon site conditions, confirmed in the field by representative of Engineering Design Group,
temporary slopes may be cut steeper that 1:1 to limit cut/fill transitions as the building steps back
at upper levels.
Footings for retaining walls may need to be locally deepened to limit cut/fill transitions.
Any changes in the proposed design should be reviewed by this office for any revisions to the
recommendations herein.
8.0 EARTHWORK
Based upon our review of building elevations, grading is anticipated to include the creation of new cut/fill
slopes in the area of the building pad, 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 concrete slabs-on-grade floors, in general we anticipate
foundations will extend into competent rock material with areas spanning retaining wall backfill. 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.
Webster Residence Page No. 4
Argonauta Street (APN: 215460-05), Caiisbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
GEOT CHNTCAI. 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 basement pad and second level pad
subgrade. We anticipate grading will consist in the removal of unsuitable soil to competent material, the
scarification of subgrade to a minimum depth of 8— 12 inches, creation of keyways, benching, placement
and re-compaction of fill material (90 percent minimum relative compaction and 95 percent minimum
relative compaction in upper 3 feet of fill within building footprint) in the areas of the proposed
improvements.
8.3 Transitions
We anticipate the lower two levels will generally extend to competent rock material and building
foundations will be placed on competent rock material. We anticipate building foundations will be placed
on competent rock material, fill and backfill material. Removal depths should be visually verified by a
representative of our firm prior to placement of improvements. Where this condition is not met,
undercuts may be necessary. Based upon site conditions, confirmed in the field by representative of
Engineering Design Group, temporary slopes may be cut steeper that 1:1 to limit cut/fill transitions as the
building steps back at upper levels.
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
Webster Residence Page No. 5
Argonauta Street (APN: 215.460-05), Carlsbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
GEOUC1INICAI, CIVIl. SIRUCTURALCCNSULTAKIS
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 and 95 percent relative compaction in the upper 3
feet of fill within building footprint (based on ASTM D1557). 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. Where basement level retaining
walls backfill is second level foundation subgrade, backfill shall be compacted to at least 95 percent
relative compaction (based on ASTM D1557 - latest edition).
Fills should generally be placed in lifts not exceeding 6-8 inches in thickness. Imported soils might be
necessary and should have a low potential for expansion (Ek50), 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).
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Argonauta Street (APN: 215-460-05), Carlsbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
G(OTTCHNICAt. CNII. STRUCTURAL CONSULTANTS
9.0 FOUNDATIONS
The following design parameters may be utilized for new foundations founded on competent material.
9.1 Footings bearing uniformly in competent material 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.
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
SDI (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 15inches 18inches
2 15 inches 18 inches
3 18inches 24inches
Footings are anticipated to be founded in competent material.
Webster Residence Page No. 7
Argonauta Street (APN: 215460-05), Carlsbad, California Job No. 175864.1
ENGINEERING DESIGN GROUP
GEOUCHNICAL. CIVIL. STRUCflJRALCONSULTM4TS
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.
9.7 For footings adjacent to slopes a minimum of 10 feet 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 Cl, 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 SO, mild to moderately corrosive due to sulfate attack to
concrete structures.
Webster Residence
Argonauta Street (APN: 215-460-05). Carlsbad, California
ENGINEERING DESIGN GROUP
GEOncHN1CAI. CIVIL. STRUCTURAL CONSULTANTS
Page No. 8
Job No. 175864-1
10.3 In consideration of the subterranean nature of the structures proposed, ACI standards and the
corrosion potential of the onsite soils as indicated above, 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 In non-moisture sensitive areas, we recommend 2,500 psi minimum compressive strength.
10.5 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.
10.6 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.
10.7 Slab Underlayment: We recommend the following beneath proposed slab-on-grade floors.
10.7.a. In the proposed below-grade and subterranean areas (i.e. basements) we recommend
a waterproof membrane. In non-basement moisture-sensitive areas we recommend a
vapor barrier.
10.7.b. The slab underlayment for non-basement moisture-sensitive areas consists of 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.
10.7.c. 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.
Webster Residence Page No. 9
Argonauta Street (APN: 215.460-05). Carlsbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL. civiL STRUCTURAL CONSULTANTS
10.7.d. 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.
10.8 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 rock material and on
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 improvements and new driveways 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: % - 1 inch.
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.
Webster Residence Page No. 10
Argonauta Street (APN: 215-460-05), Carlsbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL. S1RUCTURALCONSULTAN1
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:
u.S.a. New flatwork in areas of encountered expansive soil (not anticipated) should be
detailed with 6 inches of base material.
11.5.b. New flatwork should have a minimum thickness of 4 inches with steel reinforcement
per industry standards.
u.S.c. 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.d. Concrete slump should not exceed 4 inches.
11.5.e. 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.f. 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.
11.5g. 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.h. Isolation joints should be installed at exterior concrete where exterior concrete is
poured adjacent to existing foundations.
11.5.i. 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.
11.5.j. 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 12 feet are anticipated and should be designed and constructed in accordance
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Argonauta Street (APN: 215-460-05), Carlsbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
GEOTECHNWAL. STRUCTURAL CONSULTANTS
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.l. <50) will be used for backfill, and that the backfill surface will be level. Where soil
with potential for expansion is not low (E.l. >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. Horizontal ground acceleration value kH = 0.29 g.
12.6.b. 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.c. The unit weight of 120 pcf for the onsite soils may be utilized.
Webster Residence Page No. 12
Argonauta Street (APN: 215-460-05), Carlsbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
GEOTECHNWAL. CiViL STRUCTURAL CONSULTANTS
12.6.d. 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.e. Passive soil resistance may be calculated using an equivalent fluid pressure of 350 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.f. 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.
12.6g. 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.h. 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.
12.61 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 AND BIORETENTION
Bioretention/infiltration facilities shall maintain sufficient horizontal and vertical offset to the future
Webster Residence Page No. 13
Argonauta Street (APN: 215.460.05), Carlsbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
G(O1ICHCM. 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 ta a maximum
of 40 horizontal feet. At the toe of new fill slopes infiltration facilities shall maintain a minimum 10 feet
horizontal offset. Proposed infiltration facilities at the toe of new fill slopes shall not undermine the slope.
Where bioretention or infiltration facilities are located at the toe of slopes, new retaining walls at the toe
of the slope should be detailed, where toe would extend into unconsolidated engineered fill and the
bottom of the basin shall be lined with an impervious barrier.
If permeable payers 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 payers 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 10 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
Webster Residence . Page No. 14
Argonauta Street (APN: 215-460-05), Carlsbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
GEO1ICHMCM. civil. STRUCTURAL COHWLTANIS
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
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.
Webster Residence Page No. 15
Argonauta Street (APN: 215-460-05), Carlsbad, California Job No. 175864.1
ENGINEERING DESIGN GROUP
GEOTEcHNICA. CIVIL S1RUCTURALCONSULTANTS
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.
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
Webster Residence Page No. 16
Argonauta Street (APN: 215-460-05), Carlsbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
GOTECHNICAL. ciVil. SIRUCIUML CONSULTANTS
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
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.
Webster Residence Page No. 17
Argonauta Street (APN: 215-460-05), Carlsbad, California Job No. 175864.1
ENGINEERING DESIGN GROUP
G!OTLcHNAL. civIl. S1UCURALCO$6ULTANI
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Project: Webster Residence FIGURE 2
Address: (APN:21 5-460-05) Argonauta Street, Carlsbad, California
EDG Project No: 175864-1 Site Map
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Project: Webster Residence FIGURE 3
Address: (APN:215-460-05)Argonauta Street, Carlsbad, California Site Plan and Approximate
EDG Project No: 175864-1 Location of Test Trenches
Project Name: Webster Residence TEST PIT LOG NO. I
EDG Project
Number: 175864.1
Location: See Figure 3— Approx. Location of Trenches Sheet I of I
Date(s)
Excavated: 11222017 Total Depth: 22" Groundwater
Level: Not encountered
Approx. Surface Backfllled Logged By: ER Elev. Finished Surface - Approx. 67 (date) Same Day
Excavation
Method: Mini Excavator
Soil Type Depth Material Description and Notes UCSC Sample
TOPSOIL, FILL, WEATHERED
Brown to reddish brown with traces of light grey and white, dry to slightly SMSC A 0— 18" moist, medium dense, silty sands and sandy silts with angular cobbles up to
8-10 inches.
METAVOLCANIC ROCK
B 18"— 22" Yellowish brown to reddish brown, dry, hard, fractured.
GRAPHIC REPRESENTATION
FT. B.A.G. FG \Jj
1
. ,.
vzzzl 1.5 if
2.5
Project Name: Webster Residence TEST PIT LOG NO. 2
EDG Project
Number: 175864.1
Location: See Figure 3— Approx. Location of Trenches Sheet I of I
Date(s)
Excavated: 11-22-2017 Total Depth: 24" Groundwater
Level: Not encountered
Logged By: ER Approx. Surface
Elev. Finished Surface - Approx. 67 Backflied
(date) Same Day
Excavation
Method: Mini Excavator
Soil Type Depth Material Description and Notes UCSC Sample
TOPSOIL FILL, WEATHERED
A 0-22" Light brown to reddish brown, dry, medium dense, silty sands and sandy silts SM-SC
with angular cobbles up to 6 to 8 inches.
22" - 24"
METAVOLCANIC ROCK
B Yellowish brown to reddish brown, dry, hard, fractured.
GRAPHIC REPRESENTATION
FT. B.A.G. FG
®...( 1
1.5
2.5
Project Name: Webster Residence TEST PIT LOG NO. 3
EDG Project
Number: 1758641
Location: See Figure 3— Approx. Location of Trenches Sheet I of I
Date(s)
Excavated: 11.22.2017 Total Depth: 24"
Groundwater
Level: Not encountered
Approx. Surface Backfiiled Logged By: ER Elev. Finished Surface - Approx. 67 (date) Same Day
Excavation
Method: Mini Excavator
Soil Type Depth Material Description and Notes UCSC Sample
TOPSOIL. FILL, WEATHERED
Light brown to reddish brown, dry, medium dense to dense, silty sands and SM-SC A 0-22 sandy silts with angular cobbles up to 6 to 8 inches. Roots in upper 12
inches.
METAVOLCANIC ROCK
B 22" - 24" Yellowish brown to reddish brown, dry, hard, fractured.
GRAPHIC REPRESENTATION
FT. B.A.G. FG
1.5 !. '
I. .'
2.5
APPENDIX A
REFERENCES
California Geological Survey, Probabilistic Seismic Hazards Mapping Ground Motion Page.
California Department of Conservation, Divisionof Mines and Geology, Fault Rupture Zones in California, Special
Publication 42, Revised 1990.
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.
County of San Diego, Planning and Development Services Archive, Various Aerial Photographs, Various Dates.
Day, Robert W. 1999. Geotechnical and Foundation Engineering Design and Construction. McGraw Hill.
6. DZN Partners, Plans for Argonauta Project, Dated 01-04-2018.
Greensfelder, R.W., 1974 Maximum Credible Rock Acceleration from Earthquakes in California Division of Mines
and Geology, Map Sheet 23.
Kennedy, Michael P. and Tan Siang S., Geologic Map of the Oceanside 30'x60' Quadrangle, San Diego County
California. Dated 2002.
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.
Ploessel, M.R. and Slossan, J.E., 1974 Repeatable High Ground Acceleration from Earthquakes: California
Geology, Vol. 27, No. 9, P. 195-199.
State of California, Fault Map of California, Map No. 1, Dated 1975.
State of California, Geologic Map of California, Map No. 1, Dated 1977.
Structural Engineers Association of Southern California (SEAOSC) Seismology Committee, Macroseminar
Presentation on Seismically Induced Earth Pressure, June 8, 2006.
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
is. 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.
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.
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 I 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 Subdraln 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.AIl 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
EXISTING GROUND
-
100, FINISHED SLOPE FACE- —FINISHED CUT PAD PROJECT I TO I LINE
FROM TOP OF SLOPE TO
OUTSIDE EDGE OF KEY
OVERBURDEN OR OR PAD OVEREXCAVATION DEPTH UNSUITABLE
MATERIAL t/AI AND RECOMPACTION MAY BE RECOMMENDED BY THE
GEOTICHNICAL CONSULTANT
BENCH BASED ON ACTUAL FIELD
CONOITIONSENCOUNTERED... L
.. --
2 I150 MIN.I —COMPETENT BEDROCK OR MIN. LOWEST , MATERIAL AS EVALUATED
DEK BENCH PTH ( BY T
CONSULTANT AL
HE GEOTECHNIC
NOTE: Subdrairt details and-key width recommendations to be provided based
on exposed subsurface conditions
STABILITY FILL! BUTTRESS DETAIL
OUTLET PIPES
-4' 0 NONPERPORATED PIPE.
i001 MAX. D.C. HORIZONTALLY.
30 MAX. O.C. VERTICALLY -'--SACK CUT 1:1 OR FLATTER
BENCH
SEE SUBDRAIN TRENCH DETAIL
LOWEST SUBORAIN SHOULD
BE SITUATED AS LOW AS
POSSIBLE TO ALLOW SUITABLE OUTLET
KEY DEPTH I
N. 10' MIN. PERFORATED -
EACH SIDE PIPE
LCAP
MIN M.CQC:
-4
I KEY WIDTH
AS NOTED ON.31111ADING PLANS is, MIN.
,.SEE T-CONNECTION
8 MIN. / DETAIL
OVERLAP
3/4'- 1-1/2'
.) 6' MIN. (3ft3/ft. MIN
CLEAN GRAVEL
_.•111cOVECOVER
0 4' NON-PERFORATED •• : Ø PERFORATED PIPF... • ____ PIPE
FILTER FABRIC -
ENVELOPE (MIRAFI
140N OR APPROVED
EQUIVALENT)*
SUBDRAIN
NON-PERFORATED
OUTLET PIPE _-
T-CONNECTION DETAIL
* IF CALTRANS CLASS 2 PERMEABLE
MATERIAL IS USED IN PLACE OF
314'-1-1/2' GRAVEL, FILTER FABRIC
MAY BE DELETED
SPECIFICATIONS FOR CALTRANS
CLASS 2 PERMEABLE MATERIAL
U.S. Standard
Sieve Size Z Passing
10 100
3/4" 90-100
3/8" 40-100
No. 4 25-40
No. 8 18-33
No. 30 5-15
No. 50 0-7
No. 200 0-3
Sand Equivalent >75
5% MIN.
4' MIN. BEDDING
NCH DET
NOTES: For buttress dImensions, see geotechnical report/plans. Actual dimensions of buttress and subdraifl
may be changed by the geotechfliCai consultant based on field conditions.
SUBDRAIN INSTALLATION-SUbdr*In pIpe should be Installed with perforations down as depicted.
At locations recommended by the g.t.ChfllCZl consultant, nonperforatod pipe should be Installed
SUBDRAIN TYPE-Subdraln type should be AcrylOn trile Butadiene Styrene (A.B.S.), Polyvinyl Chloride
(PVC) or approved equivalent. Class 125,SOR 32.5 should be used for maximum fill depths of 35 feet.
Class 200,30111 21 should be used for maximum fill depth' of 100 feet.
3/4_1112a CLEAN
GRAVEL (91101ft. MIN.)
CANYON SUBDRAIN DETAILS
-EXISTING
GROUND SURFACE
BENCHING
'-REMOVE
UNSUITABLE
MATERIAL
TRENCH
SEE BELOW
SUBDRAIN TRENCH DETAILS
' MIN. OVERLAP
FILTER FABRIC ENVELOPE -e' MIN. OVERLAP
(MIRAFI 140N OR APPROVED
EQUIVALENT)* \ ç1•,/
68 MIN. 6 ll MIN.
COIER COVER 3/0-1-1/2' CLEAN
GRAVEL
_________________________________________•• 40 MI (9110/ft. MIN.MIN. BEDDING
—6' 0 MIN. -
PERFORATED
PIPE
DETAIL OF CANYON SUBDRAIN TERMINAL
: :•:
MIN. PIPE H MIN.sI5'MINj ._...__. PERFORATED
NflMPDcflDArcn a' um
*iF CALTRANS CLASS 2 PERMEABLE
MATERIAL IS USED IN PLACE OF
3/4-1-1/2' GRAVEL, FILTER FABRIC
MAY BE DELETED
SPECIFICATIONS FOR CALTRANS
CLASS 2 PERMEABLE MATERIAL
U.S. Standard
Sieve Size % Psing as
1" 100
3/41 90-100
3/8" 40-100
No. 4 25-40
No. 8 18-33
No. 30 5-15
No. 50 0-7
No. 200 0-3
Sand Equivalent >75
DESIGN FINISH SUODRAIN GRADE --::. TRENCH
-SEE ABOVE
- ... -... S...-. W — .r..
Subdrain should be Constructed only on competent material as evaluated by the Qeotechnical
Consultant.
SUBORAIN INSTALLATION Subdrain pipe should be installed with perforations down as depicted.
At locations recommended by the g.otechnical consultant, nonperlaratsd pipe should be installed.
SUBORAIN TYPE-Subdraln type should be Acrylonitrile Butadlene Styrene (A.B.S.). Polyvinyl
Chloride (PVC) or approved equivalent. Class 125,SDR 32.5 should be used for maximum
fill depths of 33 feet. Class 200, SOR 21 should be used for maximum fill depths of 100 feet.
KEY AND BENCHING DETAILS
FILL SLOPE PROJECT 1 TO I LINE
FROM TOE OF SLOPE
TO COMPETENT MATERIAL
EXISTING GROUND SURFACE
*11 REMOVE
UNSUITABLE
MATERIAL
BENCH
2' MIN •15' MIN
KEY LOWEST DEPTH BENCH
(KEY)
FILL-OVER-CUT SLOPE
EXISTING
GROUND SURFACE\
- -
2' LOWEST
WI. BENCH
DEPTH
CUT SLOPE (TO BE EXCAVATED
PRIOR TO FILL
BENCH
REMOVE
UNSUITABLE
MATERIAL
PLACEMENT) , --
CUT-OVER-FILL SLOPE
PROJECT I TO I
LINE FROM TOE
OF SLOPE TO
COMPETENT
MATERIAL
-.
EXISTING GROUND
CUrr SLOPE
(TO BE EXCAVATED
PRIOR TO FILL
PLACEMENT)
"-REMOVE
UNSUITABLE MATERIAL
CH
.-•- t 2' MIN.' LOWEST I BENCH KEY. DEPTH (KEY)
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
FINISH GRADE
SLOPE FACE
---------------- -.--___-.-
GRANULAR SOIL (3.E. SO) TO BE Q—
DENSIFIED IN PLACE BY FLOODING
DETAIL
TYPICAL PROFILE ALONG WINDROW
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.
Rocks with maximum dimensions greater than 4 feet should not be utilized in fills.
Rock placement, flooding of granular soil, and tiii placement should be observed by the
geotechnical consultant.
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).
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
~~jm -T
Job Name: . . Engineering Design Group - Webster CtE Job No: 10-3988L/175864 Tested By: JNC
Lab No: 278073 . Date Sampled: 1/16/2017
Soil Location: N/A Date Tested: 1/17/2017•
Soil Description: Moderate Reddish Brown SC
LAB WORK SHEET EXPANSION INDEX TEST.
ASTM D 4829
TEST RESULTS
Initial .. . Final
WET WEIGHT (g) 129.3 407.8
DRY WEIGHT (g) 115.9 332.9
% MOISTURE (%) 11.5 .. 22.5
WEIGHT OF RING & SOIL (g) 743.0
WEIGHT OF RING (g) 366.3
WEIGHT OF SOIL (lbs'.)l 0.8305
. . VOLUME OF RING (ft.3) 0.0073
WET DENSITY (pcf) . 114.2
DRY DENSITY (pcf) 102.4
% SATURATION (%)1 48.4
EXPANSION READING
DATE TIME: INITIAL READING _INCH
10.01831 . VERY LOW 0-20
. . S LOW 21-50
MEDIUM 51-90
FINAL READING. • . • HIGH 91-130
. 10.03301. VERY HIGH 130>
EXPANSION INDEX._____
I 15
NOTES:
El at saturation between 48-52%
Measured El: 14.7
Measured Saturation: 48.4
El at 48-52% Saturation:FiT"1
'.
mENGINEERING ' 2121 Montiel Road, San Marcos, CA 92069 IJDESIGN GROUP 760.839.7302
wwwdesigngroupca.com
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
(10000ppm=1% by weight)
Webster Residence
(APN: 215-460-05) kgonauta Street, Carlsbad, California Job No. 175864-1
ENGINEERING DESIGN GROUP
GEOTECHNICAL, CML, STRUCTURAl. CONSLLTANTS
11 UUMIR]
ENGINEERING DESIGN GROUP
2121 MONT1EL ROAD PHONE: (760) 839-7302
SAN MARCOS. MFDRNIA 92089 FAX: (760) 480-7477
1 f• 2
La g 12 0
FGAU UV PROTECT= BMW FIX
DOW SOfiND BACKM BOAFA
WALL
MY MORAMNS OF NA70FROOFING
/
o-
HE BROUGHT 70 THE ATIENJIGN
C=XTNT/UMLFAClUffR IN
., .. ADVANCE AND SEALED PER NANUFACRMERS _____
! 101 MANN ":,. L'•';f'2,.'.iI
j;J FABRIC L!I MIN IV
40 DIA POWMIED DRAIN LAW (SCH 40 OR
EXACT FFE LWAIM TO HE DETMWD BY
SITE CONSIROM
[g
AD TO BACK EDGE OF FOOTM
4U4ia; dp