HomeMy WebLinkAboutTract Map 9833-3 Lot 6 Soils & Foundation
I
'I
I
-I
'I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
RECEIVED
NOV 2 91995
CITY OF TEMECUU\
ENGINEERiNG DEPAR1i,,:::1JT
SOIL AND FOUNDATION INVESTIGATION
PROPOSED SINGLE FAMILY RESIDENCE
LOT 6
TRACT 9833~-3
r
CALLE DE VELARDO
RANCHO CALIFORNIA. TEMECULA. CALIFORNIA
FOR
FOR MR. ROBERT DOYLE
PROJECT NO. 95-110
DATED NOVEMBER 8. 1995
Lakeshore Engineering
\
I
I
I
I
I
I
I
I
I
I
II
I
I
I
I
I
I
I
I
LAKESHORE
Engineering
Consulting Civil Engineering and Geologists
Client:
Subject:
Gentlemen:
INTRODUCTION
November 8, 1995
Project No. 95-110.PI
Mr. Robert and LaBecca Doyle
30449 Corte Santa Lina
Murrieta, CA 92563
(909) 676-0082
Soil and Foundation Investigation
Proposed Single Family Residence
Lot 6, Tract 98333-3
Calle de Velardo, Temecula
Riverside County, California
This report presents the findings and conclusions of a soil and
foundation investigation for the proposed development of a single
family residence to be located at the subject site. The purpose of our
site investigation was to 1) evaluate the foundation materials,
subsurface and general geologic conditions at the site, and 2) provide
pertinent foundation recommendations for a proposed single family
residential development to be located at the subject site.
Our investigation included the following scope of work:
1) Performed two exploratory trenches on the lot to
determine subsurface conditions, and collect representative
soil samples for laboratory testing (Appendix A).
2) Laboratory testing of a representative soil sample to
evaluate the engineering properties. Laboratory test results
are presented in Appendix B.
3) Engineering analyses for foundation and necessary earthwork.
4) General geology and seismicity in the area and the
preparation of this report.
PROPOSED DEVELOPMENT
The proposed development will consist of a one and/or two story single
family residences of conventional construction, with driveway and
surrounding landscape areas. Foundation plans'have yet to be provided.
31606 Railroad Canyon Road, #201 . Canyon Lake, CA 92587 . (909) 244-2913 . FAX: (909) 244-2987
z..
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
VICINITY MAP
Source: Thomas Guide
Riverside Co.
Scale: 1/2 mile/Inch.
LAKESHORE
Engineering
FOR: MR. & MRS. DOYLE
SANTIAGO ESTATES
LOT 6, TRACT: 9833-3
CALLE DE VELARDO
TEMECULA, CA
CONSULTING CIVIL ENGINEERS
Project No:
95-110
Rgure No:
1
Dote
11/08/95
N
,;
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
November 8, 1995
Project No: 95-110.PI
Page Two
SITE INVESTIGATION
The site investigation consisted of a visual site reconnaissance,
subsurface backhoe exploration and engineering analysis of field data.
A description of the field investigation, as well as exploratory trench
logs, are presented in Appendix A. Results of the laboratory test data
are included in Appendix B. A description of the site and conditions
encountered are presented below.
SITE DESCRIPTION
The subject lot is located approximately 2 miles due east of the
Temecula old town center. The native terrain here lies near the SW end
of the hog back country that typifies sections east of Temecula. In the
general area the topography takes the form of a pronounced series of
low broad-backed NE-SW, trending ridges. Relief is usually not much
more than 100 feet. However, slopes may be moderately steep and
drainages incised. At the site, the area is part of a new upper scale,
ranch style neighborhood. The property itself, is located on a west-
trending knoll. Slopes to the north and south are moderately steep.
Total relief from the top of the ridge to the valley floor is
approximately 150 feet. Ground cover, consists of a growth of annual
grasses, trash and debris are lacking.
The San Diego Aqueduct cuts through the area on a north-south path
approximately 1/4 mile to the west.
The ridge top setting of the property provides exceptional views of the
mountains regions, which lie on 3 sides to the east, San Jacinto, south
Agua Tibia, and west, the La Cresta area.
SUBSURFACE CONDITIONS
A total of two exploratory trenches were performed to a maximum depth
of 5 l/2 feet. The location of exploratory trenches is shown on the
plot plan, figure 1.
Ridge crests in the area are directly underlain by late Pleistocene,
terrace deposits. These are underlain, in turn, at various depths, by
the pauba Sandstone, also of Pleistocene age. The subject site is not
an exception. However, the sections of the exploratory trenches show a
couple of feet of recent slope wash above the terrace deposits. This
modification is due to the location of the trenches down somewhat on
the ridge slopes, below the high ground. The ridge crest, itself, can
be expected to be underlain by at least 5 ft. of the terrace formation.
In the trenches, it is an indurated, reddish brown, clayey sand,
Lakeshore Engineering
4.
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
TOPOGRAPHIC MAP
Source: CDMG.Sp.Rpt.13l
Scale: 1 mile = 2.l5 Inches
LAKESHORE
Engineering
FOR: MR. & MRS. DOYLE
SANTIAGO ESTATES
LOT 6, TRACT: 9833-3
CALLE DE VELARDO
TEMECULA, CA
CONSULTING CIVIL ENGINEERS
Project No:
95-1(D0
Rgure No:
2
Dote
11/08/95
N
~
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
November 8, 1995
Project No: 95-110
Page Three
commonly containing pebbles up to 4-inches across. The pauba Sandstone,
below, is an indurated, grayish yellow, silty, fine-grained sand.
The moisture content of the units can be appreciable. Amounts around
10% are expectable.
The consistency of units varies from loose near the surface to dense in
lower areas of the trench section. Roots are found to a depth of 5
feet.
SEISMICITY
The site is located about 3/4-mile east of the active Wildomar Fault
strand of the Elsinore Fault zone. Consequently, the setting is acutely
seismic. Most recent considerations (DMG.O.F.92-1) give the Elsinore
faul t zone a seismic rating of 7 1/2. Accompany maps prepared for
internal use by Caltrans indicate that the site may experience a
maximum credible earthquake, which could generate peak accelerations of
0.6.g. Therefore, repeatable accelerations may approach 0.40g.
Some secondary affects may be noteable. The setting of the site is at
the top of a ridge, underlain by young and relatively soft sedimentary
units. Thickness are not well known. However, the Pauba Formation is
said to have an exposed thickness of 225 ft.; the underlying Temecula
Arkose at nearby Pechange, a thickness of 1500 feet (CDMG. Sp. Rpt.
131). Such thickness are sufficient to adversely affect the site
seismicity. The soil condition may be classified as S (UBC Table
16-J). An enhancement of shaking could be expected. Both the duration
and intensity could be extended over a bedrock setting.
The location of the site on a ridge crest, by itself, could be a
negative factor. Some focusing of earthquake energy on ridge tops has
been observed.
Also focusing of energies by a variety of other parameters may be
possible, according to some seismologists.
Generally, a conservative view of the site seismicity should be
entertained by the design engineers.
CONCLUSION AND RECOMMENDATION
GENERAL
From a soil and foundation engineering standpoint, the site will be
suitable for the proposed one or two story single family residential
construction, provided the conclusions and recommendations presented in
this report are incorporated in the design considerations, project
plans and specifications.
Lakeshore Engineering
'"
I
I
I
I
, I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
November 8, 1995
Project No: 94-110.PI
Page Four
GRADING AND EARTHWORK - General
Based upon our site observation, it is our understanding that there
will be minimal to moderate site grading. Site grading will be required
to provide: 1) nearly level building pad; 2) suitable foundation
conditions to support the proposed residential building; and 3)
adequate surface gradients for control of water runoff; 4) excavation
into native soils and/or compacted fills to accommodate the
installation of foundation and utility systems and 5) the preparation
of subgrade for proposed driveway.
After the areas to be graded have been stripped and cleared of
vegetation, the on-site soils will be considered satisfactory for reuse
in the construction of structural fills.
Based on our field trenching and review of laboratory test results, it
is our opinion that the surficial soils are loose and considered
unsuitable for use as structural support at present. The existing
ground should first be excavated to a depth of approximately 4 to 5
below grade, and the bottom scarified another 12 inches and densified
to at least 90 percent of the maximum laboratory dry density as
determined by the A.S.T.M. Dl157-78 compaction method. This preparation
should extend at least 5 feet beyond the building footprints and/or
where the limits of new fills are to be placed.
A review of the grading plan indicates that the proposed rough grading
will create a transitional cut/fill building pad. Cut slopes will be in
the order of 2 to 10 feet with fill slopes of similar height. Slopes
will be sloped at 2:1 (H:V). Cut areas will require overexcavation of
4 to 5 feet below pad grade to provide for a uniform compacted fill mat
underneath the foundation.
Any surface or subsurface obstructions encountered during grading such
as utility/irrigation lines should be removed from any areas to receive
fills. No underground obstructions nor facilities should remain in any
structural areas which will receive compacted fills, building
foundations, concrete slabs and/or pavements. Depressions and/or
cavities created as a result of the grading obstruction removal, should
be properly backfilled with suitable fill materials and compacted under
engineering observation and testing.
All imported soils should be approved by the consultant prior to use.
Caution should be exercised to prevent mixing of native or imported
materials with soils containing debris and/or organic matter. Any
objectionable substance, as determined by the consultant should be
stripped and removed from the property or stockpiled for landscaping
purposes. All fills should be densified in conformance with the
appropriate grading code but shall not be less than 90 percent relative
compaction, by mechanical means only.
Lakeshore Engineering
1
I
I
I
I
! I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
November 8, 1995
Project No: 94-110.PI
Page Five
Excavatinq Condition and Riooabilitv
Excavation of on-site materials should not be difficult to accomplished
with standard earthmoving equipment such as a D-4 or 5. The walls of
temporary construction trenches should stand near vertical, provided
the total depth does not exceed 5 feet. Shoring of excavation walls or
flattening of slopes is expected to be required, if greater depths are
necessary. For deeper cuts, slopes should not be made steeper than 1:1
(H:V) .
All work associated with trench shoring must conform to the State of
California Safety Code. Native organic free soils, may be utilized for
trench backfill. Flooding of the trench backfill may be permitted
provided both the backfill and the native materials have a minimum sand
equivalent of 30 and the required relative compaction can be achieved.
Slooe Stability
Cuts and fill slopes are proposed at less than 20 feet in vertical
height and sloped at 2:l (H:V). The proposed cut slopes should be
considered grossly stable from deep seated bedrock failure. Fill slopes
should be stable provided they are constructed under engineering
supervision and in accordance with UBC grading specifications.
Guidelines are attached in the appendix for surficial erosion control
and long term slope prevention.
Gradinq Control
All grading and earthwork including trench backfill should be performed
under the observation and testing of the Consulting Engineer for proper
subgrade preparation, selection of satisfactory materials, placement
and compaction of structural fills. Sufficient notification prior to
stripping and earthwork construction is essential in order that the
work be adequately observed and tested.
In order for us to provide a written opinion as to the adequacy of the
soil compaction and trench backfill, the entire operation, most
importantly at the time of trench backfill, should be performed under
our observation and testing.
Lakeshore Engineering
~
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
November 8, 1995
Project No: 94-110.PI
Page Six
FOUNDATION DESIGN
Footinqs
The proposed residential development may be supported on conventional
spread footings established in competent reworked soils. These spread
footings may be designed for an allowable bearing value of 1500 pounds
per square foot. This design value may be increase by one third, if the
Structural Engineer takes into consideration short duration structural
loading conditions, such as induced by wind and/or seismic forces.
Footings should be founded at least 12 or l8 inches below the lowest
adjacent ground surface, for one or two story structures, respectively.
All continuous foundations should be reinforced with one number 4 bar
at top and one at bottom and also in accordance with the
recommendations of the Structural Engineer or Architect.
Settlement
After the rework of on-site soils, total settlement due to structural
loads should not be a design factor as they should be less than 3/4
inch. Differential settlement should be within tolerable limits.
Lateral Capacity
For design, resistance to lateral loads can be assumed to be provided
by friction acting at the based of the foundations and by passive earth
pressure and may be combine without reduction. If passive earth
pressure is used, it is important that backfill should be placed under
engineering observation and testing.
A coefficient of friction of 0.30 may be used with the dead load
forces. An allowable lateral passive earth pressure of 200 pounds per
square foot per foot of depth may be used for the sides of footings
poured against undisturbed and/or recompacted soils.
The lateral bearing values indicated above are for the total of dead
and frequently applied live loads. If the normal code requirements are
used for seismic design, the values may be increased by 1/3 for short
durations of the loading which include the effect of wind or seismic
forces.
Lakeshore Engineering
q
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
November 8, 1995
Project No: 94-110.PI
Page Seven
EXPANSIVE SOILS
Based upon our exploratory efforts and testing, the site is underlain
by 4 to 6 feet of moderately expansive soils. Our laboratory test
result of onsite soils indicated Expansion Index of 45. Due to the
extensive grading proposed, the expansion potential of building pad
subgrade soils should be revaluated near the conclusion of rough
grading.
Concrete Slab - on - Grade
The subgrade soils at present are considered to be moderately
expansive. The interior building floor slabs may be supported directly
on properly prepared subgrade. If a floor covering that could be
critically affected by moisture, such as vinyl tile, slabs should be
protected by a plastic vapor barrier of six-mil thickness. The sheet
should be covered by at least two inch of sand cushion to prevent
punctures and aid in concrete cure. presaturation of subgrade soils to
120% of optimum to 12 inches in depth is required.
The concrete floor slabs should be at least 4 inches thick nominal and
reinforced with at least 6" x 6" / no. 10 - 10 welded wire mesh.
Concrete driveway, sidewalk, fire pit and patio slabs should also be
reinforced as suggested above.
Retaininq walls
No retaining walls are proposed at this time.
DRAINAGE
Positive drainage should be provided around the perimeter of all
structures to minimize water infiltrating into the underlying soils.
Finish subgrade adjacent to exterior footings should be sloped down and
away to facilitate surface drainage. All drainage should be directed
off-site via non-erosive devices. Care should be taken to preserve
existing native drainage.
The homeowner should be made aware of the potential problems which may
develop when drainage is altered through construction of retaining
walls, patios and pools. Ponded water, leaking irrigation systems,
overwatering or other conditions which could lead to ground saturation
must be avoided.
Lakeshore Engineering
\0
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
November 8, 1995
Project No. 94-110.PI
Page Eight
FOOTING EXCAVATION
All footing excavations should be inspected and approved by the Soils
Consultant prior to placement of forms, reinforcement, or concrete.
Materials generated from the footing excavations should not be spread
on slab-on-grade areas, unless they are compacted and tested.
GENERAL INFORMATION
The findings and recommendations of this report were prepared in
accordance with generally accepted professional engineering principles
and practices in the fields of soil mechanics and foundation
engineering. This warranty is in lieu of all other warranties, either
expressed or implied.
We sincerely appreciate the opportunity to be of service. If you have
any questions concerning this report or require further information and
services, please contact this office at your convenience
Respectfully Submitted,
LAKE SHORE
(
FEN YONG
R.C.E. 3
AI'-)
FY/fy
ENCLOSURES: GRADING PLAN IN POCKET
APPENDIX A - EXPLORATION
APPENDIX B - LABORATORY TESTING
APPENDIX C - SUGGESTED GRADING GUIDELINES
AND SLOPE EROSION GUIDELINES
Lakeshore Engineering
\\
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
APPENDIX A
FIELD EXPLORATION
Field exploration was performed by using a backhoe (Mike Monteleone).
The soils were continuously logged by our field personnel and
classified by visual examination in accordance with the Unified
Classification System. Our trench logs and/or boring logs are attached
for review.
To evaluate the compaction characteristics of the fill material, field
density tests were performed. Also, representative bulk samples were
recovered and shipped to the laboratory in polythelene bags for
laboratory testing.
Lakeshore Engineering
\z..
I
I
i I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
PLOT PLAN
EXPLAN~TION.
~
G
"f
1
~0
.J
<(
u
dl
T-t APPROXIMATE LOCATION OF TRENCH
LAKESHORE
Engineering
FOR: MR. & MRS. DOYLE
SANTIAGO ESTATES
LOT 6, TRACT: 9833-3
CALLE DE VELARDO
TEMECULA, CA
Pro)ec:t No:
95-110
Dote
11/08/95
CONSULTING CIVIL ENGINEERS
Rgure No:
3
\~
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
TRENCH LOG
.>:
Logged By: r:. 5", Trench
Date 11-3-rS- / / Number
EqUiPment:.F;..l-ej...~ ~",/., C;CdV.o< ~r
Thill lag ill repreurtation of sublurtb.sol ind grooodwltBf conditio.. it the lime and place 01 excavation, -r= /
with tM paaage of time or at any other location therony be ClWequenUal changaln conditlon..
:7f..?/ 55 W,p <""'1'''' f'~ ,:I,
(0";' ""/,/ ""If'" "or),
//,/
5
10
15
20
Surface Elevation:
Trench Orientation: IV' ..FE
Trench Dimensions: :s'", 6f;t' x /$-/
Groundwater Depth~, ~,Ii /../ .--p,~,/
5.D IO'Z.!3 5 c
1t>fl. \\015
Logged By: .I",! ,;,,;- .JI!n/ d"f'''Z r,' ,/'/"1-
./li'$/ ,f]: t'/~.J.,t.- :'/0 $Pur..-f....
Date
Equipment:
A> /l ,p-,,-
Trench
Number
7=.2
sc
,
5NI
10
1: fJ, - -t~ y/
ffi tf;,...vuL~'/"-
15
20
LAKESHORE
Engineering
CONSULTING ENGINEERS AND GEOLOGIST
g,~
U\LLl'Z
L6.1i I ,b=- .
J)f. u'8.:lt~.o
Fig. No. I e;;::.
PROJ. NO.
C1'(~rlo~L
\~
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
APPENDIX B
LABORATORY TESTING
MOISTURE DENSITY RELATIONSHIP
Moisture - density information usually provides a gross indication of
the soil consistency and can delineate local variations at the time of
investigation and provide a correlation between soils found on this
site. The dry unite weight and field moisture content were determined
for selected samples, and the results are shown on the log of boring
sheets.
MAXIMUM DENSITY - OPTIMUM MOISTURE TESTS
A selected soil sample was tested in the laboratory to determine
maximum dry density and optimum moisture content using the A.S.T.M.
D1557-78 compaction test method. This test procedure uses a 10 pound
hammer falling a height of 18 inches on each of five layers to a 1/30
cubic foot cylinder. The results of the tests are presented below:
Trench
No.
Depth
(Ft. )
Soil
Description
Maximum Dry
Density (P.C.F)
Optimum Moisture
Content (% Dry Wt.)
---------------
-------------------
T-1
0-3
Silty SAND(SC/SM)
W/trace of clay
131.5
9.5
EXPANSION INDEX TEST
A representative soil sample was collected in the field and tested in
the laboratory in accordance with the A. SC. E. Expansion Index Test
Method as specified by U.B.C. The degree of expansion potential was
evaluated from measured soil volume changes obtained during soil
moisture alterations. The results of the test are presented below:
Trench Depth Soil Expansion Expansion
No. (Ft. ) Description Index Potential
------ ----- ----------- ----------- ----------
T-1 0 -3 Sil ty SAND 45 LOW/MEDIUM
W/trace of clay
Lakeshore Engineering
~
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
APPENDIX C
SUGGESTED ITEMS TO INCLUDE IN
STANDARD GRADING SPECIFICATIONS
These specifications present the usual and minimum requirements
for grading operations performed under the observation and
testing of LAKESHORE ENGINEERING, INC.
No deviation from these specifications will be allowed, except
where specifically superseded in the preliminary geology and
soils report, or in other written communication signed by the
Soils Engineer or Engineering Geologist.
I
GENERAL
A. The Soils Engineer and Engineering Geologist are the
Owner's or Builder's representative on the project.
For the purpose of these specifications, observation
and testing by the Soils Engineer includes that
observation and testing performed by any person or
persons employed by, and responsible to, the licensed
Civil Engineer signing the soil report.
B. All clearing, the site preparation or earthwork
performed on the project shall be conducted by
the Contractor under the observation of the
Soils Engineer.
C. It is the Contractor's responsibility to prepare the
ground surface to receive the fills to the
satisfaction of the Soils Engineer and to place,
spread, mix, water and compact the fill in accordance
with the specifications of the Soils Engineer. The
Contractor shall also remove all materials considered
unsatisfactory by the Soils Engineer.
D. It is also the Contractor's responsibility to have
suitable and sufficient compaction equipment on the
jobsite to handle the amount of fill being placed.
If necessary, excavation equipment will be shut down
to permit completion of compaction. Sufficient
watering apparatus will also be provided by the
Contractor, with due consideration for the fill
material, rate and time of year.
E. A final report will be issued by the Soils Engineer
and Engineering Geologist attesting to the
Contractor's conformance with these specifications.
Lakeshore Engineering
\cp
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Suggested Items to Include in
Standard Grading Specifications
II
SITE PREPARATION
A. All vegetation and deleterious material such as
rubbish shall be disposed of offsite. This removal
must be concluded prior to placing fill.
B. The Soils Engineer shall locate all houses, sheds,
sewage disposal systems, large trees or structures
on the site or on the grading plan to the best of
his knowledge prior to preparing the ground
surface.
C. Soil, alluvium or rock materials determined by the
Soils Engineer as being unsuitable for placement in
compacted fills shall be removed and wasted from
the site. Any material incorporated as a part of
a compacted fill must be approved by the Soils
Engineer.
D. After the ground surface to receive fill has been
cleared, it shall be scarified, disced or bladed
by the Contractor until it is uniform and free from
ruts, hollows, hummocks or other uneven features
which may prevent uniform compaction.
The scarified ground surface shall then be brought
to optimum moisture, mixed as required, and
compacted as specified. If the scarified zone is
greater than twelve inches in depth, the excess
shall be removed and placed in lifts restricted to
six inches.
Prior to placing fill, the ground surface to
receive fill shall be inspected, tested and
approved by the Soils Engineer.
E. Any underground structures such as cesspools,
cisterns, minimum shafts, tunnels, septic tanks,
wells, pipe lines or others not located prior to
grading are to be removed or treated in a manner
prescribed by the Soils Engineer.
Lakeshore Engineering
\1
I
I.
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Suggested Items to Include in
Standard Grading Specifications
III
COMPACTED FILLS
A. Any materials imported or excavated on the property
may be utilized in the fill, provided each material
has been determined to be suitable by the Soils
Engineer. Roots, tree branches and other matter
missed during clearing shall be removed from the
fill as directed by the Soils Engineer.
B. Rock fragments less than six inches in diameter may
be utilized in the fill, provided:
1. They are not placed in concentrated pockets.
2. There is a sufficient percentage of fine-
grained material to surround the rocks.
3. The distribution of the rocks is observed by
the Soils Engineer.
C. Rocks greater than six inches in diameter shall be
taken offsite, or placed in accordance with the
recommendations of the Soils Engineer in areas
designated as suitable for rock disposal. Details
for rock disposal such as location, moisture
control percentage of rock placed, etc., will be
referred to in the "Conclusions & Recommendations"
section of the soils report.
If rocks greater than six inches in diameter were
not anticipated in the preliminary soils and
geology report, rock disposal recommendations may
not have been made in the "Conclusions and
Recommendations" section. In this case, the
Contractor shall notify the Soils Engineer if rocks
greater than six inches in diameter are
encountered. The Soils Engineer will than prepare
a rock disposal recommendation or request that such
rocks be taken offsite.
D. Material that is spongy, subject to decay, or
otherwise considered unsuitable shall not be used
in the compacted fill.
Lakeshore Engineering
\~
I
II
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Suggested Items to include in
Standard Grading Specifications
E. Representative samples of materials to be utilized
as compacted fill shall be analyzed in the
laboratory by the Soils Engineer to determine their
physical properties. If any material other that
previously tested is encountered during grading,
the appropriate analysis of this material shall be
conducted by the Soils Engineer as soon as
possible.
F. Material used in the compacting process shall be
evenly spread, watered or dried, processed and
compacted in thin lifts not to exceed six inches
in thickness to obtain a uniformly dense layer.
The fill shall be placed and compacted on a
horizontal plane, unless otherwise approved by the
Soils Engineer.
G. If the moisture content or relative compaction
varies from that required by the Soils Engineer,
the Contractor shall rework the fill until it is
approved by the Soils Engineer.
H. Each layer shall be compacted to 90 percent of the
maximum density in compliance with the testing
method specified by the controlling governmental
agency. (In general, ASTM D1557-70T will be used.)
If compaction to a lesser percentage is authorized
by the controlling governmental agency because of
a specific land use or expansive soil conditions,
the area to receive fill compacted to less than 90%
shall either be delineated on the grading plan or
appropriate reference made to the area in the soil
report.
I. All fills shall be keyed and benched through all
topsoil, colluvium, alluvium or creep material,
into sound bedrock or firm material where the slope
receiving fill exceeds a ratio of five horizontal
to one vertical, in accordance with the recommend-
ations of the Soils Engineer.
J. The key for side hill fills shall be a minimum of
15 feet within bedrock or firm materials, unless
otherwise specified in the soils report. (See
detail on Plate GS-1.)
Lakeshore Engineering
\0.
I
I I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Suggested Items to Include in
Standard Grading Specifications
K. Drainage terraces and subdrainage devices shall be
constructed in compliance with the ordinances of
the controlling governmental agency, or with the
recommendations of the Soils Engineer and
Engineer of Record.
L. The Contractor will be required to obtain a minimum
relative compaction of 90 percent out to the finish
slope face of fill slopes, buttresses and stabil-
ization fills. This may be achieved by either
over building the slope and cutting back to the
compacted core, or by direct compaction of the
slope face with suitable equipment, or by any
other procedure which produces the required
compaction.
The Contractor shall prepare a written detailed
description of the method or methods he will employ
to obtain the required slope compaction. Such
documents shall be submitted to the Soils Engineer
for review and comments prior to the start of
grading.
If a method other than over building and cutting
back to the compacted core is to be employed,
slope tests will be made by the Soils Engineer
during construction of the slopes to determine
if the required compaction is being achieved.
Where failing tests occur or other field prob-
lems arise, the Contractor will be notified by the
Soils Engineer.
If the method of achieving the required slope
compaction selected by the Contractor fails to
produce the necessary results, the Contractor
shall rework or rebuild such slopes until the
required degree of compaction is obtained, at no
additional cost to the Owner or Soils Engineer.
M. All fill slopes should be planted or protected from
erosion by methods specified in the soils report
or by means approved by the governing authorities.
N. fill-over-cut slopes shall be properly keyed
through topsoil, colluvium or creep material into
rock or firm materials; and the transition shall be
stripped of all soil prior to placing fill. (see
detail Plate GS-2.)
Lakeshore Engineering
2J9
I
II
I
I
,
II
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Suggested Items to Include in
Standard Grading Specifications
IV
CUT SLOPES
A. The Engineering Geologist shall inspect all cut
slopes excavated in rock,. tithified or formation
material at vertical intervals not exceeding ten
feet.
B. If any conditions not anticipated in the prelim-
inary report such as perched water, seepage,
lenticular or confined strata of a potentially
adverse nature, unfavorably inclined bedding,
joints or fault planes are encountered during
grading, these conditions shall be analyzed by the
Engineering Geologist and Soils Engineer; and
recommendations shall be made to treat these
problems.
C. Cut slopes that face in the same direction as the
prevailing drainage shall be protected from slope
wash by a nonerosive interceptor swale placed at
the top of the slope.
D. Unless otherwise specified in the soils and
geological report, no cut slopes shall be excavated
higher or steeper than that allowed by the
ordinances of controlling governmental agencies.
E. Drainage terraces shall be constructed in compli-
ance with the ordinances of controlling govern-
mental agencies, or with the recommendations of
the Soils Engineer or Engineering Geologist.
IV
GRADING CONTROL
A. Inspection of the fill placement shall be provided
by the Soils Engineer during the progress of
grading.
B. In general, density tests should be made at inter-
vals not exceeding two feet of fill height of every
500 cubic yards of fill placed. This criteria will
vary depending on soil conditions and the size of
the job. In any event, an adequate number of field
density tests shall be made to verify that the
required compaction is being achieved.
C. Density tests should also be made on the surface
material to receive fill as required by the Soils
Engineer.
Lakeshore Engineering
2Ar
T
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Suggested Items to Include in
Standard Grading Specifications
D. All cleanouts, processed ground to receive fill,
key excavations, subdrains and rock disposal must
be inspected and approved by the Soils Engineer
(and often by the governing authorities) prior to
placing any fill. It shall be the Contractor's
responsibility to notify the Soils Engineer and
governing authorities when such areas are ready
for inspection.
VI
CONSTRUCTION CONSIDERATIONS
A. Erosion control measures, when necessary, shall be
provided by the Contractor during grading and prior
to the completion and construction of permanent
drainage controls.
B. Upon completion of grading and termination of
observations by the Soils Engineer, no further
filling or excavating, including that necessary
for footings, foundations, large tree wells,
retaining walls, or other features shall be per-
formed without the approval of the Soils Engineer
or Engineering Geologist.
C. Care shall be taken by the Contractor during final
grading to preserve any berms, drainage terraces,
interceptor swales, or other devices of a permanent
nature on or adjacent to the property.
Lakeshore Engineering
'jP
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
1'-
..
APPENDIX C-2
SOIL EROSION CONTROL RECOMMENDATIONS
FOR SLOPE AREAS
To minimize water-induced surficial erosion/sloughing to existing
slopes or new fill and cut slopes, permanent erosion control measures
should be planned as soon as possible. However, all soil slopes will
undergo some erosion when subject to sustained water application. To
minimize long-term erosion, we have listed below some important
points to be considered when planning, designing and
installing/implementing slope erosion control plans.
1) All berms, terrace drains and surface drain inlets should be
properly maintained. A qualified Engineer should review any
proposed additions or revisions to these systems, to evaluate
their impact on slope erosion.
2) Local experience that the upper 3 to 5 feet of slope soils may
be subject to water-induced mass erosion. Therefore, a suitable
portion of slope plantings should have root systems which will
develop well below 5 feet. We suggest consideration of
drought-resistant shrubs and low trees for this purpose.
Intervening areas can then be planted with lightweight surface
p1antings with shallower roots systems. In any event,
lightweight, low-moisture plantings should be used.
3) Construction delays, climate/weather conditions, and plant growth
rates may be such that additional short term, non-plant erosion
control measures may be needed: examples would be matting,
netting, plastic sheets, deep (5 feet) staking.
4) Major erosion can be initiated by seemingly insignificant events:
rodent burrowing, human tresspass (foot prints) in damp areas,
small concentrations of controlled surface/subsurface water:
or poor compaction of utility trench backfill on slopes.
5) All possible precautions should be taken to minimize soil
moisture percolating deep into the slope soils. Slope
irrigations systems should be properly operated,and maintained
and system controls should be placed under strict control.
The duration of each cycle of irrigation should be short and
may be more frequent in order to reduce the saturation of the
deeper soils.
z:=b
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
APPENDIX C-2 -CONTINUED-
6) High water content in slope soils is a major factor in slope
erosion or slope failures. Therefore, all possible precautions
should be taken to minimize soil moisture. Slope irrigation
systems should be properly operated and maintained and system
controls should be placed under strict control.
7) If completion of new slopes occurs during the rainy season,
contingency plans should be developed to provide prompt
temporary protection against major erosion/ sloughing. One
method would be to place plastic sheeting over the slopes.
If this is carefully coordinated with the Landscape
Architect/Contractor, plantings might be placed prior to
sheeting placement, thus minimize any delays in the plant
growth program.
We strongJy recommend that a "team effort" be used to develop the
erosion control program. The team should consist of the Civil and
Soils Engineers, the Engineering Geologist, the Landscape
Architect/Contractor and the Developer/Owner. To assist in
developing a landscape program, we have listed (below) several
references.
Finally, we recommend that a "Slope Area Maintenance Manual" be
developed by the erosion control team, for use by homeowners and
their Associations.
The above recommendations are intended for guidance purposes.
Situations will vary and therefore, erosion control plans will
differ. No guaratee is made as to performance, but we believe these
recommendations meet the generally accepted standards of our
profession at this time.
zt\
I
I
I
I
I
I
I
I
I
I
II
I
I
I
II
I
I
I
I
,
EROSION CONTROL REFERENCES
1. "Slope Protection for Residential Developments", National
Academy of Sciences, Washington, D.C. (1969)
2. "Guide for Erosion and Debris Control in Hillside Areas",
Department of Building and Safety, City of Los Angeles (1970)
3. "Slope Stability Report", Orange County Department of Building
and Safety (l973)
4. "Guides of Erosion and Sediment Control" Soil Conservation
Service, Davis California, U.S. Department of Agriculture (l977)
5. "Rain-Care and Protection of Hillside Homes", brochure undated,
published by Buiolding and Safety Divsion, Los Angeles County
Engineer.
6. "Guidelines for Erosion and Sediment Control Planning and
Implementation", Office of Research and Monitoring, U.S.
Environmental Protection Agency, (l972)
7. "Resource Conservation Glossary", Soil Conservation Society of
America (1970)
8. "Standards and Specifications for Soil Erosion and Sediment
Control Developing Areas:' Soil Conservation Service, U.S.
Department of Agriculture
9. "Homeowners Guide for Debris and Erosion Control"' Los Angeles
County Flood Control District (undated)
lO. "Grading Guildelines (8 pages, stapled sheets), Building and
Safety Division, Department of County Engineer, County of Los
Angeles (undated, but probably about 1977)
~
I
,
..1
--
f
I
I
.'
I
I
j
i
I
i
i
,
I
I
i
i'
I
f
CUT LOT
-
--
---
.'
"~l GR~OL -
N~l~_
-- -- ~.
NSIl\,~al<
/ ~~'tR\~~
, .~ -~. ~ '~~~~A_~~EO'.' . :!~ './' .
.~. .~
'. . ..... .
.. ...... ,,,,';:;,m .....~;:f/-
. .. ....~SU\,~ '~".'
. .'. .'.- . u\\ t~\~\. ,'.
'. . . ~ .... ~~ .
~~. '.,'.j:>.:
-....-......~....
'.. .' . ,.
...~..
~..-_....
. ,
3'MIN.J
-----
I
J.
OVEREXCAVATE ANO
RECOMPACT
'AlMPETENl MATERIAL ACCEPTABLE
~O THE 5011 ENGINEER
CUT Fill lOT (TRANSITION)
,G~~
llf>.Nllf>.y
~ ,.
~
,.
-1
OVER EXCAVATE ANO
RECOMPACT
r
3' MIN.' .J
'OEEPER OVER{'C~VAflljN M~, BE
REWMMEllOEO BY THE SOil EN';"'<:_
,.', SiEEP rRANSlT'ONS
~EE ~ECTlOtl ~.5 OIC OF THEse
SPECIFICA TIONS
COI.IPETENr MATERIAL ACCEPTABLE
TO THE 501, ENGINEER
TITLE:
FIGURE:
TYPICAL CUT/FILL OVEREXCAVATION 0-1
.
2fp
I-
I
I-
i-
I
I
.. ..
-.
.
.
i
I-
i
i
I
j
I
I
i
i
I
COMP4CTED Fill '\/":-:' _
,,/' -.
,,/' .
/.
/. ....1 ----
PROJECT SLOPE GRAOIENT) ,,/' .. . . ,__~
(1:1 MAX,I ,,/. . ___~ . . '00-
/-..' ~ .. ,-
./ ' .' - l VARI4BLE --~
. . - \,\~1tR\~ I
BACKCUT-.VARIES ---::\/. Y~t\,\Q'lt I)ll~~~lt_,_
COMPE1ENT I,(4TERI4l
OVERFILL REOUIREMENTS
PER puTt NO.4
TOE OF SLOPE SHOWN
ON GRAOING PLAN
---n"
--~'MINIMUM II
KEY OEPTH J
PLACE COMPACTEO
BACKFILL TO ORIG.
INAL GRADE
4.
LMIN.
MIfIIMUM HEIGHT OF BENCHES
IS . FEET OR 4S RECOM-
MENDED BY THE SOIL ENGI-
j--r- MINIMUM r nLT BACK NE:R
'- OR 2"- SLOPE
(WHICHEVER IS GREATER)
KtvWAY IN COMPETENT M4T.
ERIAl, MINIMUM WIOTH OF 15
FEET OR AS RECOMMENOED BY
THE SOIL ENGINEER. KtvW4Y
MAY NOT BE REOUIRED IF FILL
SLOPE IS LESS THAN 5' IN
HEIGHT_ AS ilECOMMENDED BY
. T,HE SOIL ENGiNEER.
~/.......~.c"/...../~
NOTE.
BENCHING SHALL BE REOUIRED
WHEN NATURAL SLOPES ARE
EOUAL TO OR mEPER THAN 5; 1
OR WHEN RECOMMENDED BY
THE SOIL ENGINEER.
TITLE: FIGURE:
TYPICAL FILL ABOVE NATURAL SLOPE 0-5
2.-1-
I {
I
f
I'
I
I
~I
I
I
f
i
i
I
i
I
I
I
i
I
De SIGN
FINISH SLOPE
OUTLETS TO BE SPACED
AT 100' MAXIMUM INTER.
VALS. EmNO 12 INCHES
BEYOND FAce OF SLOPE
AT TIME OF ROUGH GRAD.
ING CONSTRUCTION. '. '
BUliRESS
OR SIOEHILL ~
FILL _""'"
" [ """
MAX. 2' 12'" . . . .
2'
CLEAR
'FILTER MATERIAL" TO MEET FOLLOWING SPECIFI.
CATION OR APPROVED EOUIVALENT: ICONFORMS TO
EMA STD. PLAN 323}
SIEVE SIZE PERCENTAGE PASSING
I" 100
314" 90.100
3/B" 40.'00
NO.4 2S-"0
NO. B 18.33
NO. 30 5.15
NO. 50 0.7
NO. 200 0.3
OUTlET PIPE TO BE CON.
NECTED TO SUBORAIN PIPE
WITH TEE OR ELBOW
.NOTES.
I. TRENCH FOR OUTLET PIPES TO BE BACXFILLEO
WITH ON-SITE SOIL
TITLE:
10' MIN,
25' MAll' _'
'-I BLANKE~ FILL IF
RECOMMENDED
BY SOIL ENGI.
NEER
\,":>'7'
l 4.INCH DIAMETER NON-PERFORATED
ounET PIPE TO BE LOCATED IN FIELD
BY THE SOIL ENGINEER.
-GRAVEL' TO MEET FOLLOWING SPECIFICATION OR
APPROVED EOUIVALENT:
MAXIMUM
SIEVE SIZE PERCENTAGE PASSING
1..... 100
NO.4 SO
NO. 200 8
SAND EOUIV~LENT - MINIMUM OF 50
FILTER MATERIAL - MINIMUM OF FIVE
CUBIC FEET PER FOOT OF PIPE. SEE
ABOVE FOR FIlTER MATERIAL SPECIFI.
CATION.
AlTERNATIVE IN LIEU OF FILTER MAT.
ERIAl FIVE CUBIC FEET OF GRAVEL
PER FOOT OF PIPE MAY BE ENCASED
IN FILT€R FABRIC. SEE ABOVE FOR
GRAVEL SPECIFICATION.
FILTER FABRIC SHALL BE MIRAFI 140
OR EOUIVALENT. FILTER FABRIC SHALL
BE LAPPED A MINIMUM OF 12 INCHES
ON ALL.JOINTS.
MINIMUM 4.IHCH DIAMETER PVC SCH 40 OR ABS CLASS SDR 35 WITH
A CRUSHING STRENGTH OF AT LEASE 1.000 POUNDS. WITH A MINIMUM
OF B UNIFORMLY SPACED PERFORATIONS PER FOOT OF PIPE INSTALLED
WITH PERFORATiONS ON BOTTOM OF PIPE. PROVIDE CAP AT UPSTREAM
END OF PIPE. SLOPE AT 2 PERCENT TO OUTLET PIPE
FIGURE:
TYPICAL FILL SUBDRAIN DETAIL
D-7
~