HomeMy WebLinkAboutPD 16-05; SOILS INVESTIGATION REPORT; 2015-11-19REVISED FINAL
SOILS INVESTIGATION REPORT
PROPOSED
AVIARA COMMUNITY PARK EXPANSION
6435 AMBROSIA LANE
CARLSBAD, CALIFORNIA
(K2 Engineering Job No. G2015012-1)
Prepared for:
Schmidt Design Group
November 19, 2015
RECEIVED
MAR 112016
LAND DEVELOPMENT
ENGINEERING
ENGINEERING, INC.
V%kGEOTECHNICAL CONSULTANTS
REVISED FINAL
SOILS INVESTIGATION REPORT
PROPOSED
AVIARA COMMUNITY PARK EXPANSION
6435 AMBROSIA LANE
CARLSBAD, CALIFORNIA
(K2 Engineering Job No. G2015012-1)
11
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12595 RAGWEED STREET, SAN DIEGO, CALIFORNIA 92129 9 PHONE (858)484.2347 • FAX (858)484-8682
Schmidt Design Group G2015012-1
Aviara Community Park Expansion, Carlsbad, California Revised Final
TABLE OF CONTENTS
Text Page No.
1.0 Summary ............................................................................................................1
2.0 Scope .................................................................................................................2
3.0 Project Description ............................................................................................3
4.0 Site Conditions ..................................................................................................3
4.1 Existing Conditions..................................................................................3
4.2 Subsurface Conditions..............................................................................4
5.0 Percolation Testing ............................................................................................5
6.0 Conclusions and Recommendations .................................................................6
6.1 General .....................................................................................................6
6.2 Foundations .............................................................................................6
6.3 Excavation ...............................................................................................9
6.4 Grading ....................................................................................................9
6.5 Seismic Design Parameters .....................................................................11
6.6 Retaining Walls .......................................................................................12
6.7 Slopes and Erosion Control .....................................................................13
6.8 Floor Slab Support ...................................................................................14
6.9 Paving ......................................................................................................16
7.0 Soil Corrosivity .................................................................................................18
8.0 Basis for Recommendations ..............................................................................19
Appendix A Explorations and Laboratory Tests
List of Plates Plate No.
SitePlan ......................................................................................................................
Boring Logs .................................................................................................................A-1.1 -A-1.4
Unified Soil Classification System .............................................................................A-2
DirectShear Test Data ................................................................................................A-3
CompactionTest Data .................................................................................................A-4
R-Value Test Data .......................................................................................................A-5
ExpansionIndex Test Data .........................................................................................A-6
CorrosivityTest Results ..............................................................................................A-7
4 ENGINEERING, INC.
GEOTECHNICAL CONSULTANTS
November 19, 2015
Mr. Jeffrey T. Barr
Schmidt Design Group
1111 Sixth Avenue, Suite 500
San Diego, CA 92101
Transmitted via e-mail: JTBarr @schmidtdesign.com
(K2 Engineering Job No. G2015012-1)
Dear Mr. Barr:
We are pleased to submit our "Revised Final Soils Investigation, Proposed Aviara Community Park
Expansion, Carlsbad, California.". We previously submitted the results of our soils investigation in a
report dated September 23, 2015. After submittal of that report, we were requested to provide
recommendations for pervious concrete pavement.
Recommendations for design of pervious pavement along with the results of our field explorations
and laboratory tests, as well as recommendations for design of foundations and earthwork for the
proposed park improvements are presented in this report.
Please call us if you have any questions or if we can be of further service to you on this or future
projects. It has been a pleasure working with you.
Respectfully submitted,
K2 ENGINEERING, INC.
Susana Kemmerrer, RGE 2287
President
K2/Reports/SCHMIDTDESIGN/Aviara Park G2015011-1 REV Final 11-19-15.doc
12595 RAGWEED STREET, SAN DIEGO, CALIFORNIA 92129 9 PHONE (858)484-2347 9 FAX (858)484.8682
Schmidt Design Group G2015012-1
Aviara Community Park Expansion, Carlsbad, California Revised Final
IL1IJIi1Wi
This report presents the results of our soils investigation performed to provide earthwork and
foundation recommendations for the proposed Aviara Community Park Expansion. The proposed
expansion projects are planned on the northwest portion of Aviara Community Park located at 6435
Ambrosia Lane in Carlsbad, California. The location of the exploratory excavations is presented on
Plate 1, Site Plan. A summary of our findings and recommendations is presented below.
. Fill soils were not encountered in the borings, but may be present at locations not explored.
Formational materials were encountered in all four borings to the maximum depth explored of
16',4 feet. The formational materials consisted of dense to very dense, weakly to moderately
cemented silty sandstone.
Groundwater was not encountered in the exploratory borings.
The proposed improvements may be supported on the very dense to dense, undisturbed
formational materials.
Heavy duty earthmoving equipment in good working condition may be required to excavate the
formational materials.
Based on our review of historical aerial photos, a building previously occupied the south-central
portion of the site. Project grading plans indicated noted "Trailer Pad per City" for the area.
For purposes of this report, it has been assumed that foundations were not installed at this
location. Additional recommendations will be required if disturbed formational materials occur
within the footprint of the proposed community room.
Percolation testing performed on site indicated very slow to slow percolation rates.
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Schmidt Design Group G2015012-1
Aviara Community Park Expansion, Carlsbad, California Revised Final
2.0 SCOPE
This report presents the results of a soils investigation performed to provide planning and design
criteria for the proposed expansion of the Aviara Community Park in Carlsbad, California. The
approximate locations of the exploratory excavations are presented in Plate 1, Site Plan.
The purpose of this investigation was to determine the static physical characteristics of the on-site
soils; and to provide geotechnical recommendations for foundation design, grading, excavation and
backfill for the proposed facilities. More specifically, the scope of the investigation included the
following:
Evaluation of the existing surface and subsurface conditions, including groundwater
conditions (if encountered), within the areas of proposed construction.
Drilling and logging of four borings to a maximum depth of 16V2 feet.
Performing two percolation tests to evaluate the permeability of the on-site soils.
Laboratory tests to estimate the physical properties of the onsite materials.
Providing recommendations for grading.
Providing recommended foundation systems together with the associated design
parameters.
Presenting general recommendations concerning construction procedures and quality
control measures relating to earthwork.
Our recommendations are based on the results of our field explorations, laboratory tests and
associated geotechnical analyses. The results of our field explorations and laboratory tests are
presented in Appendix A. This investigation did not include studies to assess the geologic or
environmental hazards that may affect the site however, this does not imply that such hazards affect
the site.
Our professional services have been performed using that degree of care and skill ordinarily
exercised, under similar circumstances, by reputable geotechnical consultants practicing in this or
similar localities. No other warranty, express or implied, is made as to the professional advice
included in this report. This report has been prepared for Schmidt Design Group and their design
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Schmidt Design Group G2015012-1
Aviara Community Park Expansion, Carlsbad, California Revised Final
consultants to be used solely in the evaluation of the subject project. The report has not been prepared
for use by other parties, and may not contain sufficient information for purposes of other parties or
other uses.
3.0 PROJECT DESCRIPTION
Aviara Community Park is a 25-acre park located at 6435 Ambrosia Lane in the City of Carlsbad,
California. The existing park facilities include two soccer fields, a baseball field, basketball courts,
picnic and playground areas and concessions/restroom buildings and associated parking.
Based on available information, the proposed new facilities will be located on the northwest portion
of the existing park, north of the soccer fields parking area. The planned facilities will include an
outdoor amphitheatre, a 1,000-square-foot community room, shade structures, picnic areas, and
associated hardscaped and landscaped areas.
4.0 SITE CONDITIONS
4.1 EXISTING CONDITIONS
The site is an approximately 1-acre pad located on the northwest corner of the park, the north of the
existing parking area and soccer fields. The expansion site is currently vacant and was previously
graded during construction of the park by cutting into the previously existing topography. The pad is
generally flat. From about the mid section it slopes down gently to the north-northwest within the
fenced area. Beyond the fence, steep slopes descend from the pad to the north, east and west to the
adjacent canyons.
Paved driveways were observed on the southeast portion of the site, the remaining of the site is
unpaved. The driveways are about 140 feet in length and run in a north-south and east-west direction.
Based on our review of historical aerial photos, a building occupied the south-central portion of the
site. Project grading plans indicated that a "Trailer Pad per City" for the area. Utility hook-ups were
noted at that location.
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Aviara Community Park Expansion, Carlsbad, California Revised Final
Piles of loose soils with debris as well piles of plant cuttings were observed at various locations within
the site.
4.2 SUBSURFACE CONDITIONS
The subsurface conditions were explored by drilling four small-diameter borings extending to depths of
6Y2 to 16Y2 feet below the existing ground surface. In addition, two percolation test holes were
excavated to depths of approximately 3 feet.
Fill soils were not encountered at the locations drilled, but may be encountered at other locations not
explored.
Formational materials consisting of Quaternary-aged terrace deposits (Tan and Kennedy, 1996) were
encountered at the boring locations. The formational materials consisted of dense to very dense,
weakly to moderately cemented silty sandstone and extended to the maximum depth explored.
The on-site soils have a very low expansion potential (Expansion Index of 7).
Groundwater was not encountered within any of the borings or percolation test holes during drilling.
However, groundwater conditions could develop and/or seepage may occur depending on annual
precipitation and irrigation. Seepage may occur along lithologic changes within the on-site soils and
at the interface between the fill and the less permeable formational materials.
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Aviara Community Park Expansion, Carlsbad, California Revised Final
5.0 PERCOLATION TESTS
Two percolations tests were performed to evaluate the infiltration characteristics of the on-site soils
and to provide information for the design of the proposed water retention facilities or
improvements. The approximate percolation test locations are presented on Plate 1, Site Plan.
The percolation tests were performed in accordance with the general guidelines of the San Diego
County Public Health Department. The tests results are indicative of the permeability of the on-site
soils at their current condition. Percolation rates will be affected by future construction activity
such as earthmoving and compaction.
The percolation tests consisted of drilling two 6-inch diameter test holes extending to a depth of
approximately 3 feet on August 11, 2015. The test holes were excavated into the silty sandstone
materials. After completion of drilling, the loose soils were removed from the bottom of the borings
and approximately 2-inches of pea gravel were placed in the holes. A minimum of 12 inches of clean
water was carefully poured into the percolation holes and presoaked for a minimum of 6 hours. At the
end of the presoaking, water was left in the holes overnight.
Percolation testing was performed on August 12, 2015. Observations prior to the start of the tests
indicated that the holes still had water remaining. Approximately six inches of clean water was added
to each of the holes and the variations in the water level were measured at approximate 30 minute
intervals. Refilling of the holes was performed as needed to maintain a 6-inch water level at the start
of each interval. The average of the last three 30-minute interval readings was used to determine the
percolation rate. After two hours of no change in the reading the tests were terminated. The
percolation test results indicate a range of percolation rates of about 952 minutes per inch (mpi).
According to the USDA the soils are considered to have a very slow to slow flow rate. The results of
the tests are presented in the table below.
Pr,nhi*inn Tef Ppiii1+c
Test Number Percolation Rate
. .
Permeability
. (I Rate of Flow (mm/inch) (mn/hr)
AP-1 952 0.063 Very Slow to Slow
AP-2 952 0.063 Very Slow to Slow
''iiasea on U1L)A Ozl survey (ilossary
Schmidt Design Group G2015012-1
Aviara Community Park Expansion, Carlsbad, California Revised Final
6.0 CONCLUSIONS AND RECOMMENDATIONS
6.1 GENERAL
Fill soils were not encountered at the locations drilled, but may be encountered at other locations not
explored. The formational materials consist of dense to very dense silty sandstone. The soils have a
very low expansion potential.
The proposed facilities may be supported on the dense to very dense undisturbed formational
materials.
Based on our review of historical aerial photos, a building occupied the south-central portion of the
site. Project grading plans identified it as "Trailer Pad per City". For purposes of this report, it has
been assumed that foundations were not installed at this location. Additional recommendations will
be required if the formational materials were disturbed and/or foundations were installed within the
footprint of the proposed community room.
6.2 FOUNDATIONS
6.2.1 Bearing Value
To provide more uniform support, we recommend that footings for the proposed building extend at
least 2 feet below the lowest adjacent final grade or 6 inches into the formational materials, whichever
is deeper. A bearing value of 4,000 pounds per square foot may be used for footings at least 24 inches
in width and supported on the firm undisturbed formational materials.
A one-third increase in the bearing value may be used for wind or seismic loads. Since the
recommended bearing value is a net value, the weight of the concrete in the footings may be taken as
equal to 50 pounds per cubic foot, and the weight of the soil backfill may be neglected.
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Aviara Community Park Expansion, Carlsbad, California Revised Final
6.2.2 Settlement
If the footings are supported on the dense to very dense formational materials, the total settlement is
estimated to be within acceptable limits for the proposed structure.
6.2.3 Lateral Loads
Lateral loads may be resisted by friction and by the passive resistance of the undisturbed formational
materials beneath the footings. A coefficient of friction of 0.35 may be used between the foundations
and the supporting materials. The passive resistance of the formational materials may be assumed to
be equal to the pressure developed by an equivalent fluid with a density of 350 pounds per cubic foot.
The frictional resistance and the passive resistance of the materials may be combined without
reduction in determining the total lateral resistance.
6.2.4 Footing Observation
To verify that footings are supported in accordance with our recommendations, all foundation
excavations should be observed by a qualified geotechnical firm. Foundations should be deepened
if necessary to reach satisfactory bearing materials. Any unsuitable materials including,
undocumented fill, organic, loose or disturbed natural materials should be removed prior to
placement of any steel or concrete. Footing excavations extending into the natural materials should
be left uneven or backfilled with a 3-sack sand-cement slurry mix or structural concrete.
All applicable requirements of the local governing bodies, the Occupational Safety and Health Act of
1970, and the Construction Safety Act should be met. Inspection of footing excavations may be
required by the appropriate reviewing governmental agencies. The contractor should familiarize
himself with the inspection requirements of the reviewing agencies.
6.2.5 Backfill
All required fill around the foundations and all utility trench backfill should be mechanically
compacted in layers, not more than 8 inches in loose thickness; flooding should not be permitted.
Backfill should be moisture-conditioned to a minimum 2% over the optimum moisture content and be
compacted to at least 90% of the maximum density obtainable by ASTM Designation D1557-12
method of compaction. The exterior grades should be graded to drain away from the structures in
order to reduce ponding of water adjacent to structures.
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Compaction of the backfill as recommended in this report will be necessary to reduce settlement of
the backfill and consequent settlement of the overlying improvements and buried utilities. Even at
90% compaction (ASTM D1557-12), some settlement of the backfill may be anticipated.
Accordingly, any utilities supported therein should be designed to accept differential settlement,
particularly at connection points to the structure.
In order to reduce the amount of backfill required, the foundations may be cut neat and poured against
the excavated fill soils.
6.2.6 Light Pole Foundations
Dense to very dense formational materials were encountered in the borings to the maximum depth
explored of 16'/2 feet. Individual piers should be adequate to support the lighting pole foundations.
Embedment depth and diameter for the lighting pole piers to resist lateral loads where no-
constraint is provided at ground surface may be determined using the following formula per 2013
CBC Section 1807.3.2.1:
d = A/2 {1 + [1+(4.36h/A)]v2}
Where:
A= 2.34P/Sib
b = Pier diameter in feet
d = Embedment depth in feet (but not over 12 ft for purpose of computing
lateral pressure)
h = Distance in feet from ground surface to point of application of "P"
P = Applied lateral force in pounds
= Allowable lateral soil bearing pressure $ = 400 psf/ft. (Table 1806.2 for
Class 2 soil and Section 1806)
An allowable soil vertical bearing pressure of 4,000 pounds per square foot may used in the design
of the piers at least 2 feet in diameter and extending at least 3 feet below the lowest adjacent grade.
The values provided are for the dense to very dense undisturbed formational materials.
Excavations may need to be deepened to obtain the desired resistance.
Installation: The drilled pier shall be placed in conformance to ACT 336 guidelines. Excavation
for piers should be inspected by the geotechnical consultant. The bottom of the excavation for piers
should be reasonably free of loose or slough material. A tremie pipe should be used to pour
concrete from the bottom up and to ensure less than five feet of free fall.
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6.3 EXCAVATION
Temporary unsurcharged vertical excavations less than 5 feet in height may be excavated without
shoring. Where the necessary space is available, temporary unsurcharged excavations may be sloped
back in lieu of using shoring. Temporary unsurcharged excavations may be sloped back at 1:1
(horizontal to vertical). The exposed excavations should be observed by a competent geotechnical
firm so that modifications of the excavation criteria may be made if necessary. All applicable
requirements of the local governments, the Occupational Safety and Health Act of 1970, and the
Construction Safety Act should be met. Conventional earth moving/excavation equipment may be
used to excavate the on-site materials.
6.4 GRADING
6.4.1 General
According to the available information, the site was graded during earthwork performed during
construction of the park by cutting into the previously existing topography. Dense to very dense
formational materials were encountered at the boring locations. These materials have a low expansion
potential.
The proposed facilities may be supported on the dense to very dense undisturbed formational
materials. Prior to placement of fills or improvements, any fill soils, loose and/or disturbed natural
materials should be removed as to expose undisturbed formational materials. Within the proposed
building, the resulting voids may be backfilled with structural concrete or a 3-sack slurry fill.
The on-site sandstone materials have a low expansion potential and may be used as fill. Retaining
wall backfill should consist of non-expansive compacted fill.
The silty sandstone materials are dense to very dense and weakly to moderately cemented, heavy duty
earthmoving equipment in good working condition may be required to excavate the formational
materials.
To reduce moisture infiltration beneath the proposed improvements, site drainage should be provided.
Finish grates should be sloped to drain away from the features.
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6.4.2 Site Preparation and Compaction
After clearing the site, the exposed materials should be carefully observed to verify the complete
removal of unsuitable deposits. Prior to placement of any new fills or improvements, any existing top
soil, fills, debris, organic, material, expansive clays and soft or loose soils should be removed and
replaced. Voids within the formational materials may be backfihled with structural concrete or a 3-
sack slurry fill. A qualified geotechnical firm should observe the exposed materials to verify the
complete removal of unsuitable deposits.
Any required fill should be placed in loose lifts not more than 8 inches in. thickness. All fill soils
should be compacted to 90% of the maximum dry density (ASTM D1557-12). The moisture content
of the on-site or imported non-expansive fill soils at the time of compaction should vary no more than
2% below or above optimum moisture content.
For areas paved with pervious concrete, the subgrade soils should be compacted between 89% and
93% of the maximum dry density. If desired, in areas were overexcavation and recompaction are
needed, the overexcavated materials may be replaced with permeable base in lieu of compacted fill.
6.4.3 Material for Fill
Expansive soils (Expansion Index greater than 21) should not be used as fill beneath structures,
pavements or hardscaped areas. The on-site materials, less any debris, organic matter, contaminated
soils, and rocks greater than 6 inches in maximum dimension may be used as fill.
If required, imported fill soils should consist of relatively non-expansive soils with an Expansion
Index of less than 21, an angle of internal friction of at least 33°, and a minimum R-value of 40. The
material should contain sufficient fines (binder material) to result in a stable subgrade.
6.4.4 Grading Observation
The reworking of the upper soils and the compaction of all required fill should be observed and tested
by a qualified geotechnical engineering firm. Imported fill material should be approved prior to use
as fill.
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Aviara Community Park Expansion, Carlsbad, California Revised Final
6.5 SEISMIC DESIGN PARAMETERS
The materials beneath the site consist of dense to very dense silty sandstone and sandy siltstone.
Based on the results of the field explorations and geologic evaluation, stiff soil classification "C" was
assigned to the site. The coordinates of the proposed park are N33.1152* and Wi 17.28300.
The design of the proposed structures should be performed in accordance with the codes and
regulations appropriate to the project. As such we are providing the seismic design parameters in
accordance with the 2013 California Building Code (CBC), the following design parameters may be
used for design of the proposed improvements.
Ss = 108% g Maximum Considered Ground Motion for 0.2 second Spectral Response
Acceleration, 5% of Critical Damping, Site Class B
S1 = 42% g Maximum Considered Ground Motion for 1.0 second Spectral Response
Acceleration, 5% of Critical Damping, Site Class B
The following spectral acceleration factors may be used to develop the response spectra for the
deterministic Maximum Considered Earthquake.
Fa 1.0
F= 1.4
Sms = FaSs
Smi = FS1
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6.6 RETAINING WALLS
6.6.1 Lateral Pressures
For design of cantilevered retaining walls with heights of 15 feet or less, where the backfill consists of
on-site or non-expansive granular materials and the surface of backfill is level and well drained, it
may be assumed that the on-site non-expansive soils will exert lateral pressures equal to that
developed by a fluid with a density of 40 pounds per cubic foot. Where wall rotation or movement is
not acceptable, we recommend that the walls below grade be designed for "at rest" pressures. When
considering "at rest" pressures where the surface of the retained earth is level it may be assumed that
the soils will exert an equivalent fluid pressure of 58 pounds per cubic foot. For backfihls sloped back
2:1, the lateral active pressure may be assumed equal 60 pounds per cubic foot. The at rest pressure
may be assumed that the soils will exert a pressure of 87 pounds per cubic foot.
6.6.2 Backfill
All required backfill should be mechanically compacted in layers not more than 8 inches in loose
thickness; flooding should not be permitted. Compaction of the backfill as recommended will be
necessary to reduce settlement of the backfill and of overlying slabs, walks, and paving and to reduce
infiltration of surface water into the backfill. The backfill should be compacted to at least 90% of the
maximum density obtainable by the ASTM Designation Dl 557-12 method of compaction.
6.6.3 Drainage
If the backfill is placed and compacted as recommended and good surface drainage is provided,
infiltration of water into the backfill adjacent to the proposed retaining walls should be small. To
reduce the potential for water entrapment, surface and subsurface drains behind all retaining walls are
recommended.
Weep holes, backdrains, or other drainage measures should be provided in retaining walls to reduce
the potential for entrapment of water in the backfill behind the walls. Adequate drainage of adjacent
planters should be provided to prevent water infiltration into wall backfihls. Drainage could consist of
vertical gravel drains about 12 inches wide connected to a 4-inch-diameter perforated pipe. The
perforated pipe should be surrounded by at least 1 foot of filter gravel (or uniformly graded gravel or
Class II permeable material) wrapped in a geosynthetic filter fabric, such as Mirafi 140 N.S. The
drain pipe should be located near the base of the wall and should discharge in a controlled manner
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away from the proposed structures. As an alternative to the vertical gravel drains, a drainage
geocomposite such as Miradrain may be used.
To reduce the potential for soil loss through the gravel drain, we recommend that a filter compatible
with the backfill materials be placed between the gravel drain and the backfill. The filter requirement
may be evaluated when the source for backfill materials is determined.
6.7 SLOPES AND EROSION CONTROL
Local topography slopes down to the north, east and west, beyond the fenced area. Concrete drainage
swales were observed along the slopes.
To reduce the potential for erosion of the slope faces, permanent erosion control and drainage devices
should be provided as soon as feasible after grading. Slope erosion, including sloughing, riling and
slumping of surface soils may be anticipated if the slopes are left unprotected for a long period of
time, especially during the rainy season. Erosion control may include, but may not be limited to:
erosion resistant vegetation and/or erosion control geofabrics. Slopes should be planted with
appropriate drought-resistant vegetation as recommended by a landscape architect. Slopes should not
be over-irrigated.
Drainage devices designed to carry surface water from overlying areas should not be blocked or
destroyed, and should be maintained regularly. Water should be prevented from ponding in pad areas,
or from overtopping and flowing down graded or natural slopes. Concrete drainage swales should be
installed at a minimum at the top of the slopes to prevent surface runoff over the top of the slope and
to reduce the erosion at the face and toe of the slope.
Animal burrows can serve to collect normal sheet flow on slopes and cause rapid and destructive
erosion, and should be controlled or eliminated.
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6.8 FLOOR SLAB SUPPORT
If the soils are prepared as recommended, concrete slabs-on-grade may be supported entirely on the
undisturbed formational materials.
To reduce the potential for water entrapment and to provide protection against vapor or water
transmission through the slabs, we recommend that, at a minimum, the slabs-on-grade be underlain
by a layer of Caltrans Class 2 permeable material or crushed rock at least 6 inches thick. A suggested
gradation for the gravel layer is as follows:
Suggested Gravel Gradation
Percent Passing Sieve Size
3/4 90-100
No.4 0-10
No. 100 0-3
To provide additional protection against water vapor transmission through the slab in areas where
vinyl or other moisture-sensitive floor covering is planned, we recommend that a durable 10-mil-
thick impermeable membrane such as Stego Wrap, Perminator or equivalent be installed below the
slab. The vapor barrier should be installed in accordance with the manufacturer's instructions. We
recommend that at least a 2-foot lap be provided at the membrane edges or that the edges be sealed.
As an alternative to the gravel layer, a 4-inch layer of clean concrete sand may be used. To provide
additional protection against water vapor transmission through the slab in areas where vinyl or other
moisture-sensitive floor covering is planned, we recommend that the impermeable layer be placed
over the sand layer.
Care should be taken during concrete placement to prevent displacement of the sand. A low-slump
concrete (4-inch maximum slump) should be used to further minimize possible curling of the slabs.
The concrete slabs should be allowed to cure properly before placing vinyl or other moisture-sensitive
floor covering.
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Concrete slab thickness should be provided in accordance with the anticipated use and loadings on the
slab and as recommended by the Structural Engineer. As a minimum, slabs-on-grade should be 4
inches in thickness and shall contain No. 3 reinforcing bars placed at mid-height in the slab at 18
inches on center both horizontal directions. These recommendations are minimums only and should
be verified by the Structural Engineer. The required thickness and reinforcing of the concrete slabs
will depend on the imposed loadings as well as the structural characteristics of the concrete.
Construction joint spacing and placement should be provided by the Structural Engineer.
Concrete Flatwork
A minimum thickness of 4 inches is recommended for all concrete walks and slabs. Flatwork
reinforcement should consist of a minimum No. 3 bars with an 18-inch spacing in both directions
and placed at slab mid-height. Final reinforcement configuration should be provided by the
structural engineer. A minimum 28-day concrete compressive strength of 2,500 pounds per square
inch is recommended for pedestrian sidewalks and other non-traffic hardscaped areas. If pervious
concrete is used in pedestrian walkways, we recommend that a minimum of 4'/2 inches of pervious
concrete over 4 inches of aggregate base be used.
Weakened plane joints should be placed in sidewalks at intervals that are no greater than 15 feet on
center. Weakened plane joints should beat least 1-inch deep. Full depth construction joints should be
placed at 45 feet intervals. Rectangular patio areas should have weakened plane joints at 10 feet on
center in both directions. Expansion joint material should be placed adjacent to any vertical surfaces
(walls, buildings or columns).
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6.9 PAVING
Tests performed on a sample of the on-site soils indicated an R-value of 13. The test results are
presented in the Appendix. For purposes of pavement design, it was assumed that the subgrade will
consist of undisturbed formational materials. The pavement thickness should be confirmed prior to
construction so that any required modifications may be made based on the actual fill materials to be
used.
To provide support for paving, the subgrade soils should be prepared as recommended in the previous
sections on Grading. Compaction of the subgrade to at least 90%, including trench backfills, will be
important for paving support.
For areas paved with pervious concrete, the subgrade soils should be compacted between 89% and
93% of the maximum dry density (ASTM D1557). If desired, in areas were overexcavation and
recompaction are needed, the overexcavated materials may be replaced with permeable base in lieu of
compacted fill.
Asphalt Paying
A Traffic Index of 5 was assumed for design of the proposed pavements. The assumed traffic
includes automobile and light truck traffic such as the maintenance trucks. If heavy trucks, such as
fire trucks are anticipated the pavement sections should be revised to include the heavier loads.
Paving sections for areas subject to automobile traffic (Traffic Index of 5) should be at least 4 inches
of asphalt paving over 6 inches of aggregate base (AB).
The aggregate base should meet the specifications for Class 2 Aggregate Base as defined in Section
26 of the 2010 State of California, Department of Transportation, Standard Specifications.
Alternatively, the base course could meet the specifications for untreated base as defined in Section
200-2 of the 2012 edition of the Standard Specifications for Public Works Construction. The base
course should be compacted to at least 95%. Careful inspection should be performed to verify that the
recommended thickness or greater are achieved and that proper construction procedures are used.
Page 16
Schmidt Design Group G2015012-1
Aviara Community Park Expansion, Carlsbad, California Revised Final
Concrete Paving
In completing the design we have assumed that the conventional portland cement concrete (PCC)
pavement will have a 28-day flexural strength of 650 pounds per square inch or a compressive
strength of at least 4,000 pounds per square inch. The aggregate base should meet the specifications
for aggregate base as described above.
The pervious concrete pavement (PCP) sections provided were developed based on the Caltrans
design guidelines. A void content of 22% or less and a compressive strength of 2,500 pounds per
square inch are recommended for the pervious concrete. Placement and testing of the pervious
concrete should be completed in accordance with the Caltrans Specifications.
Table 2, Concrete Pavement
Traffic Subgrade PCC' Pervious Concrete'
Automobile and On-site compacted fill 8W'PCC + 12" AB 6" PCP + 9" PAB
light truck traffic Imported fill (R-value > 40) 8W'PCC + 6" AB 6" PCP +6 PAB
Heavy trucks On-site compacted fill 8Y2"PCC + 12" AB 6" PCP + 11" PAB
(maintenance
trucks) Imported fill (R-value > 40) 8'/2"PCC + 6" AD 6" PCP ± 9" PAB
'Caltrans Design Criteria
PCC - Portland Cement Concrete Pavement
AB - Caltrans Class 2 Aggregate Base
PCP - Pervious Concrete Pavement
PAB - Pervious Aggregate Base
The pervious aggregate base should meet the specifications for Class 4 Aggregate Base as defined in
the Special Provisions of Section 26 of the 2010 State of California, Department of Transportation,
Standard Specifications. Alternatively, the base course could meet the gradation of ASTM No. 57
stone. A filter fabric such as Mirafi HP270 or equivalent is recommended between the subgrade and
the aggregate base. The geotextile is not required in areas subject to pedestrian traffic only. A
schematic representation is presented below.
Page 17
Schmidt Design Group G2015012-i
Aviara Community Park Expansion, Carlsbad, California Revised Final
Pervious Concrete
Pervious Base
Filter Fabric (HP270)
Non-expansive I
compacted fill 12" (min fill) or
undisturbed formational
Undisturbed formational
(NOT TO SCALE)
Pervious Concrete Pavement
Due to the low infiltration characteristics of the on-site materials, additional drainage devices such as
the use of collector pipes may be required.
7.0 SOIL CORROSWITY
Based on the laboratory test results, the on-site soils have low sulfate ion concentrations (730 parts per
million (ppm) and low concentrations of chloride ions (170 ppm). The test results are presented on
Plate A-7, Corrosion Test Data. Therefore Type I, II or V cement may be used during construction.
Concrete should be thoroughly vibrated. Laboratory tests show a very low resistivity value (500.
ohm-cm), indicating a very severe potential for metal loss due to electrochemical corrosion processes.
Therefore, a minimum concrete cover of 3 inches should be provided over all re-bar, anchor bolts or
metallic embeds placed within the foundations and to 18 inches above the ground surface.
Reinforcing steel should be protected with a concrete cover of at least 1 /2 inches for formed surfaces
not exposed to weather or not in contact with the ground. If the minimum cover is not achieved
corrosion protection of steel members such as epoxy or asphalt coatings may be used. We
recommend that a corrosion engineer be consulted for final corrosion protection
recommendations.
Page 18
Schmidt Design Group G2015012-1
Aviara Community Park Expansion, Carlsbad, California Revised Final
8.0 BASIS FOR RECOMMENDATIONS
The recommendations provided in this report are based on our understanding of the described project
information and on our interpretation of the data collected during the subsurface exploration. We
have made our recommendations based on experience with similar subsurface conditions under
similar loading conditions. The recommendations apply to the specific project discussed in this
report; therefore, any change in the facility loads, expected traffic conditions, facility location, or site
grades shall be provided to us so we may review our conclusions and recommendations and make any
necessary modifications.
We request an opportunity to review the final construction documents and specifications for the
proposed facility to verify that the recommendations presented are incorporated into the final design.
The recommendations provided in this report are also based on the assumption that the necessary
geotechnical observations and testing during construction will be performed by representatives of our
firm. The field observation services are considered a continuation of the geotechnical investigation
and essential to verify that the actual soil conditions are as anticipated. This also provides for the
procedure whereby the Client can be advised of unanticipated or changed conditions that would
require modifications of our original recommendations. In addition, the presence of our
representatives at the site provides the Client with an independent professional opinion regarding the
geotechnical related construction procedures. If another firm is retained for the geotechnical
observation services, our professional responsibility and liability would be reduced to the extent that
we are no longer the engineer of record.
Page 19
SITE PLAN
Z. - .V.F' -
V-V - V - - .2 • - S - S -
-. V. - • V - - - -
-• t..-._.. .. V PROPOSED
AVIARA COMMUNITY PARK
EXPANSION
CARLSBAD, CALIFORNIA
:::;
-
•.S.VI . S S
V.-
V
r
V . V
V.55 V
(SCALE 1 = 60')
KEY:
AB-1
0 Approximate Boring Location
AP-1 A Approximate Percolation Test
Location
REFERENCE: Aerial Photograph (undated) provided by Schmidt Design Group 42 ENIMEMW INC.
PLATE 1
Schmidt Design Group G2015012-1
Aviara Community Park Expansion, Carlsbad, California Revised Final
APPENDIX A
FIELD EXPLORATIONS AND LABORATORY TESTS
Schmidt Design Group G2015012-1
Aviara Community Park Expansion, Carlsbad, California Revised Final
APPENDIX A
FIELD EXPLORATIONS AND LABORATORY TESTS
FIELD EXPLORATIONS
The soil conditions beneath the site were explored by drilling four borings and two percolation test
holes at the locations shown on Plate 1. The coordinates of the exploratory excavations are listed
in Table A-i. The borings and test holes were drilled to depths of 3 to 16Y2 feet using truck-mounted
hollow-stem auger drilling equipment with a 6-inch diameter auger. After completion of the
excavation, the exploratory excavations were backfilled using the excavated soils.
The soils encountered were logged by our field engineer, who obtained bulk samples for laboratory
observation and testing. A California-modified sampler was used to retrieve relatively undisturbed
samples. This sampler consisted of a brass-ring-lined split-tube with an inside diameter of 2-1/2
inches and an outside diameter of 3 inches. The hammer used to drive the sampler weighed 140
pounds, and a drop of about 30 inches was used. The number of blows required to drive the sampler
12 inches is indicated on the logs. The logs of the borings are presented on Plates A-1.1 through
A-i .4; the depths at which relatively undisturbed samples were obtained are indicated to the left of the
logs.
The soils are classified in accordance with the Unified Soil Classification System described on Plate
A-2.
LABORATORY TESTS
The field moisture content and dry density of the soils encountered were determined by performing
tests on the relatively undisturbed samples. The results of the tests are shown to the left of the boring
logs.
To aid in classifying the soils, one sample was tested to determine the percent passing the No. 200
sieve. The results are presented in the Boring Logs.
Page A-i
Schmidt Design Group G2015012-1
Aviara Community Park Expansion, Carlsbad, California Revised Final
Direct shear tests were performed on relatively undisturbed samples. The tests were performed at
various surcharge pressures after saturation. The peak point values determined from the direct shear
tests are presented on Plate A-3, Direct Shear Test Data.
The optimum moisture content and maximum dry density of the soils were determined by performing
a compaction test on a sample in accordance with ASTM D1557 method. The results of the test are
presented on Plate A-4, Compaction Test Data.
To provide information for paving design, a Stabilometer (R-value) test was performed on a sample of
the on-site soils. The test was performed in accordance with Standard 301 of the State of California
Department of Transportation. The test results are presented on Plate A-5, R-Value Test Data.
The Expansion Index of the on-site soils was determined by testing one sample in accordance with
ASTM D4829. The tests results are shown on Plate A-6, Expansion Index Test Data.
To evaluate the corrosion potential of the on-site soils, one soil sample was tested at an analytical
laboratory for pH, resistivity, sulfate and chloride content in accordance with the following standards.
Resistivity and pH - California Test 643
Soluble Chlorides - California Test 417
Soluble Sulfates - California Test 422
The test results are presented on Plate A-7, Corrosivity Test Data.
Page A-2
Schmidt Design Group G2015012-1
Aviara Community Park Expansion, Carlsbad, California Revised Final
Table A-i,
Exploratory Excavations Coordinates
Excavation No.
Coordinates
Latitude Longitude
AB-1 33.11530 117.28320
AB-2 33.11550 117.28310
AP-3 33.11550 117.28260
AB-4 33.11520 117.28300
AP-1 33.11550 117.28310
AP-2 33.11520 117.28300
Page A-3
— U) BORING AB-1
— -
Cl) 0 —
2 O
2 cc - U. -JO
I— 1 4 uJ
DATE DRILLED: 8/11/2015
EQUIPMENT USED: 6-Diameter Hollow-stem-auger
uJ C !)
*
— — — — — — — ELEVATION — Z SM TERRACE DEPOSITS (Qt4) .;
SILTY SANDSTONE - fine grained, moderately cemented, 4.8 108 98
.: very dense, moist, reddish brown : Light yellowish brown and light greyish brown
7.4 ill 93 Light greyish brown
5 .;
7.8 118 76 :
NOTES: Groundwater not encountered. No caving. Boring
backfilled with soil cuttings.
4.4.BLOWS/FOOT - Number of blows required to drive the
sampler 12 inches using a 140-pound hammer with a 30-inch
drop.
20
25
30
35
40
LOG OF BORING
0~ 4V2 =11mmi
DI AT ILl I
10
15
-
-
BORING AB-2
— a C) z o 2 U.
p — LU EoCl)>w
— z DATE DRILLED: 8/11/2015
w >---J- EQUIPMENT USED: 6-Diameter Hollow-stem-auger
uJ — *U)
*
— — — — —
*(/)
— — ELEVATION —
; SM TERRACE DEPOSITS (Qt4)
: SILTY SANDSTONE - fine to medium grained, moderately
100 cemented, dense to very dense, moist, light reddish brown
and light yellowish brown
Some gravel and cobbles 8.5 107 100 Light yellowsih brown
.5 --
8.2 I 115 I 97
Weakly to moderately cemented, light greyish brown
10
I --- I 92 I VI[l1 I Very dense
Light reddish brown
15
11.9 1 104 I 100 I Light grey
NOTES: Groundwater not encountered. No caving. Boring
20 backfilled with the soil cuttings.
25
30
35
40
LOG OF BORING
PlATA..1
—
2 o
'U -1
*
—
—
CL
—
>
-
U) (D 2
—
'U
w -
—
uj
—
U)
z
—
o-
—
BORING AB-3
DATE DRILLED: 8/11/2015
EQUIPMENT USED: 6-Diameter Hollow-stem-auger
ELEVATION — SM TERRACE DEPOSITS (Qt4)
SILTY SANDSTONE - medium grained, dense, weakly to
8.0 112 73 I moderately cemented, moist, light orangish brown
Very dense
4- Fine to medium grained, very dense, some Clay, light brown o o -
8.3 114 80 I
5
8.7 119 100 J - Moderately cemented, some oxide staining, light greyish 0 brown and light grey 0
4-
LU >v
4- 0
C 10 - - X o
o NOTES: Groundwater not encountered. No caving. Boring C E backfilled with soil cuttings.
oc —o
CC
1.00
.c o
15
F—
- -
LU 5'-
U
- 20 - og
0.0
I- o 25 -
-
0
0 .0 30 - - - - -
U 0 4-
H
0 35 - - -—C
-F-
00 4-
40 - - - -
D -)
LOG OF BORING
01 AT A..1 '
- BORING AB-4 - —JQ IU)
2 - Z --
0. a Ci) — _
W _j
. DATE DRILLED: 8/11/2015 >
OR
- co L 4x EQUIPMENT USED: 6-Diameter Hollow-stem-auger
LU — *(I)
*
— — — — —
*c,)
— — ELEVATION — SM TERRACE DEPOSITS (Qt4)
SILTY SANDSTONE - fine to medium grained, weakly to
6.3 99 84 I moderately cemented, very dense, moist, light orangish
brown and light yellowish brown a,
5.9 103 100 Fine grained
0 1 Light greyish brown .5
a, 79 p
4- .4 4- :
IJ C
:
.10 -----------—::
.2 . 9.2 104 95 I :i Fine to medium grained, moderately cemented, grey and light
greyish browm
—a, .:
.4
.0
15
9.1 --- 100 j -
Light grey
CL
a,,..
a, ° NOTES: Groundwater not encountered. No caving. Boring
C 20 backfilled with soil cuttings. -
(ao
CL
CL
- .c .u- 25
8
-
ga, .0 30--------
a, u a,4-
.4- 0
0) 4- g - .2 35 - -
a, (8 'J..-
a, 4-
pj 1 1-40
D -)
LOG OF BORING
DI AT ILl &
MAJOR DIVISIONS GROUP TYPICAL NAMES SYMBOLS
- GW Well graded gravels or gravel - sand mixtures,
CLEAN GRAVELS :ä GRAVELS
little or no fines.
(Li le or no fines) . Poorly graded gravels or gravel - sand mixtures,
coarse
(More than 50% of
•.. GP little or no fines.
fraction is ,W'i GRAVELS GM Silty gravels, gravel - sand - silt mixtures. COARSE LARGER than the WITH FINES
GRAINED No. 4 seive size) (Appreciable
SOILS amount of fines) GC Clayey gravels, gravel - sand - clay mixtures.
(More than 50% of
material is Well graded sands, gravelly sands,
LARGER than No. SANDS CLEAN . SW little or no fines.
20 sieve size) (More than 50% of SANDS
(Little or no fines) : Poorly graded sands, gravelly sands, coarse little or no fines. fraction is
SMALLER than SANDS
JJ
SM Silty sands, sand - silt mixtures. the No. 4 seive WITH FINES
size) (Appreciable
amount of fines SC Clayey sands, sand - clay mix
ML
tures. )
clayey fine sands or clayey silts with slight plasticity.
FINE
Inorganic silts and very fine sands, rock flour, silty or
SILTS AND CLAYS CL Inorganic clays of low to medium plasticity, gravelly clays,
GRAINED (Liquid limit LESS than 50) sandy clays, silty clays, lean clays.
SOILS = : OL Organic silts and organic silty clays of low plasticiy. (More than 50% of
material is
- rvii-i Inorganic silts, micaceous or diatomaceous SMALLER than fine sandy or silty soils, elastic silts. No. 200 sieve
size) SILTS AND CLAYS CH Inorganic clays of high plasticity, fat clays. (Liquid limit GREATER than 50)
OH Organic clays of medium to high plasticity,
organic silts.
HIGHLY ORGANIC SOILS Z Pt Peat and other highly organic soils.
BOUNDARY CLASSIFICATIONS: Soils possessing characteristics of two groups are designated by combinaions of group symbols.
PARTICLE SIZE LIMITS
No. 200 No. 40 No.10 No. 4 3/4" 3" 12'
US STANDARD SIEVE SIZE
Key:
California Sampler Continuous Auger Coring
Standard Penetration rn [1J HQ Coring
No Recovery Bulk or Chunk Sample ENGINEERING, INC. OEOTI!GKNICAI. CONS&TANTS
t
6 0
t
SILT OR CLAY SAND GRAVEL I I
Fine Medium I Coarse I Fine I Coarse COBBLES BOULDERS
PLATE A-2
SHEAR STRENGTH in Pounds per Square Foot
0 1000 2000 3000 4000 5000 6000
0
AB-3@ I
1000
AB-3@I'
co 2000
Cl)
0.
Ch
AB-3@I'
3000
VALUES USED IN
\ ANALYSIS
CL
w4000
5000
6000
KEY:
A Relatively undisturbed samples
All samples tested after saturation
SHEAR SUMMARY
4 ENGINaffiNG, INC. Job No. G2015012-1
PLATE A-3
BORING NUMBER AND
SAMPLE DEPTH AB-2 @ 0-3'
SOIL TYPE SILTY SANDSTONE
MAXIMUM DRY DENSITY 128
(lbs per cubic foot)
OPTIMUM MOISTURE
CONTENT
(% of dry weight)
COMPACTION TEST DATA
(ASTM D1557)
Job No. G2015012-1 4fEN6NEERING, INC.
PLATE A -4
BORING NUMBER AND
SAMPLE DEPTH
SOIL TYPE
R-VALUE
by Exudation
by Expansion
at Equilibrium
AB-3 @ 0 - 2-1/2'
SILTY SANDSTONE
13
48
13
R-VALUE TEST DATA
(ASTM D1557)
Job No. G2015012-1
46~ENGINEENNG, INC.
PLATE A -5
BORING NUMBER AND
SAMPLE DEPTH AB-3 @ 0 - 2-1/2'
SOIL TYPE SILTY SANDSTONE
FINAL MOISTURE
CONTENT
DRY DENSITY
(in pounds per cubic foot)
EXPANSION INDEX
EXPANSION POTENTIAL
16.8
110
7
VERY LOW
EXPANSION INDEX TEST DATA
(ASTM D4829)
Job No. G2015011-1 4 \ENGINEERING, INC.
PLATE A-6
BORING NUMBER
AND SAMPLE DEPTH AB-3 @ 0-2-1/2 Caltrans Method
SILTY
SOIL TYPE SANDSTONE
pH 5.5 643
Resistivity
(in ohms-cm) 500 643
Soluble Sulfate
(%) 0.073 417
Soluble Chloride
N . 0.017 422
CORROSIVITY TEST DATA
I%\ENGINEERING, INC.
Job No. G2015012-1
PLATE A-7