HomeMy WebLinkAboutParcel Map 13901 Parcel 3 Geotechnical Rough Grading
.1 IE INLAND, INC.
I. Geotechnical Consulting
1
I
I
I
I
1
1
I
I
I
I
I
I
I
II
I
I 40935 County Center Drive' Suite A' Temecula, CA 92591 . (951) 719-1076 . Fax (951) 719-1077
GEOTECHNICAL REPORT OF ROUGH GRADING
PROPOSED SINGLE FAMILY RESIDENCE
PARCEL 3 OF PARCEL MAP 13901, ASSESSORS
PARCEL NUMBER 945-120-008, LA PRESS A
LOOP, CITY OF TEMECULA
RIVERSIDE COUNTY
CALIFORNIA
Project No. 105908-30
Dated: May 18, 2005
Prepared For:
MR. KEVIN McDANIEL
1731 W. Lincoln Avenue
Anaheim, California 92801
\
.
I
'.
May 18, 2005
.
I
I Subject:
I
I
I
I
I
I
I
I
I
I
I
I
V
I 40935 County Center Drive' Suite A' Temecula, CA 92591 . (951) 719-1076 . Fax (951) 719-1077
IE INLAND, INC.
Geotechnical Consulting
Project No. IOS908-30
MR. KEVIN McDANIEL
1731 West Lincoln Avenue
Anaheim, California 92801
Geotechnical Report of Rough Grading, Proposed Single Family Residence, Parcel 3 of Parcel
Map 13901, Assessor's Parcel Number 945-120-008, La Pressa Loop, City ofTemecula, Riverside
County, California
References:
Gunvant Thakkar, P.E., Grading Plan, Parcel 3 of P.M 13901, La Pressa Loop, 30-Scale, dated May 26,
2005.
International Conference of Building Officials, 1997, Uniform Building Code, SIn/ctural Engineering Design
Provisions.
This report presents a summary ofthe observation and testing services provided by LGC inland, Inc., (LGC) during
rough grading operations to develop the subject site located at Parcel 3 of Parcel Map 13901, Assessors Parcel
Number 945-120-008, on La Pressa Loop in the City ofTemecula, Riverside County, California. Conclusions and
recommendations pertaining to the suitability of the grading for the proposed residential construction are provided
herein, as well as foundation design recommendations based on the as-graded soil conditions.
The purpose of grading was to develop a pad for construction of a single family residence. The proposed structure
will be one- and two-story with wood or steel-framed construction and concrete slab on grade. Grading on the
subject pad began on April 24, 2005 and was completed on April 29, 2005. The grading generally conformed to the
proposed building location shown on the original precise grading plan. The As-Graded Geotechnical Map, Plate I,
reflects "as-built" conditions based on information obtained by our field technician using crude measuring
instruments and is for the purpose of locating our field density tests.
1.0
REGULATORY COMPLIANCE
Removal and recompaction oflow-density surface soils, processing of the exposed bottom surfaces or placement of
compacted fill under the purview ofthis report have been completed under the observation and with selective testing
by LOC. Earthwork and grading operations were performed in general accordance with the recommendations
presented in the referenced reports (see References) and the Grading Code of the City ofTemecula, California. The
completed earthwork has been reviewed and is considered adequate for the construction now planned. On the basis
of our observations and field and laboratory testing, the recommendations presented in this report were prepared in
conformance with generally accepted professional engineering practices and no further warranty is expressed or
implied.
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
2.0 ENGINEERING GEOLOGY
2.1 General
Oeologic conditions exposed during the process of grading were frequently observed and mapped by LOC's
technical staff.
2.2 Geolordc Units
Earth materials within the site included artificial fill, Quarternary alluvium consisting of fine to coarse sands
and silts and Pauba Formation bedrock.
2.3 Groundwater
During overexcavations, no free groundwater was encountered.
2.4 Faultinl!
No faults were observed during grading operations on the site.
3.0 SUMMARY OF EARTHWORK OBSERVATIONS AND DENSITY TESTING
3.1 Site Clearinl! and Grubbinl!
Prior to grading, all grasses and weeds were stripped and removed from the site.
3.2 Ground Preparation
The purpose of this grading operation was to remove and recompact existing low density fills and-to provide
a compacted fill mat under the building site. Removals throughout the remaining portion of subject site
varied from approximately 2 to 4 feet below original grades, with locally deeper removals.
Prior to placing fill, the exposed bottom surfaces were scarified to depths of 6 to 8 inches, watered or
air-dried as necessary to achieve at or slightly above optimum moisture content and then recompacted in-
place to a minimum relative compaction of 90 percent. Moisture conditions at the exposed depths were
generally below optimum moisture content.
Fill was placed on competent Pauba Formation bedrock to design grade.
Once the exact location of building footprints are known, additional overexcavation will be needed to
eliminate any "cut-fill transition" in order to provide a uniform compacted fill mat beneath the building(s).
3.3 Disposal of Oversize Rock
Oversize rock (rock generally greater than I-foot in maximum dimension) was not encountered during the
removal operations.
J
ProjecINo.105908-30
Page 2
May 17, 2005
I
I
I
I
I
I
I
I
I
,I
I
I
I
I
I
I
I
I
I
3.4 Fill Placement and Testinl!
Fill materials consist of onsite soils. All fills were placed in lifts restricted to approximately 6 to 8 inches in
maximum thickness, watered or air-dried as necessary to achieve near optimum moisture conditions, then
compacted in-place to a minimum relative compaction of90 percent by rolling with a bulldozer or loaded
water truck. The maximum vertical depth of fill placed within the subject pad as a result of grading is
approximately ISio feet.
Field density and moisture content tests were performed in accordance with ASTM Test Methods D2922 and
D30l7 (nuclear gauge). Test results are presented on Table I (attached) and test locations are shown on the
enclosed As-Oraded Oeotechnical Map (Plate I).
Field density tests were taken at vertical intervals of approximately I to 2 feet and the compacted fills were
tested at the time of placement to verify that the specified moisture content and minimum required relative
compaction of90 percent had been achieved. At least one (I) in-place density test was taken for each 1,000
cubic yards of fill placed and/or for each 2 feet in vertical height of compacted fill. The actual number of
tests taken per day varied with the project conditions, such as the number of earthmovers (scrapers) and
availability of support equipment. When field density tests produced results less than the required minimum
relative compaction of 90 percent, the approximate limits of the substandard fill were established. The
substandard area was then reworked or removed, moisture conditioned, re-compacted, and retested until the
minimum relative density was achieved.
Visual classification of earth materials in the field was the basis for determining which maximum dry density
value, summarized in Appendix A, was applicable for a given density test. One-point checks were
periodically performed to supplement visual classification.
3.5 Slopes
Slopes constructed within the subject house pad consist of low height 2: I horizontal to vertical (h:v) fill
slopes varying up to a maximum height of 20ic feet and low height 2: I (h:v) cut slopes varying up to a
maximum height of I Oic feet. Prior to constructing fill slopes, fill keys were excavated a minimum of2 feet
into the underlying bedrock. The fill key bottoms were constructed back into the slope and were a minimum
of I y, times the equipment width wide.
The cut slopes exposed competent materials and are considered stable in their current configuration.
4.0 LABORATORY TESTING
4.1 Maximum Drv Densitv
Maximum dry density and optimum moisture content for the major soil types observed during grading were
determined in our laboratory in accordance with ASTM Test Method DI557-00. Pertinent test values are
summarized in Appendix A.
Projecl No. 105908-30
Page 3
May 17, 2005
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
4.2 Expansion Index Tests
Expansion index tests were performed on representative samples of soil existing at or near finish pad grade
within the subject pad. These tests were performed in accordance with ASTM D4829. Test results are
summarized in Appendix A.
4.3 Soluble Sulfate Analvses
Water soluble sulfate contents were also determined for representative samples of soil existing at or near pad
grade of the subject pad in accordance with California Test Method No. 417. These tests resulted in
negligible sulfate contents ofless than 0.1 percent. Test results are summarized in Appendix A.
5.0 POST GRADING CONSIDERA TIONS
5.1 Landscapinl! and Mailltellallce of Graded Slopes
The slopes within the subject lot vary up to a maximum height of less than 20 feet. Unless long term
mitigation measures are taken, the slopes may be subject to a low to moderate degree of surficial erosion or
degradation during periods of heavy rainfall. Therefore, it is recommended that the slopes be landscaped
with a deep rooted, drought resistant, woody plant species. To provide temporary slope protection while the
woody materials mature, the slopes should be planted with an herbaceous plant species that will mature in I
season or provided with some other protection, such as jute matting or polymer covering. The temporary
protection should be maintained until the woody material has become fully mature. A landscape architect
should be consulted to determine the most suitable plant materials and irrigation requirements.
To mitigate future surficial erosion and slumping, a permanent slope-maintenance program should be
initiated. Proper slope maintenance must include regular care of drainage- and erosion-control provisions,
rodent control, prompt repair ofleaking irrigation systems and replacement of dying or dead plant materials.
The irrigation system should be designed and maintained to provide constant moisture content in the soils.
Over watering, as well as over drying, of the soils can lead to surficial erosion and/or slope deterioration.
Potential problems can develop when drainage on the pad and adjacent slopes is altered in any way.
Drainage can be adversely altered due to the placement of fill and construction of garden walls, retaining
walls, walkways, patios, swimming pools and planters.
5.2 Pad Draillal!e
Drainage on the pad should be designed to carry surface water away from all graded slopes and structures.
Pad drainage should be designed for a minimum gradient of2 percent with drainage directed to the adjacent
streets. After the dwelling is constructed, positive drainage away from the structure and slopes should be
provided on the lot by means of earth swales, sloped concrete flatwork and area drains.
l\
ProjecINo.105908-30
Page 4
May 17, 2005
I
I
I
I
I
I
I
I
I
II
II
I
I
I
I
I
I
I
I
I
5.3 Utilitv Trellches
All utility trench backfill within street right-of-ways, utility easements, under sidewalks, driveways and
building floor slabs and within or in proximity to slopes, should be compacted to a minimum relative
compaction of 90 percent. Where onsite soils are utilized as backfill, mechanical compaction will be
required. Density testing, along with probing, should be performed by a LGC representative to verify
adequate compaction. Excavations for trenches that exceed 4 feet in depth should be laid-back at a
maximum gradient of I: I (h:v).
For deep trenches with vertical walls, backfills should be placed in lifts no greater than 8 inches in thickness
and then mechanically compacted with a hydra-hammer, pneumatic tampers or similar equipment. For deep
trenches with sloped walls, backfill materials should be placed in lifts no greater than 8 inches and then
compacted by rolling with a sheepsfoot tamper or similar equipment.
To avoid point-loads and subsequent distress to clay, cement, or plastic pipe, sand bedding should be placed
at least I-foot above all pipe in areas where excavated trench materials contain significant cobbles.
Where utility trenches are proposed parallel to any building footing (interior and/or exterior trenches), the
bottom of the trench should not be located within a I: I (h:v) plane projected downward from the outside
bottom edge of the adjacent footing.
6.0 FOUNDATION DESIGN RECOMMENDATIONS
6.1 Gelleral
Conventional shallow foundations are considered feasible for support of the proposed residential structure.
Foundation recommendations are provided herein. LOC does not recommend placing structures across
cut/fill transitions without special precautions being taken which can be provided upon request.
6.2 Allowable Bearillf! Values
An allowable bearing value of 1,500 pounds per square foot (pst) is recommended for design of 24-inch
square pad footings and 12-inch wide continuous footings founded at a minimum depth of 12 inches below
the lowest adjacent final grade. This value may be increased by 20 percent for each additional I-foot of
width and/or depth to a maximum value of2,SOO psf. Recommended allowable bearing values include both
dead and live loads and may be increased by one-third when designing for short duration wind and seismic
forces.
6.3 Settlemellt
Based on the general settlement characteristics of the soil types that underlie the building site and the
anticipated loading, it has been estimated that the maximum total settlement of conventional footings will be
less than approximately %-inch. Differential settlement is expected to be about \I,-inch over a horizontal
distance of approximately 20 feet, for an angular distortion ratio of I :480. It is anticipated that the majority
of the settlement will occur during construction or shortly thereafter as building loads are applied.
ProjecllVo.105908-30
Page 5
May 17, 2005
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
The above settlement estimates are based on the assumption that the project geotechnical consultant will
observe or test the soil conditions in the footing excavations.
6.4 Lateral Resistallce
A passive earth pressure of 250 psf per foot of depth to a maximum value of 2,500 psf may be used to
determine lateral bearing resistance for footings. Where structures are planned in or near descending slopes,
the passive earth pressure should be reduced to 150 psf per foot of depth to a maximum value of 1,500 psf.
In addition, a coefficient of friction ofOAO times the dead-load forces may be used between concrete and the
supporting soils to determine lateral sliding resistance. The above values may be increased by one-third
when designing for short duration wind or seismic forces.
The above values are based on footings placed directly against either compacted fill or excavated into
competent bedrock. In the case where footing sides are formed, all backfill placed against the footings
should be compacted to a minimum of 90 percent of maximum dry density.
6.5 Footilll! Observatiolls
All foundation excavations should be observed by the project geotechnical engineer to verify that they have
been excavated into competent bearing soils. The foundation excavations should be observed prior to the
placement offorms, reinforcement or concrete. The excavations should be trimmed neat, level and square.
All loose, sloughed or moisture softened soil should be removed prior to concrete placement.
Excavated materials from footing excavations should not be placed in slab-on-grade areas unless the soils
are compacted to a minimum 90 percent of maximum dry density.
6.6 Expansive Soil COllsideratiolls
Results of the laboratory tests indicate onsite soil and bedrock materials exhibit an expansion potential of
VERY LOW as classified in accordance with 1997 UBC Table l8-I-B.
6.6.1 Verv Low Expallsioll Potential (Expansiollll1dex of 20 or Less)
Since the onsite soils exhibit expansion indices of less than 20, the design of slab on ground
foundations is exempt from the procedures outlined in Section 1815. Based on the above soil
conditions, it is recommended that footings and floors be constructed and reinforced in accordance
with the following minimum criteria. However, additional slab thickness, footing sizes and/or
reinforcement should be provided as required by the project architect or structural engineer.
6.6.1.1 Footilll!s
.
Exterior continuous footings may be founded at the minimum depths indicated in UBC Table
18-I-C (i.e. 12-inch minimum depth for one-story and l8-inch minimum depth for two-story
construction). Interior continuous footings for both one- and two-story construction may be
founded at a minimum depth of 12 inches below the lowest adjacent grade. All continuous
footings should have a minimum width of 12 and 15 inches, for one-story and two-story
buildings, respectively, and should be reinforced with two (2) No.4 bars, one (1) top and one
(1) bottom.
-:5
ProjecIJVo.105908-30
Page 6
May 17, 2005
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
. Exterior pad footings intended for the support of roof overhangs, such as second story decks,
patio covers and similar construction should be a minimum of24 inches square and founded
at a minimum depth of 18 inches below the lowest adjacent final grade. No special
reinforcement of the pad footings will be required.
6.6.1.2 Buildill!! Floor Slabs
. Concrete floor slabs should be 4 inches thick and reinforced with either 6-inch by 6-inch,
No.6 by No.6 welded wire mesh (6x6-W2.9xW2.9); or with No.3 bars spaced a maximum
of24 inches on center, both ways. All slab reinforcement should be supported on concrete
chairs or bricks to ensure the desired placement near mid-depth.
. Concrete floor slabs should be underlain with a moisture vapor barrier consisting of a
polyvinyl chloride membrane such as 6-mil visqueen, or equivalent. All laps within the
membrane should be sealed, and at least 2 inches of clean sand be placed over the membrane
to promote uniform curing of the concrete.
. Oarage area floor slabs should be 4 inches thick and should be reinforced in a similar manner
as living area floor slabs. Oarage area floor slabs should also be placed separately from
adjacent wall footings with a positive separation maintained with %-inch minimum felt
expansion joint materials and quartered with weakened plane joints. A 12-inch wide grade
beam founded at the same depth as adjacent footings should be provided across garage
entrances. The grade beam should be reinforced with a minimum of two (2) No.4 bars, one
(l) top and one (I) bottom.
. Prior to placing concrete, the subgrade soils below all living area and garage area floor slabs
should be pre-watered to promote uniform curing of the concrete and minimize the
development of shrinkage cracks.
6.7 Corrosivitv to COllcrete and Metal
The National Association of Corrosion Engineers (NACE) defines corrosion as "a deterioration of a
substance or its properties because of a reaction with its environment." From a geotechnical viewpoint, the
"environment" is the prevailing foundation soils and the "substances" are the reinforced concrete
foundations or various buried metallic elements such as rebar, piles, pipes, etc., which are in direct contact
with or within close vicinity of the foundation soil.
In general, soil environments that are detrimental to concrete have high concentrations of soluble sulfates
and/or pH values of less than 5.5. Table 19-A-4 of the U.B.C., 1997, provides specific guidelines for the
concrete mix design when the soluble sulfate content of the soils exceeds 0.1 percent by weight or 1,000
ppm.
Based on testing performed within the project area, the onsite soils are classified as having a negligible
sulfate exposure condition in accordance with Table 19-A-4 ofU.B.C., 1997. Therefore, in accordance with
Table 19-A-4 structural concrete in contact with earth materials should have cement of Type 1 or 11.
4>
Projecl No. 105908-30
Page 7
May 17, 2005
I
i I
I
I
I
! I
II
I
I
I
I
I
I
I
I
I
I
I
I
Despite the minimum recommendation above, LGC is not a corrosion engineer, therefore, we recommend
that you consult with a competent corrosion engineer and conduct additional testing (if required) to evaluate
the actual corrosion potential of the site and provide recommendations to mitigate the corrosion potential
with respect to the proposed improvements. The recommendations of the corrosion engineer may supercede
the above requirements.
6.8 Structural Setbacks
Structural setbacks in addition to those required in the UBC, are not required due to geologic or geotechnical
conditions within the site. Building setbacks from slopes, property lines, etc. should conform to 1997 UBC
requirements.
7.0 RETAINING WALLS
7.1 Active alld At-Rest Earth Pressures
An active earth-pressure represented by an equivalent fluid having a density of 35 pounds per cubic foot
(pcf) should tentatively be used for design of cantilevered walls up to 10 feet high retaining a drained level
backfill. Where the wall backfill slopes upward at 2: I (h:v), the above value should be increased to 52 pcf.
All retaining walls should be designed to resist any surcharge loads imposed by other nearby walls or
structures in addition to the above active earth pressures.
For design of retaining walls up to 10 feet high that are restrained at the top, an at-rest earth pressure
equivalent to a fluid having a density of 53 pcf should tentatively be used for walls supporting a level
backfill. This value should be increased to 78 pcffor ascending 2:1 (h:v) backfill.
7.2 Draillafle
Weep holes or open vertical masonry joints should be provided in retaining walls to prevent entrapment of
water in the backfill. Weep holes, if used, should be 3 inches in minimum diameter and provided at
minimum intervals of 6 feet along the wall. Open vertical masonry joints, if used, should be provided at
32-inch minimum intervals. A continuous gravel fill, 12 inches by 12 inches, should be placed behind the
weep holes or open masonry joints. The gravel should be wrapped in filter fabric to prevent infiltration of
fines and subsequent clogging of the gravel. Filter fabric may consist of Mirafi 140N or equivalent.
In lieu of weep holes or open joints, a perforated pipe-and-gravel subdrain may be used. Perforated pipe
should consist of 4-inch minimum diameter PVC Schedule 40 or ABS SOR-35, with the perforations laid
down. The pipe should be embedded in I Y, cubic feet per foot of %- or I y,-inch open graded gravel wrapped
in filter fabric. Filter fabric may consist of Mirafi 140N or equivalent.
The backfilled side of the retaining wall supporting backfill should be coated with an approved
waterproofing compound to inhibit infiltration of moisture through the walls.
1
ProjecINo.105908-30
Page 8
May 17, 2005
I
I
I
I
I
I
I
I
I
I
I
I
I
7.3 Temoorarv Excavatiolls
All excavations should be made in accordance with OSHA requirements. LOC is not responsible for job site
safety.
7.4 Wall Backfill
All retaining wall backfill should be placed in 6- to 8-inch maximum lifts, watered or air dried as necessary
to achieve near optimum moisture conditions and compacted in place to a minimum relative compaction of
90 percent.
8.0 MASONRY GARDEN WALLS
Footings for masonry garden walls should also be reinforced with a minimum off our (4) No.4 bars, two (2) top and
two (2) bottom. In order to mitigate the potential for unsightly cracking, positive separations should also be
provided in the garden walls at a maximum horizontal spacing of 20 feet. These separations should be provided in
the blocks only and not extend through the footing. The footing should be placed monolithically with continuous
rebars to serve as an effective "grade beam" below the wall.
In areas where garden walls may be proposed on or near the tops of descending slopes, the footings should be
deepened such that a minimum horizontal clearance of 5 feet is maintained between the outside bottom edges of the
footings and the face of the slope.
9.0 CONCRETE FLATWORK
9.1 Thicklless alld Joillt Spacinf!
To reduce the potential of unsightly cracking, concrete sidewalks and patio type slabs should be at least 3\1,
inches thick and provided with construction or expansion joints every 6 feet or less. Any concrete driveway
slabs should be at least 4 inches thick and provided with construction or expansion joints every 10 feet or
less.
9.2 Subl!rade Preparation
II
!
I
I
I
I
I
As a further measure to minimize cracking of concrete fIatwork, the subgrade soils underlying concrete
flatwork should first be compacted to a minimum relative compaction of90 percent and then thoroughly
wetted to achieve a moisture content that is at least equal to or slightly greater than optimum moisture
content. This moisture should extend to a depth of 12 inches below subgrade and be maintained in the soils
during the placement of concrete. Pre-watering of the soils will promote uniform curing of the concrete and
minimize the development of shrinkage cracks. A representative ofthe project geotechnical engineer should
observe and verify the density and moisture content ofthe soils and the depth of moisture penetration prior
to placing concrete.
Project No. 105908-30
Page 9
fb
May 17, 2005
, I
II
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
9.3 Draillaee
Drainage from patios and other flatwork areas should be directed to local area drains and/or graded-earth
swales designed to carry runoff water to the adjacent streets or other approved drainage structure. The
concrete flatwork should also be sloped at a minimum gradient of2 percent away from building foundations,
retaining walls, masonry garden walls and slopes.
9.4 Tree Wells
Tree wells are not recommended in concrete- flatwork areas since they can introduce excessive water into the
subgrade soils or allow for root invasion, both of which can result in uplift of the flatwork.
10.0 PLANTERS AND PLANTER WALLS AND LANDSCAPING
10.1 Planters
Planters that are located within 5 feet of building foundations, retaining walls, masonry garden walls and
slope areas should be provided with sealed bottoms and bottom drains to prevent infiltration of water into
the adjacent foundation soils. The surface of the ground in these areas should also be maintained at a
minimum gradient of2 percent and direct drainage to area drains or earth swales.
The sealed planter bottoms should consist of either reinforced concrete having a minimum thickness of 4
inches or a polyvinyl-chloride membrane of sufficient thickness to prevent puncturing by plant roots. If
concrete is used to line the planters, minimum reinforcement should consist of No. 3 bars spaced IS inches
on centers, both ways, or 6-inch by 6-inch, No.6 by No.6 welded wire mesh. If a polyvinyl-chloride
membrane is used, a minimum thickness of 30-mil is recommended. Furthermore, the bottoms of the
planters should be sloped to direct subsurface water to collector drains connected to drain lines designed to
10.2 Planter Walls
Low height planter walls should be supported by continuous concrete footings constructed in accordance
with the recommendations presented for masonry block wall footings.
10.3 Lalldscapine
In recognition that, as the homeowner, you will add either soft-scape or hard-scape after precise grading, the
following recommendations may be used as a guide. It is paramount that homeowners consult with a
professional engineer to ensure that the construction of future landscaping improvements will not cause
obstruction of existing drainage patterns or does not cause surface water to collect adjacent to the
foundation, creating saturated soils adjacent to the foundation.
Area drains should be maintained and kept clear of debris in order to properly function. Homeowners should
also be made aware that excessive irrigation of neighboring properties can cause seepage and moisture
conditions on adjacent lots. Homeowners should be furnished with these recommendations communicating
the importance of maintaining positive drainage away from structures towards streets when they design their
improvements.
'\
Projecl No. 105908-30
Page 10
May 17, 2005
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
The irnpact of heavy irrigation or inadequate runoff gradients can create perched water conditions. This may
result in seepage or shallow groundwater conditions where previously none existed. Maintaining adequate
surface drainage and controlled irrigation will significantly reduce the potential for nuisance type moisture
problems. To reduce differential earth movements such as heaving and shrinkage due to the change in
moisture content of foundation soils, which may cause distress to a residential structure and associated
improvements, moisture content of the soils surrounding the structure should be kept as relatively constant as
possible.
10.4 Swimmilll! Pools and Spas
No pools or spas are shown on the plans. In general, LGC does not recommend pools or spas be located
within 15 feet of the top of2: I (h:v) slopes or within a cut/fill transition without special foundation design
considerations. While expansive soil related cracking of concrete flatwork and garden walls may only be
cosmetic in nature, and thus tolerable, such cracking in pools and/or spas cannot be tolerated. Soil expansion
forces should be taken into account for design and construction of a swimming pool and/or spa.
For soils having a very low expansion potential, we recommend a lateral earth pressure of78 pcfbe used for
design of pools/spa shells.
To avoid localized saturation of soils, landscaping of the backyard should not be planned with unlined
planter boxes in the immediate vicinity of the pool/spa shell.
The excavated material from the pool/spa area is often used to build elevated planter boxes and/or other
structures adjacent to the pool area. This practice imposes significant loads at the location of these structures
and induces differential settlements. This practice couldjeopardize the integrity of the pool/spa and possibly
other improvements. Pool decking should also receive special design considerations, since the pool is
founded generally 6 to 8 feet below grade. If pool decking is not correctly designed for expansive soils,
differential movement between the flatwork and pool will occur. A geotechnical consultant should be
retained to evaluate the impact of planned improvements and provide proper recommendations for design.
Whether the pool/spa shell is in the zone of influence of the building or wall footing, the need for shoring or
support for the building or wall footing should also be taken into consideration.
11.0 POSTGRADlNGOBSERVATIONSAND TESTING
LGC should be notified at the appropriate times in order to provide the following observation and testing services
during the various phases of post grading construction.
11.1 BuildillJ! COllstructioll
. Observe all footings when first excavated to verify adequate depth and competent soil bearing
conditions.
. Re-observe all footings, if necessary, if trenches are found to be excavated to inadequate depth and/or
found to contain significant slough, saturated or compressible soils.
ProjecINo.105908-30
Page 11
,0
May 17, 2005
I
II
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
'I
I
II
11.2 Retaillilll! Wall Constructioll
. Observe all footing trenches when first excavated to verify adequate depth and competent soil bearing
conditions.
. Re-observe all footing trenches, if necessary, if trenches are found to be excavated to inadequate depth
and/or found to contain significant slough, saturated or compressible soils.
. Observe and verify proper installation of subdrain systems prior to placing wall backfill.
. Observe and test placement of all wall backfill.
11.3 Masollrv Garden Walls
. Observe all footing trenches when first excavated to verify adequate depth and competent soil bearing
conditions.
. Re-observe all footing trenches following removal of any slough and/or saturated soils and re-excavate
to proper depth.
11.4 Exterior Concrete Flatwork COllstructioll
. Observe and test sub grade soils below all concrete flatwork areas to verify adequate compaction and
moisture content.
11. 5 Utilitv Trench Backfill
. Observe and test placement of all utility trench backfill.
11.6 Re-Gradillf!
. Observe and test placement of any fill to be placed above or beyond the finish grades shown on the
grading plans.
12.0 LIMITATIONS
Our services were performed using the degree of care and skill ordinarily exercised, under similar circumstances, by
reputable engineers and geologists practicing in this or similar localities. No other warranty, expressed or implied, is
made as to the conclusions and professional advice included in this report.
This report is issued with the understanding that it is the responsibility of the owner, or ofhislher representative, to
ensure that the information and recommendations contained herein are brought to the attention of the architect
and/or project engineer and incorporated into the plans, and the necessary steps are taken to see that the contractor
and/or subcontractor properly implements the recommendations in the field. The contractor and/or subcontractor
should notify the owner if they consider any of the recommendations presented herein to be unsafe.
\\
Projecl No. 105908-30
Page 12
May 17, 2005
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
The findings of this report are valid as of the present date. However, changes in the conditions of a property can and
do occur with the passage of time, whether they be due to natural processes or the works of man on this or adjacent
properties.
In addition, changes in applicable or appropriate standards may occur, whether they result from legislation or the
broadening of knowledge. Accordingly, the findings of this report may be invalidated wholly or partially by changes
outside our control. Therefore, this report is subject to review and modification, and should not be relied upon after a
period on years.
The opportunity to be of service is appreciated. Should you have any questions regarding the content of this report,
or should you require additional information, please do not hesitate to contact this office at your earliest
convemence.
Respectfully submitted,
Chad E. Welke
Associate Geologist/Engineer, PO 7341, RCE 63712
LGC INLAND, INC.
JDO/SMP ICW Its
Attachments: Table I - Summary ofField Density Tests (Rear of Text)
Appendix A - Laboratory Testing Procedures and Test Results (Rear of Text)
Plate I - As-Oraded Geotechnical Map (In Pocket)
Distribution: (4) Addressee
\~
Projecl No. 105908-30
Page 13
May 17, 2005
~I
I~I-i'^ -
I ;
~I
51:
g ;.:
~'~ -
'I
c._.
~I
il
0:-,
~I
~I
LF
T'-.'-.
- ~: --
--I
~ .
0-
~Ic
"'I-
i!! "
= ~-~.'
~"
'-.'
~
~I
~-I
~-~
~- -
III
I~I-
~ '.-
~I.'
I ,,~
'! ":
TABLE I
SUMMARY OF FliELD DENSITY TESTS
\2>
~ - ---
~--- - --:.:
"_."'..'__._. _ ..-_.~".,.c._.
--~'. --- ,---+-,-~"'~---'-'-
L:-,.- _, _~._~_
~.. .-.
~~ _~~''''i.,_",__,
='"~"":::~
- . . . --' "-
_n ,....:.:: :-._ ....:....::_... ".0',.
(_:t5~"'7~-Ib::.~-~:'= - -~-~'= ui G~~-~~_~"~_-c_'-~~_ ~
~~;:::~-'--"--~=~----=--=--~-: -- -- ~:;::;--;;;.::::;-~-::----",:~~v----~ -~~~
II
I
Project No. /05908-30
TABLE /
McDaniel Residence
SUMMARY OF flELD DENSITY TESTS
: - - - ,~ ir ;' i, ' ,~ ~ ~-,~ --! ";~ 'I <'" ~'f ell"f - ~[I\,:;tl)1;.'1iTm 1 ~\,i.b(,.- :.~\.
\ I I ~ ~ - "" -,
, I l:t';:lr ,I '1~;,J;j' . 1";;{j ~. ,--:tt~.f:li'[.lt, I ,,'tIn ~ 1: 'D:t:ril;;n~'I ~ &'illft.:J4(( . ~"HMli~> \"Wil'~
I _ 1__ ;
l 't~~J~~;t ~ft,f~.. :l 1j)-F:.1~" 't: ....;j;1j '-;';:'[(f.lWJj c.: (~t@~\ ~~ - _'YF!f::::~J~ Cf!t~R). J ",;:{(;;;1J"N, -I. (~~J~) , Jr~) ~
I
I
1 N 04/25/05 CF House Pad / Mass Fill 1131 1 117.7 10.1 128.0 92
2 N 04/25/05 CF House Pad / Mass Fill 1134 1 116.5 9.8 128.0 91
3 N 04/25/05 CF House Fad / Mass Fill 1138 1 115.8 9.8 128.0 91
4 N 04/26/05 CF House Pad / Mass Fill 1141 1 116.3 11.2 128.0 91
5 N 04/26/05 CF House Pad / Mass Fill 1144 1 120.1 10.5 128.0 94
6 N 04/27/05 CF House Pad / Mass Fill 1146 1 118.8 8.7 128.0 93
7 N 04/27/05 CF House Pad / Mass Fill 1145 1 115.9 9.2 128.0 91
8 N 04/27/05 CF House Pad / Mass Fill 1149 I 117.8 9.3 128.0 92
9 S 04/27/05 FG House Pad / Mass Fill FG I 117.2 9.5 12S.0 92
I
I
I
I
I
I
I
I
II
I
I
I
I
I
I
N - Nuclear Test Method
CF - Compacted FiII
I
S - Sand Cone Test Method
FG - Finish Grade
May 2005
Il\
I
"'I
~ ~,
~.
~I
'1
~I
~~.
.:~' -
I
12.1
j::'
lii..I-
"~".'
I
~I
tl~
'"I
,~-
I
~I
-I
~:
-'1
--:
:-1
::.,,~
--I
~:
"I
-~
"'I
I
'" ---
APPENDIXA
LABORATORY TESTING PROCEDURES AND TEST RESULTS
-~ - ~ --
. ~-;,,'-ii = ,_...
...
\~
- "'- .."
., ~,;-~~~,:;.~,;: '-:;:,-.' ="":----~:-~~==::-:.:.~~"'-,-'~.,--':/:~< ::,~~~
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
APPENDIX A
Laboratorv Testinl! Procedures and Test Results
The laboratory testing program was directed towards providing quantitative data relating to the relevant engineering
properties of the soils. Samples considered representative of site conditions were tested in general accordance with
American Society for Testing and Materials (ASTM) procedure and/or California Test Methods (CTM), where
applicable. The following summary is a brief outline of the test type and a tables summarizing the test results.
Expansioll IlIdex: The expansion potential of selected samples was evaluated by the Expansion Index Test, ASTM
D4829. Specimens are molded under a given compactive energy to approximately the optimum moisture content and
approximately 50 percent saturation or approximately 90 percent relative compaction. The prepared I-inch thick by
4-inch diameter specimens are loaded to an equivalent 144 psf surcharge and are inundated with tap water until
volumetric equilibrium is reached.
SAMPLE SAMPLE COMPACTED DRY EXPANSION EXPANSION
NUMBER DESCRIPTION DENSITY (pcf) INDEX POTENTIAL *
I E-l I Silty Sand I 111.2 I 5 I Vel)'Low I
· Per Table 18-I-B of 1997 UBC.
Maximum Dellsitv Tests: The maximum dry density and optimum moisture content of typical materials were
determined in accordance with ASTM DISS7.
SAMPLE SAMPLE MAXIMUM DRY OPTIMUM MOISTU
NUMBER DESCRIPTION DENSITY (pcf) CONTENT (%)
I Dark grayish brown silty fine to 128.0 9.0
coarse Sand wi trace gravel
Soluble Sulfates: The soluble sulfate contents of selected samples were detennined by standard geochemical methods
(CTM 417). The soluble sulfate content is used to detennine the appropriate cement type and maximum water-cement
ratios. The test results are presented in the table below:
. SULFATE
SAMPLE SAMPLE CONTENT % by SULFATE
NUMBER DESCRIPTION EXPOSURE*
. weight
E-l Silty Sand 0.003 Negligible
· Based on the 1997 edition of the Uniform Building Code (U.B. C.), Table No. 19-A-4, prepared by the International
Conference of Building Officials (lCBO, 1997).
\Co