HomeMy WebLinkAboutMS 13-08; TIERRA LA COSTA; PRELIMINARY GEOTECHNICAL INVESTIGATION; 2013-12-169~3 CONSTRUCTION TESTING & ENGINEERING, INC.
1441 MOTiU ROAD. SUITE 115 I (scouiuo, Ca 91026 1160.148.4955 I FAX 160.146.9806
PRELIMINARY GEOTECHNICAL INVESTIGATION
PROPOSED GORTZEN HOMES DEVELOPMENT
NORTHEAST OF VENADO AND ESFERA STREETS (APN: 223-250-14)
CARLSBAD, CALIFORNIA
14M 21. 201
LPND DE\IELOPMT
ENGINEERING
Prepared for:
GOERTZEN HOMES AND GS DEVELOPMENTS
ATTENTION: MR. GREG GOERTZEN
P.O. BOX 91335
SAN DIEGO, CALIFORNIA 92169
Prepared by:
CONSTRUCTION TESTING & ENGINEERING, INC.
1441 MONTIEL ROAD, SUITE 115
ESCONDIDO, CALIFORNIA 92026
CTE JOB NO.: 10-I1657G December 16, 2013
SAN DIEGO I RIVERSIDE I VENTURA I MERCED I TRACY I SACRAMENTO I PASADENA I HAGATNA, GUAM
GEOTECHNICAL I ENVIRONMENTAL I CONSTRUCTION INSPECTION AND TESTING I CIVIL ENGINEERING I SURVEYING
TABLE OF CONTENTS
1.0 INTRODUCTION AND SCOPE OF SERVICES ...................................................................
1.1 Introduction...................................................................................................................1
1.2 Scope of Services..........................................................................................................
2.0 SITE DESCRIPTION ...............................................................................................................2
3.0 FIELD INVESTIGATION AND LABORATORY TESTING................................................2
3.1 Field Investigation........................................................................................................2
3.2 Laboratory Testing........................................................................................................3
4.0 GEOLOGY...............................................................................................................................4
4.1 General Setting .............................................................................................................4
4.2 Geologic Conditions.....................................................................................................4
4.2.1 Previously Placed Fill....................................................................................4
4.2.2 Metavolcanic Rock........................................................................................5
4.3 Groundwater Conditions...............................................................................................5
4.4 Geologic Hazards..........................................................................................................5
4.4.1 Surface Fault Rupture....................................................................................6
4.4.2 Local and Regional Faulting..........................................................................6
4.4.3 Liquefaction and Seismic Settlement Evaluation..........................................7
4.4.4 Tsunamis and Seiche Evaluation...................................................................7
4.4.5 Landsliding ....................................................................................................8
4.4.6 Compressible and Expansive Soils................................................................8
4.4.7 Corrosive Soils ............... . ................................................................................ 8
5.0 CONCLUSIONS AND RECOMMENDATIONS ...................................................................9
5.1 General..........................................................................................................................9
5.2 Site Preparation...........................................................................................................10
5.3 Site Excavation ...........................................................................................................11
5.4 Subdrains and Fill Placement and Compaction..........................................................12
5.5 Fill Materials...............................................................................................................12
5.6 Temporary Construction Slopes .................................................................................13
5.7 Foundations and Slab Recommendations...................................................................14
5.7.1 Foundations..................................................................................................14
5.7.2 Foundation Settlement.................................................................................15
5.7.3 Foundation Setback......................................................................................16
5.7.4 Interior Concrete Slabs ................................................................................16
5.8 Seismic Design Criteria..............................................................................................17
5.9 Lateral Resistance and Earth Pressures ......................................................................18
5.10 Exterior Flatwork......................................................................................................20
5.11 Vehicular Pavements .................................................................................................20
5.12 Drainage....................................................................................................................21
5.13 Slopes........................................................................................................................22
5.14 Construction Observation.........................................................................................22
5.14 Plan Review..............................................................................................................23
6.0 LIMITATIONS OF INVESTIGATION.................................................................................23
FIGURES
FIGURE 1
FIGURE 2
FIGURE 3
FIGURE 4
SITE LOCATION MAP
GEOLOGIC/ EXPLORATION LOCATION MAP
REGIONAL FAULT AND SEISMICITY MAP
GEOLOGIC/EXPLORATION LOCATION MAP
APPENDICES
APPENDIX A
APPENDIX B
APPENDIX C
APPENDIX D
REFERENCES
FIELD EXPLORATION METHODS AND BORING LOGS
LABORATORY METHODS AND RESULTS
STANDARD GRADING SPECIFICATIONS
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1.0 INTRODUCTION AND SCOPE OF SERVICES
1.1 Introduction
This report presents the results of the preliminary geotechnical investigation, performed by
Construction Testing and Engineering, Inc. (CTE), and provides conclusions and recommendations
for the proposed improvements at the subject site located northeast of Venado and Esfera Streets in
Carlsbad, California. We have performed this work in general accordance with the terms of our
proposal no. G-2897, dated June 28, 2013.
CTE understands that the proposed development consists of grading the site to create two building
pads to construct residential structures with associated improvements. Other associated
improvements will likely consist of retaining walls, landscaping, utilities, and flatwork. Preliminary
recommendations for excavations, fill placement, and foundation design for the proposed
improvements are presented in this report. Reviewed references are provided in Appendix A.
1.2 Scone of Services
The scope of services provided included:
Review of readily available geologic and soils reports.
Site Reconnaissance.
Excavation of limited access exploratory borings and track-hoe excavator test pits for soil
sampling and observation.
Laboratory testing of selected soil samples.
Description of site geology and evaluation of potential geologic hazards.
Engineering and geologic analysis.
Preparation of this summary report.
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2.0 SITE DESCRIPTION
The subject site is located northeast of Venado and Esfera Streets (APN: 223-250-14) in Carlsbad,
California (Figure 1). The site currently consists of an undeveloped building pad supporting bushes
and trees as well as stockpiled rock and soil. Existing site conditions are illustrated on Figure 2.
Based on reconnaissance and review of area topography, the slightly southwest sloping site is
located at the base of an approximately 40-foot high 2:1 to 4:1 (horizontal: vertical) slope to the
northeast with lesser slopes ascending up to Esfera Street to the southeast, Venado Street to the
southwest and a residence to the northwest. Surface elevations at the site range from approximately
305 feet above mean sea level (msl) in the southern portion of the site to approximately 360 feet msl
in the northern portion-of the site.
3.0 FIELD INVESTIGATION AND LABORATORY TESTING
3.1 Field Investigation
CTE conducted the field investigations on November 25 and December 3, 2013. Investigations
consisted of a visual site reconnaissance and excavation of three limited access exploratory borings
followed by excavating two deep test pits with an excavator. The borings were excavated with a
limited access tn-pod drill rig equipped with six-inch diameter solid-stem augers that were advanced
to refusal at a maximum depth of approximately five feet below the existing ground surface (bgs).
Bulk and relatively undisturbed driven samples were collected from the cuttings and by driven
Modified California sampler.
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After encountering significant rock fills in the borings and reviewing the previously prepared "Final
Report on Compacted Filled Ground" (Benton Engineering, Inc. 1977), we mobilized a 15,000
pound track-hoe type excavator to better determine the limits of the rock fills. Our two test pit
locations were based on the mapped rock fill areas presented on the figures in the referenced report.
Test Pit 1-1 in the southern portion of the site extended to a depth of approximately 22 feet bgs and
Test Pit T-2 extended to a depth of approximately 20 feet bgs. Bulk samples were collected from the
cuttings.
The soils were logged in the field by a CTE Geologist and visually classified in general accordance
with the Unified Soil Classification System. The field descriptions have been modified, where
appropriate, to reflect laboratory test results. Boring and Test Pit logs, including descriptions of the
soils encountered are included in Appendix B. The approximate locations of the explorations are
presented on Figure 2.
3.2 Laboratory Testing
Laboratory tests were conducted on selected soil samples for classification purposes and to evaluate
physical properties and engineering characteristics. Laboratory tests included: Modified Proctor,
Expansion Index, gradation, Atterberg Limits and chemical characteristics for corrosivity. Test
descriptions and laboratory test results are included in Appendix C.
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4.0 GEOLOGY
4.1 General Setting
San Diego is located with the Peninsular Ranges physiographic province, which is characterized by
northwest-trending mountain ranges, intervening valleys, and predominantly northwest trending
regional faults. The San Diego Region can be further subdivided into the coastal plain area, a
central mountain—valley area and the eastern mountain valley area. The project site is located within
the coastal plain area, which ranges in approximate elevation from sea level to 1200 feet above mean
sea level and is characterized by Cretaceous and Tertiary sedimentary deposits that onlap an eroded
basement surface consisting of Jurassic and Cretaceous crystalline rocks.
4.2 Geologic Conditions
Based on the regional geologic map prepared by Kennedy and Tan (2005), the surficial geologic unit
underlying the site consists of Metavolcanic rock. However, based on our explorations, Quaternary
Previously Placed Fill Soil was found to overlie the Metavolcanic bedrock. Descriptions of the
geologic units are presented below.
4.2.1 Previously Placed Fill
The Previously Placed Fill deposits were encountered in all the explorations and were
observed to a maximum depth of approximately 22 feet below ground surface (bgs) in Test
Pit 1-1. Where observed, this material generally consists of loose to medium dense, dry to
wet, light grayish brown to reddish brown, clayey fine to medium grained sand with gravel.
The fill slope in the northern portion of the site appears to consist of a significantly deep
rock fill with a thin layer of previously placed fill at the surface. Other rock fills would
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likely be encountered in isolated locations at depth throughout the site. In addition, an old
channel that has been filled in appears to run through the near central and southeastern
portion of the site with fill depths greater than 50 feet based on the previous report (Benton
1977).
4.2.2 MetavolcanicRock
Metavolcanic rock is anticipated at depth throughout the site and was encountered in Test Pit
T-2 at a depth of approximately 19 feet. Where observed, this unit was found to consist of
moderately weathered Metavolcanic rock that generally excavated to angular gravel and
cobble sized clasts.
4.3 Groundwater Conditions
Subsurface water, likely perched, was encountered at depths of approximately 19 feet bgs and 15
feet bgs in Test Pits T-1 and T-2, respectively. Subsurface water elevations are anticipated to
fluctuate following periods of sustained precipitation or excessive irrigation. Perched groundwater
conditions could also be encountered in other areas given the nature of the subsurface lithologies
with variable permeability. Therefore, it is anticipated that subsurface water could require diversion
or mitigation measures during grading operations. Due to the variable site conditions, it is generally
recommended to install a subdrain beneath and across the proposed building pads.
4.4 Geologic Hazards
Geologic hazards that were considered to have potential impacts to site development were evaluated
based on field observations, literature review, and laboratory test results. Based on this information
and the conditions observed during our study, it appears that the geologic hazards at the site are
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primarily limited to those caused by shaking from earthquake-generated ground motions. The
following paragraphs discuss the geologic hazards considered and their potential risk to the site.
4.4.1 Surface Fault Rupture
Based on the site reconnaissance and review of referenced literature, the site is not within a
City-designated fault zone or State of California-designated Alquist-Priolo Earthquake Fault
Studies Zone and no known active fault traces underlie or project toward the site. According
to the California Division of Mines and Geology, a fault is active if it displays evidence of
activity in the last 11,000 years (Hart and Bryant, revised 2007). Therefore, the potential for
surface rupture from displacement or fault movement beneath the proposed improvements is
considered to be low.
4.4.2 Local and Regional Faulting
The California Geological Survey (CGS) and the United States Geological Survey (USGS)
broadly group faults as "Class A" or "Class B" (Cao, 2003; Frankel et al., 2002). Class A
faults are identified based upon relatively well-defined paleoseismic activity, and a fault-slip
rate of more than 5 millimeters per year (mm/yr). In contrast, Class B faults have
comparatively less defined paleoseismic activity and are considered to have a fault-slip rate
less than 5 mm/yr. The, nearest known Class B fault is the Rose Canyon Fault, which is
approximately 11.5 kilometers west of the site (Blake, T.F., 2000). The nearest known Class
A fault is the Julian segment of the Elsinore Fault, which is located approximately 38.5
kilometers east of the site. Regional faults are presented on Figure 3.
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The site could be subjected to significant shaking in the event of a major earthquake on any
of the faults listed above or other faults in the southern California or northern Baja California
area.
4.4.3 Liquefaction and Seismic Settlement Evaluation
Liquefaction occurs when saturated fine-grained sands or silts lose their physical strengths
during earthquake-induced shaking and behave like a liquid. This is due to loss of
point-to-point grain contact and transfer of normal stress to the pore water. Liquefaction
potential varies with water level, soil type, material gradation, relative density, and probable
intensity and duration of ground shaking. Seismic settlement can occur with or without
liquefaction; it results from densification of loose soils.
The site is underlain by compacted fill and very dense Metavolcanic bedrock. Therefore, it
is our opinion that the potential for liquefaction or seismic settlement at the site is low.
4.4.4 Tsunamis and Seiche Evaluation
According to McCulloch (1985), the potential in the San Diego County coastal area for
"1 00-year" and "500-year" tsunami waves is approximately five and eight feet, or less. This
suggests that there is a low probability of a tsunami reaching the site based on elevation
above sea level. Inaddition; California Emergency Management Agency mapping (San
Onofre Bluff Quadrangle, 2009) indicates that the site is not susceptible to tsunami
inundation. Oscillatory waves (seiches) are considered unlikely due to the absence of large
adjacent bodies of water.
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4.4.5 Landsliding
According to mapping by Tan and Griffen (1995), the northeastern portion of site is
considered "generally susceptible" to landsliding. However, no landslides are mapped in the
site area. In addition, landslides were not encountered during our field exploration, and they
were not indicated in the referenced report. Therefore, landsliding is not considered a
significant geologic hazard within or adjacent to the site.
4.4.6 Compressible and Expansive Soils
Based on observations and testing, the upper portion of the Previously Placed Fill is
considered to be potentially compressible in its current condition. Therefore, it is
recommended that these soils be overexcavated and properly compacted as recommended
herein. Rock fills are not anticipated to be compressible. Based on the field data, site
observations, and experience with similar soils in the vicinity of the site, the underlying
Metavolcanic bedrock is not considered to be subject to significant compressibility under the
proposed loads.
Based on geologic observation, the near-surface materials generally have low expansion
potential (El of 50 or less). Therefore, the presence of expansive materials is not anticipated
to adversely impact the proposed improvements based on the recommendations provided
herein.
4.4.7 Corrosive Soils
Testing of representative site soils was performed to evaluate the potential corrosive effects
on concrete foundations and buried metallic improvements. Soil environments detrimental
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to concrete generally have elevated levels of soluble sulfates and/or pH levels less than 5.5.
According to the American Concrete Institute (ACI) Table 318 4.3.1, specific guidelines
have been provided for concrete where concentrations of soluble sulfate (SO4) in soil exceed
0.10 percent by weight. These guidelines include low water: cement ratios, increased
compressive strength, and specific cement type requirements. A minimum resistivity value
less than approximately 5,000 ohm-cm and/or soluble chloride levels in excess of 200 ppm
generally indicate a corrosive environment for buried metallic utilities and untreated
conduits.
Chemical test results indicate that near-surface soils at the site present a negligible corrosion
potential for Portland cement concrete. Based on resistivity testing, the site soils appear to
have a severe corrosivity potential to buried metallic improvements. As such, it would
appear prudent for buried utilities to utilize plastic piping and/or conduits, where feasible.
However, CTE does not practice corrosion engineering. Therefore, if corrosion of
improvements is of more significant concern, a qualified corrosion engineer could be
consulted.
5.0 CONCLUSIONS AND RECOMMENDATIONS
5.1 General
CTE concludes that the proposed development of the site is feasible from a geotechnical standpoint,
provided the recommendations in this report are incorporated into the design and construction of the
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project. Recommendations for the proposed earthwork and improvements are included in the
following sections and Appendix D. However, recommendations in the text of this report supersede
those presented in Appendix D should conflicts exist. These recommendations should either be
confirmed as appropriate or updated during or following rough grading of the site.
5.2 Site Preparation
Following removal of the existing trees/shrubs and brush that are not to remain, the proposed
improvement areas should be cleared of existing debris and deleterious materials. Objectionable
materials, such as vegetation, and other deleterious materials not suitable for structural backfill
should be properly disposed of off site.
In areas to receive structures, expansive, surficially eroded, desiccated, burrowed, or otherwise loose
or disturbed soils should be excavated to a minimum depth of four feet below existing grades or to
the depth of suitable material, whichever is deeper. In the area of proposed retaining walls
overexcavation should extend a minimum of two feet below and behind the wall footing(s) and
suitable soil placed in the void. In addition, rock fill slopes should be capped with a minimum 12
inches of suitable soil. The attached Figure 4 shows the conceptual geometry for the recommended
soil cap over the rock fill. Density testing should be performed on any Previously Placed Fill to
remain in place in order to confirm that it meets the minimum recommendations presented herein.
Excavations should extend laterally at least five feet beyond the limits of the proposed structures or
the distance resulting from a 1:1 (horizontal: vertical) extending from the bottom outside edge of the
footings, whichever is greater.
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Due to the anticipated need to generate compactable fill soils at the site, the aforementioned
minimum overexcavation depths could be disregarded and instead all existing suitable soil across the
site could be excavated and stockpiled for use as compacted fill. This should minimize the amount
of import soils, if necessary.
An engineer or geologist from CTE should observe the exposed ground surface or bottom of
overexcavations prior to placement of compacted fill to verify competent underlying materials.
After approval by this office, exposed soil subgrades should be scarified a minimum of six inches,
moisture conditioned, and properly compacted prior to receiving fill.
If encountered, existing below ground utilities should be removed or redirected around structures.
Utilities that are to extend through the proposed footings should be sleeved and caulked to minimize
the potential for moisture migration below the structure slab. Abandoned pipes exposed by grading
should be securely capped to prevent moisture from migrating beneath foundation and slab soils.
5.3 Site Excavation
Based on investigation observations, shallow excavations at the site should be feasible using well-
maintained heavy-duty construction equipment run by experienced operators. However, oversized
rock has been observed in our explorations and may be encountered throughout the site which may
require special handling. Also, if excavations are to extend into the Metavolcanic rock, excavation
should be very difficult and could require specialized equipment.
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5.4 Subdrains and Fill Placement and Compaction
Due to the variable site conditions, it is generally recommended to install a subdrain beneath and
across the proposed building pads. The subdrains should extend below and behind any retaining
walls, and are envisioned to extend across and below the proposed building footprints. Retaining
wall drains may be connected to the subdrains. The subdrains should outlet our daylight to a
suitable storm drain or area as per the project civil engineer or record.
Following recommended removals of any loose or disturbed soils, the areas to receive fills or
improvements exposed soils should be scarified a minimum of six inches, moisture conditioned, and
properly compacted. Exposed rock fill areas should be sufficiently flooded with sand to fill rock fill
void space and proof rolled to the degree feasible prior to placing fills. Fill and backfill should be
compacted to a minimum relative compaction of 90 percent at a moisture content of at least two
percent above optimum, as evaluated by ASTM D 1557. The optimum lift thickness for fill soil will
depend on the type of compaction equipment used. Generally, backfill should be placed in uniform,
horizontal lifts not exceeding eight inches in loose thickness. Fill placement and compaction should
be conducted in conformance with local ordinances.
5.5 Fill Materials
Very low to low expansion potential soils derived from the on-site materials are considered suitable
for reuse on the site as compacted fill. If used, these materials should be screened of degradable
debris or organics and materials generally greater than three inches in maximum dimension.
Irreducible materials greater than three inches in maximum dimension generally should not be used
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in shallow fills (within three feet of proposed grades). In utility trenches, adequate bedding should
surround pipes.
Imported fill beneath structures and distress sensitive surface improvements such as pavements or
flatwork should have an Expansion Index of 20 or less (ASTM D 4829). Imported fill soils for use
in structural or slope areas should be evaluated by the soils engineer before importation to the site.
Retaining wall backfill located within a 45-degree wedge extending up from the bottom of the heel
of the wall foundation should consist of soil having an Expansion Index of 20 or less (ASTM D
4829) with less than 30 percent passing the No. 200 sieve. As such, some onsite soils may not be
suitable for use as wall backfill. The upper 12 to 18 inches of wall backfill could consist of lower
permeability soils, in order to reduce surface water infiltration behind walls. The project structural
engineer and/or architect should detail proper wall backdrains, including gravel drain zone fills,
filter fabric, and perforated drain pipes.
5.6 Temporary Construction Slopes
The following recommended slopes should be relatively stable against deep-seated failure, but may
experience localized sloughing. On-site soils are considered Type B and Type C soils with
recommended slope ratios as set forth in the table below.
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TABLE 5.6
RECOMMENDED TEMPORARY SLOPE RATIOS
SOIL TYPE SLOPE RATIO MAXIMUM HEIGHT (Horizontal: vertical)
B (Metavolcanic rock) 1:1 (OR FLATTER) 10 Feet
C (Previously Placed Fill) 1.5:1 (OR FLATTER) 10 Feet
Actual field conditions and soil. type designations must be verified by a "competent person" while
excavations exist, according to Cal-OSHA regulations. In addition, the above sloping
recommendations do not allow for surcharge loading at the top of slopes by vehicular traffic,
equipment or materials. Appropriate surcharge setbacks must be maintained from the top of all
unshored slopes.
5.7 Foundations and Slab Recommendations
The following recommendations are for preliminary design purposes only. These recommendations
should be reviewed after completion of earthwork to verify that conditions exposed are as
anticipated and that the recommended structure design parameters are appropriate.
5.7.1 Foundations
Continuous and isolated spread footings are suitable for use at this site. We anticipate that
all building footings will be founded entirely in properly compacted fill derived from onsite
materials as recommended herein with a low expansion potential (Expansion Index of 50 or
less). Foundation dimensions and reinforcement should be based on allowable bearing
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values of 2,000 pounds per square foot (psf) for minimum 15-inch wide footings embedded
at least 24 inches below the lowest adjacent subgrade. The allowable bearing value may be
increased by 200 psf for each additional six inches of embedment, up to a maximum value of
3,000 psf. However, if footings are deepened, the overexcavation depths should also be
deepened in order to maintain a minimum two feet of properly compacted fill soil below the
bottoms of all footings. The allowable bearing value may also be increased by one-third for
short-duration loading which includes the effects of wind or seismic forces.
An uncorrected subgrade modulus of 130 pounds per cubic inch is considered suitable for
elastic foundation design.
Minimum footing reinforcement for continuous or spread footings should be as per the
structural engineer. However, we recommend continuous footing reinforcement consist of a
minimum of two #5 bars near the top and two #5 bars near the bottom.
The structural engineer should provide recommendations for reinforcement of any spread
footings and footings with pipe penetrations. Footing excavations should generally be
maintained at above optimum moisture content until concrete placement.
5.7.2 Foundation Settlement
The maximum total static settlement is expected to be on the order of one inch and the
maximum differential settlement is expected to be on the order of /2 inch. Due to the
absence of a shallow stabilized groundwater table and the generally dense nature of
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underlying materials, dynamic settlement is not expected to adversely affect the proposed
improvements.
5.7.3 Foundation Setback
Footings for structures should be designed such that the horizontal distance from the face of
adjacent slopes to the outer edge of the footing is at least 10 feet. In addition, footings
should bear beneath a 1:1 plane extended up from the nearest bottom edge of adjacent
parallel trenches and/or excavations. Deepening of affected footings may be a suitable
means of attaining the prescribed setbacks.
5.7.4 Interior Concrete Slabs
Lightly loaded concrete slabs should be a minimum of 4.5 inches in thickness. Minimum
slab reinforcement should consist of #3 reinforcing bars placed on maximum 16-inch
centers, each way, at above mid-slab height, but with proper concrete cover.
In moisture-sensitive floor areas, a suitable vapor retarder of at least ten-mil thickness (with
all laps or penetrations sealed or taped) overlying a two-inch layer of consolidated aggregate
base or sand (with SE of 30 or more) should be installed. An optional maximum two-inch
layer of similar material may be placed above the vapor retarder to help protect the
membrane during steel and concrete placement. This recommended protection is generally
considered typical in the industry. If proposed floor areas or coverings are considered
especially sensitive to moisture emissions, additional recommendations from a specialty
consultant could be obtained. CTE is not an expert at preventing moisture penetration
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through slabs. A qualified architect or other experienced professional should be contacted if
moisture penetration is a more significant concern.
Slabs subjected to heavier loads may require thicker slab sections and/or increased
reinforcement. A 120-pci subgrade modulus is considered suitable for elastic design of
minimally embedded improvements such as slabs-on-grade. Subgrade materials should
generally be maintained near or above optimum moisture content until slab underlayment or
concrete are placed.
5.8 Seismic Design Criteria
The seismic ground motion values listed in the table below were derived in accordance with both the
California Building Code (CBC), 2010, and the ASCE 7-10 Standard that is incorporated into the
California Building Code 2013 (that are scheduled to take affect this coming January 1, 2014). This
was accomplished by establishing the Site Class based on the soil properties at the site, and then
calculating the site coefficients and parameters using the United States Geological Survey (USGS)
Java Ground Motion Parameter Calculator - Version 5. 1.0 for the 2010 CBC values, and the United
States Geological Survey Seismic Design Maps application for the 2013 CBC values. Results for
each set of seismic ground motion values were based on the site coordinates of 33.0851° latitude and
-117.2350° longitude. These values are intended for the design of structures to resist the effects of
earthquake ground motions.
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Preliminary Geotechnical Investigation Page 18
Proposed Goertzen Homes Development
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December 16. 2013 CTE Job No. 10-11657G
. -- - TABLE 5.8- - - -
SEISMIC GROUND MOTION VALUES
PARAMETER CBC 2010 CBC 2013 CBC REFERENCE
Site Class D D Table 1613.5.2
Mapped Spectral Response 1.118 1.030 Figure 16 13.5(3) Acceleration Parameter, 5s
Mapped Spectral Response 0.420 0.399 Figure 16 13.5(4) Acceleration Parameter, S1
Seismic Coefficient, F. 1.053 1.088 Table 1613.5.3(1)
Seismic Coefficient, Fv 1.58 1.602 Table 1613.5.3(2)
NICE Spectral Response 1.178 1.121 Section 1613.5.3 Acceleration Parameter, Sms
MCE Spectral Response 0.664 0.639 Section 16 13.5.3 Acceleration Parameter, SMI
Design Spectral Response 0.785 0.747 Section 16 13.5.4
Acceleration, Parameter SDS
Design Spectral Response 0.442 0.426 Section 1613.5.4 Acceleration, Parameter 5D1
5.9 Lateral Resistance and Earth Pressures
Lateral loads acting against structures may be resisted by friction between the footings and the
supporting soil or passive pressure acting against structures. If frictional resistance is used, we
recommend allowable coefficients of friction of 0.30 (total frictional resistance equals the coefficient
of friction multiplied by the dead load) for concrete cast directly against compacted fill. A design
passive resistance value of 250 pounds per square foot per foot of depth (with a maximum value of
1,250 pounds per square foot) may be used. The allowable lateral resistance can be taken as the sum
of the frictional resistance and the passive resistance, provided the passive resistance does not
exceed two-thirds of the total allowable resistance.
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Preliminary Geotechnical Investigation Page 19
Proposed Goertzen Homes Development
Northeast of Venado and Esfera Streets, California
December 16, 2013 CTE Job No. 10-1 165 7G
Retaining walls up to approximately eight feet high and backfilled using granular soils may be
designed using the equivalent fluid weights given in Table 5.9 below.
TABLE 5.9
EQUIVALENT FLUID UNIT WEIGHTS
(pounds per cubic foot)
SLOPE BACKFILL
WALL TYPE LEVEL BACKFILL 2: (HORIZONTAL:
VERTICAL)
CANTILEVER WALL 35 60 (YIELDING)
RESTRAINED WALL 55 80
Lateral pressures on cantilever retaining walls (yielding walls) due to earthquake motions may be
calculated based on work by Seed and Whitman (1970). The total lateral thrust against a properly
drained and backfilled cantilever retaining wall above the groundwater level can be expressed as:
PAE = PA + LPAE
For non-yielding (or "restrained") walls, the total lateral thrust may be similarly calculated
based on work by Wood (1973):
PKE = PK + LPKE
Where PA = Static Active Thrust (given previously Table 5.9)
PK = Static Restrained Wall Thrust (given previously Table 5.9)
L\PAE = Dynamic Active Thrust Increment = (3/8) kh 7H2
LPKE = Dynamic Restrained Thrust Increment = kh 'yH2
kh = Y2 Peak Ground Acceleration = V2 (SDs/2.5)
H = Total Height of the Wall
= Total Unit Weight of Soil = 135 pounds per cubic foot
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Preliminary Geotechnical Investigation S Page 20
Proposed Goertzen Homes Development
Northeast of Venado and Esfera Streets, California
December 16, 2013 CTE Job No. 10-11657G
The increment of dynamic thrust in both cases should be distributed trapezoidally (essentially an
inverted triangle), with a line of action located at 0.6H above the bottom of the wall.
These values assume non-expansive backfill and free-draining conditions. Measures should be taken
to prevent moisture buildup behind all retaining walls. Drainage measures should include free-
draining backfill materials and sloped, perforated drains. These drains should discharge to an
appropriate off-site location. Any waterproofing should be as specified by the project architect.
5.10 Exterior Flatwork
To reduce the potential for cracking in exterior flatwork caused by minor movement of subgrade
soils and concrete shrinkage, we recommend that such flatwork measure a minimum 4.5 inches in
thickness and be installed with crack-control joints at appropriate spacing as designed by the project
architect. Additionally, we recommend that flatwork be installed with at least number 3 reinforcing
bars on maximum 24-inch centers, each way, at above mid-height of slab, but with proper concrete
cover, or with other reinforcement per the project consultants. All subgrades should be prepared
according to the earthwork recommendations previously given before placing concrete. Positive
drainage should be established and maintained next to all flatwork. Subgrade materials shall be
maintained at, or be elevated to, above optimum moisture content until just prior to concrete
placement.
5.11 Vehicular Pavements
It is anticipated that the proposed development will include paved vehicle drive and parking areas.
The upper 12 inches of subgrade and any base materials beneath pavement areas should be
\Esc_server\projects\IO- II 657GRpt_GeotechnicaI.doc
Preliminary Geotechnical Investigation Page 21
Proposed Goertzen Homes Development
Northeast of Venado and Esfera Streets, California
December 16, 2013 CTE Job No. 10-11657G
compacted to 95% relative compaction in accordance with ASTM D1557, at a minimum of two
percent above optimum moisture content. Based on site soil conditions, it is recommended that
concrete pavements be a minimum of five inches in thickness where subject to typical automobile
and light pickup truck traffic. Thicker sections could be warranted for large vehicles such as RVs or
similar could be routinely driven or parked. Concrete paved areas should be designed and
constructed in accordance with the recommendations of the American Concrete Institute or other
Widely recognized authority, particularly with regard to thickened edges, joints, and drainage.
Concrete pavements should have minimal reinforcement as per the recommendations for flatwork in
Section 10 or, alternatively, they could be unreinforced with expansion/contraction or construction
joint spacing no more than 24 time the pavement thickness in nearly square patterns.
5.12 Drainage
Surface runoff should be collected and directed away from improvements by means of appropriate
erosion-reducing devices and positive drainage should be established around the proposed
improvements. Positive drainage should be directed away from improvements at a gradient of at
least two percent for a distance of at least five feet. However, the project civil engineers should
evaluate the on-site drainage and make necessary provisions to keep surface water from affecting the
site.
Generally, CTE recommends against allowing water to infiltrate building pads or adjacent to slopes.
We understand that some agencies are requiring the use of storm water cleansing devices and
encouraging the use of storm-water infiltration devices. Use of infiltration devices tends to increase
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Preliminary Geotechnical Investigation Page 22
Proposed Goertzen Homes Development
Northeast of Venado and Esfera Streets, California
December 16. 2013 CTE Job No. 10-1165 7G
the possibility of high groundwater and slope instability. If storm water cleansing devices must be
used, then we generally recommend that they be underlain by an impervious barrier and that the
storm water be collected via subsurface piping and eventually discharged off site.
5.13 Slopes
Based on anticipated soil strength characteristics, fill slopes should be constructed at slope ratios of
2:1 (horizontal: vertical) or flatter. These fill slope inclinations should exhibit factors of safety
greater than 1.5.
Although properly constructed slopes on this site should be grossly stable, the soils will be
somewhat erodible. Therefore, runoff water should not be permitted to drain over the edges of
slopes unless that water is confined to properly designed and constructed drainage facilities.
Erosion-resistant vegetation should be maintained on the face of all slopes.
Typically, soils along the top portion of a fill slope face will creep laterally. CTE recommends
against building distress-sensitive hardscape improvements within five feet of slope crests.
5.14 Construction Observation
The recommendations provided in this report are based on preliminary design information for the
proposed construction and the subsurface conditions observed in the exploratory borings. The
interpolated subsurface conditions should be checked in the field during construction to verify that
conditions are as anticipated. Foundation recommendations may be revised upon completed
improvement plans.
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Preliminary Geotechnical Investigation Page 23
Proposed Goertzen Homes Development
Northeast of Venado and Esfera Streets, California
December 16, 2013 CTE Job No. 10-1 1657G
Recommendations provided in this report are based on the understanding and assumption that CTE
will provide the observation and testing services for the project. All earthwork should be observed
and tested to verify that grading activity has been performed according to the recommendations
contained within this report. The project engineer should evaluate all footing trenches before
reinforcing steel placement.
5.14 Plan Review
CTE should be authorized to review the project grading and foundation plans before commencement
of earthwork to identify potential conflicts with the intent of the recommendations provided.
6.0 LIMITATIONS OF INVESTIGATION
The field evaluation, laboratory testing, and geotechnical analysis presented in this report have been
conducted according to current engineering practice and the standard of care exercised by reputable
geotechnical consultants performing similar tasks in this area. No other warranty, expressed or
implied, is made regarding the conclusions, recommendations and opinions expressed in this report.
Variations may exist and conditions not observed or described in this report may be encountered
during construction.
The findings of this report are valid as of the present date. However, changes in the conditions of a
property can occur with the passage of time, whether they are due to natural processes or the works
of man on this or adjacent properties. In addition, changes in applicable or appropriate standards
may occur, whether they result from legislation or the broadening of knowledge. Accordingly, the
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Preliminary Geotechnical Investigation Page 24
Proposed Goertzen Homes Development
Northeast of Venado and Esfera Streets, California
December 16, 2013 CTE Job No. 10-I 1657G
findings of this report may be invalidated wholly or partially by changes outside our control.
Therefore, this report is subject to review and should not be relied upon after a period of three years.
CTE's conclusions and recommendations are based on an analysis of the observed conditions. If
conditions different from those described in this report are encountered, our office should be notified
and additional recommendations, if required, will be provided.
We appreciate this opportunity to be of service on this project. If you have any questions regarding
this report, please do not hesitate to contact the undersigned.
Respectfully submitted,
CONSTRUCTION TESTING & ENGINEERING, INC.
ESSI
Dan T. Math, GE #2665 Aaron J. Beeby, CEO #2603
Principal Engineer OFCA.' Certified Engineering Geologist
:SIY No.2603 .—
11nw U,
'• DNEER1NG GEOL0GST Ei. 3/31/I
OF CM.'1
AJBIDTM :nri
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CONSTRUCTION TESTING & ENGINEERING, IN
GEOTECHNICAL AND CONSTRUCTION ENGINEERING TESTING AND INSPECTION
1441 MONTIEL ROAD, STE 115 ESCONDIDO CA. 92026 (760) 746-4955
SITE INDEX MAP
CTE JOB NO:
Sec 0)a Wdp PROPOSED GOERTZEN HOMES DEVELOPMENT SCALE:
- EAST OF VENADO STREET AND NORTH OF ESFERA STREET NO SC -:
CARLSBAD CALIFORNIA DATE: FIGUF
12/13
— — — — — — — — — — — — — — — — — — —
ATP /
69- 1932- 800- 8 PERIOD 1868 1931 2010 o IS, - , - ED Y . .
\ !\\N 00
6569 Q • ED
, 55 590 • 0 N \ 0 0
LAST TWO DIGITS OFM>6.5
\i N 40 EARTHQUAKE YEAR
- ., I•'S .\ yey
/) f' •'..
I' \ \\
/ /Io
I \ (
0
\\ , '' '
' . •.
N\NN ç 40
NOTES; FAULT ACTIVITY MAP OF CALIFORNIA, 2010, CALIFORNIA 000U)GIC DATA MAP SERIES MAP NO. 6; REGIONAL FAULT AND SEISMICITY MAP 10-11657G EPICFNTFRO OF AND AREAS DAMAGED BY M>5 CALIFORNIA EAICflQUAKFO, 1950-1999 ADAPTED CONSTRUCTION TESTING & ENGINEERING, INC PROPOSED GORTZEN HOMES DEVELOPMENT neh = 12 miI I AYI'FR TOPPOZAOA, HRAMM FETFRSEN, HAIlSTORM, CRAMER. AND RECOIl 2000 . , F AST OF VENADO STREET AND NORTh OF FSFERA STREET , CDMG MAP SMECT AS , , CARIBAD CALIFORNIA 2/1,1 RF.FF.RFNCF FOR ADDITIONAl VXPIANATION; MODIFIER !STH ClOY AND USGS OFISAAIC MAPS
24m MINIMUM
12" MINIMUM
SLOPE PER GRADING PLAN
COMPACTED BENCHING
FILL SOILS
H/2
r
24' MIN 2%MIN
CLEAN SAND SHOULD BE FLOODED
INTO EXPOSED ROCK FILL SLOPE
PRIOR TO PLACING FILL
ROCK FILL
KEY-DIMENSION PER SOILS ENGINEER
(4' MINIMUM)
DIMENSIONS ARE MINIMUM RECOMMENDED
CONSTRUCTION TESTING & ENGINEERING, INC.
PLANNING -CIVIL ENGINEERING. LAND SURVEYING - GEOTECHNICAL
1441 MONTIEL ROAD. SUITE 115 ESCONOIDO CA. 52021. P0:(160) 146-4551
PROPOSED SLOPE DETAIL I sc I it
PROPOSED_COERTZEN ROME DEVELOPMENT NOT TO SCAlE I 12/13
VENADO ncuT AND N. OF ESFERA MW I CTE JOB NO.: frcuR
CARlSBAD, CAlifORNIA I
APPENDIX A
REFERENCES
REFERENCES
I. ASTM, 2002, "Test Method for Laboratory Compaction Characteristics of Soil Using
Modified Effort," Volume 04.08
Benton Engineering, Inc., 1977, Project No. 74-5-2D, Final Report on Compacted Filled
Ground, La Costa Vale Unit Nos. 3 and 4, Carlsbad Tract Nos. 72-20 and 76-3, Carlsbad,
California, dated February 4.
Blake, T.F., 2000, "EQFAULT," Version 3.00b, Thomas F. Blake Computer Services and
Software.
California Building Code, 2010, "California Code of Regulations, Title 24, Part 2, Volume 2
of 2," California Building Standards Commission, published by ICBO, June.
California Division of Mines and Geology, CD 2000-003 "Digital Images of Official Maps
of Alquist-Priolo Earthquake Fault Zones of California, Southern Region," compiled by
Martin and Ross.
Hart, Earl W., Revised 1994, Revised 2007, "Fault-Rupture Hazard Zones in California,
Alquist Priolo, Special Studies Zones Act of 1972," California Division of Mines and
Geology, Special Publication 42.
Jennings, Charles W., 1994, "Fault Activity Map of California and Adjacent Areas" with
Locations and Ages of Recent Volcanic Eruptions.
Kennedy, M.P. and Tan, S.S., 2005, "Geologic Map of the Oceanside 30' x 60' Quadrangle,
California", California Geological Survey; Map No. 2, Plate I of 2.
McCulloch, D.S., 1985, "Evaluating Tsunami Potential" in Ziony, J.I., ed., Evaluating
Earthquake Hazards in the Los Angeles Region - An Earth-Science Perspective, U.S.
Geological Survey Professional Paper 1360.
Rick Engineering Company, 1974, Grading Plans for Carlsbad Track No. 72-20 (La Costa
Vale) Unit No. 3, Sheet 3 of 19, Drawing No. 176-2A.
Seed, H.B., and R.V. Whitman, 1970, "Design of Earth Retaining Structures for Dynamic
Loads," in Proceedings, ASCE Specialty Conference on Lateral Stresses in the Ground and
Design of Earth-Retaining Structures, pp. 103-147, Ithaca, New York: Cornell University.
Tan, S. S., and Griffen, G., 1995, Landslide Hazards in the Northern Part of the San Diego
Metropolitan Area, San Diego County, California, Rancho Santa Fe Quadrangle Landslide
Distribution Map - Plate 35E.
Wood, J.H. 1973, Earthquake-Induced Soil Pressures on Structures, Report EERL 73-05.
Pasadena: California Institute of Technology.
APPENDIX B
EXPLORATION LOGS
CONSTRUCTION TESTING & ENGINEERING, INC.
BIOlICIlulCAt I COUSTIUCIIOU ESuItlRluS TIltINC ANN INsPeCtION
tIlt 1111111 lOON. $1111 Ill I CIC001INI. CI 0900 11116.141.4151
PROJECT: DRILLER: SHEET: of
CTE JOB NO: DRILL METHOD: DRILLING DATE:
LOGGED BY: SAMPLE METHOD: ELEVATION:
2
LL.I r' BORING LEGEND Laboratory Tests
06
5 c La
DESCRIPTION
.4— - Block or Chunk Sample - - - -
.4— - Bulk Sample - - - -
4— - Standard Penetration Test - - - -
0— - Modified Split-Barrel Drive Sampler (Cal Sampler) -- - - -
I - - Thin Walled Army Corp. of Engineers Sample - - - -
Groundwater Table
- Soil Type or Classification Change
- Formation Change [(Approximate boundaries queried (?)]
- "Sm.Quotes are placed around classifications where the soils
exist in situ as bedrock
— - - — — — — —
FIGURE: 1 BL2
CONSTRUCTION TESTING & ENGINEERING. INC.
BCOT(CMNIC*L I COUTUOCTIOU ENGINEERING TIHINO UO INSPECTION 1441 111911111. Inc.11111 115 I t$CCUID,. (I Ilul 1161.141.4151
PROJECT:GORTZEN HOME DEVELOPMENT DRILLER: MANSOLF SHEET: I of
CTE JOB NO: 10-I 1657G DRILL METHOD: SOILD-STEM AUGER DRILLING DATE: 11/25/2013
LOGGED BY: MB SAMPLE METHOD: BULK, RING, AND SPT ELEVATION: -330 FEET
CL — E DO BORING: B-i Laboratory Tests
2 3
U
IM
DESCRIPTION
- - -
- - OUATERNARY PREVIOUSLY PLACED FILL (Onpfl:
• Loose to medium dense, dry to slightly moist, reddish brown, silty
SAND.fine to medium erained _____________________________
GP Poorly graded rock fill, clasts to_ approxiamtely 18" in diameter.
- Total Depth: 3' (Refusalon Gravel)
No Groundwater Encountered
-5-
15-
20-
25-
- - I B-I
9*9 CONSTRUCTION TESTING & ENGINEERING, INC.
OtbUtMuIL I COUItIUCIOU EUSIDIIDIND TIITINS AND INAPICTISU
14401 1110111111. lOAD. SOlID III I I1100101. (A 11111 1111.141.4115
PROJECT:GORTZEN HOME DEVELOPMENT DRILLER: MANSOLF SHEET: I of
CTE JOB NO: I0-I1657G DRILL METHOD: SOILD-STEM AUGER DRILLING DATE: 11/2512013
LOGGED BY: AJB SAMPLE METHOD: BULK, RING, AND SPT ELEVATION: —316 FEET
C-. a - 2
' - ' BORING: B-2 Laboratory Tests
I Ui 42
iE 3
u
c
DESCRIPTION
0- - - - -
- OUATERNARY PREVIOUSLY PLACED FILL (Opnfl:
- Loose to medium dense, dry to slightly moist, light grayish brown,
clayey fine to medium grained SAND with angular gravel.
Total Depth: 4' (Refusal on Gravel)
40-
No Groundwater Encountered
20-
25-
—
I B-2
I \ CONSTRUCTION TESTING & ENGINEERING, INC. SI- of. TECHNICAL I CONSTRUCTION CUSOCISIUS TESTING AND IUIPICIISI
________________________ 1411 USIIIR SIlL SIlls III I 1101101.11 1551$ I IU.II1.4III
PROJECT:GORTZEN HOME DEVELOPMENT DRILLER: MANSOLF SHEET: I of
CTh JOB NO: 10-I 16570 DRILL METHOD: SOILD-STEM AUGER DRILLING DATE: 11/25/2013
LOGGED BY: MB SAMPLE METHOD: BULK, RING, AND SPT ELEVATION: -.308 FEET
.E
I BORING: B-3 Laboratory Tests
L4 z
,
4q V In
DESCRIPTION
0- - - - -
- OUATERNARY PREVIOUSLY PLACED FILL (Onpfl:
- Loose to medium dense, dry to slightly moist, light grayish brown,
clayey fine to medium grained SAND with angular gravel.
A 3
- 3 MD, AL
- Total Depth: 5' (Refusal on Gravel)
-10-
No Groundwater Encountered
-45-
-20- S
2 25-
— I B-3
CONSTRUCTION TESTING & ENGINEERING, INC.
OCOTCCHNICM. I CONSTRUCTION IUiIIiRIU TESTING LUG INSPECTION 1411 UGNIIIL IDA., Dint lit I tftoiulti. CA 11111 1111.141.4111
PROJECT:GORTZEN HOME DEVELOPMENT DRILLER: MANSOLF SHEET: 1 of
CTE JOB NO: 10-I I657G DRILL METHOD: SOILD-STEM AUGER DRILLING DATE: 12/3(2013
LOGGED BY: AJB SAMPLE METHOD: BULK, RING, AND SPT ELEVATION: -308 FEET
a 2
I '
to BORiNG: T- 1 Laboratory Tests
ci .2 5 in
DESCRIPTION
- - -SIC
- OUATERNARY PREVIOUSLY PLACED FILL (Opufl:
- Loose to medium dense, dry to slightly moist, light grayish brown,
to reddish gray, clayey fine grained SAND with angular gravel.
- MAX, El, CHM
-5—
Becomes reddish brown, fine to medium grained SAND with
- increased clay content. Approximately 20% angular gravel to
3" in diameter.
GS
40-
- CL I i re
------------------------------------------------------
brown, iin is.i c
- Approximely 20-30% angular gravel to 6" in diameter.
AL
GC/CL Medium dense, moist, reddish brown, clayey GRAVEL/ sandy CLAY
-
15-
with gravel. Approximately 40-60% angular gravel to 6" in diameter.
CL
-S
Stiff, moist to wet, reddish brown, fine to medium grained sandy
CLAY with gravel. Approximately 20% angular gravel to 6" in
diameter.
20- Groundwater seepage encountered at 19'
- Total Depth: 22'
Groundwater Seepage Encountered at 19'
25-
- — I 1-1
A
\ CONSTRUCTION TESTING & ENGINEERING. INC. ¶/ gtoTuurncaL I cauiticclulu IuSIatlAlu. 1151111 *50 IN1PLC1I08 1441 MSIIIR lOAD, 01111 115 I fUCII1: ts USD1 I IU.141.I156
PROJECT: GORTZEN HOME DEVELOPMENT DRILLER: MANSOLF SHEET: I of
CTE JOB NO: 10-I I657G DRILL METHOD: SOILD-STEM AUGER DRILLING DATE: 1213(2013
LOGGED BY: AJB SAMPLE METHOD: BULK, RING, AND SPT ELEVATION: -316 FEET
. .
5
BORING: T-2 Laboratory Tests
0 1
DESCRIPTION
0 - - - -
- QUATERNARY PREVIOUSLY PLACED FILL (Onpfl:
- Loose to medium dense, dry to slightly moist, light grayish brown,
to reddish gray, clayey fine grained SAND with angular gravel.
- Boulder to approximately 3' in diameter encountered
Becomes reddish brown, fine to medium grained SAND with
- S increased clay content. Approximately 20-30% angular gravel to
10" in diameter.
- At approxiamtely 6-9' discontinuous concentration of rock to
10-
12" in diameter.
1 Groundwater seepage encountered at 15'
CL
---------------------------------------------------------------Stiff, wet, brown, fine to medium grained sandy CLAY with gravel.
- Approximely30-40% angular gravel to 3" in diameter.
GP - METAVOLCANIC ROCK:
20- - - - - - - Moderately weathered metavolcanic rock, oxidized.
- Total Depth: 20'
Groundwater Seepage Encountered at 15'
-25-
I T-2
APPENDIX C
LABORATORY METHODS AND RESULTS
APPENDIX C
LABORATORY METHODS AND RESULTS
Laboratory Testing Program
Laboratory tests were performed on representative soil samples to detect their relative engineering
properties. Tests were performed following test methods of the American Society for Testing
Materials or other accepted standards. The following presents a brief description of the various test
methods used.
Classification
Soils were classified visually according to the Unified Soil Classification System. Visual
classifications were supplemented by laboratory testing of selected samples according to ASTM
D2487. The soil classifications are shown on the Exploration Logs in Appendix B.
In-Place Moisture and Density
To determine the moisture and density of in-place site soils, a representative sample was tested for
the moisture and density at time of sampling.
Modified Proctor
To determine the maximum dry density and optimum moisture content, a soil sample was tested in
accordance with ASTMD-1557.
Expansion Index
Expansion testing was performed on selected samples of the matrix of the on-site soils according to
ASTM D 4829.
Atterberg Limits
The procedure of ASTM D4518-84 was used to measure the liquid limit, plastic limit and plasticity
index of representative samples.
Chemical Analysis
Soil materials were collected with sterile sampling equipment and tested for Sulfate and Chloride
content, pH, Corrosivity, and Resistivity.
CONSTRUCTION TESTING & ENGINEERING. INC.
OIOtICIIUlC*I I CS.ITUCIIOU EuOI.ttU,UO TIIIIUO £NO I.IPIC?ON flu Ms.iult uo., nut its I sisit I
EXPANSION INDEX TEST
ASTM D 4829
LOCATION DEPTH EXPANSION INDEX EXPANSION
(feet) POTENTIAL
T-I 0-6 44 LOW
IN-PLACE MOISTURE AND DENSITY
LOCATION DEPTH % MOISTURE DRY DENSITY
(feet)
B-3 3 14.8 81.7
SULFATE
LOCATION DEPTH RESULTS
(feet) ppm
T-I 0-6 118.8
CHLORIDE
LOCATION DEPTH RESULTS
(feet) ppm
T-I 0-6 199
LOCATION DEPTH RESULTS
(feet)
T-1 0-6 5.2
RESISTIVITY
CALIFORNIA TEST 424
LOCATION DEPTH RESULTS
(feet) ohms/cm
1-1 0-6 1080
ATTERBERG LIMITS
LOCATION DEPTH LIQUID LIMIT PLASTICITY INDEX CLASSIFICATION
(feet)
B-3 3 45 30 CL
T-1 13-15 39 21 CL
MODIFIED PROCTOR
ASTM D 1557
LOCATION DEPTH MAXIUM DRY DENSITY OPTIMUM MOISTURE
(feet) (PCF) (%)
1-I 6-10 113.8 14.4
LABORATORY SUMMARY CTE JOB NO. 10-I 1657G
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.
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PARTICLE SIZE ANALYSIS
CONSTRUCTION TESTING & ENGINEERING, INC. ¶0
U JOB I1NUMBER: J[,11J11
APPENDIX D
STANDARD SPECIFICATIONS FOR GRADING
Appendix D Page D-1
Standard Specifications for Grading
Section 1 - General
Construction Testing & Engineering, Inc. presents the following standard recommendations for
grading and other associated operations on construction projects. These guidelines should be
considered a portion of the project specifications. Recommendations contained in the body of
the previously presented soils report shall supersede the recommendations and or requirements as
specified herein. The project geotechnical consultant shall interpret disputes arising out of
interpretation of the recommendations contained in the soils report or specifications contained
herein..
Section 2 - Responsibilities of Project Personnel
The geotechnical consultant should provide observation and testing services sufficient to general
conformance with project specifications and standard grading practices. The geotechnical
consultant should report any deviations to the client or his authorized representative.
The Client should be chiefly responsible for all aspects of the project. He or his authorized
representative has the responsibility of reviewing the findings and recommendations of the
geotechnical consultant. He shall authorize or cause to have authorized the Contractor and/or
other consultants to perform work and/or provide services. During grading the Client or his
authorized representative should remain on-site or should remain reasonably accessible to all
concerned parties in order to make decisions necessary to maintain the flow of the project.
The Contractor is responsible for the safety of the project and satisfactory completion of all
grading and other associated operations on construction projects, including, but not limited to,
earth work in accordance with the project plans, specifications and controlling agency
requirements.
Section 3 - Preconstruction Meeting
A preconstruction site meeting should be arranged by the owner and/or client and should include
the grading contractor, design engineer, geotechnical consultant, owner's representative and
representatives of the appropriate governing authorities.
Section 4 - Site Preparation
The client or contractor should obtain the required approvals from the controlling authorities for
the project prior, during and/or after demolition, site preparation and removals, etc. The
appropriate approvals should be obtained prior to proceeding with grading operations.
STANDARD SPECIFICATIONS OF GRADING
Page 1 of 26
Appendix Page D-2
Standard Specifications for Grading
Clearing and grubbing should consist of the removal of vegetation such as brush, grass, woods,
stumps, trees, root of trees and otherwise deleterious natural materials from the areas to be
graded. Clearing and grubbing should extend to the outside of all proposed excavation and fill
areas.
Demolition should include removal of buildings, structures, foundations, reservoirs, utilities
(including underground pipelines, septic tanks, leach fields, seepage pits, cisterns, mining shafts,
tunnels, etc.) and other man-made surface and subsurface improvements from the areas to be
graded. Demolition of utilities should include proper capping and/or rerouting pipelines at the
project perimeter and cutoff and capping of wells in accordance with the requirements of the
governing authorities and the recommendations of the geotechnical consultant at the time of
demolition.
Trees, plants or man-made improvements not planned to be removed or demolished should be
protected by the contractor from damage or injury.
Debris generated during clearing, grubbing and/or demolition operations should be wasted from
areas to be graded and disposed off-site. Clearing, grubbing and demolition operations should be
performed under the observation of the geotechnical consultant.
Section 5 - Site Protection
Protection of the site during the period of grading should be the responsibility of the contractor.
Unless other provisions are made in writing and agreed upon among the concerned parties,
completion of a portion of the project should not be considered to preclude that portion or
adjacent areas from the requirements for site protection until such time as the entire project is
complete as identified by the geotechnical consultant, the client and the regulating agencies.
Precautions should be taken during the performance of site clearing, excavations and grading to
protect the work site from flooding, ponding or inundation by poor or improper surface drainage.
Temporary provisions should be made during the rainy season to adequately direct surface
drainage away from and off the work site. Where low areas cannot be avoided, pumps should be
kept on hand to continually remove water during periods of rainfall.
Rain related damage should be considered to include, but may not be limited to,.erosion, silting,
saturation, swelling, structural distress and other adverse conditions as determined by the
geotechnical consultant. Soil adversely affected should be classified as unsuitable materials and
should be subject to overexcavation and replacement with compacted fill or other remedial
grading as recommended by the geotechnical consultant.
STANDARD SPECIFICATIONS OF GRADING
Page 2 of 26
Appendix D Page D-3
Standard Specifications for Grading
The contractor should be responsible for the stability of all temporary excavations.
Recommendations by the geotechnical consultant pertaining to temporary excavations (e.g.,
backcuts) are made in consideration of stability of the completed project and, therefore, should
not be considered to preclude the responsibilities of the contractor. Recommendations by the
geotechnical consultant should not be considered to preclude requirements that are more
restrictive by the regulating agencies. The contractor should provide during periods of extensive
rainfall plastic sheeting to prevent unprotected slopes from becoming saturated and unstable.
When deemed appropriate by the geotechnical consultant or governing agencies the contractor
shall install checkdams, desilting basins, sand bags or other drainage control measures.
In relatively level areas and/or slope areas, where saturated soil and/or erosion gullies exist to
depths of greater than 1.0 foot; they should be overexcavated and replaced as compacted fill in
accordance with the applicable specifications. Where affected materials exist to depths of 1.0
foot or less below proposed finished grade, remedial grading by moisture conditioning in-place,
followed by thorough recompaction in accordance with the applicable grading guidelines herein
may be attempted. If the desired results are not achieved, all affected materials should be
overexcavated and replaced as compacted fill in accordance with the slope repair
recommendations herein. If field conditions dictate, the geotechnical consultant may
recommend other slope repair procedures.
Section 6 - Excavations
6.1 Unsuitable Materials
Materials that are unsuitable should be excavated under observation and
recommendations of the geotechnical consultant. Unsuitable materials include, but may
not be limited to, dry, loose, soft, wet, organic compressible natural soils and fractured,
weathered, soft bedrock and nonengineered or otherwise deleterious fill materials.
Material identified by the geotechnical consultant as unsatisfactory due to its moisture
conditions should be overexcavated; moisture conditioned as needed, to a uniform at or
above optimum moisture condition before placement as compacted fill.
If during the course of grading adverse geotechnical conditions are exposed which were
not anticipated in the preliminary soil report as determined by the geotechnical consultant
additional exploration, analysis, and treatment of these problems may be recommended.
STANDARD SPECIFICATIONS OF GRADING
Page 3 of 26
Appendix D Page D-4
Standard Specifications for Grading
6.2 Cut Slopes
Unless otherwise recommended by the geotechnical consultant and approved by the
regulating agencies, permanent cut slopes should not be steeper than 2:1 (horizontal:
vertical).
The geotechnical consultant should observe cut slope excavation and if these excavations
expose loose cohesionless, significantly fractured or otherwise unsuitable material, the
materials should be overexcavated and replaced with a compacted stabilization fill. If
encountered specific cross section details should be obtained from the Geotechnical
Consultant.
When extensive cut slopes are excavated or these cut slopes are made in the direction of
the prevailing drainage, a non-erodible diversion swale (brow ditch) should be provided
at the top of the slope.
6.3 Pad Areas
All lot pad areas, including side yard terrace containing both cut and fill materials,
transitions, located less than 3 feet deep should be overexcavated to a depth of 3 feet and
replaced with a uniform compacted fill blanket of 3 feet. Actual depth of overexcavation
may vary and should be delineated by the geotechnical consultant during grading,
especially where deep or drastic transitions are present.
For pad areas created above cut or natural slopes, positive drainage should be established
away from the top-of-slope. This may be accomplished utilizing a berm drainage swale
and/or an appropriate pad gradient. A gradient in soil areas away from the top-of-slopes
of 2 percent or greater is recommended.
Section 7 - Compacted Fill
All fill materials should have fill quality, placement, conditioning and compaction as specified
below or as approved by the geotechnical consultant.
7.1 Fill Material Quality
Excavated on-site or import materials which are acceptable to the geotechnical consultant
may be utilized as compacted fill, provided trash, vegetation and other deleterious
materials are removed prior to placement. All import materials anticipated for use on-site
should be sampled tested and approved prior to and placement is in conformance with the
requirements outlined.
STANDARD SPECIFICATIONS OF GRADING
Page 4 of 26
Appendix D Page D-5
Standard Specifications for Grading
Rocks 12 inches in maximum and smaller may be utilized within compacted fill provided.
sufficient fill material is placed and thoroughly compacted over and around all rock to
effectively fill rock voids. The amount of rock should not exceed 40 percent by dry
weight passing the 3/4-inch sieve. The geotechnical consultant may vary those
requirements as field conditions dictate.
Where rocks greater than 12 inches but less than four feet of maximum dimension are
generated during grading, or otherwise desired to be placed within an engineered fill,
special handling in accordance with the recommendations below. Rocks greater than
four feet should be broken down or disposed off-site.
7.2 Placement of Fill
Prior to placement of fill material, the geotechnical consultant should observe and
approve the area to receive fill. After observation and approval, the exposed ground
surface should be scarified to a depth of 6 to 8 inches. The scarified material should be
conditioned (i.e. moisture added or air dried by continued discing) to achieve a moisture
content at or slightly above optimum moisture conditions and compacted to a minimum
of 90 percent of the maximum density or as otherwise recommended in the soils report or
by appropriate government agencies.
Compacted fill should then be placed in thin horizontal lifts not exceeding eight inches in
loose thickness prior to compaction. Each lift should be moisture conditioned as needed,
thoroughly blended to achieve a consistent moisture content at or slightly above optimum
and thoroughly compacted by mechanical methods to a minimum of 90 percent of
laboratory maximum dry density. Each lift should be treated in a like manner until the
desired finished grades are achieved.
The contractor should have suitable and sufficient mechanical compaction equipment and
watering apparatus on the job site to handle the amount of fill being placed in
consideration of moisture retention properties of the materials and weather conditions.
When placing fill in horizontal lifts adjacent to areas sloping steeper than 5:1 (horizontal:
vertical), horizontal keys and vertical benches should be excavated into the adjacent slope
area. Keying and benching should be sufficient to provide at least six-foot wide benches
and a minimum of four feet of vertical bench height within the firm natural ground, firm
bedrock or engineered compacted fill. No compacted fill should be placed in an area
after keying and benching until the geotechnical consultant has reviewed the area.
Material generated by the benching operation should be moved sufficiently away from
STANDARD SPECIFICATIONS OF GRADING
Page 5 of 26
Appendix D Page D-6
Standard Specifications for Grading
the bench area to allow for the recommended review of the horizontal bench prior to
placement of fill.
Within a single fill area where grading procedures dictate two or more separate fills,
temporary slopes (false slopes) may be created. When placing fill adjacent to a false
slope, benching should be conducted in the same manner as above described. At least a
3-foot vertical bench should be established within the firm core of adjacent approved
compacted fill prior to placement of additional fill. Benching should proceed in at least
3-foot vertical increments until the desired finished grades are achieved.
Prior to placement of additional compacted fill following an overnight or other grading
delay, the exposed surface or previously compacted fill should be processed by
scarification, moisture conditioning as needed to at or slightly above optimum moisture
content, thoroughly blended and recompacted to a minimum of 90 percent of laboratory
maximum dry density. Where unsuitable materials exist to depths of greater than one
foot, the unsuitable materials should be over-excavated.
Following a period of flooding, rainfall or overwatering by other means, no additional fill
should be placed until damage assessments have been made and remedial grading
performed as described herein.
Rocks 12 inch in maximum dimension and smaller may be utilized in the compacted fill
provided the fill is placed and thoroughly compacted over and around all rock. No
oversize material should be used within 3 feet of finished pad grade and within 1 foot of
other compacted fill areas. Rocks 12 inches up to four feet maximum dimension should
be placed below the upper 10 feet of any fill and should not be closer than 15 feet to any
slope face. These recommendations could vary as locations of improvements dictate.
Where practical, oversized material should not be placed below areas where structures or
deep utilities are proposed. Oversized material should be placed in windrows on a clean,
overexcavated or unyielding compacted fill or firm natural ground surface. Select native
or imported granular soil (S.E. 30 or higher) should be placed and thoroughly flooded
over and around all windrowed rock, such that voids are filled. Windrows of oversized
material should be staggered so those successive strata of oversized material are not in
the same vertical plane.
It may be possible to dispose of individual larger rock as field conditions dictate and as
recommended by the geotechnical consultant at the time of placement.
STANDARD SPECIFICATIONS OF GRADING
Page 6 of 26
Appendix D Page D-7
Standard Specifications for Grading
The contractor should assist the geotechnical consultant and/or his representative by
digging test pits for removal determinations and/or for testing compacted fill. The
contractor should provide this work at no additional cost to the owner or contractor's
client.
Fill should be tested by the geotechnical consultant for compliance with the
recommended relative compaction and moisture conditions. Field density testing should
conform to ASTM Method of Test D 1556-00, D 2922-04. Tests should be conducted at
a minimum of approximately two vertical feet or approximately 1,000 to 2,000 cubic
yards of fill placed. Actual test intervals may vary as field conditions dictate. Fill found
not to be in conformance with the grading recommendations should be removed or
otherwise handled as recommended by the geotechnical consultant.
7.3 Fill Slopes
Unless otherwise recommended by the geotechnical consultant and approved by the
regulating agencies, permanent fill slopes should not be steeper than 2:1 (horizontal:
vertical).
Except as specifically recommended in these grading guidelines compacted fill slopes
should be over-built two to five feet and cut back to grade, exposing the firm, compacted
fill inner core. The actual amount of overbuilding may vary as field conditions dictate. If
the desired results are not achieved, the existing slopes should be overexcavated and
reconstructed under the guidelines of the geotechnical consultant. The degree of
overbuilding shall be increased until the desired compacted slope surface condition is
achieved. Care should be taken by the contractor to provide thorough mechanical
compaction to the outer edge of the overbuilt slope surface.
At the discretion of the geotechnical consultant, slope face compaction may be attempted
by conventional construction procedures including backrolling. The procedure must
create a firmly compacted material throughout the entire depth of the slope face to the
surface of the previously compacted firm fill intercore.
During grading operations, care should be taken to extend compactive effort to the outer
edge of the slope. Each lift should extend horizontally to the desired finished slope
surface or more as needed to ultimately established desired grades. Grade during
construction should not be allowed to roll off at the edge of the slope. It may be helpful
to elevate slightly the outer edge of the slope. Slough resulting from the placement of
individual lifts should not be allowed to drift down over previous lifts. At intervals not
STANDARD SPECIFICATIONS OF GRADING
Page 7 of 26
Appendix Page D-8
Standard Specifications for Grading
exceeding four feet in vertical slope height or the capability of available equipment,
whichever is less, fill slopes should be thoroughly dozer trackrolled.
For pad areas above fill slopes, positive drainage should be established away from the
top-of-slope. This may be accomplished using a berm and pad gradient of at least two
percent.
Section 8 - Trench Backfill
Utility and/or other excavation of trench backfill should, unless otherwise recommended, be
compacted by mechanical means. Unless otherwise recommended, the degree of compaction
should be a minimum of 90 percent of the laboratory maximum density.
Within slab areas, but outside the influence of foundations, trenches up to one foot wide and two
feet deep may be backfilled with sand and consolidated by jetting, flooding or by mechanical
means. if on-site materials are utilized, they should be wheel-rolled, tamped or otherwise
compacted to a firm condition. For minor interior trenches, density testing may be deleted or
spot testing may be elected if deemed necessary, based on review of backfill operations during
construction.
If utility contractors indicate that it is undesirable to use compaction equipment in close
proximity to a buried conduit, the contractor may elect the utilization of light weight mechanical
compaction equipment and/or shading of the conduit with clean, granular material, which should
be thoroughly jetted in-place above the conduit, prior to initiating mechanical compaction
procedures. Other methods of utility trench compaction may also be appropriate, upon review of
the geotechnical consultant at the time of construction.
In cases where clean granular materials are proposed for use in lieu of native materials or where
flooding or jetting is proposed, the procedures should be considered subject to review by the
geotechnical consultant. Clean granular backfill and/or bedding are not recommended in slope
areas.
Section 9 - Drainage
Where deemed appropriate by the geotechnical consultant, canyon subdrain systems should be
installed in accordance with CTE's recommendations during grading.
Typical subdrains for compacted fill buttresses, slope stabilization or sidehill masses, should be
installed in accordance with the specifications.
STANDARD SPECIFICATIONS OF GRADING
Page 8 of 26
Appendix D Page D-9
Standard Specifications for Grading
Roof, pad and slope drainage should be directed away from slopes and areas of structures to
suitable disposal areas via non-erodible devices (i.e., gutters, downspouts, and concrete swales).
For drainage in extensively landscaped areas near structures, (i.e., within four feet) a minimum
of 5 percent gradient away from the structure should be maintained. Pad drainage of at least 2
percent should be maintained over the remainder of the site.
Drainage patterns established at the time of fine grading should be maintained throughout the life
of the project. Property owners should be made aware that altering drainage patterns could be
detrimental to slope stability and foundation performance.
Section 10 - Slope Maintenance
10.1 - Landscape Plants
To enhance surficial slope stability, slope planting should be accomplished at the
completion of grading. Slope planting should consist of deep-rooting vegetation
requiring little watering. Plants native to the southern California area and plants relative
to native plants are generally desirable. Plants native to other semi-arid and and areas
may also be appropriate. A Landscape Architect should be the best party to consult
regarding actual types of plants and planting configuration.
10.2 - Irrigation
Irrigation pipes should be anchored to slope faces, not placed in trenches excavated into
slope faces.
Slope irrigation should be minimized. If automatic timing devices are utilized on
irrigation systems, provisions should be made for interrupting normal irrigation during
periods of rainfall.
10.3 - Repair
As a precautionary measure, plastic sheeting should be readily available, or kept on hand,
to protect all slope areas from saturation by periods of heavy or prolonged rainfall. This
measure is strongly recommended, beginning with the period prior to landscape planting.
If slope failures occur, the geotechnical consultant should be contacted for a field review
of site conditions and development of recommendations for evaluation and repair.
If slope failures occur as a result of exposure to period of heavy rainfall, the failure areas
and currently unaffected areas should be covered with plastic sheeting to protect against
additional saturation.
STANDARD SPECIFICATIONS OF GRADING
Page 9 of 26
Appendix D Page D- 10
Standard Specifications for Grading
In the accompanying Standard Details, appropriate repair procedures are illustrated for
superficial slope failures (i.e., occurring typically within the outer one foot to three feet of
a slope face).
STANDARD SPECIFICATIONS OF GRADING
Page 10of26
BENCHING FILL OVER NATURAL
SURFACE OF FIRM
EARTH MATERIAL
FILL SLOPE
15' MIN. (INCLINED 2% MIN. INTO SLOPE)
BENCHING FILL OVER CUT
SURFACE OF FIRM
EARTH MATERIAL
FINISH FILL SLOPE
FINISH CUT
SLOPE
4' TYPICAL
o MIN 10,
PICAL
15' MIN OR STABILITY EQUIVALENT
ENGINEERING (INCLINED 2% MIN. INTO SLOPE)
NOT TO SCALE
BENCHING FOR COMPACTED FILL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 11 of 26
TOE OF SLOPE SHOWN
ON GRADING PLAN
FILL
V%ON 41
-. • -. . - -
1
.001.01.00.00
loll
/
10' TYPICAL BENCH
WIDTH VARIES
COMPETENT EARTH
MATERIAL
2%MIN ----
-
MINIMUM _/ 15' MINIMUM BASE KEY WIDTH
DOWNSLOPE
KEY DEPTH
TYPICAL BENCH
HEIGHT
PROVIDE BACKDRAIN AS REQUIRED
PER RECOMMENDATIONS OF SOILS
ENGINEER DURING GRADING
WHERE NATURAL SLOPE GRADIENT IS 5:1 OR LESS,
BENCHING IS NOT NECESSARY. FILL IS NOT TO BE
PLACED ON COMPRESSIBLE OR UNSUITABLE MATERIAL.
NOT TO SCALE
FILL SLOPE ABOVE NATURAL GROUND DETAIL
STANDARD SPECIFICATIONS FOR GRADING
I Page 12of26
NATURAL
TOPOGRAPHY
-
CUT SLOPE*
REMOVE ALL TOPSOIL, COLLUVIUM,
AND CREEP MATERIAL FROM
TRANSITION
CUT/FILL CONTACT SHOWN
ON GRADING PLAN
CUT/FILL CONTACT SHOWN
ON "AS-BUILT"
FILL
Z,- -72% MIN-,
TYPICAL
15' MINIMUM BEDROCK OR APPROVED
FOUNDATION MATERIAL
10' TYPICAL
*NOTE: CUT SLOPE PORTION SHOULD BE
MADE PRIOR TO PLACEMENT OF FILL
NOT TO SCALE
FILL SLOPE ABOVE CUT SLOPE DETAIL
SURFACE OF
COMPETENT
MATERIAL
-----------------
/1
COMPACTED FILL
TYPICAL BENCHING
,
SEE DETAIL BELOW
INCLINE TOWARD DRAIN
AT 2% GRADIENT MINIMUM
DETAIL
MINIMUM 9 FP PER LINEAR FOOT MINIMUM 4" DIAMETER APPROVED
OF APPROVED FILTER MATERIAL PERFORATED PIPE (PERFORATIONS
DOWN)
6" FILTER MATERIAL BEDDING
14"
REMOVE UNSUITABLE
MATERIAL
NOT TO SCALE
FILTER MATERIAL TO MEET FOLLOWING
SPECIFICATION OR APPROVED EQUAL:
SIEVE SIZE PERCENTAGE PASSING
in 100
3/4w 90-100
40-100
NO.4 25-40
NO. 30 18-33
NO.8 5-15
NO. 50 0-7
NO. 200 0-3
APPROVED PIPE TO BE SCHEDULE 40
POLY-VINYL-CHLORIDE (P.V.C.) OR
APPROVED EQUAL. MINIMUM CRUSH
STRENGTH 1000 psi
PIPE DIAMETER TO MEET THE
FOLLOWING CRITERIA, SUBJECT TO
FIELD REVIEW BASED ON ACTUAL
GEOTECHNICAL CONDITIONS
ENCOUNTERED DURING GRADING
LENGTH OF RUN PIPE DIAMETER
INITIAL 500 4-
500' TO 1500' 6'
> 1500' 8"
TYPICAL CANYON SUBDRAIN DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 14of26
CANYON SUBDRAIN DETAILS
SURFACE OF
COMPETENT.
MATERIAL
-
/
COMPACTED FILL
TYPICAL BENCHING
REMOVE UNSUITABLE
MATERIAL
SEE DETAILS BELOW
INCLINE TOWARD DRAIN
AT 2% GRADIENT MINIMUM
TRENCH DETAILS
6 MINIMUM OVERLAP
MINIMUM 9 FT3 PER LINEAR FOOT OPTIONAL V-DITCH DETAIL
- -
OF APPROVED DRAIN MATERIAL
MIRAFI 140N FABRIC
OR APPROVED EQUAL MIRAFI 140N FABRIC
OR APPROVED EQUAL
6" MINIMUM OVERLAP
724-
MINIMUM
L 24
MINIMUM
MINIMUM 9 FT5 PER LINEAR FOOT
OF APPROVED DRAIN MATERIAL
60° TO 90°
APPROVED PIPE TO BE
SCHEDULE 40 POLY-
VINYLCHLORIDE (P.V.C.)
OR APPROVED EQUAL.
MINIMUM CRUSH STRENGTH
1000 PSI.
DRAIN MATERIAL TO MEET FOLLOWING
SPECIFICATION OR APPROVED EQUAL:
SIEVE SIZE PERCENTAGE PASSING
iY2" 88-100
1" 5-40
3/4w 0-17
0-7
NO. 200 0-3
PIPE DIAMETER TO MEET THE
FOLLOWING CRITERIA, SUBJECT TO
FIELD REVIEW BASED ON ACTUAL
GEOTECHNICAL CONDITIONS
ENCOUNTERED DURING GRADING
LENGTH OF RUN PIPE DIAMETER
INITIAL 500' 4.
500' TO 1500' 6-
> 1500' 8-
NOT TO SCALE
GEOFABRIC SUBDRAIN
STANDARD SPECIFICATIONS FOR GRADING
Page 15 of 26
FRONT VIEW
----
CONCRETE °.
'. 6° Mm.
CUT-OFF WALL
•
SUBDRAIN PIPE 6° Mm.
24° Mi
6" Mm.
SIDE VIEW
—112° Mm. i- 6"
CONCRETE
CUT-OFF WALL WALL_-- 6" Mm.
SOILD SUBDRAIN PIPE PERFORATED SUBDRAIN PIPES
II J
NOT TO SCALE
RECOMMENDED SUBDRAIN CUT-OFF WALL
STANDARD SPECIFICATIONS FOR GRADING
Page 16 of 26
FRONT VIEW
.1 ! ..' -
S *
24 Mm. SUBDRAIN OUTLET
PIPE (MINIMUM 4 DIAMETER)
* * S S P. s
- .. - - .•
p ._ '•_ '
S S S
IL S S
Mm.
SIDE VIEW
ALL BACKFILL SHOULD BE COMPACTED
IN CONFORMANCE WITH PROJECT
SPECIFICATIONS. COMPACTION EFFORT
SHOULD NOT DAMAGE STRUCTURE
CONCRETE
HEADWALL L
NOTE: HEADWALL SHOULD OUTLET AT TOE OF SLOPE
OR INTO CONTROLLED SURFACE DRAINAGE DEVICE
ALL DISCHARGE SHOULD BE CONTROLLED
THIS DETAIL IS A MINIMUM DESIGN AND MAY BE
MODIFIED DEPENDING UPON ENCOUNTERED
CONDITIONS AND LOCAL REQUIREMENTS
NOT TO SCALE
TYPICAL SUBDRAIN OUTLET HEADWALL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 17 of 26
4" DIAMETER PERFORATED
PIPE BACKDRAIN
4" DIAMETER NON-PERFORATED
PIPE LATERAL DRAIN
15' MINIMUM
SLOPE PER PLAN
=flT
FILTER MATERIAL ENCHING
2'M
f,,
2% MIN
L TT1 AN ADDITIONAL BACKDRAIN iII1-i AT MID-SLOPE WILL BE REQUIRED FOR
SLOPE IN EXCESS OF 40 FEET HIGH.
KEY-DIMENSION PER SOILS ENGINEER
(GENERALLY 1/2 SLOPE HEIGHT, 15' MINIMUM)
DIMENSIONS ARE MINIMUM RECOMMENDED
NOT TO SCALE
TYPICAL SLOPE STABILIZATION FILL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 18 of 26
4" DIAMETER PERFORATED
PIPE BACKDRAIN
4" DIAMETER NON-PERFORATED
PIPE LATERAL DRAIN
15' MINIMUM
SLOPE PER PLAN
9ffl\
FILTER MATERIAL -_ BENCHING
• Jnffl4/I
/ I I-ii1rn"i-i--r_— •
L_. ADDITIONAL BACKDRAIN AT
'I MID-SLOPE WILL BE REQUIRED
70, FOR SLOPE IN EXCESS OF 40
FEET HIGH.
KEY-DIMENSION PER SOILS ENGINEER
DIMENSIONS ARE MINIMUM RECOMMENDED
NOT TO SCALE
TYPICAL BUTTRESS FILL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 19 of 26
FINAL LIMIT OF DAYLIGHT
EXCAVATION LINE
FINISH PAD
OVEREXCAVATE 3'
AND REPLACE WITH
COMPACTED FILL
OVEREXCAVATE
..
AAYAVAYAYAYA LVAMAWTAV
- I-COMPETENT -
2' MINIMU\ \ 'L_. TYPICAL BENCHING
OVERBURDEN \ \..._. LOCATION OF BACKDRAIN AND
(CREEP-PRONE) \ OUTLETS PER SOILS ENGINEER
\ AND/OR ENGINEERING GEOLOGIST
\ DURING GRADING. MINIMUM 2%
\ FLOW GRADIENT TO DISCHARGE
\ LOCATION.
\. EQUIPMENT WIDTH (MINIMUM 15')
NOT TO SCALE
DAYLIGHT SHEAR KEY DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 20 of 26
NATURAL GROUND
PROPOSED GRADING
1.5
COMPACTED FILL -
I
BASE WIDTH "W DETERMINED
BY SOILS ENGINEER
71. PROVIDE BACKDRAIN, PER
BACKDRAIN DETAIL. AN
ADDITIONAL BACKDRAIN
AT MID-SLOPE WILL BE
REQUIRED FOR BACK
SLOPES IN EXCESS OF
40 FEET HIGH. LOCATIONS
OF BACKDRAINS AND OUTLETS
PER SOILS ENGINEER AND/OR
ENGINEERING GEOLOGIST
DURING GRADING. MINIMUM 2%
FLOW GRADIENT TO DISCHARGE
LOCATION.
NOT TO SCALE
TYPICAL SHEAR KEY DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 21 of 26
FINISH SURFACE SLOPE
3 FV MINIMUM PER LINEAR FOOT
APPROVED FILTER ROCK*
CONCRETE COLLAR
PLACED NEAT COMPACTED FILL
4" MINIMUM DIAMETER
SOLID OUTLET PIPE
SPACED PER SOIL
ENGINEER REQUIREMENTS
DURING GRADING TYPICAL
BENCHING
- 4" MINIMUM APPROVED
PERFORATED PIPE
(PERFORATIONS DOWN)
MINIMUM 2% GRADIENT
TO OUTLET
BENCH INCLINED
TOWARD DRAIN
flITAII A..A
TEMPORARY FILL LEVEL
MINIMUM MINIMUM 40 DIAMETER APPROVED ILL
12" COVE
.
L
SOLID OUTLET PIPE
MINIMUM
*FILTER ROCK TO MEET FOLLOWING
APPROVED PIPE TYPE: SPECIFICATIONS OR APPROVED EQUAL:
SCHEDULE 40 POLYVINYL CHLORIDE SIEVE SIZE PERCENTAGE PASSING (P.V.C.) OR APPROVED EQUAL. 1" 100 MINIMUM CRUSH STRENGTH 1000 PSI 3'4" 90-100
40-100
NO.4 25-40
NO. 30 5-15
NO. 50 0-7
NO. 200 0-3
NOT TO SCALE
TYPICAL BACKDRAIN DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 22 of 26
FINISH SURFACE SLOPE
MINIMUM 3 FP PER LINEAR FOOT
OPEN GRADED AGGREGATE"
TAPE AND SEAL AT COVER
CONCRETE COLLAR
PLACED NEAT COMPACTED FILL
MINIMUM 4" DIAMETER
SOLID OUTLET PIPE
SPACED PER SOIL
ENGINEER REQUIREMENTS
TYPICAL '
BENCHING
lIVAII A A
II '- MIRAFI 140N FABRIC OR
APPROVED EQUAL
4" MINIMUM APPROVED
PERFORATED PIPE
(PERFORATIONS DOWN)
MINIMUM 2% GRADIENT
TO OUTLET
BENCH INCLINED
TOWARD DRAIN
,- TEMPORARY FILL LEVEL
MINIMUM
12" COVER BACKFILL MINIMUM 4" DIAMETER APPROVED
SOLID OUTLET PIPE
12"
*NOTE: AGGREGATE TO MEET FOLLOWING
SPECIFICATIONS OR APPROVED EQUAL:
SIEVE SIZE PERCENTAGE PASSING
100
1" 5-40
34 0-17
0-7
NOT TO SCALE
NO. 200 0-3
BACKDRAIN DETAIL (GEOFRABIC)
STANDARD SPECIFICATIONS FOR GRADING
Page 23 of 26
FILL SLOPE
I
CLEAR ZONE —/
SOIL SHALL BE PUSHED OVER QUIPMENT WIDTH ROCKS :i' FLOODED INTO PACT AROUND
AND OVER EACH WINDROW.
rwgY
STACK BOULDERS END TO END.
DO NOT PILE UPON EACH OTHER.
J.
10,
FILL SLOPE
15' ROWS
NOT TO SCALE
ROCK DISPOSAL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 24 of 26
FINISHED GRADE BUILDING I
SLOPE
STREET
15'
NO,
5' MINIMUM OR BELOW
DEPTH OF DEEPEST
UTILITY TRENCH
(WHICHEVER GREATER)
TYPICAL WINDROW DETAIL (EDGE VIEW)
GRANULAR SOIL FLOODED
TO FILL VOIDS
HORIZONTALLY PLACED
COMPACTION FILL F.
PROFILE VIEW
NOT TO SCALE
ROCK DISPOSAL DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 25 of 26
I - NO OVERSIZE, AREA FOR 10 FOUNDATION, UTILITIES,
I AND SWIMMING POOLS
ct
16 4
0 0
WINDROW I
GENERAL GRADING RECOMMENDATIONS
CUT LOT
.—ORIGINAL
GROUND
0•
TOPSOIL, COLLUVIUM AND
WEATHERED BEDROCK
2—f 51
5' MIN
3' MIN
OVEREXCAVATE
UNWEATHERED BEDROCK AND REGRADE
CUT/FILL LOT (TRANSITION)
ORIGINAL
..-"GROUND
MIN
3' MIN COMPACTED FILL
\—OVEREXCAVATE
00000l .00.01.00-
AND REGRADE
UNWEATHERED BEDROCK
- NOT TO SCALE
TRANSITION LOT DETAIL
STANDARD SPECIFICATIONS FOR GRADING
Page 26 of 26