HomeMy WebLinkAbout; Hariri Residence Argonauta Street; Soils Report; 1989-05-26ALLIED EARTH TECHNOLOGY, INC.
1466 PIONEEi WAY, SUITE 8 ,., EL CAION, CALIFORNIA 9mm
ROBERT CHAN, P.E. TELEPHONE (619) 447-4747
SOlI, INVESTIGATION
PROPOSED RESIDENTIAL BUILDING SITE
NORTII SIDE OF ARGONAUTA STREET. N0RTllWEST OF OBELISCO CIRCLE
CARI.SUAI), CALIFORNIA
FOR
MR. IIAMIR REZAI RARIRI
ENGINEERING DEPT. LIBRARY ., . City of Carlsbad ;,, 2075 Las Palmas Drive rf-
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Carlsbad, CA92009-4859
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1 I c”II m ALLIED -EARTH TECHNOLOGY, INC.
ROBERT WAN, P.E.
1466 PIONEER WAY, SUITE 8
EL CAJON, CALIFORNIA 92020
TELEPHONE (619) 447-4747
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May 26, 1086
Mr. Ffamld Rezal Rarlrl
7880 Laurelrld~e Road San Dlego, Ca. 92120
SubJect : J’roJect No. 2OC4
Sol1 IlwcstIgat.1nn
proposed Resldrnt.Inl Salldln~ Site
Nor~th Side of Argonauta Street, Northwest’ of Obellsco Circle Carlshad, Callfornln
Dear Mr. .tlarltil :
In acc0rdaiw’b wll~h your request and aulhorlzat.lon dated May 15, 1989, we have completed a sol1 Investlgatlon for the proposed development of
subject property, more spcclflcally referred to as’ being Lot 728 of La Costa Meadows Unit No. I, acrordlng to Map thereof No. 7367, In the Clty of Carlsbad, State of Cal~lfornla.
Wee-ar-e .yltased to suhmlt the accompanying report to present our flndlngs,
conclusions and recommendations relative to the proposed project.
The Investlgatlon was performed under the ~upervlslnn of the under- slgned. The scope of our lnvestlgatlon Included field exploration, labo-
ratory testing, and geotechnlcal analysis.
No maJor “adverse soil condftlons were encount.ered that would prohibit the currently proposed development of the property, provided that the
site development Is nccompllshed In accordance with the approved grading plans.
Flease feel free t,o contact our offlce lf you have any questlons regarding the contents of this report. We greatly appreciate this opportunity to be __~.
INTRODUCTION..
DESCRIPTION OF : PROJECT
SCOPE OF WORK
FIELD INVESTIGATION
LABORATORY TESTS
SITE DESCRIPTION
FAULTS - SEISMICITY
GROUNDWATER
TADLE OF CONTENTS
Page No.
CONCLUSIONS AND RECOMMENDATIONS General
Grading
Fouridatlon Design
Retalnlng Walls and Lateral Loads Slope St ahlllt y Surface Dralnage and Maintenance Grading Plan Review
LIMITATIONS. AND UNIFORMITY OF CONDITIONS
Figure No. 1 - Locat.lon Map Figure No. 2 - Approximate Locatlon of Exploratory Trenches
Figure Nos. 3 and 4 - Trench Log Sheet
Appendix I - Recommended Earthwork Specltlcatlons
Appendlx II - Sampling Tcchnlqucs and Laboratory Test procedures Appendix IV - Laboratory Test Results
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May 26, 1989
SOIL INVESTIGATION
INTRODUCTION -----_--_-_-
Thls report presents the findlngs and conclusions of a sol1 Investigation
conducted at the site of 8 proposed resldentlal bulldlng, located
on the north side of Argonautr Street, northwest o
In the Clty of Carlsbad, State of Callfornla.
f Obellsco Circle,
The location of the property Is shown on the Locat Ion Map (Refer to Figure
No. 1).
The subJect property Is more specIfIcally referred to as belng Lot 728 of
La Costa Meadows .Unlt No. 4, In the Clty of Carlsbad, State,.of Callfornla,
according to Map thereof No. 73137.
DESCRIPTION OF PROJECT ~’ _--_------------------
It Is our understandlng that the currently proposed site development
consists qf, th.e c,onstructlon of a single:famlly residence of typlcal wood-
frame construction. A grading plan for subJect prolect, prepared by
Callfornla Engltjeerlng Corporation, has been provlded to us for use In this
Investigation.
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ProJ@ct~ No. 2OC4 Hnmld Rezal-Harlrl 05/26/89 Page 2
SCOPE OF WORK ---_---_-----
The objectIves of the lnvestlgatlon were to Inspect and determlne the
subsurface sol1 condltlons and certain physlcal, englneerlng propertles
of the solIs beneath the stte, and to evaluate any potentlally ,adverse
sol1 condltlons that could affect the proposed proJect,In’order that
englneerlng recommendations could be presented relative to the safe and
economlcal grading of the site and design of foundatlons for the proposed
structure.
In order to a&ompllsh these obJectives, a total of three trenches were
excavated and Inspected, and representative samples of the subsurface
~011s were collected for laboratory testing and analysis. The data
derived from our field observations and the laboratory test results
were reviewed and analyzed, and a summary of our prellmlnary flndlngs,
opinions and recommendations Is presented In this report.
FIELD INVESTIGATION -------__---_--_---
The field exploration phase of our investlgatlon was’ performed on
May 19, 1989, and Involved the excavation of three trenches wlth a tractor-
mounted backhoe equlpped with a 24-Inch bucket. The approximate location
of the exploratory trenches are showu on Flgure No. 2, entitled,
“Approximate Locatlou of Exploratory Trenches”. The trenches were
excavated to a depth of 3.0 feet below existing ground surface. The
trenching opbratlon was performed under the dIrectIon of our field Personnel
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ProJect No. ?O.C4 Hamld Rezal-Harlrl 05/26/89 ., Page 3
and a continuous log of the sol1 types encountered In the trenches was
recorded at tbe time of excavation, and 1s shown on Figure Nos. 3 and 4,
each entitled, “Trench Log Sheet”.
The stills tier* visually and texturally classlfled by the fleld lden-
tlflcatlon procedures set forth on the Unlfled Sol1 Classlflcatlon
Chart, a copy of which IS provided In Appendix II hereto.
Relatively undlsturbed chunk samples and loose-bag samples were obtalned
at varlous depths In the trenches. The general procedures used In fleld
sampling are brlefly described In Appendix 11 under “Sampling”.
LABORATORY TESTS --------------_-
The samples collected during our field investlgatlon were subJected to
varlous~ tests In,the 1aForatory to evaluate thelr englneerlng charac-
terlstlcs. The tests were performed In accordance. with current A.S.T.M.
testing standards or other regulatory agency testing procedures. The
general procedures used for some of the tests are brlefly described In
Appendlx II. A summary of the tests that were performed and the flnal
test results arc presented In Appendix IV hereto.
The tests~. that yere performed Included determlnattons of the ln-place
dry densltles and molsture contents of the solls, and the results of
these tests are tabulated on the Figure Nos. 3 and 4, each entltled,
“Trench Log Sheet”. Compactlon tests were performed on representative
ProJec.t ,No, 2OC4 Flamld Rexal-Narlrl 05/26/89 Page 4
samples of the maJor soil types encountered. Direct shear tests were
performed on saturated and dralned samples of the solls encountered
to determine thelr internal angle of frlctlon and apparent cohesion.
The Expansion Index of the soils encountered was also determlned.
SITE DESCRIPTION ---- -----------
Subject property Is a trapezoidal-shaped property, conslstlng of 0.75
acres. The exlstlng topography at the site’ may be described as sloping In
a general northerly dlrectlon away from Argonauta Street at gradients
varying from 15 to 20 percent. The site 1s presently vacant, and covered
with native grass and chaparral,
According ~to .the Soil Map of San Dlego County prepared by the U.S.D.A.,
the general area IS underlaln by ~011s of the Exchequer Series, which con-
sists of very shallow to shallow, (8 to 17 Inches) well-dralned silt loams
that formed III material weathered from hard metabaslc rock.
In this lnvestlgatlon, approximately 12 Inches of reddish brown sandy clay
was encountered, overlylng weathered metavolcanlc rocks. Refusal In the
metavolcaulc rocks was met w1t.h tbe backhoe at relatively shallow depth of
3.0 feet.
FAULTS - SEISMICITY ------ ----------
No faults or signlflcant shear zones were encountered on or near subject
site. Nearby .faults will not adversely impact the property.
ProJect No. 2OC4 lfamld Rezal-Ifal 05/26/89 Page 5
Distant faults, which are conslderecl lctlve by geologists, ~111 periodl-
tally affect the site. These may Include the Elslnore and San Jaclnto/
San Anmdre.a.s fault zones to the east, and off-shore faults to the west.
Low to moderate levels of ground shaklng tlurlng fault actlvlty may be
expected at subJect property. Ground separation as a result of fault
activity 1s not antlclpated.
GROUNDWATER
Groundwater was not encountered In the exploratory trenches, and no seeps
or springs were observed on the site during our site lnvestlgatlon.
CONCLUSIONS AND RECOMMENDATlONS ----------- --- ---------------
General
1. No maJor adverse sol1 condltlons were encountered which would prohibit
the currently proposed development of the proJect site.
2. All of the solIs and/or rocks encountered on the site are consldered
to be sult~able for use as supporting materials for the proposed
structure .~and/or fill solls.
3. Laboratory test results indicate that the sandy clays, similar to those
encountered In all trench locatlons to a depth of 1.0 foot, possess
high expansion potential (Expansion ludex = 95).
ProJect No. 2OC4 Ramld Rezal-Rarlrl 05/26/89
Gradlng
Page 6
4. A review of the grading plan of subject proJect provided to us Indicates
that grading on the site will consist prlmarlly of Imported soils
placed for the constructlon of the proposed drlveway. Foundations for
tbe proposed residence wlll be founded In natural ~011s.
5. It Is recommended that the grading on the slte be accompllsbed In
accordance with the Grading Ordinance of the City of Carlsbad, and the
“Re,commended Earthwork Speclflcatlons” presented In Appendlx 1.
Wbere tbe recommendations of this sectlon of the report conflict wlth
those of Appendix I, this sectlon of the report takes precedence.
6. Site preparatlon should begln with the removal of all vegetation and
other deleterlous debrls from areas to be graded. Such materials
should be exported from the site.
7. Loose topsolls slmllar to those encountered In all trench locatlons
to~,a depth of 12 Inches, that remain below finlshed grade, should be
removed and uniformly recnmpacted prior to the placement of addltlonal
flll.
8. All flll soils should be placed and compacted In layers intll flnal
elevations are reached. Layers of flll should be no thicker than
that which wlll allow for adequate bondlng and compactlon. Imported
flll materials should be from a borrow site approved by the City of
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Project No. 2OC4 llantd Rozal-Harlrl 05/26/89 Page 7
Carlsbad and our firm. All fill ~011s should be compacted to at least
90 percent of maximum dry density as determlned by A.S.T.M. D1557,
Me,thod A or C.
9. It IS recommended that a preconstructlon conference be held at the
site with the developer, clvll engineer, contractor, and, geotechnlcal
engineer In at t endnnco. Speclal sol1 handling and the approved grading
plans can be discussed at that time.
Foundation Design
10. It Is recommended that l,he foundation for the proposed residence be
extended through the. upper soft sandy clays at least 12 inches into the
underlylng competent weathered metavolcanlc rocks.
II. A safe allowable sol1 bearing value of 2,500 pounds per square foot
may be used In the design of foundatlons that are a minimum of 12
inches In horlzontal dlaenslon, and are embedded at least 12 Inches
Into the compelent weathered metavolcanlc rocks.
12. The above safe allowable soil bearing value IS ‘applicable for suppor-
ting dead plus live loads, and may be Increased by one-third for
design loads that Include wind or selsmlc analysis. i -
13. It Is further recommended that all cant tnuous foundations be reln-
forced with a mlnlmum of 2 #5 rebars. One rebar located 3 lncbes
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above, the bottom of the foundatlon, and one rebar located 1 l/2 inches
below the top of the foundation.
14. The settlement of the foundation, loaded to 2,500 pounds per square
foot and relnforced as recommended above, Is estlmaled to be wlthln
acceptable tolerance llmlts.
Retaining Walls and Lat.eral Loads --------- ----- --- ------- -----
15. Retalnlng wall foundatlons should conform to Lhe recummendatlons under
Iteins 10 through 13 above.
16. Active earth pressures-against walls wfll depend upon the slope of
backflll and the degree of wall restraint. Unrestralned walls free to
rotate at the top and with level backflll should.be deslgned to resist
an active pressure equivalent to tbat generated by a fluld weighing 35
pounds per cubic foot. For rlgid, absolutely restralned walls, an i -
addttlonal unlform surcharge pressure of 50 pounds per square foot
should be added to the ahove loading.
17. Unrestralned walls free to rotate at the top and wltb 2 : 1 (horl-
zontal : vertfcal) backflll should be deslgned to resist an active
pressure equivalent to that generated by a fluld welgbing 48 pounds
per cubic foot.
18. Lateral loads may bc reslst~ed by a passive pressure equlvalent to
that generated by a fluld welghlng 350 pounds per cubic foot for fOUn-
ProJect No. 2OC4 llamld Rezal-JJarJrl 05/26/&a Page 9
dations founded In tlie dense weathered metavolcanlc rocks. A coeffl-
clent of, frlctlon of 0.35 may be used to calculate tlie resistance to
sliding along the concrete/sol1 Interface.
19. Retalnlng walls should be properly waterproofed and provided with
gravel and perforated pipe drain systems to reduce the potential for
hydrostatic pressure bulldup beltlnd walls. Tlie gravel portlon of the
draln should extend at least two--1JiJrds the helgbt of tlie wall and
sJlou1.d be enclosed In a filter fahrlc envelope. An alternatlve to
gravel draln systems would be a dralnage product such as “Mlradraln”,
which is placed directly against the back of the retalnlng wall.
Gravel and a perforated pipe are placed at the bottom 12 Inches of
the dralnage product. Our firm Is avallable to provide assistance In
deslgnlng approprlate drainage systems for retalnlng walls.
Slope Stablllty ----- ----.- ____
20. PI11 sl~opes on tlie order of 20 feet In maximum helgJJt, and with slope
rat10 of 2 : 1 (Jiorlxontal : vertical), are Proposed for the site.
It Is our conclusJon that these fill slopes wlll be safe agalnst
massive slope fallurc, provided tAat tlie Imported fill materials
used in the construct.ton of t.Jie slopes meet our requirements prior
t 0. placement. TJie fill slopes sliould consist of non-expansive
materials’ (SW, SM, Ml; etc) a.nd contalnlng rocks less than 6 Inches
In dlameter.
ProJect No. 2OC4 Jlamld Rezal-tlarlrl 05/26/&S Page 10
Surfac~e Dralnage and Malnt enance ------- -------- --- -----.------
21. Adequate dralnage control and proper maintenance of all dralnage
~fatillltles are Imperative to mJnlm1z.e lnflltratlon of surface water
Into the underlyJng’soIl mass In or.der to reduce settlement potentlal
and to mlnlmlze erosion. The huildlng area should have drainage swales
wblcb direct storm and excess lrrlgatlon water away from the structure
and Into ,strcel gutters or other dralnage facllltles. No surface
runoff should be
Grading Plan Review ------- _.--- _.-----
22. It Is ~recomnknded
allowed to J’ond ad.Jacent to the footlngs.
that our firm revlew the flnal grading plan for
the proposed site development to verify tllelr compliance wlth the
recommendations presented In tills report., and with the Uniform
BulldIng Code, Cliapter 70, as requlred by the State of California.
LIMITATIONS AND UNIFORMJTY OF CONDITIONS ------,__--- _.-_ _- _____ -__ __ .~~~ .._. -- _._..
1. The prellmlnary flndtngs and rccommendatlons contalned in this report
pertain or&y to the site Jnvestignlecl and are based on the assumptlon
that the. ~~011 condlt~lons beneath lhe entlre slle tlo .not deviate sub-
stantlally from those disclosed in the exploratory excavations. If
any varIrt.lons or undeslrahlo condltlnns are encountered during
grading, or If the scope of the proJect differs from that planned at
the present time, our firm should be notlfled In order that supple-
me,ntal, repommendatlons can he presented, II necessary.
ProJecf ‘No; ‘2OC4. JJamld Rezai-lhrlrl 05/2IVfJS
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Tills report Is Issued wltlt tile understandlng tllat It Is the respon-
btllty of tlie Owner, or his representative, to ensure that the
lnformatlon and recommendations presented hereln are brought to the
attentlon of the ProJect hrchttect and Engineer and are Incorporated
Into the plans and speclflcntlons for tile proJect. Furthermore, the
Owner, or his represontatlvc, will also be responsible for taklng
the necessary measures to ensure that the Contractor and Subcon-
tractors properly carry out the recommendations In the field.
Professlonal opJnIons and recommendations presented In this report
ar,e based partly on our cvaluatlon and analysis of the technlcal
lnformatlon gathered during our study, partly on the currently
available Informatlon regarding the proposed proJect, and partly on
our preilous experience with slmllar sol1 conditions and JJroJects of
slmllar scope. Our study Jlas been performed fin accordance wlth the
mlnlmum standards of care exercised by otlier .professlonal geoteclrnical
consultants currently practlcing In tJie same locality. We do not,
however, guarantee tJle performance of the proposed proJect In any
respect, and no warr.antJcs of any kind, expressed or lniplled, are
made or Intended In connection wltb the study performed by our firm.
4. The flndlngs and recommendat.Ions contalned In tills report are valid
as of the present date. Jlowever, changes In the conditions of tile
property could occur witit tJ1c Jjassage of time, wlletlier they be due
ProJect No. 2OC4 llamld Rezal-.IlarIrl 05/26/89 Page 12
to natural processes or due to man-made actlons on the subject and/or
adJacent propertles. In addltlon, changes In applicable or appr,oprlate
standards may occur, whether lhey result from lcgislatlon or the
broadenIn% of knowledge. hccordln(tly, the flndlngs of thls report may
be Invalidated, wholly or part.lally, by changes outslde of our control.
Therefore, this report Is subJect to review by our flrm and should not
be rellcd upon after a period of two years.
Figure Nos. 1 to 4, Inclusive, and Appendlces 11 II, and IV are parts
of this report.
.,
(3) Addressee
LOCATION MAP.
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FIGURE 1
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TRENCH LOG SHEET
Trench no. 3 Elevation 512-o
Reddish brown, dry, loose
3 .:;'/: Q ~",",~-,",lnoiw,n;;;;;, dense YE&Y TO C3ARSE SAVD 4.5 122:7
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Bottom of Trench (Refusal)
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0, Indicates undisturbed chunk samrile
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Trench no. 1 Elevation 494.5 ti w- ? ? .OlL DL.C(I,PTION. it
Reddish brown, dry, loose SANDY CLAY with 15% rocks
Reddish brown, dry, dense Yetavolcanic rocks YE')TUY TO COARSZ SAW
Very dense
Bottom ot: Trench (Refusal)
Trench Yo. 2 Elevation 493.0
Reddish brown, drv, loose
Reddish brown, 3ry, dense ,Metavolcanic rocks :
SANDY CLAY with iS% rocks
.MEDIUM TO C09RSE SAND
Bottom OF Trench '(refusal)
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APFENDIX I ----- , ,
RECOMMENDED EARTIIWORK SPECIFICATIONS -__- -
1. General Uescription. ---?~--- .__._ ---.- The objective is to obtain uniformity and internal str:ength in filled ground by proven engineering
EXOCtXhi6S at~d tests i,n order to provide a safe foundation
support fog the propased str~uct~~t-es. The procedures include the clr?arinq and yrubbinq, removal of existing structures, preparation of l.and to be filled, processing the fill soils, filling of the land, and tile spreadi.nq alld compaction of the filled areas to conform with the grades and slopes as shown on the approved plans.
The owner or his authorized agent shall retain a qualified Soil Enqiueer (herein referred to as Engineer) to inspect and test the Filled ql-ound during pl,accmmt to verify its uniformity of compacti.on to the sprcifi 4 30 percent of maximum dry den- sity. The Enqineer shall, advise tile owner or his agent and the grading contractor immedj,atcly if any unsatisfactory con- di.tiolks are ol,served to exi.sl. and shall have the authority to reject tile compacted filled yrolllld until the necessary correc- tive measures at-e taken, in ot-c?e~- to comply with the project specifications. It shall. be the s~lc resllonsibility of the yradinq contractor to achieve the specified degree of compaction.
2. Clearitlq, tirubbi.ny, ---- and ,Freparinq Areas to be Filled --. ..- ----.-. -
(a) Al.1 structures, any vegetation not utili,zed in landscaping and other biodeyradable reCuse shall be piled and removed, or otherwise disposed of as to leave the areas to be filled fret of vcqctat~ion and debris. hy uncompacted filled ground or loose compressible IlaCuraS qrouud. shall be removed unless the report recotruwmrls otherwise.. Any unstable, soft, swampy. or otllerwise unsuitable areas shall be corrected by draining or removal, or both.
(b) Any sei>tic or other buried tanks if encountered, and debris
must be removed from tl~e site pr;.or to any building, qradinq or fill o[~eratj.ons. Septic tanks, includinq all connecting drain fields and other l.iities, must be totally removed and
tile resulting depreos.iot:s properly reconstructed and filled to the complete satisfaction of tl;e Enqineer.
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Appendix I Page 2 of 6
All water wells on the site which are to be abandoned shall be capped in accordance with the regulations of the San Diego County Health Department. The strength of the cap shall be at least equal to the adjacent soil.
The final elevation of the top of the well casing must be a minimum of 36 inches below the lowest adjacent grade prior to any grading operations.
The natural ground which is determined to be satisfactory for the support of the filled'ground shall then be plowed or scarified to a depth of at least six inches, and until the surface is free from ruts, hummocks, or other uneven feat,ures which would tend to prevent uniform,compaction by the equipment to be used.
After the natural ground has been prepared, it shall then be.brought to the proper moisture content and compacted to not less than 90 percent of maximum dry density in accordance with the A.S.T.M. D1557-70 method which uses 25 blows of a 10 pound rammer falling 18 inches on each of 5 layers in a 4-inch diameter l/30 cubic foot cylin- drical mold.
Where fills are made on hillsides or exposed slope areas, with gradients greater than 10 percent, horizontal benches shall be cut into firm undisturbed natural ground in order to provide both lateral and vertical stability (refer to Figure 1). This is to provide a horizontal base so that each layer is placed and compacted on a horizontal plane. The initial bench at the toe of the fill shall'be at least 10 feet in width on firm undisturbed natural ground at the elevation of the toe stake placed by the surveyor. The Engineer shall determine the width and frequency of all succeeding benches which will vary with the soil conditions and the steepness of slope.
3. Materials and Special Requirements,
(a) The fill soils shall consist of select materials free from vegetable matter, and other deleterious substances, and shall not contain rocks or lumps greater than 6 inches in diameter. This may be obtained from the excavation of banks, borrows pits or any other sources approved by the Engineer and by mixing soils from one or more sources.
If excessive vegetation, rocks or soils with inadequate strength or other unacceptable physical characteristics are encountered, these shall be disposed of in waste areas as shown on the plans or as directed by the Engineer.
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Placement of oversized rock (larger than 6 inches in di- ameter) shall be performed under the supervaision of the Etigineer. Figure 2 schematically illustrates some of the areas where oversized rock may be placed. No rocks will be allowed to “nest” nnd all void spaces must be carefully filled with gravel and/or earth, and properly compacted.
1 If, during grading operktions, soils are found which were not encountered and ~tested in the preliminary investigation, te.sts on these soils shall be performed to determine their physical characteristics. Any special treatment recommended in the prel-iminary or subsequent soil report not covered herein shall become an addendum to these specifications.
The testing and specifications for the compaction of sub- grade, subbase and base materials for roads, streets, highways, or other public property or rights-of-way shall be in accordance with the standards of the governmental agency having jurisdiction.
,cing, Spreading, and Compacting Fill Materials
Wllen the moisture content of the fill material is below. that specified by the Engineer, water shall be added in the borrow pit until the moisture content is near optimum ‘.
to assure uniform mixing and effective compaction.
W11e1l the moisture content OF the fill material is above tllat specified by the Engineer, resulting in inadequate compaction or unstable fill, the fill material shall be aer;lted by bl.aLiitlg and scarifying or other satisfactory methods until the moisture content is near optimum as specified.
After processing, the &i.tab.Le fill material shall be placed
'ill layers which, when compacted, shall not exceed six inches
(6”). Each layer shall ,be spread evenly and shall be thor- ouf;lhly ,n,ixed during the spreading to ensure uniformity of material and moisture in each layer.
After each layer has been placed, mixed and spr.ead evenly,
it. shaJ.l be thorouyh1.y compacted to not less than the den- sity set forth in paragraph 2 (e) above. Compaction shall bc accomplished with slleepsfoot rollers, multiple-wheel l?neumat.ic-rollers, or other approved types of compaction equipment, such as vibratory erjuipment that is specially designed for certain soil types. Rollers shall be of such design and maintaJ.ned to such a level ,that they will be ab1.e to compact the fi1.J. material to the specified density. ‘I’amping feet of sheepsfoot rollers shall be maintained such .~ that the soil will be compaqted rather than sheared by the rol.l,er. Rolling: shall. be ~complished while the fill mate- rial is at ttle specified moisture content.
5.
6.
7.
8.
(e)
(f)
(9)
Appendix <I Page4of6
Rolling of each layer shall be continuous over its entire area and the rollers shall make sufficient trips to insure that the specified density has been obtained. Rolling shall be accomplished in a planned procedure such that the entire areasto be Filled shall receive uniform compactive effort.
’
The surfaces of the fill slopes shall be compacted by ,mean’s ‘of sheepsfoot rol.lers or other suitable equipment. Compacting operations shall be continued until the slopes are stable as determined by the Engineer and until there is no appreciable amount of loose soil on the slopes. Compacting of the slopes shall be accomplished by back- rolling the slopes in increments of 3 to 5 Ee.et. in eleva- tion gain or by other methods producing satisfactory re- sults.
Field density tests shall be taken EOC every two. feet in eleva- tion gain, after compaction, but may be taken at more frequent intervals (less’ than 24 inches in elevation gain) if required by the Engineer. The location of the tests in plan shall be so spaced to give the best possible coverage and shall be taken no farther apart than 100 feet. Tests shall be ‘taken on corner and terrace lots for each two feet in eleva- tion gain. The Engineer may take additional tests as con- sidered necessary to clleck on the uniformity of compaction. ’ Where sheepsfoot rollers are used, the tests shall be taken in the compacted material below the disturbed surface. No additional layers of fill. shall be spread until the field density tests indicate that the specified density has been obtained.
The Eill operation shall be continued in six-inch compacted layers as specified above, until the fill has been brought to the finished slopes and grades as shown on the approved grading plans.
Ins= ion. Sufficient inspection by the Engineer shall be FZintarllecf during the filling and compacting operations so that he can verify that the fill was constructed in accordance with the accepted specifications.
Seasonal’ Limits. No Eill material shall be placed, spread, or rolled. If ,wgather conditions increase the moisture content above permissible limits. When the work is interrupted by rain, fill operations shall not be resumed until Eield tests by the Engineer indicate that the moisture content and density of the fill mate- rials are as previously specified.
Limiting Values of Non-expansive Soils. Those soils which expand
3.0 percent or le5s from aifrjFy to saturation under a unit load of 150 pounds per square foot are considered to be non-expansive.
All recommendations presented in the attached report are a part of these specifications.
toosoil and/or disturbed natural ground to-be stripped in a.ccordance with,the Soil Engineer's recommendations
slope to be such treat sloughing or s1;sin-J does not OCCar
NOTES
1. Revs or benches are reuuired where the nakal slooe is steer& than 10 hori- (
Slope Ratio: Borizontal(A) Vertical(V)
zontal to l-vertical,-or where specified by the Soil Ingineer.
‘no3 ’
2. The outside edge of the bottom key/bench shall be below topsoil, or loose surface 'natural .soils.
3. The minimum width of the key/bench shall be two feet wider than the grading equip- ment, but in any event shall not be less than. ten feet.
see note no 2
Figure 1 I I lPPLNDlX I
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. . - varies7 I I
st:eet minimum soil cover 115’ mini on. I c
:"' ':""":~':::::::::'j:: ": ': Original ground sur?ace
ComEacted t;lJ-d ground; no ove:size rock -*-a- in .his area.
,rlay glace oversize rock in t:his area: the boulders should be surrounded bv sufficient fine grained materials to obtain
proper compaction and to avoid "nesting".
Xatural soils
NOTZS:
1. No rock mav be -&aced within 4 feet below finish grade or within anticipated depth of utilities, whichever is deeper.
2. No rock greater'than 4 feet in maximum dimension may be used in the oversize rock fill.
3. Rocks greater than 2 feet in size should be com&letely surrounded by properly compacted soils such that no "nesting" occurs.
Fieurc 2 WIED EARTH' TECJSWQJ,OCY,.TNC. ' APPENDIX I
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APPENIJIX I I
SAMPLING TECIINIQUES AND LAUORATORY TEST PROCEDURES
Sampling (Undisturbed Samples)
Undisturbed drive.~samples are ohtaineti by driving a spccitil ~Gmpling tube into undisturbed soil strata at’the bottom of an exploratory excavation. The sampling tube consists of a steel barrel, 3.0 inches outside diameter, with a spccial~ cutting tip and inside lin- ing of twelve thin brass rings, each one-inch long by 2.42 inches inside diameter. The smlpler , connected to a twelve-inch long waste barrel, is either pushed or driven approximately 18 inches into the sdil and a six-inch section of the centcr portion of the sample is collected for laboratory testing. The soil samples, which are still confined in .tlle brass rings after extraction from the sampler tube, are transported to the laboratory in close fitting waterproof~con- tainers in drder tb retain tile field moisture. The driving energy is calculated as the average energy Ian foot-kips required to force the sampling tube through twelve inches oE soil at the depth at which the sample is obtained.
In cases where it is impractical to obtain undisturbed drive.samples then undisturhecl chunk samples will be obtained. A chunk sam’ple is a representative portion of the soil mass, which is taken en masse
Cram the stratum being investigated. l’he sample is then placed in a waterproof container to retain the field moisture and carefully . . transported to the laboratory.
Sampling (Disturhcd Samples)
Whenever practical, the in-situ density of the soil mass is deter- mined by applying the current applicable protiisions of A.S.T.M. Test Method D1556-74.
Determination of, Moisture Content
The moisture content of the soil is determined in the. laboratory in
aCCOKdalv2e with A.S.T.H. Test Method D2216-71.
Soil Classification
Field identificatiqn of the various soil types is performed on the basis of the Unified Soil Classification System, a copy of which is presented as Figure 1 hereto.
APPENDIX II Page 2 of 3
Shear Tests ,
The shear tests are run using a direct shear machine of the strain control type in.which the rate of deformation is approximarely 0.05 inch per minute. The machine is so designed that the tests can be conducted without removing the soil samples from the brass liner rings, in which they were secured. Each sample is sheared under a normal load equivalent to the weight of the soil above the point of sampling. In some instances, samples are sheared under various normal loads in order to obtain the internal angle of friction and cohesion. Where considered necessary,. samples are saturated and drained before shearing in order to simulate extreme field moisture conditions.
Consolidatidti Tests
The apparatus used for the consolidation tests is designed to receive one of the one-inch high brass rings containing the soil samples as it comes from the field. Loads are applied in several increments to the upper surface of the test specimen and the resulting deformations are recorded at selected time intervals for each increment. Generally, each load increment is maintained on the sample until the rate of deformation is equal to or less than’ l/10,000 inch per hour. Porous stones are placed in contact with the top and bottom of each specimen to permit the ready addition or release of water.
Expansion Tests
Expansion tests ar’e performed on air dried samples or on soil samples remolded at optitium moisture content. In the first case, one-inch high samples confined in the brass rings are permitted to air dr,y at 105 degrees Fahrenheit over a period of at least 48 hours pfior to placing in the expansion apparatus. The sample to
be tested at optimum moisture content is remolded to 90 percent of maximum dry density at optimum moisture content and placed directly on the expansion apparatus. A unit load of 150 or 500 pounds per square foot is then applied to the upper porous stone in contact with the top of each sample. Water is permitted to contact both
the top arid’bottom of each sample through the use of porous stones.
Continuous observations are made until upward movement on the dial are recorded to be less than l/10,000 inch per hour.
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AFFENDIX IV
laboratory Test Results
1. The maxlmum dry density and optimum moisture content of the f111
materlals, as determfned In accordance with A.S.T.M. D1557-78,
Method A,~are presented as follows :
M*xlmum Opt imum
Dry Density Moisture Content
Dascrlpt ion (1bsJcu.ft.J (% Dry Wt.)
.,
Trench 2 Rreddish brown medlumn to 132.0 8.0
Bag 1 coarse sand
Depth 1.5’
2. The Expansion Index of the most. clayey ~011s encountered was determined
accordance with UBC Test Method 29-2. The results of the test are
presented as follows :
Descrlptlon
Expansion
Index
Trench 1 Rcddlsh brown sandy clay 35 *
Bag 1
Depth 1.0’
* Considered to have high expanlon potential
3. Direct shear tests were performed on samples. of the representative
solls, after being saturated and dralned. The results of the tests
are presented as follows :
Description
Apparent Angle of
Coheslon Internal Frlctlon
(1bsJsq.U.) (Degree)
Trench 2* Reddlsh brown medium to 800 33
Bag. I
Depth 1.5”~
coarse sand
*sample remolded to SO percent of maxlmum dry denslty