HomeMy WebLinkAboutCT 04-26; ROBERTSON RANCH PA 16, 17 & 18; REPORT OF ROUGH GRADING; 2008-09-17Geotechnical • Geologic • Coastal • Environmental
5741 Palmer Way Carlsbad, California 92010 (760) 438-3155 FAX (760) 931-0915
September 17, 2008
W.O. 5353-131 -SC
Brookfield San Diego Builders, Inc.
12865 Pointe Del Mar, Suite 200
Del Mar, California 92014
Attention: Ms. Teri McHugh
Subject: Report of Rough Grading, Planning Area 18 of Robertson Ranch, East Village
(Lots 195 through 304, and 309) Carlsbad Tract 04-26, Drawing 453-8A,
Carlsbad, San Diego County, California
Dear Ms. McHugh:
This report presents a summary of the geotechnical testing and observation services
provided by GeoSoils, Inc. (GSI) during the rough earthwork construction phase of
development associated with the development of Planning Area 18 (PA-1 8) of Robertson
Ranch East Village, in the City of Carlsbad, San Diego County, California. Earthwork was
performed in conjunction with the grading of the larger Robertson Ranch East Village.
Earthwork commenced in March 2007, and was generally completed in July 2008.
PURPOSE OF EARTHWORK
The purpose of grading was to prepare building pads and associated street areas for the
construction of 110 single-family residential structures, and associated surface and
subsurface improvements. Cut-and-fill grading techniques were utilized to attain the
desired graded configurations. Existing colluvium (topsoil), alluvium, and weathered
formational material were removed to suitable earth material (as defined in the approved
report for the site), and either exported from the site or recompacted as fill. The
approximate limits of grading under the purview of this report are shown on the
Geotechnical Maps (Plates 1 through 4), which use the 40-scale grading plan for this
project, prepared by O'Day Consultants (2008), as a base.
Rough grading is generally completed throughout PA-1 8. However, the area of the site is
only "sheet" graded in the vicinity of Lots 195 through 206, due to the presence of large
stockpiles of aggregate base and other rock products generated during mass grading.
Upon removal of these stockpiled materials, additional grading will be necessary to bring
these lots to the desired grades. Supplemental geotechnical observation and testing
services will need to be provided during the additional grading.
ENGINEERING GEOLOGY
Subsurface geologic conditions exposed during the process of rough grading were
observed by a representative of GSl Prior to grading, earth materials onsite consisted of
surficial deposits of colluvium (topsoil), and alluvium, underlain by formational sediments
and granitic bedrock. The subsurface conditions exposed were generally as anticipated
per our approved geotechnical report (GSl, 2007b). Perimeter grading performed prior to
this phase of earthwork was completed with geotechnical observation and testing services
provided by GSI (2006e and 2007a), along the eastern and southern sides of PA-18.
GEOLOGIC STRUCTURE
As observed onsite, the bedding structure observed within terrace deposits is generally
thickly bedded and sub horizontal. Bedding structure. was not well developed Within the
thickly-bedded Santiago Formation, but generally dips on the order of 5 to 10 degrees to
the northwest, based On mapping in the vicinity and a review of GSI (2004 and 2007b).
Jointing in granitic bedrock was observed to be generally high angle (>60 degrees), and
trending northwest and northeast.
GROUNDWATER
Naturally occurring perched groundwater within alluvial soil was evaluated in GSI (2001 b,
2002, 2004, and 2007b) and is likely to be encountered at depths generally less than
10 feet below the pre-construction grades in the vicinity of Lots 206 through 218,
233 through 259, 268 through 304, and 309, or approximately 30 to 40 feet below those
pad grades. Regional groundwater should not significantly affect the performance of the
fill, provided that prudent surface and subsurface drainage practices are incorporated into
the constructiQn plans.
Toe drains were constructed locally (see Plates 1 through 4) in order to mitigate
anticipated perched water conditions along the toe of the slopes. However, perched
groundwater conditions may develop in the future due to rainfall, excess irrigation,
homeowner altered drainage, or damaged utilities, and should be anticipated along cut/fill
contacts, zones within compacted fill with contrasting permeabilities, or in cut areas where
low permeability sediments/bedrock soils occur at, or near the surface, including Lots 196,
198, 199, 203, 204, 223, and 224. Should manifestations of perched conditions (i.e,
seepage, or ponding), develop in the future, this office should assess the conditions and
provide mitigative recommendations, as necessary. A discussion of subdrainage
constructed during grading is presented in a later section of this report.
Brookfield San Diego Builders, Inc. W.O. 5353-B1-SC
PA 18 Robertson Ranch, East Village September 17, 2008
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EARTHWORK CONSTRUCTION
Earthwork operations have been completed in general accordance with the City grading
ordinance, recommendations provided by GSI (see the Appendix), and the guidelines
provided in the field by this office. Observations during grading included removals,
excavation, and fill placement, along with general grading procedures of compacted fills
by the contractor. Table 1 presents a summary of compaction test results.
Rough Grading
Preparation of Existing Ground
Deleterious material, such as concentrated organic matter and miscellaneous
debris, were stripped from the surface and disposed of beyond the limits of grading
for the subject area, prior to placing any fill.
Loose surficial materials, i.e., existing topsoils, colluvium, near-surface alluvium, and
unsuitable formational soils, were removed to expose suitable bearing soils, as
defined in the approved report for the site.
Due to the presence of groundwater, saturated alluvial soils (up to approximately
40 feet thick) were left in place, as shown on Plates lthrough 4. The ground surface
in this area was initially prepared during grading of the adjacent College and
Cannon Road thoroughfares (GSl, 2006e) and approximately 10 to 15 feet of
engineered fill was placed to within. approximately 5 feet of planned grades (GSl,
2006e, 2007b). During interim fill placement and the subsequent waiting period
(approximately 48 months as of the date of this report), our evaluation (GSl, 2007b)
indicates that a majority of the total settlements has occurred. Furthermore,
settlement monitoring within alluvial areas, in excess of 50 feet thick, and prepared
during .grading of the College/Cannon thoroughfare (GSl, 2006e) indicated that
primary settlement had occurred by the completion of grading.
Lots containing cut/fill transitions, lots containing non-uniform native soil conditions,
and lots exposing granitic bedrock near finish grade, were undercut per the
approved report. In general, undercuts were completed to depths no less than
3 feet across a given lot, and/or to minimum depths no less than about 1/3 the
maximum fill depth across any given lot. Cut lots 196, 198, 199, 203, 204, 223, and
224, were not overexcavated at the direction of the client. Approximate as-built fill
depths across any given lot are shown in Table 2.
Subsequent to completing removals, areas to receive compacted fill were scarified,
moisture conditioned, and then compacted to attain a minimum relative compaction
of 90 percent (ASTM D 1557). These areas were then brought to grade with fill
compacted to a minimum 90 percent relative compaction, based on field
observations.
Brookfield San Diego Builders, Inc. W.O. 5353-81-SC
PA 18 Robertson Ranch, East Village September 17, 2008
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6. All processing of original ground in areas to receive fill, shown on Plates 1 through
4, was observed by a representative of GSI. Plates 1 through 4 utilize the 40-scale
grading plan (Sheets 9, 11, 12, and 14, DWG. 453-8A), prepared by O'Day
Consultants (2008), as a base map.
Fill Placement
Fill consisted of onsite and import materials which were placed in thin lifts, approximately
4 to 8 inches in thickness, brought to at least optimum moisture content, and compacted
to attain a minimum 90 percent relative compaction. Oversize rock material (i.e., generally
greater than 12 inches, but not more than 24 inches) was generally placed in the vicinity
of Lots 206 through 218, 233 through 259, 268 through 304, and 309 (Rec Lot), and no
closer than 5 feet from finish grade, in general accordance with the approved GSI
recommendations (GSl, 2007b). Approximate as-built fill depths are shown in Table 2. The
presence of scattered rock fragments, on the order of 12 inches in size, more or less,
cannot be precluded from occurring within any of the fills onsite. Compaction test results
for fills are presented in the attached Table 1.
A large stockpile of rock products, including aggregate base, 3/4 inch crushed rock, and
SE 30 material are located within the vicinity of Lots 195 through 206. As previously
indicated, Lots 195 through 206 are currently sheet graded; therefore, additional grading,
will be necessary to bring these lots to the desired configurations once the stockpiles are
removed. Earth materials used to complete these lots shall be compatible with existing,
as-built soil conditions described in Table 2. Post grading/post construction improvements
should follow the development recommendations presented herein for pools or other
settlement sensitive improvements. Overexcavation and significant grading may be
required to properly construct post construction improvements, such as pools, spas,
hardscape, etc.
Slopes
Planned Slopes
Graded slopes constructed under the purview of this report are generally on the order of
10 feet in height, or less, and should typically perform satisfactorily with respect to gross
and surficial.stability under normal conditions of care, maintenance, and rainfall (semi-arid).
Fill slopes, constructed under the purview of this report, were provided with a basal bench,
or keyway, excavated into suitable earth material in general accordance with the approved
GSI recommendations. Cut slopes were constructed using cut and fill grading techniques
in general accordance with the approved GSI recommendations (GSI, 2007b), and
exposed suitable formational earth material(s).
As a result of recent rain storms during the winter of 2007/2008, some surficial erosion of
the site slopes was observed. Prior to improvements construction, the site should be
reviewed by the geotechnical consultant and recommendations provided for slope repair,
Brookfield San Diego Builders, Inc. W.O. 5353-B1-SC
PA 18 Robertson Ranch, East Village September 17, 2008
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as necessary. Typical recommendations may include, but not be limited to, the
removal/recompaction of loose soil, moisture conditioning, and additional compactive
effort applied to the slope face.
Temporary Slopes
Any proposed/future temporary construction slopes may be constructed at a gradient of
1:1 (horizontal: vertical, [h:v]), or flatter, in compacted fill (provided adverse conditions are
not present, as evaluated by GSl prior to workers entering trenches), provided seepage
or groundwater is not present. Utility trenches may be excavated in accordance with
guidelines presented in Title 8 of the California Code of Regulations for Excavation,
Trenches, and Earthwork, with respect to "Type B" soil (compacted fill), again provided
seepage or groundwater is not present. Construction materials and/or stockpiled soil
should not be stored within 5 feet from the top of any temporary slope.
Temporary/permanent provisions should be made to direct any potential runoff away from
the top of temporary slopes.
Natural Slopes
Natural slopes are not present within PA-18
Subdrainage
Several "toe drains" were constructed (per GSI, 2007b) throughout PA-18, and are shown
schematically on Plates 1 through 4, and are outletted into the existing storm drain system.
Additional toe drainage is recommended along the rear of Lots 195 through 206, upon the
removal of existing stockpiles of aggregate base and other rock products in the vicinity
General toe drain recommendations, and schematics, are presented in a later section of
this report. Surveys performed on toe drain subdrain pipes were provided in the field by
the project surveyor (Project Design Consultants, 2008). Elsewhere, inasmuch as they
would not function as intended, subdrains were not constructed owing to the lack of
suitable fill cover (~ about 10 feet), lack of flowline gradient, lack of suitable outlet, and lack
of pie-existing canyons.
Field Testing
1. Field density tests were performed using the sand-cone method (ASTM 01556) and
nuclear (densometer) method (ASTM D 2922, D 3017). Tests taken for the
Robertson Ranch project were taken in consecutive numerical order. Only tests
within the subject site, under the purview of this report, are presented in Table 1 at
the end of the text. The approximate locations of field density tests are shown on
the Geotechnical Maps (Plates 1 through 4), which utilize the 40-scale grading plan
(Sheets 9, 11, 12, and 14, DWG. 453-8A), prepared by O'Day Consultants (2008),
as a base map.
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Field density tests were taken at periodic intervals and random locations to check
the compactive effort provided by the contractor. Rock corrections were applied
during testing of fill with significant rock fragments, as appropriate. Based on the
operations observed, test results presented herein are generally considered
representative of the fills observed under the purview of this report.
Visual classification of the soils in the field, as well as random laboratory testing,
was the basis for determining which maximum dry density value to use for a given
density test.
Testing and observations were performed on a full- and part-time basis, as solely
determine by the general contractor.
LABORATORY TESTING
Moisture-Density Relations
The laboratory maximum dry density and optimum moisture content for each major soil
type was determined in general accordance with test method ASTM D 1557. The following
table presents the test results: .
1'~'M i WMAIIN,
S.OIL'1,PE ... . .. .,
MXMLTM.DJ1
.D.ENSflY(p'cf).
lMbiuWE, LA A CøNTEN1i'(%)
A - Brown, Silty SAND 127.0 10.0
B - Dark Brown, clayey SAND 114.0 13.0
C - Gray Brown, Clayey SAND 120.5 13.0
E - Dark Broin, Silty SAND 126.0 11.0
F- Gray Brown, Gravelly SAND 134.0 8.0
H - Gray Brown, Gravelly SAND 134.0 9.0
I - Gray Brown, Gravelly SAND . . 131.0 10.0
J - Gray Clayey, SAND 121.0 12.5
L - Olive Brown, Silty CLAY . 111.0 18.5
M - Yellow Brown, Silty SAND (import) 123.0 13.0
P - Yellowish Brown, Clayey SAND (import) 124.5 10.5
Q - Yellowish Gray, Silty. SAND (import) . 127.0 11.0
R - Yellowish Brown, Silty SAND (import) . 122.0 12.0
S - Yellowish Gray, SAND w/CLAY (import) 124.0. 11.0
T - Yellowish Gray, clayey SAND (import) 118.8 16.0
Brookfield San Diego Builders, Inc. W. 0. 5353-B1-SC
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GeoSoils, Inc.
10
Is.M WN SOIL TYPE MF I
j
SITY (pcf) IMMOV CONTENT (%)
U - Yellowish Gray, Clayey SAND (import) 127.0 11.0
X - Brownish Gray, Gravelly SAND w/SILT (import) 131.5 9.0
LL - Brown, Clayey SAND 121.0 12.5
iT - Brown, Silty SAND 127.0 10.0
Expansion Index
Expansion Index ([.1.) tests were performed for the representative foundation soil types
exposed near finish grade in general accordance with ASTM D 4829 in groups of about
three to five lots, or if there was a significant change in expansive character. The E.I. test
results are presented in Table 2, at the end of this report.
Atterberg Limits
Laboratory testing was performed to evaluate the Atterberg Limits (liquid limit, plastic limit,
and plasticity index) in general accordance with ASTM D 4318 for representative soils
exposed near finish grade that exhibited an E.I. greater than 20 or had high fines,
(-200 sieve) content. The results of Atterberg Limit testing are presented in Table 2.
Corrosion Analysis
Representative samples of the site materials has been analyzed for soluble sulfates, soil
pH, and saturated resistivity by Schiff Associates, Inc. (Corrosion Consultants). Based
upon the laboratory testing, site soils are considered to be negligible (sulfate class SO) with
respect to water soluble sulfate exposure to concrete, per Table 4.2.1 and 4.3.1 of the
American Concrete Institute (ACl) document 318-08 (California Building Code [CBC],
California Building Standards Commission [CBSC], 2007). Soils are relatively neutral with
respect to soil acidity/alkalinity (pH = 6.8) (Romanoff, 1957), and are very corrosive to
exposed ferrous metals in a saturated state (saturated resistivity <1,000 ohm-cm). The
chloride ion content in soil was also noted to be below action levels per Caltrans (1999).
It is our understanding that standard concrete cover over reinforcing steel is usually
appropriate for these conditions; however, a corrosion engineer should be consulted to
provide specific recommendations regarding foundations and piping, etc. The results of
the soil sulfate evaluation are presented in Table 2
FOUNDATION RECOMMENDATIONS
In the event that information concerning the proposed development plan is not correct, or
any changes in the design, location or loading conditions of the proposed structure are
made, the conclusions and recommendations contained in this report shall not be
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considered valid unless the changes are reviewed and conclusions of this report are
modified or approved in writing by this office. The conclusions and recommendations
presented in GSl (2007b) are generally considered valid and applicable unless specifically
superceded in the text of this report.
RECOMMENDATIONS - CONVENTIONAL FOUNDATIONS
General
The foundation design and construction recommendations are based on laboratory testing
and engineering analysis of onsite earth materials by GSI. Recommendations for
conventional, and post tensioned foundation systems are provided in the following
sections. The foundation systems may be used to support the proposed structures,
provided they are founded in competent bearing material. Foundations should be'founded
entirely in compacted fill or rippable bedrock, with no exposed transitions. Conventional
foundations may be used for very low to low expansive soil subgrades, where the soils
plasticity index (P.1.) is 15, or less, and no saturated alluvium has been left in place. For
low to medium expansive soil conditions where the P.1. is greater than 15, conventional
foundations may be used, provided that they are designed in accordance with Chapter 18
(Section 1805A.8) of the CBC (CBSC, 2007). When soils have an E.I. >21 and P.1. >15,
this implies that the Code may require the use of more onerous foundations
(i.e., post-tension, mat, etc.). Where alluvium has been left-in-place, post-tension
foundations are required.
The information and recommendations presented in this section are not meant to
supercede design by the project structural engineer. Upon request, GSI could provide
additional input/consultation regarding soil parameters, as related to foundation design.
As-Built Conditions
As-built soil conditions to be minimally considered in foundation design and construction
are presented in Table 2 of this report.
Foundation Design
Based on the as-built conditions, general recommendations for minimal foundation design
and construction are presented below.
Bearing Value
1. The foundation systems should be designed and constructed in accordance with
guidelines presented in the latest edition of the CBC (CBSC, 2007).
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2. An allowable bearing value of 2,000 pounds per square foot (pso may be used for
the design of continuous footings at least 12 inches wide and 12 inches deep, and
isolated column footings at least 24 inches square and 24 inches deep, connected
by a grade beam back to the main foundation in at least one direction. This value
may be increased by 20 percent for each additional 12 inches in depth to a
maximum of 3,000 psf. No increase in bearing value is recommended for increased
footing width. The allowable bearing pressure may be increased by one-third under
the effects of temporary loading, such as seismic or wind loads.
Lateral Pressure
For lateral sliding resistance, a 0.35 coefficient of friction may be utilized for a
concrete to compacted fill, soil contact when multiplied by the dead load.
Passive earth pressure may be computed as an equivalent fluid having a density of
250 pounds per cubic foot (pcf) with a maximum lateral earth pressure of 2,500 psf.
When combining passive pressure and frictional resistance, the passive pressure
component should be reduced by one-third and the previously noted maximum
lateral earth pressure applied.
Differential Settlement
All foundation systems (conventional and post tension) should be designed to minimally
accommodate a differential settlement of at least 1 inch in a 40-foot span. This includes
long-term static as well as dynamic effects
Since primary settlement has been substantially completed. The remaining total
post-grading settlement is estimated to be on the order of 2 inches total, and 1 inch
differential, or less, over a 40-foot span (GSl, 2007b),'within areas underlain by alluvium
left in place. The cumulative effects of multiple seismic events over the life of the project
may induce settlement to exceed these values if no interim mitigation is performed.
Seismic Shaking Parameters
The table below summaries the site-specific design criteria obtained per the 2007 CBC.
We used the computer program Seismic Hazard Curves and Uniform Hazard Response
Spectra, provided by the U.S.G.S. The short spectral response uses a period of
0.2 seconds.
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CBC SEISMIC DESIGN PARAMETERS FOR SITE CLASS "0" SOILS
WAVJ(
Site Class D Table 1613.52
Spectral Response - (0.2 sec), S 1.15g Figure 1613.5(3)
Spectral Response - (1 sec) S1 0.449 Figure 1613.5(4)
Site Coefficient, Fa 1.04 Table 1613.5.3(1)
Site Coefficient, F 1.56 Table 1613.5.3(2)
Maximum Considered Earthquake Spectral
Response Acceleration (0.2 sec) SMS
1.20g Section 1613.5.3 (Eqn 16-37)
Maximum Considered Earthquake Spectral
Response Acceleration. (1 sec), SM1
0.68g Section 1613.5.3 (Eqn 16-38)
5% Damped Design Spectral Response Acceleration
(0.2 sec), S . . . .
0.79g
. .
Section 1613.5.4 (Eqn 16-39)
5% Damped Design Spectra] Response Acceleration
0 sec), S,.,,
0.46g Section 1613.5.4 (Eqn 16-40)
A probabilistic peak horizontal ground acceleration (PHSA) of 0.28 g was evaluated for this
site (GSI, 2007b). This value was chosen as it corresponds to a 10 percent probability of
exceedence in 50 years (or a 475-year return period). ..,
Conformance to the criteria above for seismic design does not constitute any kind of
guarantee or assurance that significant structural damage or ground failure will not occur
in the event of a large earthquake. The primary goal of seismic design is to protect life, not
to eliminate all damage, since such design may be economically prohibitive.
Construction
The following foundation construction recommendations are presented as a minimum
criteria from a soils engineering standpoint. Recommendations by the project's
design-structural engineer or architect, which may exceed the soils engineer's
recommendations, should take precedence over the following minimum requirements.
Minimal conventional foundation recommendations are presented in the following Table A,
followed by an explanation of the "Foundation Category," and other minimal criteria.
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1''545v3t
FOO11NG
MlNr *ct
REINFRCING
MI?INTERIORj
LtAB
555Zt MINjT
NDESB
aatt4aaases MIN
RAGELAB
ssasset. jEjRl0R
XMICKNI-SS,TEE RNFORCEMENT TWENT OC JR
12" Wide x 4 Thick 1-No. 4 Bar No. 3 Bars @ 18' 2" Sand Over lO-Mil vapor 6" x 6" None 12" Deep Top and Bottom o.c. Both Directions retarder Over 2' Sand (10/10) welded wire
Base fabric (WWF)
11 12" Wide x 4 Thick '2-No. 4 Bars No. 3 Bars @ 18 2" Sand Over 10/15-Mu 6x 6' 6"x 6" 18' Deep Top and Bottom o.c. Both Directions vapor retarder Over 2 (6/6) WWF, or loxl0 WWF
- Sand Base (15-mil for No.3 Bars @ 18' - medium expansive soils o.c Both Directions .
• - •. ' only) • for Low
12" Wide x 5' Thick 2-No. 5 Bars No.3 Bars @ 18" 2" Sand Over 15-Mil vapor Same as 6 x 6
L,
24" Deep - Top and Bottom o.c. Both Directions retarder Over 3" Sand Interior Slab (6/6) WWF - .1
-' . Base (highly expansive '
- - - soils only) ________________
1,
-
- - - -
' '' • '
TABLE A
Convetitional Perimeter Footings, and Slabs, Robertson Ranch East Village
Category Criteria • ,, '
Category I: Max. Fill Thickness is less than 20'. and E.I. is less than, or equal to, 50 (P.1. <15) and Differential Fill Thickness is
* less than 10' (see Note 1). . . . Category II: Max. Fill Thickness is less than 30 or E.I. is less than, or equal to. 90 or Differential Fill Thickness is between 10 and
20' (see Note 1). Presoaking required.
Category ill: • Max. Fill Thickness exceeds 30'. or E.I. exàeeds 90 but is less than 130, or Differential Fill Thickness exceeds
- 20' (see Note 1). Presoaking required.
Notes: 1. Conventional foundations shall als6 be designed per Section 1805A.8, Chapter 18 of the CBC (CBSC, 2007) where
the P.I. is 15, or greater. •• -' . . . 2. Post-tension foundations are required where maximurri till exceeds 30', or the ratio of the maximum fill thickness
to the minimum fill thickness exceeds 3:1, or where the E.11. 6xceeds 90, or in areas underlain with alluvial soil left
in place. Differential settlements discussed in the body of the report should be incorporated into foundation
design by the structural engineer/slab designer. . . .. * 3. • 'Footing depth measured from lowest adjacent compacted/suitable subgrade.
" The allowable soil bearing pressure is 2,000 psf.
Concrete for slabs and footings shall have a minimum compressive strength of 2,500 psi at 28 days. The
maximum stump shall be 5 inches. The water/cement ratio of concrete shall not be more than 0.5 for soils with an
' E.I. >90-
' tThe vapor retarder is not required under garage slabs. However, consideration should be given to future uses of
-
. . - the slab area, such as room conversion and/or storage of moisture-sensitive materials and disclosure. All vapor
-retarders should be placed in accordance with ASTM E 1643, and the CBC (CBSC, 2007).
• . - • - 7. IsbIated footings shall be connected to foundations per soils engineer's recommendations (see report).
,. . Sand used for base under slabs shall be a "clean" granular material, and have SE >30. 'Pea" gravel maybe
' substituted for the basal sand layer in order to improve water transmission mitigation.
. ! " Additional exterior flatwork recommendations are presented in the text of this report.
, 10. . All slabs should be provided with weken'ed plane joints to.control cracking. Joint spacing should be in
4 - accordance with correct industry standards and reviewed by the project structural engineer.
, 11. Pre-wetting is recommended for all soil conditions as follows: very low to ldw expansive (at least optimum moisture
content to a depth of 18 inches, medium expansive (at least 2-3% over optimum to a depth of 18 inches), highly
to very highly expansive (at least 4-5% over optirntirn to a depth of 24 inches).
.4 . . . , S. . '•' -. - - - -. * ç ,
- , ,' A
POST-TENSIONED SLAB DESIGN
. . .
I
.,
- - .. • . --,' 4-. • . p-', . ., :Post-tensioned slab foundation systems may be Used to support the proposed building.
Based on the as-built soil-conditions, post tensioned slabs may be designed for low to, '- highly expansive 'soil conditions, as indicated below.
, . . •••
I,. • -. 1 4 ..- .
, - *
I - . ,.- ' 4 - *' ,:
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General
The information and recommendations presented in this section are not meant to
supercede design by a..registered structural engineer or. civil engineer familiar with
post-tensioned slab designor, corrosion engineering consultant. Upon request,. GSI
could provide additional data/consultation regarding 'soil parameters as related to
post-tensioned slab design during grading: The-post-tensioned slabs should be designed
in accordance with the Post-Tensioning Institute (FTI) Method (3rd Edition). Alternatives
to the PTI method may 5 be used if equivalent systems can be proposed which
accommodate the angular distortions, expansion potential and settlement noted for this
site.
Preliminary Foundation Desigji
Based on the as-built graded conditions within the subject lots, the following table in
general accordance,with the CBC (CBSC, 2007) presents foundation desigh parameters
for post-tensioned slab foundations relative to a specific rahge of soil expansion potential.
Settlement criteria is providei in a previous section of this report and GSI (2007b)
TABLE B
Post-Tension Foundations
N
. VERO4OOW
ENTiALt (EiO-50)'.
I •'
NE.i?5i-9oD' (E.i. 1i2Oifff
e, center lift . 9.0 feet 8.7 feet 8.5 feet
em edge lift - 5.2 feet .4.5 feet
--------------
4.0 feet
y center lift 0.3 inches 0.49 inches 0.66 inches
y,,,edge lift 07 inch 1.3 inch 1.7inches
Bearing Value >
. 1,000 psi 1.000 psi 1,000 psf
Lateral Pressure 250 psf- 250 psf . 250 psf
Subgrade Modulus (k) 100 pci/inch ' 85 pci/inch 70 pci/inch
Foundation Category .
per GSI (2007b, see Reference)
Category I PT . Category II PT Category ill PT
Minimum Perimeter Footing
Embedment (2)
12 inches,. . ' 18 inches 24 inches
(1) Internal bearing values within the perimeter of thep6st-tension slab may be increased to 2,000 psf for a minimum
embedment of 12 inches, then by 20 percent for each additional foot of embedment to a maximum of 3,000 psi.
(')As measured below the lowest adjacent compacted subgrade surface:
Note: The use of open bottomed raised planters adjacent to foundations will require more onerous design parameters.
ra
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Subgrade Preparation
The subgrade material should be compacted to a minimum 90 percent of the maximum
laboratory dry density. Prior to placement of concrete, the subgrade soils should be
moisture conditioned in accordance with the following discussion.
Perimeter Footings and Pre-Wetting
From a soil expansion/shrinkage standpoint, a fairly common contributing factor to distress
of structures using post-tensioned slabs is a significant fluctuation in the moisture content
of soils underlying the perimeter of the slab, compared to the center, causing a "dishing"
or "arching" of the slabs. To mitigate this possible phenomenon, a combination of soil
pre-wetting and construction of a perimeter cut-off wall (minimum 12 inches deep) grade
beam/typical footing should be employed.
Deepened footings/edges around the slab perimeter must be used to minimize
non-uniform surface moisture migration (from an outside source) beneath the slab.
Embedment depths are presented in Table B. The bottom of the deepened footing/edge
should be designed to resist tension, usin.g cable or reinforcement per the structural
engineer. Other applicable recommendations presented under conventional foundation
recommendations in the referenced report should be adhered to during the design and'
construction phase of the project.
Floor slab subgrade should be treated in accordance with criteria presented in Table A,
Note 11 above. Pre-wetting of the slab subgrade soil prior to placement of steel and
concrete will likely be recommended and necessary, in order to achieve optimum moisture
conditions. Soil moisture contents should be evaluated at least 72 hours prior to pouring
concrete. If pre-wetting of the slab subgrade is completed prior to footing excavation, the
pad area may require period wetting in order to keep to soil from drying out. The level of
moisture needed will be dependant on the length of elapsed time between the date of the
pad(s) completion and the day of foundation/final improvements:
MITIGATION OF WATER VAPOR TRANSMISSION
The following methodologies for vapor transmission mitigation are provided below with
respect to the Robertson Ranch, East Village Project, are also presented in Table A. The
following minimum guidelines have been developed in accordance with the expansive
character of the building pad subgrade within about 7 feet of finish grade.
Very Low to Low Expansive Soils
For floor slabs bearing on very low to low expansive soil subgrades (El. of 50, or less), the
floor slab should be underlain with 2 inches of sand, over a 10-mil polyvinyl membrane
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(vapor retarder), over a 2-inch sand base. Sand used should have a minimum sand
equivalent of 30. The minimum concrete compressive strength should be 2,500 psi.
(upgraded from the prior recommendations [GSI, 20041), and constructed in accordance
with ACI 302.1R-04. All vapor retarders should be placed per ASTM E 1745 and the CBC
(CBSC, 2007).
Medium to Highly Expansive Soils
For floor slabs bearing on medium expansive soil subgrades (El. between 51 and 90), the
slab should be underlain with 2 inches of sand (SE >30), over a 15-mil vapor retarder, over
a minimum 2-inch sand (SE >30) base. The minimum concrete compressive strength
should be at least 2,500 psi. All vapor retarders should be placed per ASTM [-1643 and
the CBC (CBSC, 2007). A 2-inch layer of "pea" gravel may be substituted for the sand
layer used beneath the vapor retarder if it is desired to further mitigate water/water vapor
transmission. A 3-in6h layer of "pea" gravel or clean coarse sand is required for highly
expansive soils, if present.
Cut Lots (Lots 196, 198, 199, 203, 224, 223, and 224)
Since there is an increased potential for perched water to occur specifically on these lots,
there is an increased potential for vapor transmission. Accordingly, these lots should
utilize the recommendation mitigation for medium to highly expansive soils, discussed in
the previous section of this report regarding vapor transmission.
Other Considerations
Regardless of the soils expansion potential, an additional improvement to moisture
protection would be to extend the vapor retarder/membrane beneath all foundation
elements and grade beams. In addition, because it has been shown that the lateral
migration of water from foundation edges may contribute significantly to excess moisture
transmission, the vapor retarder/membrane could extend slightly above soils grade around
the slab/foundation perimeter and the exposed foundation face could be painted with a
latex sealer prior to color coat. Recognizing that these measures go beyond the current
standard of care, we recommend that the developer evaluate the construction issues and
costs associated with the additional measures above and determine the feasibility of
implementing them.
While these methods are considered to be overall improvements to the existing
recommendations for this project (GSI, 2004 and 2007b), they will only minimize the
transmission of water vapor through the slab, and may not completely mitigate it. Floor
slab sealants may also be used for a particular flooring product, if necessary. The use of
concrete additives that reduce the overall permeability (water reducers) of the concrete
may also be considered. Generally, slab moisture emission rates range from about 2 to
27 lbs/24 hours/1,000 square feet from a typical slab (Kanare, 2005), while typical floor
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covering manufacturers recommend about 3 lbs/24 hours as an upper limit. Accordingly,
floor coverings and improvements that can tolerate these anticipated rates should be
considered by the developer/owner.
SETBACKS
All settlement-sensitive improvements should maintain a minimum horizontal setback of
H/3 (H =slope height) from the base of the footing to the descending slope face of no less
than 7 feet, nor need not be greater than 40 feet. This distance is measured from the
improvement or footing face at the bearing elevation. Footings adjacent to unlined
drainage swales should be deepened to a minimum of 6 inches below the invert of the
adjacent unlined swale. Footings for structures adjacent to retaining walls.
,Should be deepened so as to extend below a 1:1 projection from the -heel of the wall. Alternatively,
walls maybe designed to accommodate structural loads from buildings or appurtenances,
as described in the retaining wall section of this report.
SOLUBLE SULFATES/RESISTIVITY
Based on our testing and experience in the vicinity, the majority of site soils are anticipated
to have a negligible sulfate exposure to concrete per Table 4.2.1 and 4.3.1 of the American
Concrete Institute (ACI) document 318-08, and the CBC (CBSC, 2007). Site soils are also
anticipated to be very corrosive to buried metal. This level of corrosion was evaluated by
saturated resistivity test(s). As such, the amount of soil will influence the variation in soil
Corrosivityto exposed/buried metal improvements. Consultation with a corrosion engineer
is recommended, by the designer, and/or developer.
WALL DESIGN PARAMETERS
Conventional Retaining Walls
Retaining walls should be designed in accordance with the CBC (CBSC, 2007). The
design parameters provided below assume that either non-expansive soils (Class 2
permeable filter material or Class 3 aggregate base) or native materials (up to and
including an E.I. of 50) are used to backfill any retaining walls. The type of backfill (i.e.,
select or native), should be specified by the wall designer, and clearly shown on the plans.
Building walls, below grade, should be water-proofed. The foundation system for the
proposed retaining walls should be designed in accordance with the recommendations
presented in this and preceding sections of this report regarding conventional foundation
design, as appropriate. The bottom of footings should be embedded a minimum of
18 inches below adjacent grade (excluding landscape layer, 6 inches) and should be
24 inches in width. There should be no increase in bearing for footing width-
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5,
' r a a.• - - - .. I Recommendations for specialty walls (i e cribearthstone geogrid, etc.) can be provided
upon request and would be based on site specific conditions Based on the as-built
condition of the'pad, and the current site development plan (O'Day, 2008), several cut/fill
transitions will likely occu(within the ihfluence of planned walls. Recommendations for the
*
treatment of transitions are presented in a later section of this report.
-
- - •
Restrained Walls
'S Any retaining walls that will be restrained prior to placing and compacting backfill material
or that have re-entrant or male corners, should be designed for an at-rest equivalent fluid
pressure (EFP) of 100 Ocf (native soil) or 60pcf(select), plus any applicable surcharge
loading, per Table 1610.1 oftheCBC (2007) for.YSCS,soil classification SM-SC. Forareas
of male or re-entrant corners the restrained wall design should extend a minimum distance
of twice the height of the wall (2H) laterally from the corner
Cantilevered Walls
The recommendations presented belov are.-fOrcantilevered retaining walls up to 10 feet
high Design parameters for walls less than 3 feet in height may be superceded by City
and/or County standard design. Active earth prssure may be use,d for retaining wall
design, provided the top of the wall is not restrained from minor deflections. An equivalent"',.,
fluid pressure approach may b'e used to compute the horizontal pressure against the wall.
Appropriate fluid unit weights are given below,for specific slope gradients ofthe retained
material These do not include other superimposed loading conditions due to traffic
structures, seismic events or 9dverse geologic conditions: When wall configurations, are
finalized, the appropriate loading conditions for superimposed loads can be pro'vide'd upon
request .r
-a . .:'
4 '
Level* .. .
V 35
5 , 45
.2 to 1 50 • - 60
* Level backfill,behind a retainingwall is defined as compacted 'earth materials, properly drained,
without a slope for ,a distance of 2H behind the wall.
. SE >30 and <10 percent passing No. 200 sieve. * S
, E.I. <50, SE >20, and P1 <15. . .... '. .
V
Values minimally conform to Table 1610.1 of the CBC (CBSC, 2007) • V
'a
4
V... -. .. IV
I ''_
. - •
.
V .
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Retaining Wall Backfill and Drainage
Positive drainage must be provided behind all retaining walls in the form of gravel wrapped
in geofabric and outlets. A backdrain system is considered necessary for retaining walls
that are 2 feet or greater in height. Backdrains should consist of a 4-inch diameter
perforated PVC or ABS pipe encased in either Class 2permeable filter material or 1/2-inch to 3/4-inch gravel wrapped in approved filter fabric (Mirafi 140 or equivalent). For low
expansive backfill, the filter material should extend a minimum of 1 horizontal foot behind
the base of the walls and upward at least 1 foot. For native backfill that has up to medium
expansion potential, continuous Class 2 permeable drain materials, or 1/2-inch to 3/4-flCh gravel wrapped in approved filter fabric (Mirafi 140, or equivalent) should be used behind
the wall as backfill within the active zone, defined as the area above a 1:1 projection up
from the base of the wall stem. This material should be continuous (i.e., full height) behind
the wall. The surface of the backfill should be sealed by pavement or the top18 inches
compacted to 90 percent relative compaction with native soil. For limited access and
confined areas, (panel) drainage behind the wall may be constructed. Materials with an
E.I. potential of greater than 65 should not be used as backfill for retaining walls,
regardless of the criteria for backfill summarized in the preceding table. Any wall drainage
plan should be reviewed by this office for approval prior to construction. Wall backfill
should be made by relatively light equipment. The contractor should avoid stockpiling
earth or any building material within 2H of newly completed/backfihled walls, where H is the"
,_ height of the wall, in feet.
Weeping of the walls in lieu of a backdrain is not recommended for walls greater than
2 feet in height. For walls 2 feet, or less, in height, weepholes should be no greater than
6 feet on center in the bottom coarse of block and above the landscape zone. Outlets
should consist of a 4-inch diameter solid PVC or ABS pipe spaced no greater than
±100 feet apart, with a minimum of two outlets, one on each end. The use of only weep
holes in walls higher than 2 feet should not be considered. The surface of the backfill
should be sealed by pavement or the top 18 inches compacted with native soil (E.l. <50).
Proper surface drainage should also be provided. For additional mitigation, consideration
should be given to applying a water-proof membrane to the back of all retaining structures.
The use of a waterstop should be considered for all concrete and masonry joints. Proper
surface drainage should also be provided in order to reduce the potential for surface water
penetration-
Wall/Retaining Wall Footing Transitions
Site walls are anticipated to be founded on footings designed in accordance with the
recommendations in this report. Should wall footings transition from cut to fill, the civil
designer may specify either:
a) A minimum of a 2-foot overekcavation and recompaction of cut materials for a
distance of 2H, from the point of transition.
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b) Increase of the amount of reinforcing steel and wall detailing (i.e, expansion joints
or crack control joints) such that a angular distortion of 1/360 for a distance of 2H
on either side of the transition may be accommodated. Expansion joints should be
placed no greater than 20 feet on-center, in accordance with the structural
engineer's/wall designer's recommendations, regardless of whether or not transition
conditions exist. Expansion joints should be sealed with a flexible, non-shrink grout.
C) Embed the footings entirely into native formational material (i.e., deepened
footings).
If transitions from cut to fill transect the wall footing alignment at an angle of less than
45 degrees (plan view), then the designer should follow recommendation "a" (above) and
until such transition is between 45 and 90 degrees to the wall alignment. The presence of
transitions beneath planned improvements with result in an elevated potential for distress to the particular improvement, unless the recommendations presented above are
implemented.
TOP-OF-SLOPE WALLS/FENCES/IMPROVEMENTS
Due to the potential for slope creep (see the "Development Criteria" section for a'.
discussion) for slopes higher than about 10 feet, some settlement and tilting of the
walls/fence with the corresponding distresses, should be expected. To mitigate the tilting
of top of slope walls/fences, we recommend that the walls/fences be constructed on
deepened foundations without any consideration for creep forces, where the expansion
index of the materials comprising the outer 15 feet of the slope is less than 50, or a
combination of grade beam and caisson foundations, for expansion indices greater than
50, comprising the slope, with creep forces taken into account Recommendations for
grade beam and caisson foundations can be provided upon request. Deepened
foundations should minimally provide for a lateral distance of 7 feet from the outside
bottom edge of the footing to the face of slope.
DRIVEWAY, FLATWORK, AND OTHER IMPROVEMENTS
The effects of expansive soils are cumulative, and typically occur over the lifetime of any
improvements. On relatively level areas, when the soils are allowed to dry, the dessication
and swelling process tends to cause heaving and distress to flatwork and other
improvements. The resulting potential for distress to improvements may be reduced, but
not totally eliminated. To reduce the likelihood of distress, the following recommendations
are presented for all exterior flatwork:
1. The subgrade area for concrete slabs should be compacted to achieve a minimum
90 percent relative compaction. If very low to low expansive soils are present, only
optimum moisture content, or greater, is required and specific presoaking is not
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warranted. For medium, or higher expansive soils, the subgrade should be
presoaked to 2 to 3 percentage points above (or 125 percent of) the soils' optimum
moisture content, to a depth of 12 inches below subgrade elevation. The moisture
content of the subgrade should be evaluated by the geotechnical consultant within
72 hours prior to pouring concrete.
Concrete slabs should be cast over a non-yielding surface, consisting of a 4-inch
layer of crushed rock, gravel, or clean sand, that should be compacted and level
prior to pouring concrete. If very low to low expansive soils are present, the rock
or gravel or sand is not required. The layer or subgrade should be wet-down
completely prior to pouring concrete, to minimize loss of concrete moisture to the
surrounding earth materials. Cut/Fill transitions should be mitigated beneath any
settlement sensitive improvement. The adverse effects of transitions may be
mitigated by undercutting the cut portion of the transition at least 2 feet below the
grade, and replacing with compacted fill.
Exterior slabs should be a minimum of 4 inches thick. When driveways are placed
over rock, gravel or clean sand , driveway slabs and approaches should additionally
have a thickened edge which isolates the bedding material from any adjacent
landscape area, to help impede infiltration of landscape water under the slab.
The use of transverse and longitudinal control joints are recommended to help
control slab cracking due to concrete shrinkage or expansion. Two ways to
mitigate such cracking are: a) add a sufficient amount of reinforcing steel,
increasing tensile strength of the slab; and, b) provide an adequate amount of
control and/or expansion joints to accommodate anticipated concrete shrinkage
and expansion.
In order to reduce the potential for unsightly cracks, exterior slabs may be
reinforced as indicated in Table A. The exterior slabs should be scored or saw cut,
to a minimum depth of T/4, where "T" is the thickness of the slabs in inches. Saw
cuts should be provided often enough so that no section is greater than 10 feet by
10 feet. For sidewalks or narrow slabs, control joints should be provided at intervals
of every 6 feet. The slabs should be separated from the foundations and sidewalks
with expansion/shrinkage joint filler material.
No traffic should be allowed upon the newly poured concrete slabs until they have
been properly cured to within 75 percent of design strength. Concrete compression
strength should be a minimum of 2,500 psi.
Driveways, sidewalks, and patio slabs adjacent to a structure should be separated
from the structure with expansion/shrinkage joint filler material. In areas directly
adjacent to a continuous source of moisture (i.e., irrigation, planters, etc.), all joints
should be additionally sealed with flexible mastic.
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Planters and walls should not be tied to the house.
Overhang structures should be supported on the slabs, or structurally designed
with continuous footings tied in at least two directions. If very low expansion soils
are present, footings need only be tied in one direction.
Any masonry landscape walls that are to be constructed throughout the property
should be grouted and articulated in segments no more than 20 feet long. These
segments should be keyed or doweled together.
Utilities should be enclosed within a closed utilidor (vault) or designed with flexible
connections to accommodate differential settlement and expansive soil conditions.
Positive site drainage should be maintained at all times. Finish grade on the lots
should provide for an adequate fall to the street, per the design civil engineer. It
should be kept in mind that drainage reversals could occur, including
post-construction settlement, if relatively flat yard drainage gradients are not
periodically maintained by the homeowner or homeowners association.
Air conditioning (A/C) units should be supported by slabs that are incorporated into
the building foundation, or constructed on an isolated rigid slab with flexible"
couplings for plumbing and electrical lines. NC waste water lines should be
drained to a suitable outlet.
Shrinkage cracks could become excessive if proper finishing and curing practices
are not followed. Finishing and curing practices should be performed per the
Portland Cement Association Guidelines. Mix design should incorporate rate of
curing for climate and time of year, sulfate content of soils, corrosion potential of
soils, and fertilizers used on site. If spray on typical curing is employed, apply as
soon as-possible after finishing. Use Hunt's curing compound, or equivalent.
PRELIMINARY PAVEMENT DESIGN
Preliminary pavement section design was performed in general accordance with the
California Department of Transportation (Caltrans) Highway Design Manual of Instructions
(2006), traffic index data provided by the project civil engineer, and the minimum sections
per the City. Pavement sections are based on the aforementioned criteria, the City of
Carlsbad (1993) design criteria, and the resistance fl-value data estimated for the area.
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Parking Lot Stalls/Cul De Sac! ' 4.5 .9 ' 4.0 . 5.0 Low Traffic Private Streets .
Private Streets ' 5.0 9 . 4.0
, 7.0 .
Denotes class 2Aggregate Base "R%:78, SE >25).
Final pavement sections shall'be based on site specific R-valte testing upon completion of underground improvements. All pavement construction should be performed in
accordance with the currently approved, and applicable specifications, and the standard
of practice Best management construction practices should be followed at all times
especially during inclement weather.
DEVELOPMENT CRITERIA
Slope Deformation
General
• -
Compacted fill slopes, designed using customary factors of safety for gross or surficial,
.. stability; and constructed in general accordance with the design specifications, should'be
' expected to undergo some differential vertical heave or settlement in combination
with "differential lateral movement in, the out-of-slope direction, after grading. This
rn pOst-construction movement occurs in two fors: slope creep; and, lateral fill,extension l
(LFE). . • . .- . . I
.
, . '. 2 -s .
Slope Creep
Slope creep is caused by alternate wetting and', drying of the fill soils which results in s16w
. downslope movement. This type of movement is expected to occur throughout the life"of
the slope and is anticipated to potentially affect improvements or structures (i.e.', separations and/or cracking), placed near the top-of-slope, 'generally within a horizontal
distance of approximately 15 feet, measured' from the. outer, deepest (bottom outside)
edge of the improvement, t6 the face of slope. The actual width of the zone affected i
generally dependant upon: 1) the height of the slope; 2) the amount of irrigation/rainfall the
slope receives; and, 3) the type of materials comprising the slope. This movement
generally results in rotation and differential settlement of improvements located within the
creep zone 4 -
Suitable mitigative measures to reduce the potential for distress due to lateral deformation
typically include setback of improvements from the slope faces (per the 2007 CBC)
positive structural separations (i.e, joints) between imprOvements; and, stiffening and
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deepening of foundations. Per Section 1805.3.1 of the 2007 CBC, a horizontal setback
(measured from the slope face to the outside bottom edge of the building footing) of H/3
is provided for structures, where H is the height of the fill slope in feet and H/3 need not be
greater than 40 feet. Alternatively, in consideration of the discussion presented above, site
conditions and Section 1805.3.1 of the 2007 CBC, H/3 generally need not be greater than
20 feet for the development. As an alternative to a deepened footing, where the adjacent
slope is greater than 45 feet in height and the building/footing is within 20 feet from the
slope face, a differential settlement of 0.5 inch (additional) may be applied to the design
of that portion of the structure(s). Any settlement-sensitive improvements (i.e., walls ,spas,
flatwork, etc.) should minimally consider the above.
Lateral Fill Extension (LFE)
LFE occurs due to deep wetting from irrigation and rainfall on slopes corhjrised of
expansive materials. Based on the generally very low expansive character of onsite soils,
the potential component of slope deformation due to LFE is considered minor, but may not
be totally precluded. Although some movement should be expected, long-term movement
from this source may be minimized, but not eliminated, by generally placing the fill
throughout the slope region, wet of the fill's, optimum moisture content, as was done on
this project.
Summary
It is generally not practical to attempt to eliminate the effects of either slope creep or LFE
Suitable mitigative measures to reduce the potential of lateral deformation typically include:
setback of improvements from the slope faces (per the CBC [CBSC, 2007]); positive
structural separations (i.e., joints) between improvements; stiffening; and, deepening of
foundations. All of these measures are recommended for design of structures and
improvements and minimizing the placement of "dry" fills.
Slope Maintenance and Planting
Water has been shown to weaken the inherent strength of all earth materials. Slope
stability is significantly reduced by overly wet conditions. Positive surface drainage, away
from slopes, should be maintained and only the amount of irrigation necessary to sustain
plant life should be provided for planted slopes. Over-watering should be avoided as it can
adversely affect site improvements and cause perched groundwater conditions. Graded
slopes constructed utilizing onsite materials would be erosive. Eroded debris may be
minimized and surficial slope stability enhanced by establishing and maintaining a suitable
vegetation cover soon after construction. Compaction to the face of fill slopes would tend
to minimize short-term erosion until vegetation is established. Plants selected for
landscaping should be light weight, deep rooted types that require little water and are
capable of surviving the prevailing climate. Jute-type matting, or other fibrous covers, may
aid in allowing the establishment of a sparse plant cover. Utilizing plants other than those
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recommended above will increase the potential for perched water, staining, mold, etc. to
develop. A rodent control program to prevent burrowing should be implemented.
Irrigation of natural (ungraded) slope areas is generally not recommended.
Over-steepening of slopes should be avoided during building construction activities and
landscaping.
Drainage
Adequate lot surface drainage is a very important factor in reducing the likelihood of
adverse performance of foundations, hardscape, and slopes. Surface drainage should be
sufficient to prevent ponding of water anywhere on a lot, and especially near structures and
tops of slopes. Lot surface drainage should be carefully taken into consideration during
fine grading, landscaping, and building construction. Therefore, care should be taken that
future landscaping or construction activities do not create adverse drainage ádnditions.
Positive site drainage within lots and common areas should be provided and maintained
at all times. Drainage should not flow uncontrolled down any descending slope. Water
should be directed away from foundations and not allowed to pond and/or seep into the
ground. In general, the area within 3 feet around a structure should slope away from the
structure We recommend that unpaved lawn and landscape areas have a minimum
gradient of 1 percent sloping away from structures, and whenever possible, should be
above adjacent paved areas. Consideration should be given to avoiding construction of
raised planters adjacent to structures (buildings, pools, spas, etc.). Pad drainage should
be directed toward the street or other approved area(s). Although not a geotechnical
requirement, roof gutters, down spouts, or other appropriate means may be utilized to
control roof drainage. Down spouts, or drainage devices, should outlet a minimum of
3 feet from structures or into an alternate, approved area, such as a drainage system
swale. Areas of seepage may develop due to irrigation or heavy rainfall, and should be
anticipated. Minimizing irrigation will lessen this potential. If areas of seepage develop,
recommendations for minimizing this effect could be provided upon request.
Erosion Control
Cut and fill slopes will be subject to surficial erosion during and after grading. Onsite earth
materials have a moderate to high erosion potential. Consideration should be given to
providing hay bales and silt fences for the temporary control of surface water, from a
geotechnical viewpoint.
Landscape Maintenance
Only the amount of irrigation necessary to sustain plant life should be provided.
Over-watering the landscape areas will adversely affect proposed site improvements. We
recommend that any open-bottom, raised box planters adjacent to proposed structures
be restricted for a minimum distance of 10 feet. As an alternative, closed-bottom type
- - raised planters could be utilized. An outlet placed in the bottom of the planter could be
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installed to direct drainage away from structures or any exterior concrete flatwork.
I
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r
a
i
s
e
d
box planters are constructed adjacent to structures, the sides and bottom of t
h
e
p
l
a
n
t
e
r
should be provided with a moisture retarder to prevent penetration of irrigation wate
r
i
n
t
o
the subgrade. Provisions should be made to drain the excess irrigation water f
r
o
m
t
h
e
planters without saturating the subgrade below or adjacent to the planters. Graded
s
l
o
p
e
areas should be planted with drought resistant vegetation. Consideration sho
u
l
d
b
e
given to the type of vegetation chosen and their potential effect up
o
n
s
u
r
f
a
c
e
improvements (i.e., some trees will have an effect on concrete flatwork with thei
r
e
x
t
e
n
s
i
v
e
root systems). From a geotechnical standpoint, leaching is not recommend
e
d
f
o
r
establishing landscaping. If the surface soils are processed for the purpose of
a
d
d
i
n
g
amendments, they should be recompacted to 90 percent minimum relative
c
o
m
p
a
c
t
i
o
n
.
Toe of Slope Drains/Toe Drains
Where significant slopes intersect pad areas, surface drainage down the slope allo
w
s
f
o
r
some seepage into the subsurface materials, sometimes creating conditions cau
s
i
n
g
o
r
contributing to perched and/or ponded water. Toe of slope/toe drains may be
b
e
n
e
f
i
c
i
a
l
in the mitigation of this condition due to surface drainage. The general criteria
t
o
b
e
utilized by the design engineer for evaluating the need for this type of drain is as
f
o
l
l
o
w
s
:
Is there a source of irrigation above or on the slope that could contribu
t
e
t
o
'
saturation of soil at the base of the slope?
Are the slopes hard rock and/or impermeable, or relatively permeable, or; do t
h
e
slopes already have or are they proposed to have subdrains (i.e., stabilizatio
n
f
i
l
l
s
,
etc.)?
Was the lot at the base of the slope overexcavated or is it proposed t
o
b
e
overexcavated? Overexcavated lots located at the base of a slope coul
d
accumulate subsurface water along the base of the fill cap.
Are the slopes north facing? North facing slopes tend to receive less sunlight (l
e
s
s
evaporation) relative to south facing slopes and are more exposed to the cu
r
r
e
n
t
l
y
prevailing seasonal storm tracks.
What is the slope height? It has been our experience that slopes with height
s
i
n
excess of approximately 10 feet tend to have more problems due to storm runoff
and irrigation than slopes of a lesser height.
Do the slopes "toe out" into a residential lot or a lot where perched or ponded wa
t
e
r
may adversely impact its proposed use?
Based on these general criteria, the construction of toe drains may be considere
d
b
y
t
h
e
design engineer along the toe of slopes, or at retaining walls in slopes, desce
n
d
i
n
g
t
o
t
h
e
rear of such lots. Following are Detail 1 (Schematic Toe Drain Detail) and
D
e
t
a
i
l
2
(
T
o
e
Brookfield San Diego Builders, Inc.
W.O. 5353-B1-SC PA 18 Robertson Ranch, East Village
September 17, 2008 FiIe:e:\wp9\5300\5353b1 .ror.pal8
Page 24 GeoSoils, Inc.
//- Pad grade
Drain may be
constructed into, or
at, the toe-of-slope
I Drain pipe .
Soil cap compacted to 90 percent relative compaction.
Permeable material may be gravel wrapped in filter fabric (Mirafi 140N or equivalent).
4-inch-diameter, perforated pipe (SDR-35 or equivalent) with perforations down.
Pipe to maintain a minimum 1 percent fall.
Concrete cut-off wall to be provided at transition to solid outlet pipe.
Solid outlet pipe to drain to approved area.
Cleanouts are recommended at each property line.
rr
SCHEMATIC TOE DRAIN DETAIL Detail 1
Mirafi 140 filter
fabric or equivalent
rich crushed gravel
To
Ret
Finish grad
Wall to
2:1 (H:V) slope (typical)
Backfill with compacted
rti,p t-iIc
1to2 feet' - inches1
NOTES:
Soil cap compacted to 90 percent relative compaction.
Permeable material may be gravel wrapped in filter fabric (Mirafi 140N or equivalent).
4-inch-diameter, perforated pipe (SDFI-35 or equivalent) with perforations down.
Pipe to maintain a minimum 1 percent fall.
Concrete cut-off wall to be provided at transition to solid outlet pipe.
Solid outlet pipe to drain to approved area.
Cleanbuts are recommended at each property line.
Effort to compact should be applied to drain rock.
row SUBDRAIN ALONG RETAINING WALL DETAIL Detail 2
zn
Drain Along Retaining Wall Detail). Other drains may be warranted due to unforeseen
conditions, homeowner irrigation, or other circumstances. Where drains are constructed
during grading, including subdrains, the locations/elevations of such drains should be
surveyed, and recorded on the final as-built grading plans by the design engineer. It is
recommended that the above be disclosed to all interested parties, including homeowners
and any homeowners association.
Toe drains were constructed at the completion of grading in general accordance with the
recommendations provided by this Office. The approximate locations of toe drains
constructed are shown on Plates 1 through 4. An additional toe drain is recommended
along the rear of lots 195 through 206. This drain has not been constructed to date, due
to the presence of large stockpiles of aggregate base.
Subsurface and Surface Water
Subsurface and surface water are not anticipated to affect site development, provided the
recommendations contained in this report are incorporated into final design and
construction, and that prudent surface and subsurface drainage practices are incorporated
into the construction plans. Perched groundwater conditions, along zones of contrasting
permeabilities, may not be precluded from occurring in the future due to site irrigation,
poor drainage conditions, or damaged utilities, and should be anticipated. Should,
perched groundwater conditions develop, this office could assess the affected area(s) and
provide the appropriate recommendations to mitigate the observed groundwater
conditions. Groundwater conditions may change with the introduction of irrigation, rainfall,
or other factors.
Tile Flooring
Tile flooring can crack, reflecting cracks in the concrete slab below the tile, although small
cracks in a conventional slab may not be significant. The tile installer should consider
installation methods that reduce possible cracking of the tile such as slipsheets, a vinyl
crack isolation membrane, or other approved method by the Tile Council of
America/Ceramic Tile Institute.
Site Improvements
If in the future, any additional improvements (e.g., pools, spas, etc.) are planned for the
site, recommendations concerning the geological or geotechnical aspects of design and
construction of said improvements could be provided upon request. Pools and/or spas
should not be constructed without specific design and construction recommendations from
GSI, and this construction recommendation should be provided to the homeowners
association or other interested/affected parties. This office should be notified in advance
of any fill placement, grading of the site, or trench backlilling after rough grading has been
completed. This includes any grading, utility trench and retaining wall backfills, flatwork,
etc.
Brookfield San Diego Builders, Inc. W.O. 5353-B1-SC PA 18 Robertson Ranch, East Village September 17, 2008
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GeoSoIk, Inc.
Additional Grading
This office should be notified in advance of any 1111 placement, supplemental regrading of
the site, or trench backlilling after rough grading has been completed. This includes
completion of grading in the street and parking areas and utility trench and retaining wall
backfills.
Rough grading is generally completed throughout PA-1 8. However, the area of the site is
only "sheet" graded in the vicinity of Lots 195 through 206, due to the presence of large
stockpiles of aggregate base, and other rock products generated during mass grading.
Upon removal of these stockpiled materials, additional grading will be necessary to bring
these lots to the desired grades. Earth materials used to complete these lots shall be
compatible with existing, as-built soil conditions described in Table 2.
Preliminary Pool/Spa Design Recommendations
The following minimal preliminary recommendations are provided for consideration in
pool/spa design and planning. The following recommendations should be provided to any
contractors and/or subcontractors, etc., that may perform such work.
The pool system should be designed and constructed in accordance with-
guidelines presented in the latest adopted edition of the CBC (CBSC, 2007). The
pool shell should be embedded entirely into properly compacted fill. Pools
proposed in the vicinity of Lots 206 through 218, 233 through 259,268 through 304,
and 309 may require overexcavation for the pool shell due to the presence of fill
with a high percentage Of rock fragments at depths potentially as shallow as 5 feet
below pad grade. Overexcavation depths should be reviewed on a lot by lot basis,
as plans are developed.
The equivalent fluid pressure against a cantilever wall free to yield at the top, may
minimally be assumed as 62 pcf.
The equivalent fluid pressure against a non-yielding wall or a wall restrained from
movement at the top, may be minimally assumed as 100 pcI, per the CBC
(CBSC, 2007) for these soil conditions.
The preceding unit weights do no include superimposed loading from expansive
soil pressure, earthquakes, traffic or adjacent building /wall loads. These loads
could be provided upon request.
Passive earth pressure may be computed as an equivalent fluid having a density of
250 pcI, to a maximum earth pressure of 2,500 psf.
An allowable coefficient of friction between soil and concrete of 0.35 may be used
with the dead load forces.
Brookfield San Diego Builders, Inc. W.O. 5353-B1-SC PA 18 Robertson Ranch, East Village September 17, 2008 Fi1e:e:\wp9\5300\5353b1.ror.pa18 Page 28
-
GeoSoiJs, Inc.
When combining passive pressure and frictional resistance, the passive pressure
component should be reduced by one-third.
The geotechnical consultant should review and approve all aspects of pool/spa and
flatwork design prior to construction. Recommendations for pool flatwork are
presented in a followind section. A design civil engineer should review all aspects
of such design, including drainage and setback conditions, per the CBC
(CBSC, 2007).
All aspects of construction should be reviewed and approved by the geotechnical
consultant, including during excavation, prior to the placement of any additional fill,
prior to the placement of any reinforcement or pouring of any concrete.
Where pools are planned near structures, appropriate surcharge loads need to be
incorporated into design and construction by the pool designer.
All pool walls should be designed as "free standing" and be capable of supporting
the water in the pool without soil support per Section 1805.3.3, Chapter 18 of the
CBC (CBSC, 2007).
The pool structure should be set back from any adjacent descending
slope in accordance with the CBC (CBSC, 2007).
The soil beneath the pool/spa bottom should be uniformly moist with the same
stiffness throughout. If a fill/cut transition occurs beneath the pool bottom, the cut
portion should be overexcavated to a minimum depth of 24 inches, and replaced
with compacted fill- The fill should be placed at a minimum of 90 percent relative
compaction, at over-optimum moisture conditions. The potential for grading and/or
re-grading of the pool bottom, and attendant potential for shoring and/or slot
excavation, needs to be considered during all aspects of pool planning, design, and
construction. If pool subgrade conditions are wet, or saturated, provisions for
drying back overexcavated soils, or importing/mixing with drier soils may be
necessary. In order to minimize the effects of expansive soils, soils placed above
the undercut should be low expansive (E.l. <50).
Hydrostatic pressure relief valves should be incorporated into the pool and spa
designs. A pool under-drain system should also be considered, with an appropriate
outlet for discharge, depending on pool location.
All fittings and pipe joints, particularly fittings in the side of the pool or spa, should
be properly sealed to prevent water from leaking into the adjacent soils materials.
An elastic expansion/shrinkage joint (waterproof sealant) should be installed to
prevent water from seeping into the soil at all deck joints.
Brookfield San Diego Builders, Inc. W.O. 5353-B1-SC PA 18 Robertson Ranch, East Village September 17, 2008 File:e:\wp9\5300\5353b 1 .ror.pa 18 Page 29
GeoSoils, Inc.
Reinforced grade beams should be placed around skimmer inlets to provide
support and mitigate cracking around the skimmer face.
Pool decking/flatwork should be pre-wet/pre-soaked per the Foundation Section of
this report.
Regardless of the methods employed, once the pool/spa is filled with water, should
it be emptied, there exists some potential that if emptied, significant distress may
occur. Accordingly, once filled, the pool/spa should not be emptied unless
evaluated by the geotechnical consultant.
Footing Trench Excavation
All footing excavations should be observed by a representative of this firm subsequent, to
trenching and prior to concrete form, and reinforcement placement The purpose of the
observations is to verify that the excavations are made into the recommended bearing
material and to the minimum widths and depths recommended for construction. If loose
or compressible materials are exposed within the footing excavation, a deeper footing or
removal and recompaction of the subgrade materials would be recommended at that time.
Footing trench spoil and any excess soils generated from utility trench excavations should
be compacted to a minimum relative compaction of 90 percent, if not removed from the
site.
Trenching
Considering the nature of the onsite soils, it should be anticipated that caving or sloughing
could be a factor in subsurface excavations and trenching. Shoring or excavating the
trench walls at the angle of repose (typically 25 to 45 degrees) may be necessary and
should be anticipated. All excavations should be observed by one of our representatives
and minimally conform to Cal-OSHA and local safety codes.
Utility Trench Backfill
All interior utility trench backfill should be brought to at least 2 percent above
optimum moisture content and then compacted to obtain a minimum relative
compaction of 90 percent of the laboratory standard. As an alternative for shallow
(12-inch to 18-inch) under-slab trenches, sand having a sand equivalent value of
30 or greater may be utilized and jetted or flooded into place. Observation, probing
and selective testing should be provided to evaluate the desired results.
2. Exterior trenches adjacent to, and within areas extending below a 1:1 plane
projected from the outside bottom edge of the footing, and all trenches beneath
hardscape featUres and in slopes, should be compacted to at least 90 percent of
the laboratory standard Sand backfill, unless excavated from the trench, should
Brookfield San Diego Builders, Inc. W0 5353-B1-SC PA 18 Robertson Ranch, East Village September 17, 2008 File: e:\wp9\5300\5353b 1 .ror.pa 18 Page 30
GeoSolls, Inc.
not be used in these backfill areas. Selective compaction testing and observations,
along with probing, should be accomplished to verify the desired results.
All trench excavations should conform to Cal-OSHA and local safety codes.
Utilities crossing grade beams, perimeter beams, or footings should either pass
below the footing or grade beam utilizing a hardened collar or foam spacer, or pass
through the footing or grade beam in accordance with the recommendations of the
structural engineer.
SUMMARY OF RECOMMENDATIONS REGARDING
GEOTECHNICAL OBSERVATION AND TESTING
We recommend that observation and/or testing be performed by GSI at each of the
following construction stages:
During grading/recertification.
After excavationof building footings, retaining wall footings, and free standing walls
footings, prior to the placement of reinforcing steel or concrete.
Prior to pouring any slabs or flatwork, after presoaking/presaturation of building
pads and other flatwork subgrade, before the placement of concrete, reinforcing
steel, capillary break (i.e., sand, pea-gravel, etc.), or vapor retarders (i.e., visqueen,
etc.), as necessary.
During retaining wall subdrain installation, prior to backfill placement-
During placement of backfill for area drain, interior plumbing, utility line trenches,
and retaining wall backfill, as necessary:
During slope construction/repair.
When any unusual soil conditions are encountered during any construction
operations, subsequent to the issuance of this report.
When any developer or homeowner improvements, such as flatwork, spas, pools,
walls, etc., are constructed.
A report of geotechnical observation and testing and/or field testing reports, should
be provided at the conclusion of each of the above stages as necessary, in order
to provide concise and clear documentation of site work, and/or to comply with
code requirements.
Brookfield San Diego Builders, Inc.
W.O. 5353-B1-SC PA 18 Robertson Ranch, East Village
September 17, 2008 FiIe:e:\wp9\5300\5353b1sor.pa18
Page 31
GeoSoils, Inc.
GSI should review project sales documents to homeowners/homeowners
associations for geotechnical aspects, including irrigation practices, the conditions
outlined above, etc., prior to any sales. At that stage, GSI will provide homeowners
maintenance guidelines which should be incorporated into such documents.
OTHER DESIGN PROFESSIONALS/CONSULTANTS
The design civil engineer, structural engineer, post-tension designer, architect, landscape
architect, wall designer, etc., should review the recommendations provided herein,
incorporate those recommendations into all their respective plans, and by explicit
reference, make this report part of their project plans. This report presents minimum
design criteria for the design of slabs, foundations and other elements possibly applicable
to the project. These criteria should not be considered as substitutes for actual designs
by the structural engineer/designer. The structural engineer/designer should analyze
actual soil-structure interaction and consider, as needed, bearing, expansive soil influence,
and strength, stiffness and deflections in the various slab, foundation, and other elements
in order to develop appropriate, design-specific details. As conditions dictate, it is possible
that other influences will also have to be considered. The structural engineer/designer
should consider all applicable codes and authoritative sources where needed If analyses
by the structural engineer/designer result in less critical details than are provided herein
as minimums, the minimums presented herein should be adopted. It is considered likely
that some, more restrictive details will be required. If the structural engineer/designer has
any questions or requires further assistance, they should not hesitate to call or otherwise
transmit their requests to GSI. In order to mitigate potential distress, the foundation and/or
improvement's designer should confirm to GSI and the governing agency, in writing, that
the proposed foundations and/or improvements can tolerate the amount of differential
settlement and/or expansion characteristics and design criteria specified herein.
HOMEOWNERS/HOMEOWNERS ASSOCIATIONS
It is recommended that the developer should notify, and/or make available the findings,
conclusions and recommendations presented in this report to any homeowners or
homeowners association, in order to minimize any misunderstandings regarding the
design and performance of earth structures, and the design and performance of existing
and/or future or proposed improvements.
PLAN REVIEW
Any additional project plans generated for this project should be reviewed by this office,
prior to construction, so that construction is in accordance with the conclusions and
- recommendations of this report.
Brookfield San Diego Builders, Inc. W.O. 5353-81-SC
PA 18 Robertson Ranch, East Village September 17, 2008
File: e:\wp9\5300\5353b1.ror.pale Page 32
GeoSoils, Inc.
LIMITATIONS
The materials encountered on the project site and utilized for our analysis are believed
representative of the area; however, soil and bedrock materials vary in character between
excavations and natural outcrops or conditions exposed during mass grading. Site
conditions may vary due to seasonal changes or other factors.
Inasmuch as our study is based upon our review and engineering analyses and laboratory
data, the conclusions and recommendations are professional opinions. These opinions
have been derived in accordance with current standards of practice, and no warranty,
either express or implied, is given. Standards of practice are subject to change with time.
GSI assumes no responsibility or liability for work or testing performed by Others, or their
inaction; or work performed when GSI is not requested to be onsite, to evaluate if our
recommendations have been properly implemented. Use of this report constitutes an
agreement and consent bythe user to all the limitations outlined above, notwithstanding
any other agreements that may be in place. In addition, this report may be subject to
review by the controlling authorities. Thus, this report brings to completion our scope of
services for this portion of the project. All samples will be disposed of after 30 days, unless
specifically requested by the Client, in writing.
Brookfield San Diego Builders, Inc. W.O. 5353-B1-SC PA 18 Robertson Ranch, East Village September 17, 2008 File: e:\wp9\5300\5353b1.ror.pal8
Page 33
GeoSoils, Inc.
The opportunity to be of service is sincerely appreciated. If you should have any
questions, please do not hesitate to call our office.
Respectfully submted —.. -
/N AL . \\ //'),'•'
GeoSoils, Inc A+
I IY I uj k No. GE2'2C. ?Ulj
Robert G. Crisn ?/ /Ancv T. GuaeIli 7
Engineering GeoI %34 Geotechnical EngineeE22o
Reviewed by: / 1,f:A'• 1/,\O
Fr inaering T John P. Frank ip\
Engineering G eE4
RGC/ATGIJ PF/jk/jh
Attachments: Table 1 - Field Density Test Results
Table 2 - Lot Characteristics
Appendix - References
Plates 1 through 4 - Geotechnical Maps
Distribution: (4) Addressee
(2) O'Day Consultants, Attention: Mr. Keith Hansen
Brookfield San Diego Builders, Inc. W.0 5353-B1-SC
PA 18 Robertson Ranch, East Village September 17, 2008
File:e:\wp9\5300\5353b1 .rorpa 18 Page 34
GeoSoils, Inc.
Table 1
FIELD DENSITY TEST RESULTS
NO
TEST..DATE:TEST LOCATION TRACT
NO
ELEV
OR
DEPTH (ft)
MOISTURE
CONTENT
DRY
DENSITY
REL
COMP
TEST
METHOD
SOIL
TYPE
197* 5/3/07 Lot 257 PA-1 8 78.0 9.2 111.4 88.4 ND E
197A 5/3/07 Lot257 PA-18 78.0 11.0 1144 90.8 ND E
198* 5/3/07 Lot 256 PA-18 77.5 8.8 110.1 87.4 ND E
198A 5/3/07 Lot 256 PA-18 775 11.0 115.2 91.4 ND E
199 5/3/07 Lot 270 PA-18 73.0 13.2 109.4 90.8 SC C
200 5/3/07 Lot 272 PA-1 8 73.0 14.2 109.9 91.2 ND C
201 5/3/07 Lot 274 PA-18 73.0 13.6 108.7 90.2 ND C
202 5/3/07 Lot 273 PA-1 8 74.0 10.4 114.3 90.0 ND A
203 5/3/07 Lot 271 PA-1 8 74.0 13.0 109.5 90.9 ND C
204 5/3/07 Lot 293 PA-18 72.5 13.2 108.6 90.0 SC C
205 5/3/07 Lot 309 Rec Area PA-1 8 73.0 10.3 117.2 92.3 ND A
206 5/3/07 Lot296 PA-18 73.0 13.0 109.2 90.6 ND C
207 5/3/07 Lot 299 PA-18 74.0 10.8 115.8 91.2 ND A
208 5/3/07 Lot 300 PA-1 8 74.0 13.3 108.5 1 90.0 ND C
209 5/4/07 Lot 303 PA-18 73.0 13.4 102.7 90.1 ND B
210 5/4/07 Lot 301 PA-18 74.0 13.0 104.2 91.4 sc B
211 5/4/07 K Street 12+00 PA-1 8 68.0 14.2 103.3 90.6 ND B
212 5/4/07 K Street 14+00 PA-i8 65.0 13.6 102.8 90.2 ND 13
213 5/4/07 Lot303 PA-18 75.0 13.0 105.2 92.3 ND B
214 5/4/07 Lot309 PA-18 74.5 13.8 103.7 91.0 ND B
333 5/16/07 K Street 20+00 PA-18 64.0 10.6 114.3 90.0 ND A
334 5/16/07 K Street 19+50 PA-1 8 66.0 11.4 115.8 91.2 ND A
335 5/16/07 K Street 18+50 PA-18 680 13.2 102.9 90.3 ND B
336 5/16/07 K Street 20+00 PA-18 70.0 10.1 115.1 90.6 ND A
337 5/16/07 K Street 20+50 PA-18 64.0 11.6 114.4 90.1 SC A
338 5/16/07 J Street PA-18 66.0 14.7 104.2 91.4 ND B
339 5/16/07 - - J Street PA-18 68.0 18.8 103.6 90.9 ND B
340 5/16/07 J Street PA-18 70.0 14.2 102.9 90.3 ND B
343 5/16/07 Glen Avenue 29±00 PA-18 68.0 16.1 110.4 91.6 ND C
344 5/16/07 Glen Avenue 30+00 PA-18 70.0 11.2 114.5 90.2 ND A
345 5/16/07 LStreet PA-18 64.0 13.6 109.4 90.8 sc c
346 5/16/07 LStreet PA-18 68.0 13.2 103.1 90.4 ND B
348 5/17/07 G Street PA-18 74.0 18.5 100.0 90.1 ND L
349 5/17/07 G Street PA-18 76.0 14.2 105.2 92.3 ND B
370* 5/22/07 Lot 250 PA-18 73_5 10.1 99.6 87.4 sc B
370A 5/22/07 Lot 250 PA-18 73.5 14.8 103.3 90.6 sc B
371 * 5/22/07 Lot 252 PA-1 8 74.0 11 .2 98.4 86.3 ND B
371A 5/22/07 Lot 252 PA-18 74.0 15.3 102.7 90.1 ND B
372* 5/22/07 Lot 255 PA-18 77.0 10.9 100.0 87.7 ND B
372A 5/22/07 Lot 255 PA-18 77.0 14.2 104.1 91.3 ND B
373* 5/22/07 Lot 226 PA-lB 73.0 8.7 108.2 85.2 SC A
373A 5/22/07 Lot 226 PA-1 8 1 3.0 11.0 115.2 90.7 sc A
- 374* 5/22/07 Lot 279 PA-1 8 1 72.0 6.7 109.7 86.4 SC A
Brookfield San Diego Builders, Inc. W.O. 5353-Bi-SC
PA 18 Robertson Ranch, East Village September 2008
File: C:\excel\tables\5300\5353b1.ror.pal8 Page 1
GeoSoils, Inc.
Table 1
FIELD DENSITY TEST RESULTS
TEST
NO
DATE TEST LOCATION TRACT
NO
ELEV
OR
DEPTH
MOISTURE
CONTENT
DRY
DENSITY
(Pct)
REL
COMP
TEST
METHOD
SOIL
TYPE
374A 5/22/07 Lot 279 PA-18. 72.0 10.3 114.8 90.4 SC A
375 5/22/07 Lot 250 PA-18 73.0 10.6 114.6 90.2 ND A 376 5/22/07 Lot 250 PA-18 75.0 14.7 102.6 90.0 ND B
377 5/23/07 Lot 237 PA-18 75.9 10.1 114.3 90.0 ND A
378 5/23/07 Lot 219 PA-18 78.0 10.5 114.5 90.2 ND A
379 5/23/07 Lot 233 PA-18 79.0 10.2 114.4 90.1 ND A
380 5/23/07 Lot 231 PA-1 8 80.0 10.9 115.2 90.7 ND A
381 5/23/07 Lot 229 PA-18 82.0 10.0 114.3 90.0 SC A 382* 5/23/07 Lot 236 PA-18 78.0 1.2.2 104.1 86A . ND C 382A 5/23/07 Lot 236 PA-18 78.0 14.0 108.8 90.3 ND C 383* 5/23/07 Lot 220 PA-1 8 89.9 10.8 103.3 85.7 ND C
383A 5/23/07 Lot 220 PA-1 8 89.9 14.5 108.5 90.0 SC C 384* 5/23/07 Lot 232 PA-1 8 80.0 11.7 105.8 87.8 ND C
384A 5/23/07 Lot 232 PA-18 80.0 14.3 109.3 90.7 ND C 385* 5/23/07 Lot 228 PA-18 82.5 9.6 102.9 85.4 ND C
385A 5/23/07 Lot 228 PA-18 82.5 14.1 109.2 90.6 ND C
386 5/24/07 Lot 205 PA-18 83.5 14.7 109.3 90.7 ND . C 387 5/24/07 1 Lot 206 PA-18 84.5 13.3 115.1 90.6 ND A
388 5/24/07 Lot 228 PA-18 84.5 18.8 100.7 90.7 SC L
389 5/24/07 Lot 234 PA-18 80.0 20.2 101.5 91.4 ND L 390* 5/24/07 Lot 217 PA-18 80.0 14.2 95.5 86.0 ND L
390A 5/24/07 Lot 217 PA-18 80.0 18.7 103.7 93.4 SC L
391 5/24/07 Lot 218 PA-18 83.0 18.6 99.9 90.0 ND L 392* 5/24/07 Lot 216 PA-18 78.0 13.1 100.2 90.3 ND L 392A 5/25/07 Lot 216 PA-18 78.0 18.8 100.7 90.7 ND L 393* 5/24/07 Lot 238 PA-1 8 73.0 14.5 99.9 90.0 ND L
393A 5/25/07 .. Lot 238 PA-18 73.0 19.3 100.1 90.2 ND L
394 5/24/07 Lot260 PA-18 65.0 18.8 101.7 91.6 ND L 395 5/24/07 Lot 269 PA-18 70.0 18.5 100.7 90.7 ND L 396 5/24/07 K Street PA-18 80.0 19.2 100.8 90.9 SC L 397 5/24/07 Lot 268 PA-18 70.0 18.6 101.5 91.4 ND L
398 5/24/07 Lot 257 PA-18 76.0 19.0 100.4 90.5 ND L 399* 5/25/07 Lot 260 PA-18 77.0 15.2 101.5 91.4 ND L
399A 5/25/07 Lot 260 PA-lB 77.0 19.5 100.7 90.7 ND L 400* 5/25/07 Lot 259 PA-18 77.5 14.3 103.9 93.6 ND L
400A 5/25/07 Lot 259 PA-18 77.5 18.7 100.3 90.4 ND L 401* 5/25/07 Lot 268 PA-18 74.0 16.4 101.8 91.7 SC L
401 A 5/25/07 Lot 268 PA-1 8 74.0 18.9 101.3 91.2 SC L
402 5/25/07 Lot 267 PA-18 74.5 18.7 100.2 90.3 ND L
403 5/25/07 Lot 261 PA-18 79.0 19.4 99.9 90.0 ND L 404 5/25/07 Lot 262 PA-lB 78.0 18.5 100.8 90.8 ND L 405 5/25/07 Lot 259 PA-18 79.0 18.8 100.1 90.2 1 ND L 416 5/29/07 Lot 265 PA-18 77.0 18.5 100.2 90.3 ND L
Brookfield San Diego Builders, Inc. W.O. 5353-Bi-SC
PA 18 Robertson Ranch, East Village September 2008
File: C:\excel\tables\5300\5353bl.ror.pal8 Page 2
GeoSoils, Inc.
Table 1
FIELD DENSITY TEST RESULTS
NO
1"EI LECATiCN TRACT:'
NO
'E[EV'
OR
DEPTH (ft)
MOISTURE
CONTENT
(%)
DRY
DENSITY
(pcf)
'REL"
COMP
(%)
;'TEST.''
METHOD
So IL
TYPE
417 5/29/07 Lot 267 PA-18 76.5 18.7 100.0 90.0 ND L
418 5/29/07 Lot 269 PA-lB 75.5 18.6 101.3 91.2 ND I..
419 5/30/07 Lot 270 PA-1 8 71.0 18.5 109.5 98.6 ND I..
420 5 /30/07 Lot273 PA-lB 73.0 18.7 105.0 94.5 ND L
421 5/30/07 Lot 221 PA-18 90.0 18.9 104.8 94.4 ND L
422 5/30/07 Lot 219 PA-18 87.0 18.6 109.3 98.4 ND L
423 5/30/07 Lot 226 PA-1 8 80.0 19.0 106.3 95.7 SC L
424 5/30/07 Lot 230 PA-18 82.0 18.7 106.7 96.1 ND L
425 5/30/07 Lot 228 PA-18 82.0 18.5 107.0 96.3 ND L
426 5/31/07 Lot 216 PA-18 79.0 11.1 117.5 93.2 ND E
427 5/31/07 Lot 214 PA-18 80.0 11.4 117.2 93.0 ND E
466-FG 6/6/07 Lot 250 PA-1 8 76.6 18.6 99.9 90.0 ND L
467-FG 6/6/07 Lot 251 PA-18 77.2 18.5 100.4 90.5 ND L
468-FG 6/6/07 Lot 252 PA-18 77.7 18.5 100.1 90.2 ND L
469-FG 6/6/07 Lot 253 PA-18 78.2 18.8 100.7 90.7 ND L
470-FG 6/6/07 Lot 254 PA-18 78.7 18.9 100.6 90.6 ND L
471-FG 6/6/07 Lot 255 PA-18 79.2 19.2 99.9 90.0 ND L
472-FG 6/6/07 Lot 280 PA-1 8 74.5 16.7 104.2 91.4 1 ND B
473-FG 6/6/07 Lot 279 PA-18 74.0 17.2 103.3 90.6 SC B
474-FG 6/6/07 Lot 278 PA-18 73.5 18.5 100.2 90.3 ND L
475-FG 6/6/07 Lot 276 PA-18 73.5 18.7 100.0 90.1 ND L
476-FG 6/6/07 Lot275 PA-lB 75.1 19.1 101.0 91.0 ND L
477-FG 6/6/07 Lot 277 PA-18 73.5 18.5 100.0 90.1 ND L
478-FG 6/6/07 Lot 274 PA-18 75.4 18.6 100.2 90.3 ND L
479-FG 6/6/07 Lot 273 PA-18 75.5 19.3 100.4 90.5 ND L
491-FG 6/8/07 - Lot 281 PA-18 74.9 13.5 111.0 97.4 ND B
492-FG 6/8/07 Lot 249 PA-lB 77.3 18.9 109.1 98.3 ND L
493-FG 6/8/07 Lot 265 PA-18 79.0 19.1 108.9 98.1 ND L
494-FG 6/8/07 Lot 266 PA-18 78.5 19.5 108.5 97.7 ND L
495-FG 6/8/07 Lot 267 PA-18 77.8 18.5 109.5 98.6 SC L
496-FG 6/8/07 Lot 268 PA-18 76.9 19.1 108.9 98.1 ND L
497-FG 6/8/07 Lot 269 PA-18 76.3 19.8 108.1 97.4 ND L
498-FG 6/8/07 Lot 270 PA-18 75.8 18.7 109.3 98.5 ND L
499-FG 6/8/07 Lot 271 PA-1 8 75.3 18.9 109.1 98.3 ND L
500-FG 6/8/07 Lot 272 PA-18 75.3 18.5 - 08.7 97.9 ND L
501-FG 6/8/07 Lot 225 PA-18 97.4 13.5 117.7 97.7 ND C
502-FG 6/8/07 Lot 219 PA-18 96.9 13.2 118.0 97.9 sc c
503-FG 6/8/07 Lot 218 PA-18 95.8 13.1 118.2 98.1 ND C
504-FG 6/8/07 Lot222 PA-18 94.6 13.7 117.5 97.5 ND C
505-FG 6/8/07 Lot 221 PA-18 92.9 13.0 118.4 98.3 ND C
506-FG 6/8/07 Lot220 PA-18 91.2 13.4 - 18.0 97.9 SC c
507-FG 6/8/07 Lot 219 PA-18 89.4 14.0 - 17.3 97.3 ND C
508-FG 6/8/07 Lot 218 PA-18 87.5 13.6 117.8 97.8 ND C
Brookfield San Diego Builders, Inc. W.O. 5353-B1-SC
PA 18 Robertson Ranch, East Village September 2008
File: C:\excel\tabtes\5300\5353b1.ror.2a18 Page 3
GeoSoils, Inc.
Table 1
FIELD DENSITY TEST RESULTS
TEST
NO
DATE TEST LOCATION TRACT
NO
ELEV
OR
DEPTH (ft)
CONTENT
(%)
MOISTURE:DRY-'REL
DENSITY
(pcf)
COMP
TEST
METHOD
SOIL
TYPE
509-FG 6/8/07 Lot 217 PA-18 86.3 14.5 116.8 96.9 ND C
519-FG 6/11/07 Lot 256 PA-18 81.0 14.2 108.0 94.7 ND B
520-FG 6/11/07 Lot 257 PA-18 81.8 13.9 108.4 95.1 ND B
521-FG 6/11/07 Lot 258 PA-18 82.5 14.0 108.2 94.9 ND B.
522-FG 6/11/07 Lot 259 PA-18 83.3 13.5 108.8 95.4 ND B
523-FG 6/11/07 Lot260 PA-lB 84.0 13.0 109.5 96.1 SC B
524-FG 6/11/07 Lot 261 PA-18 84.8 13.4 109.1 95.7 ND B
525-FG 6/11/07 Lot 262 PA-18 85.6 14.0 108.1 94.8 ND B
526-FG 6/11/07 Lot 263 PA-18 86.3 13.1 109.4 96.0 ND B
527-FG 6/11/07 Lot 264 PA-lB 86.8 . 13.5. .108.9 95.5 ND B
528-FG 6/11/07 Lot 216 PA-lB FG 11.8 116.3 92.3 ND E
529-FG 6/11/07 Lot 215 PA-18 FG 12.2 115.9 92.0 ND E
530-FG 6/11/07 Lot 214 PA-18 FG 11.3 117.3 93.1 1 ND E
531-FG 6/11/07 Lot 213 PA-18 FG 11.7 116.5 92.5 ND E
532-FG 6/11/07 Lot 212 PA-18 . FG 12.0 116.8 92.7 ND E
533-FG 6/11/07 Lot228 PA-18 FG 18.9 102.0 91.9 ND L
534-FG 6/11/07 Lot 229 PA-18 FG 19.2 101.3 91.3 ND . L
535-FG 6/11/07 Lot230 PA-18 FG 18.6 101.8 91.7 ND L
536-FG 6/11/07 Lot 231 PA-18 FG 19.0 102.2 92.1 Sc L
539-FG 6/12/07 Lot232 PA-18 81.8 19.0 1076 96.9 ND L
540-FG 6/12/07 Lot 233 PA-lB 81.1 18.7 107.9 97.2 ND L
589 1 6/18/07 Lot234 . PA-18 80.6 19.1 105.5 95.0 ND L
590 6/18/07 Lot235 PA-18 80.2 18.7 105.9 95.4 ND L
591 6/18/07 Lot 236 PA-18 79.4 18.5 106.4 95.9 ND L
592 6/18/07 Lot 237 PA-18 78.9 19.3 105.3 94.9 Sc L
593 6/18/07 Lot 238 PA-18 77.6 12.0 120.8 95.9 ND E
594 6/18/07 Lot239 PA-lB 77.4 11.6 121.2 96.2 ND E
595 6/18/07 Lot240 PA-18 77.7 11.2 121.7 96.6 ND E
630* 6/20/07 Lot 245 PA-1 8 76.0 8.6 108.7 88.4 Sc M
630A 6/20/07 Lot 245 PA-18 76.0 13.3 111.2 90.4 ND M
631* 6/20/07 Lot 284 PA-18 74.0 9.3 108.1 87.9 ND M
631A 6/20/07 Lot 284 PA-18 74.0 12.8 111.5 90.7 ND M
632 6/20/07 Lot 244 PA-18 77.0 13.1 111.1 90.3 ND M
647 6/21/07 Lot 282 PA-18 73.0 12.6 110.9 90.2 ND M
648 6/21/07 Lot 247 PA-18 75.0 12.5 111.1 90.3 Sc M
649 6/21/07 Lot 285 PA-lB 76.0 12.7 110.7 90.0 ND M
650 6/21/07 Lot283 PA-18 74.0 12.5 112.4 91.4 ND M
651 6/21/07 Lot 248 PA-18 75.0 13.2 111.4 90.6 ND M
652 6/21/07 Lot247 PA-18 75.0 12.8 111.5 90.7 ND M
653 6/21/07 Lot 246 PA-18 75.5 12.9 111.9 91.0 ND M
654 6/22/07 Lot 244 PA-18 77.0 12.8 111.3 90.5 Sc M
655
1
6/22/07 Lot248 PA-18 76.0 13.6 110.9 90.2 ND M
656 6/22/07 Lot 247 PA-18 76.0 14.0 112.1 91.1 ND M
Brookfield San Diego Builders, Inc. W.O. 5353-B1-SC
PA 18 Robertson Ranch, East Village September 2008
File: C:\excel\tables\5300\5353b1.ror.pal8 Page 4
GeoSoils, Inc.
Table 1
FIELD DENSITY TEST RESULTS
TEST
NO
DATE TEST LOCATION TRACT
NO
ELEV
OR
DEPTH (ft)
MOISTURE
CONTENT
(%)
DRY
DENSI1Y
(pcf)
REL
COMP
(%)
TEST
METHOD
SOIL
TYPE
657 6/22/07 Lot 246 PA-1 8 76.5 13.3 111.5 90.7 ND M
658 6/22/07 Lot 245 PA-1 8 770 121 112.5 91.5 ND M
682 6/25/07 Lot 245 PA-1 8 78.0 12.7 111.0 90.2 Sc M
683 6/25/07 Lot 246 PA-18 79.0 12.5 111.7 90.8 ND M
684 6/25/07 Lot 285 PA-18 76.0 12.9 111.3 90.5 ND M
685 6/25/07 Lot 285 PA-18 77.0 12.5 111.4 90.6 ND M
686 6/25/07 Lot 246 PA-18 79.0 13.1 110.7 90.0 ND M
698 6/26/07 Lot 243 PA-1 8 77.5 12.7 111.3 90.5 Sc M
731 6/29/07 Lot 210 PA-18 81.0 13.1 112.0 91.i ND M
732 6/29/07 Lot 211 PA-18 81.0 14.6 111.7 90.8 ND M
733 6/29/07 Lot 210 PA-1 8 83.0 12.7 113.5 92.3 ND M
734 6/29/07 Lot 211 PA-1 8 83.0 13.0 112.2 91.2 ND M
735 6/29/07 Lot 210 PA-1 8 84.0 14.2 111.9 91.0 Sc M
736 6/29/07 Lot 211 PA-18 850 12.8 113.0 91.9 ND M
737 6/29/07 Lot 210 PA-1 8 86.0 12.5 113.6 92.4 ND M
742 7/2/07 Lot 210 PA-1 8 87.0 14.2 115.5 94.7 ND 0
743 7/2/07 Lot 211 PA-18 86.0 13.8 115.9 95.0 ND
744 7/2/07 Lot 241 PA-1 8 78.0 13.2 116.5 95.5 ND 0
745 7/2/07 Lot242 PA-18 79.0 14.3 115.3 94.5 Sc 0
746 7/2/07 Lot 243 PA-18 80.0 14.1 115.7 94.8 ND 0
747 7/2/07 Lot 244 PA-18 81.0 13.7 116.0 95.1 ND Q
748 7/2/07 Lot 245 PA-18 80.0 13.3 116.4 95.4 ND 0
749 7/2/07 Lot 246 PA-18 79.0 13.9 115.8 94.9 ND 0
750 7/2/07 Lot 247 PA-18 78.0 13.1 116.9 95.8 Sc 0
751 7/2/07 Lot 248 PA-18 77.0 14.9 114.7 94.0 ND 0
755 7/3/07 - Lot 209 PA-18 80.0 13.2 116.5 95.5 ND 0
756 7/3/07 - Lot 207 PA-18 82.0 14.0 115.7 94.8 ND 0
757 7/3/07 Lot 208 PA-18 84.0 13.7 116.0 95.1 ND 0
758 7/3/07 Lot 209 PA-18 86.0 13.9 115.7 94.8 Sc 0
759 7/3/07 Lot207 PA-18 85.0 13.1 116.7 95.7 ND 0
760 7/3/07 Lot 208 PA-18 86.0 14.3 115.4 94.6 ND 0
774 7/6/07 Lot 210 PA-18 -2.0 13.2 116.7 95.7 1 ND Q
775 7/6/07 Lot 244 PA-18 -1.0 13.1 116.9 95.8 ND 0
787 7/10/07 Stability Fill Lot 209 PA-18 89.0 13.1 111.1 90.3 ND M
788 7/10/07 Stability Fill Lot 209 PA-18 91.0 12.5 110.8 90.1 SC M
793 7/11/07 Stability Fill College Blvd PA-18 97.0 12.6 110.7 90.0 ND M
794 7/11/07 Stability Fill College Blvd PA-18 99.0 12.5 112.3 91.3 Sc M
796 7/11/07 Stability Fill College Blvd PA-18 103.0 12.5 111.3 90.5 ND M
797 7/11/07 Stability Fill College Blvd PA-1 8 106.0 12.5 111.6 90.7 ND M
799 7/12/07 Stability Fill College Blvd PA-1 8 110.0 11.0 112.8 90.6 SC P
803 7/13/07 Stability Fill College Blvd PA-18 92.0 12.8 111.4 91.3 ND R
804 7/13/07 Stability Fill College Blvd PA-18 90.0 13.4 110.7 90.7 ND R
- 805 7/13/07 Lot 289 PA-18 69.0 12.6 111.0 91.0 ND H
W. 0. 5353-Bi-SC
September 2008
Page 5
Table 1
FIELD DENSITY TEST RESULTS
TEST
NO
DATE TEST LOCATION TRACT
NO
ELEV
OR
DEPTH (ft)
MOISTURE
CONTENT
(%)
DRY
DENSITY
(pcf)
REL
COMP
(%)
TEST
METHOD
SOIL
TYPE
806 7/13/07 Lot288 PA-18 69.0 12.9 112.2 92.0 SC R
807 7/16/07 Lot 290 8 -PA-1 70.0 9.4 121.3 90.5 ND F
808 7/16/07 Lot288 PA-18 71.0 10.3 121.1 90.4 ND F
809 7/16/07 Lot 287 PA-18 71.5 10.0 121.8 90.9 ND F
813 7/18/07 Lot 289 PA-18 70.0 10.3 122.1 91.1 ND H
814 7/18/07 Lot 287 PA-18 72.0 9.8 121.5 90.7 ND H
815 7/18/07 Lot288 PA-18 72.0 11.1 119.7 91.4 ND I
848 7/24/07 Lot 286 PA-ia 70.0 10.3 121.4 90.6 ND H
849 7/24/07 Lot 287 PA-1 8 69.5 10.0 121.0 90.3' ND H
922 8/1/07 Lot 285 PA-18 76.5 13.3 112.4 91.4 SC M
923 8/1/07 Lot 245 PA-1 8 80.0 12.9 113.2 92.0 SC M 957* 8/7/07 Lot 304 PA-1 8 76.5 11.0 107.0 88.4 SC J
957A 8/7/07 Lot 304 PA-1 8 76.5 13.2 112.0 92.6 SC J
958* 8/7/07 Lot 302 PA-1 8 75.0 11.8 105.0 86.8 SC J
958A 8/7/07 Lot 302 PA-1 8 75.0 12.8 111.7 92.3 SC J
967 8/9/07 Lot295 PA-18 73.5 12.0 113.3 91.4 SC S
968 8/9/07 Lot 297 PA-1 8 73.0 11.7 112.5 90.7 ND S 980* 8/10/07 Lot288 PA-18 72.0 7.4 114.7 90.3 SC U
980A 8/10/07 1-01:288 PA-18 72.0 11.4 114.8 90.4 ND U
981 8/10/07 Lot 287 PA-18 72.5 11.3 115.2 90.7 SC U
982 8/10/07 Lot 286 PA-18 73.0 12.1 114.3 90.0 SC U
983 8/13/07 Sound Berm PA-18 74.0 16.1 106.7 90.4 ND T
984 8/13/07 Sound Berm PA-18 73.0 16.0 107.0 90.7 ND T
991 8/15/07 Lot286 PA-18 75.0 11.2 112.3 90.6 ND S
992 8/15/07 Lot 287 PA-18 74.0 11.8 113.0 91.1 ND S
993 8/15/07 Lot288 PA-18 73.0 11.5 112.6 90.8 ND S
1034 8/28/07 Lot 291 PA-18 72.0 10.0 120.3 91.5 SC X
1035 8/28/07 Lot 293 PA-18 72.0 9.7 120.7 91.8 SC X
1036 8/29/07 Lot 290 PA-18 73.0 9.4 121.8 90.9 SC H
1037 8/29/07 Lot 291 PA-18 72.7 9.8 123.0 91.8 SC H
1038 8/29/07 Lot 289 PA-18 73.8 9.1 121.0 90.3 ND H
1049 9/7/07 College Blvd, West Side PA-1 8 105.0 13.1 111.4 90.6 ND M
1050 9/7/07 College Blvd, West Side PA-18 100.0 12.5 110.7 90.0 ND M
1051 9/7/07 College Blvd, West Side PA-18 95.0 12.7 112.1 91.1 ND M
1052 9/7/07 College Blvd, West Side PA-1 8 90.0 12.9 111 .5 90.7 ND M
1062 9/7/07 Lot 298 PA-18 72.0 13.7 103.5 90.8 ND B
1063 9/7/07 Lot 297 PA-18 72.0 14.0 103.2 90.5 ND B
1064 9/7/07 Lot 296 PA-18 72.0 11.0 115.4 90.9 ND A
1065 9/7/07 Lot 295 PA-18 73.0 13.6 102.6 90.0 ND B
1066 9/7/07 Lot 301 PA-18 75.0 10.6 119.7 91.0 ND X
1067 9/10/07 Street 10 18+50 PA-18 73.0 13.7 102.9 90.3 SC B
1068 9/10/07 Street 10 19+25 PA-18 74.0 14.1 102.6 90.0 SC B
1069 1 9/10/07 Street 1020+00 PA-18 72.5 13.6 103.6 90.9 ND B
Brookfield San Diego Builders, Inc. W.O. 5353-Bi-SC
PA 18 Robertson Ranch, East Village September 2008
File: C:\excel\tables\5300\5353bl.ror.palB Page 6
GeoSo Its, Inc.
Table 1
FIELD DENSITY TEST RESULTS
TEST
NO
DATE TEST LOCATION TRACT
NO
ELEV
OR
DEPTH (%)
MOISTURE
CONTENT
DRY
DENSITY
REL
COMP
TEST
METHOD
SOIL
TYPE
1070 9/10/07 Street 10 21 +00 PA-18 74.8 9.0 120.6 90.0 ND F
1072 9/10/07 Lot 286 PA-18 76.5 9.2 125.4 95.4 ND X
1073 9/10/07 Lot 287 PA-1 8 75.4 10.0 124.0 94.3 ND x
1074 9/10/07 Lot 288 PA-lB 74.9 9.8 123.7 94.1 ND X
1075 9/10/07 Lot 289 PA-18 74.3 99 123.2 93.7 ND X
1076 9/10/07 Lot 290 PA-18 73.9 10.2 122.9 93.5 ND X
1077 9/10/07 Lot 291 PA-lB 73.2 9.2 125.1 95.1 ND X
1078 9/10/07 Lot 292 PA-18 73.3 9.7 123.8 94.1 ND X
1079 9/10/07 Lot 293 PA-18 74.1 11.0 122.1 92.9 ND x
1080 9/10/07 Lot 294 PA-18 75.0 10.5 122.7 93.3 SC X
1081 '9/10/07 Lot 295 PA-18 75.0 9.4 124.8 94.9 ND X
1082 9/10/07 Lot 296 PA-lB 74.6 9.1 125.6 95.5 D X
1083 9/10/07 Lot 297 PA-18 74.6 94 124.7 94.8D X
1084 9/10/07 Lot298 PA-18 75.0 9.9 123.3 93.7C
FSCX
X
1085 9/10/07 Lot 299 PA-18 ' 75.5 9.4 124.7 94.8D X
1086 9/10/07 Lot 300 PA-18 76.0 9.9 123.3 93.7
1087 9/10/07 Lot 301 PA-18 76.5 9.2 125.1 95.1 ND
1088 9/10/07 Lot302 PA-18 77.2 9.8 123.5 93.9 ND X
1089 9/10/07 Lot303 PA-18 77.8 10.2 122.9 93.4 ND X
1090 9/10/07 Lot 304 PA-18 78.3 10.0 123.0 93.5 ND X
1249 11/4/08 Sound Berm Lot 312 PA-18 90.0 13.6 112.0 92.6 ND LL
1250 11/7/08 Sound Berm Lot 312 PA-18 92.0 13.2 112.5 93.0 ND LL
1251 11/9/07 Sound Berm PA-18 85.0 14.2 112.6 93.1 SC LL
1252 11/9/07 Sound Berm PA-18 87.0 15.1 112.2 92.7 ND LL
1380 7/23/08 College Blvd 116+05 PA-18 74.0 10.4 121.7 95.8 ND TI
1381' 7/23/08 College Blvd 116+20 PA-18 76.0 10.1 122.3 96.2 ND TI
1382 7/23/08 College Blvd 116+50 PA-18 75.0 10.7 120.3 94.7 ND IT
1383' 7/24/08 College Blvd 116+25 PA-18 78.0 10.8 119.9 94.4 ND TI
1384' 7/24/08 College Blvd 116+50 PA-18 78.0 10.4 120.7 95.0 ND TI
1385' 7/24/08 College Blvd 116+70 PA-18 72.0 10.1 122.1 96.1 ND TI
1386 7/24/08 College Blvd 117+00 PA-18 740 10.0 1202 94.6 Sc TI
1387' 7/24/08 College Blvd 116+75 PA-18 74.0 10.5 120.2 94.6 Sc IT
1388' 7/25/08 College Blvd 117+20 PA-lB 73.0 11.2 119.2 93.8 ND TI
1389 7/25/08 College Blvd 116+80 PA-18 750 10.9 119.7 94.2 ND TI
1390 7/25/08 College Blvd 117+15 PA-18 74.0 10.2 122.0 960 ND TI
1391 7/25/08 College Blvd 116+50 PA-18 80.0 10.6 120.7 95.0 ND TI
1392 7/25/08 College Blvd 116+35 PA-18 80.0 10.3 121.4 95.5 ND TI
1393 7/28/08 College Blvd 116+78 PA-18 75.0 10.8 119.0 93.7 ND TI
1394 7/28/08 College Blvd 116+55 PA-18 750 10.4 119.6 94.1 ND TI
1395 7/28/08 College Blvd 116+30 PA-18 82.0 10.7 119.3 93.9 ND TI
1396 7/28/08 College Blvd 116+15 PA-18 82.0 10.0 120.2 946 ND TT-
1397 7/29/08 College Blvd 116+80 PA-18 76.0 10.1 120.0 944 ND TI
1398 7/29/08 College Blvd 116+65 1 PA-18 76.0 10.6 119.3 939 ND TI
Brookfield San Diego Builders, Inc. W.O. 5353-B1-SC
PA 18 Robertson Ranch, East Village September 2008
File: C:\excel\tables\5300\5353b1.ror.pal8 Page 7
GeoSoils, Inc.
TahIc 1
FIELD DENSITY TEST RESULTS
.........I: IC f
NO NO OR CONTENT DENSITY COMP MET ROD TYPE
DEPTH (ft) (%)
1402 7/30/08 Choker Arapaho 21+20 PA-18 75.0 10.9 118.0 92.9 ND TI
1403 7/30/08 Choker Arapaho 20+80 PA-18 75.0 . 10.4 118.8 93.5 1 SC TT
1404 7/30/08 Choker Arapaho 21+00 PA-18 75.0 10.0 120.7 95.0 ND TI
1405 7/30/08 Arapaho 20+60 PA-lB 73.0 10.1 120.5 94.8 ND II
1406 7/30/08 Arapaho 21 +00 PA-1 8 73.0 10.4 119.0 93.7 ND . TI
1407 7/31/08 Arapaho 20+55 PA-18 74.0 10.7 118.5 93.3 ND TI
1408 7/31/08 Arapaho 20+80 PA-18 . 74.0 10.4 118.9 93.6 SC IT
1409 7/31/08 Lot 285 PA-18 76.0 10.9 118.0 92.9 ND TI
1410 7/31/08 Lot 245 PA-18 78.0 11.3 117.6 92.5' ND TI
1411 7/31/08 Lot285 PA-18 78.0 10.0 120.8 95.1 ND TI
1412 7/31/08 Lot 245 PA-1 8 80.0 10.0 120.7 95.0 SC TI
LEGEND:
Repeated Test Number
* = Failed lest
A = Retest
FG = Finish Grade
ND = Nuclear Densometer Test
SC = Sand Cone Test
Brookfield San Diego Builders, Inc. W.O. 5353B1SC
PA 18 Robertson Ranch, East Village September 2008
File: C:\excel\tables\5300\5353bl.ror.pal8 Page 8
GeoSoils, Inc.
V
V GeoSoils, Ic
V
bIUN
21
195** 5 Very Low Negligible .g 15 3-4 I or I PT Preliminary
196** 5 Very Low Negligible g15 cut loriPT Preliminary
197**
V Very Low Negligible g15 3-4 IorlPTPreliminary
198** 5 Very Low Negligible s~ 15 dut I or I PT Preliminary
199* 5 Very Low Negligible T g15 cut I or I PT Frliminary
200** 5 Very Low Negligible :05 3-4 loriPT Preliminary
201 ** 5 Very Low Negligible -05 3-4 I or I PT Preliminary
202** 5 Very Low Negligible ~15 3-4 lorIPT Preliminary
203** 5 Very Low Negligible !05 cut I or I PT Preliminary
204** 5 Very Low Negligible ~15 cut loriPT Preliminary
205** 5 Very Low Negligible 5,15 3-4 I or I PT Preliminary
206** 5 Very Low Negligible :~15 4-12 I PT Preliminary
207 58 Medium Negligible 20-26 20-23 II PT
208 58 Medium Negligible 20-26 20-23 II PT
209 58 Medium Negligible 20-26 20-23 II PT
210 58 Mddium ' Negligible 20-26 V
20-22 II PT
V
211 58 Medium Negligible -20-26 V 20-22 II PT
212 55- Medium ,Negligible 18-24 20-22 II PT
213 55 Medium Negligible 18-24 V 20-23 II PT
214 V 55 Medium Negligible 18-24 19-21 V It PT
215 55 Medium Negligible 18-24 V 18-20 II PT
216 55 Medium Negligible 18-24 18-20 11 PT
217 55 Medium Negligible V 18-24 6-16 11 PT V
218 55 Medium V Negligible
V 18-24 5:13 II PT
219 55 Medium
V V
Negligible 18-24 5-13 If or II PT
220 55 Medium V Negligible 18-24 4-10 V II or II PT
221 24 Low Ngligible !05 3-4 I or I PT
222 24 V Low Negligible V - g15 . V
V 3-4 I or I PT V
223 24 V - LOW Negligible 05 cut I or I PT
224 24 - Low Negligible
V - S1.5 V cut V V I or I PT
225 24 Low V V Negligible V:g15 3-4 I or I PT
226 56 V Medium Negligible V 20-25 V 14-16 II or Il PT
227 56 Medium Negligible 20-25 5-15 II or II PT
11
I -
1 V• -
4 .
LOT 18 cHARAcTERISTICS, A-.,-
04
(PER.
ASTM EXPANSION SULFATE PLASTICITY
04829) OXE4TIL. EXPOSPRE 1 INDEX (PI) ,
,
APPROX.
DEPTH OF
FILL
(RANGE IN
EJ) FQUND.. IQV4Jy}E )
228
I
56 Medium Negligible
I
20-25
I
4-10 - II or II PT
229 -56 Medium. Negligibl .20-25 4-5 II or 11 PT•
230 - 56 . Medium Negligible 20-25 3-6 It or II PT
231. 56 Medium Negligible 20-25 II or II PT
232 56 . Medium V Negligible 20-25 4-10 II or II PT
233 80 V Medium Negligible - 30-35 V 5-14 If PT,
234 80 Medium Negligible 30-35
V
9-12 II PT V
235 80 - 'Medium V
V Negligible- - 30-35 12-16 . II PT
236 80 Medium * - Negligible . 30-35 15-17 II PT
237 80 Medium Negligible 30-35 . 15-17 If PT
238 52 Medium Negligible. V 20-25 . 15-17 II PT -
239 52 Medium
-
Negligible V
V 20-25 15-17 If PT
240 52 Medium. Negligible 20-25 15-17 -II PT
241 52 V Medium Negligible 20-25 15-17 II PT
242 51 Medium Negligible 20-25 - 15-17 II PT V
243 51 Medium Negligible - 20-25 16-18 II PT
244 51, Medium Negligible 20-25 17-19 lip
245 52 Medium Negligible 20-25 18-20 II PT -
246 V 52. - Medium - _Negligible
-
20-25 18-20 II PT
247 52 Medium Negligible - 20-25 16-18 11 PT
248 55 Medium - Negligible 20-25 15-17 1 II PT
249 55 Medium Negligible 20-25 -. 15-17 Il PT
250 55 Medium - - Negligible . 20-25 . 1648 ' II PT
251 V 55 V Medium , Negligible - 20-25 17-19 II PT
252 55 Medium Negligible V 20-25 17-19 VII PT
253 - 55 Medium Negligible - 20-25 - 17-19 II PT
254 V 55 V
Medium Negligible 20-25 - 17-19 II PT
255 55 Medium, Negligible- - - 20-25. 18-20 II PT - -
256 - 93 High
-
Negligible 35-38 19-21 III PT
257 - * 93 - High Negligible 35-38
-' 21-23 III PT
258 93 High Negligible. - 35-38 - 12-23 III PT - -
259 93 V High - Negligible 35-38 15-23 III PT
Brookfield San Diego Builders, Inc. ' - - W.O. 5353-B1-SC
File:e:wp9\5300\5353b1VPA18 Table 2 Page 2
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GeoSoils, Inc.
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-- ,. - -
*1
Pm
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260 - 93 High Negligible 35-38 - 8-24 III PT
261 80 Medium - Negligible 30-35 ". 17-20 II or II PT-
262 80 - Medium Negligible - -30-35 9-16 II or 11 PT
263 80 Medium .. Negligible . - 30:35 - 4-6 ' II Or II PT
-
264 -
80 Medium Negligible ' 30-35 3-4 II or II PT
265 56 -' Medium - Negligible - 20-26 3-4 II or II PT
266 56 - Medium Negligible-. 20-26 4-11 II or'll'PT
267 - -- 56 Medium - Negligible -. -- 20-26 4-12. - II or Il PT
268 56 Medium Negligible 20-26 11-13 .
-
IIPT
269 56 - - Medium . Negligiblé 20-26 10-19 11 PT
270 56 - •- Medium Negligible. - 20-26 15-18 II PT -
271 56 .. Medium Negligible * 20-26 - 16-18 II PT
272 - 56 Medium . Negligible 20-26 16-18 - .11 PT
273 - 51 -. Medium Negligible - 16-20 16-18 - II PT
274 51 Medium Negligible - 16-20 16-18 II PT
275 -51 Medium - Negligibl. 16-20 15-17 II PT
276 51 .Medium Negligible . 16-20- 14-16 -' II PT
277 51, Medium Negligible 16-20 13-15 II PT
278 51 Medium Negligible. . 16-20 - 13-15 II PT.
279 51 Medium - - - Negligible 16-20 13-15 II PT -
280 51 Medium - Negligible' 16-20 14-16 II
281 51 - Medium Negligible - 16-20 15-17 II PT
282 - 51 Medium Negligible - 16-20 14-16 - II PT
283 - 51 Medium Negligible 16-20 14-16 II PT
-
284 . - 51.
.
Medium
-
' Negligible '
,•-.
16-20 -
V
. 15-17
.
II PT •., -
285 51 Medium Negligible.' '' 16-20 ' 15-17 II PT
286 2 Very Low ' Negligible <15 16-18 I PT
287 -. - 2 Very Low Negligible. - -'- <15
-
16-18 - I PT
288 2 -
Very Low Negligible <15 . 15-17 I PT
289
-
2 , Very Low Negligible-. - - <15 15-17 , I PT
290 6 -: : _Very Low. Negligible - -. <15 - -. 14-16 1 P
?91 -- - 6 - Very Low Negligible <15 ' - 14-16 . - IPT -
-- - - •
"Brookfield San Diego Builders, Ind.. ' , ", •- - - W•O 5353-B1-SC -•
.1 File e:\wp9\5300\5353b1.PA1 8 Table 2 - Page 3
I • - • . • -. , - • - - - ) GeoSolls, Inc.
ISO
OT
292 6 Very Low Negligible <15 - 14-16 I PT
29.3 6 Very Low ' Negligible <15 '- 14-16 I PT - -
294 k 42 Low - Negligibl
- 16-20 - 14-16 - I PT
295 .. 42 ' Low Negligible 16-20 - 1517 I PT'
296 42 Low Negligible -
-
16-20 17-19 1 PT
297 42 - . Low . Negligible . 16-20
- 17-19 I.PT.
298 . 42 - Low ' '. Negligible 16-20 18-20 I PT -
- 299 42 . Low r Negligible 16-20 18-20 . I PT
300 43 Low - Negligible - - 16-20 - 18-20
- -- I PT
301 43 -, Lows Negligible 16-20 , . 18-20 I PT -
302 43 Low Negligible. - . 16-20 20-22 I PT
303 - 43 - Low . Negligible - 16-20 20-22
- 1 PT I
304 43 --Low Negligible ' 16-20 20-22 I PT
- 309 42 Low - - Negligible. 16-20 - - 14-16 -
(t) Per ASTM 4829.
2 Per ACI318-08 Tables 4.2.1 and 4.3.1 (CBC,2007)
The higher value in the range provided, should be used for design purposes. Per GSI (2007b).
** Lots 195 through 206 are sheet graded. Additional gradirg to complete these lots shall use similar site soils a
s
i
è
d
i
c
a
t
e
d
in this table, and as pre-approved by GSI. The use of soils with different soil èxjansion, plasticity, etc. will pote
n
t
i
a
l
l
y
r
e
s
u
l
t
in more onerous foundation design criteria for these lots. Preliminary foundation types only have been p
r
o
v
i
d
e
d
f
o
r
t
h
e
s
e
lots.
Recreation Area Foundation design to be lot specific based on proposed use; will be provided upon review of site
development. I . . .
I;
AL
I.
APPENDIX
REFERENCES
American Concrete Institute, 2008, Building code requirement for structural concrete
(ACt 318-08) and commentary, an.ACI standard reported by ACI Committee 318,
dated January.
2004, Guide for concrete floor and slab construction: reported by ACt Committee
302; Designation ACt 302.1 R-04, dated March 23.
American Society for Testing and Materials, 1998, Standard practice for installation of
water vapor retarder used in contact with earth or granular fill under concrete slabs,
Designation: E 1643-98 (Reapproved 2005).
1997, Standard specification for plastic water vapor retarders used in contact with
soil or granular fill under concrete slabs, Designation: E 1745-97 (Reapproved
2004).
California Building Standards Commission, 2007, California building code.
Caitrans, 1999, Interim corrosion guideline for foundation investigations, Corrosion and
Technology Section, Office of Materials and Foundations, dated May.
Carlsbad, City of, 1993, Standards for design and construction of public works
improvements in the City of Carlsbad
GeoSoils, Inc., 2008, Geotechnical update of seismic design criteria for Robertson Ranch,
East Village, City of Carlsbad, San Diego County, California, W.O. 5353-B-SC, dated
March 17.
2007a, Compaction report of geotechnical observation and testing services, 84-inch
storm drain improvements for Cannon Road, Robertson Ranch East Village,
Carlsbad, San Diego County, California, Carlsbad, San Diego County, California,
W.O. 5355-D-SC, dated August 16.
2007b, Updated geotechnical evaluation of the Robertson Ranch, East Village
Development, Carlsbad Tract 02-16, Drawing 433-6, Carlsbad, San Diego County,
California, W.O. 5353-A-SC, dated January 15.
2006a, Supplemental recommendations regarding pier supported bridge
abutments, Robertson Ranch East Project, City of Carlsbad, San Diego County,
California, W.O. 3098-A2-SC, dated November 30.
2006b, Memorandum: update of the geotechnical report with respect to site
grading and the current grading plan, Robertson Ranch East, City of Carlsbad,
W.O. 3098-A2-SC, dated November 15.
GeoSoils, Inc.
2006c, Memorandum: discussion of earthwork recommendations in the vicinit
y
of a planned 84-inch storm drain, Cannon Road, Stations 127 to 136 +32 , Improvements for Robertson Ranch East, City of Carlsbad, California,
W.O. 3098-A2-SC, dated July 28.
2006d, Supplement to the update geotechnical evaluation regarding the distributio
n
of wick drains, Robertson Ranch East, Carlsbad, San Diego County, Californ
i
a
,
W.O. 3098-A-SC, dated June.
2006e, Report of rough grading, Calavera Hills II, College Boulevard and Cann
o
n
Road Thoroughfare, District No. 4 (B&TD), Carlsbad Tract 00-02, Drawing 39
0
-
9
A
,
Carlsbad, San Diego County, California, W.O. 3459-132-SC, dated January 27.
2004, Updated geotechnical evaluation of the Robertson Ranch property, Carl
s
b
a
d
,
San Diego County, California, W.O. 3098-A2-SC, dated September 20.
2002, Geotechnical evaluation of the Robertson Ranch property, City of Carls
b
a
d
,
San Diego County, California, W.O. 3098-Al -SC, dated January 29.
2001a, Preliminary findings of the geotechnical evaluation, Robertson R
a
n
c
h
,
Property, City of Carlsbad, California, W.O. 3098-A-SC, dated July 31.
2001 b, Preliminary geotechnical evaluation, Calavera Hills II, College Boulevard
a
n
d
Cannon Road Thoroughfare, District No. 4 (B&TD), City of Carlsbad, California,
Wfl. 2863-A-SC, dated January 24.
Kanare, Howard, 2005, Concrete floors and moisture, Portland Cement Asso
c
i
a
t
i
o
n
,
Skokie, Illinois.
O'Day Consultants, 2008, Grading plans for Robertson Ranch PA 16, 17, 18, S
h
e
e
t
s
9
,
1
1
,
12, and 14, Job no. 01-1014, Carlsbad Tract C.T. 004-26, Drawing no.453-8A,
d
a
t
e
d
August.
Project Design Consultants, 2008, Survey of as-built toe drains, Robertson Ran
c
h
,
J
o
b
No. 3481.
Romanoff, M., 1989, Underground corrosion, National Bureau of Standards Circul
a
r
5
7
9
,
Published by National Association of Corrosion Engineers, Houston, Te
x
a
s
,
originally issued April 1, 1957.
State of California, Department of Transportation, 2006, Highway design ma
n
u
a
l
o
f
instructions, sixth edition, September printing.
Brookfield San Diego Builders, Inc.
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GeoSoils, Inc.