HomeMy WebLinkAbout; Heli Hangar - Palomar Airport Rd; Soils Report; 1980-10-30REKRT OF SOIL INVESCIGATION
Heli-Hangar
Aircraft Koad and Patomar Airport Koad
Carlsbad, California
JOB NO. 80-1580
xl October 1980
prepared fOI
Mr. DDug staky
Lusardi Construction
ENGINEERING DEPT. LIBRARY city o! Carl&d 2075 Las Palmas Drive Carl&ad, CA92009-4859
prepared by
CEOTECtNlCAL EXPLORATIUU, INC.
8145 Ronson Koad, Suite H
San Diego, CA 92111
,b
GEOTECHNICAL EXPLORATION, INC.
SOIL & FOUNDATION ENGINEERING
GROUNDWATER. GEOPHYSICS l ENGINEERING GEOLOGY
30 October 1980
Mr. Doug staley
Lusardi Construction
P. 0. Box 35
San Marcos, California 92069
Subject: REPOKT OF SOIL INVESTtGATlON
Heli-Hangar
Aircraft Koad and Palomar Airport Koad
Carlsbad, California
Dear Mr. Staley:
JOB NO. EO-1SltO
In accordance with your request, Ceotechnical Exploration, Inc. has performed an
investigation of the surface and subsurface soil conditions at the location of the
subject proposed Heli-Hangar Building Site. The field work was performed on 21
October 1980 by our Project Engineer.
.
It is our understanding that the site is king developed to receive a concrete tilt-up
hangar. The structure is to be a maximum of one story in height and will be on
conventional, continuous foundations or spread footings with concrete slab on grade.
It is further our understanding, three (3) concrete helicopter landing pads will be
located west of the proposed building.
Our investigation revealed moderately compacted fill soils up to thirteen (13) feet in
thickness exist at the western limit of the proposed helicopter landing pads. The
proposed building area, in general, is underlain with good bearing sands. Moderately
expansive topsoils were encountered near the surface.
In our opinion, if the conclusions and recommendations presented in this report are
implemented during site preparation, the site will be suited for the proposed develop-
ment.
This opportunity to be of service is sincerely appreciated. Should you have any ques-
tions concerning the following report, please do not hesitate to contact US. Refer-
ence to our Job No. 80-1580 will expedite response to your inquiries.
Respectfully submitted,
CEOTECHNICAL EXRORATICY4, INC-
KayID r(p J. Scararr#lla, Vice President
K JS:med
Enclosures
8145 RONSON ROAD, SUITE H l SAN DIEGO. CALIFORNIA 92111 . (714) 560-0428
REPORT OF SOIL INVESTIGATION
Heli-Hangar
Aircraft Road and Paiomar Airport Road
Carlsbad, California
JOB NO. fKF1580
The following report presents the findings and recommendations of CEOTECtWICAL
EXPLORATION, INC. for the subject project.
SCOPE OF WORK
It is our understanding, based on communications with Mr. Doug St&y, that the site
is intended for the’construction of a concrete tilt-up helicopter hangar and three (3)
concrete slab helicopter landing pads. The proposed building will be founded on
continuous perimeter foundations with concrete floor slab on grade. The proposed
improvements will be founded at the existing grade. \Vith the above in mind, the
Scope of Work is brieflv outlined as follows:
1.
2.
3.
4.
Identify and classify the surface and subsurface soils to depths, in conformance
with the Unified Soil Classification System (refer to Appendix A).
Oetermine the allowable bearing pressures for the natural ground and the soils
to be used in compacted fill, based on their shear-strength characteristics and
our experience with the soils.
Recommend treatment for any expansive soils and/or uncompacted fill soils that
could cause detrimental damages to the proposed structure.
Predict the settlement of the natural-ground soils, as well as recompacted fill
soils (recompacted to at least 90 percent of Maximum Urv Density), under the
proposed structural loads.
Heli-Hangar
30 October 1980
SITE -
Job No. 80-1500
Page 2
The site, consisting of approximately 1.2 acres, is located northwest of the intersection
between Palomar Airport Road and Aircraft Road, in the Carlsbad area. The property
is roughly rectangular in shape, being approximately 85 feet in width and approximately
700 feet in length. The property is bordered on the north and east by Aircraft Road,
on the south by Palomar Airport Road and to the west by undeveloped land.
Presently, the site is undeveloped and supports a light to moderate growth of
chaparral. A previous grading operation generated a relatively level pad that drains
gently towards the southwest. The eastern half of the south property line is bordered
by a cut slope constructed at a ratio of 1.0 horizontal to 1.0 vertical and ranging from
three (3) to six (6) feet in vertical height. Rough field measurements indicate the top
of the existing cut slope is located south of the south property line.
FtELO
Five (5) test trenches were placed on the site, specifically in areas where structures
and improvements will be located. The test trenches were located in the field by
referring to a Site Plan, prepared by Lusardi Construction, dated 8 October 1980. The
test trenches were visually inspected by our Fidd Engineer, and samples were taken of
the predominant soils throughout the field operation. Trench logs have been prepared
on the basis of our inspection and the results have been surrmarized on Figure No. It.
The predominant soils have been classified in conformance with the Unified Soil
Classification System (refer to Appendix A).
SOIL.5
The soits encountered in the proposed building area consist of a topsoil approximately
one and one-half (1 l/2) feet in thickness. The topsoils primarily consist of brown,
fine to medium grained, clayey sands. These soils are in a loose to medium dense
state and are classifiwl as moderately expansive; therefore, possess a swell range from
four (4) to six (6) percent as measured by the County of San Diego Test for Expansive
Soils.
&Ii-Hangar
30 October 1980
Job No. 80-15&l
Page 3
Underlying the topsoils and extending at depth are medium dense, light brown to gray,
fine, formational sands. These soils possess good strength characteristics for bearing
support and slope stability. The formational sands are classified as nonexpansive;
therefore, possess less than three (3) percent swell.
Encountered at the west edge of the proposed building and extending to the west
property line, underlying the proposed helicopter pads are poorly to moderately
compacted fill soils. The fill soils are primarily composed of silty sand and sands with
some asphalt debris. The fill soils encountered were classified as nonexpansive;
therefore, possess less than three (3) percent swell. The approximate location of the
fill soils is shown on Figure No. I, located at the end of this report. The fill extends
to a maximum depth of 15 feet below the existing ground surface at the west end of
the proposed helicopter pad.
LABORATORY TEST.5
Laboratory tests were performed on the disturbed and undisturbed soil samples in
order to determine their physical and mechanical properties and their ability to sup-
port the proposed structure. The following test; were conducted on the sampled
soils:
1. Moisture Content
2. Density Lkterrninations
3. Mechanical Anal.ysis
4. Expansion Tests
5. Direct Shear Tests
CCNCLUSICX’JS AND RFCWMENDATIONS
The following conclusions and recommendations are based upon the practical field
investigations conducted by our firm, and resulting laboratory tests, in conjunction
with our knowledge and experience with the soils in the~carlsbad area.
Iieli-Hangar job No. 80-15&J
30 October 1900 Page 4
1. The natural-ground topsoils on this site consis; of one and one-half (1 l/2)
feet of brown, fine to medium, clays sand. The clayey sands were tested and
found to possess four (4) to six (6) percent swell, as measured by the County
o.f San Diego Test for Expansive Soils. The topsoils are underlain by medium
dense, light brown to gray, fine, formational sands.
2. Unless properly de& with, the moderately expansive characteristics of the
topsoil clayey sands described previously can cause significant damage to the
structure and associated improvements (such as those planned for the subject
PropeW. In order to reduce significantly the potentid for such damage, one
of the recommendations herein must be followed:
2.1 If the planned structure and improvements are to lx constructed using
standard, nonexpansive-soils, design criteria, the site shall be prepared as
follows:
2.1.1 The moderately expansive clayey sands shall be removed from
all structural areas to a minimum distance of fiw (5) feet outside
perimeter footings. The clay soils shall be removed to a minimum depth
of three (3) feet bdow the proposed, rough, finish-grade elevations.
2.1.2 Excavated areas shall be backfilled with nonexpansive soils
(such as onsite, sands or soils obtained from an approved offsite borrow
pit). The nonexpansive select materials must be placed and. compacted to
at least 90 percent of Maximum L>ry Density, in accordance with the
requirements of the County of San Diego Grading Ordinance. upon
satisfactory completion of the backfilling operation, continuous and
spread footings may be designed, in accordance with the soil-bearing
value assigned to the compacted nonexpansive fill materials. The
continuous and spread footings shall have a minimum width of 12 inches
and extend a minimum depth of 12 inches into the compacted fill soils.
Heli-Hangar
30 Cktober 190
Job No. W-1580
Page 5
2.1.3 Areas receiving improvements, such as patios, sidewalks,
A.C. pavement (parking areas), et cetera, shall be underlain by at least
four (4) inches of compacted fill materials, such as that used in the
backfilling operations for building locations.
2.2 If it is intended to construct the proposed structure and improvements
on the moderately expansive clay soils without preparation of the site (as
described in Recommendation No. 2.1), the following recommendations
become applicable:
2.2.1 The continuous foundations and spread footings shall
extend a minimum depth of 18 inches into the firm natural ground or
compacted fill. The continuous foundations shall be reinforced with two
(2) No. 4 steel bars; one (1) bar shall be located near the top of the
foundations and one bar near the bottom.
2.2.2 Concrete floor slabs, if used, shall be founded on at least
four (4) inches of sand or decomposed granite, overlying visqueen. The
slabs shall be reinforced with 6 x 6 - lO/lO steel wire mesh.
2.2.3 Prior to pouring footings and foundations, ‘and prior to
placement of floor slab base sections, the clayey soils shall be thoroughly
watered such that they possess a moisture content of two (2) percent
above optimum moisture content (or more) at a depth of 12 inches below
the footing grade.
2.2.4 It is recommended that all nonstructural concrete slabs
(such as patios, driveways, sidewalks, et cetera), and all parking areas, be
founded on at least four (4) inches of nonexpansive soils.
3. Poorly to moderately compacted fill soils were encountered on the site during
our investigation. The fill soils ‘daylight’ with the natural ground soils near
Heli-Hangar Job No. 80-1580
30 October 19&l Page 6
the west end of the proposed-hangar and increase to a maximum thickness of 15
feet at the western most proposed helicopter pad (see Figure No. I for the
approximate location of existing fill soils). It is our opinion, based on typical
representative samples taken from the encountered fill soils, that the fill soils
possess moderately compressible characteristics, and could consolidate up to
two (2) inches, should they become wet or saturated. Should the fill soils be
recompacted up to at least 90 percent of maximum dry density, then the
settlement potential would be less than 0.5 inches. Prior to preparation of
building pads and areas to receive structural improvements, the loose fill soils
should be prepared in the following manner:
3.1
3.2
3.3
3.4
All loose fill soils shall be removed to expose firm natural ground. The
ground shall then be scarified to 12 inches in depth, watered to approxi-
mate optimum moisture contents and shall then be recompacted to at
least 90 percent of Maximum Dry Density in accordance with A.S.T.M.
D-1556, Method D.
The removed loose soils shall be cleaned of all significant debris and
vegetal matter, and shall be watered to approximate optimum moisture
contents.
The prepared fill soils shall then be placed and compacted, as required, to
achieve the design elevations for the project. The materials shall be
placed in layers, not exceeding six (6) inches in compacted thickness, and
shall be compacted to at least ‘XI percent of Maximum Dry Density.
The existing fill soils, located in the proposed building area and extending
for a distance of at least five (5) feet beyond the perimeter thereof, shall
be excavated to a depth exposing firm natural ground, or to a depth
approved by the Field Soils Technician. The bottom of the excavation
shall be scarified to a depth of at least 12 inches, watered to optimum
moisture content and compacted to at least 90 percent of Maximum Dry
Hefi-Hangar Job No. @O-15&l
30 October 1980 Page 7
Density. The excavated fill soils shall be cleaned of debris and deleteri-
ous materials. The fill soils shall be placed into the excavation in layers
not exceeding eight (8) inches in thickness, then watered to optimum
moisture content and then compacted to at least 90 percent of Maximum
Dry Uensity. It is recommended that nonexpansive soils be placed within
three (3) feet of finish-ground grade.
4. Utilizing an Angle of Internal Friction of at least 35 degrees, and a cohesion of
300 pounds per square foot (with the appropriate Terzaghi Equation), the
maximum safe soil-bearing value (at a depth of 12 inches into the natural
materials or compacted fill soils on this site) is at least 2500 pounds per square
foot. This soil-bearing value may be utilized in the design of continuous
foundations and spread footings when founded a minimum of 12 inches into the
firm natural ground or compacted fill. This soil-bearing value may be increased
one third for design loads that include wind or seismic analysis. If imported
soils are required to bring the site to grade, the import soils shall be
nonexpansive and shall be obtained from an approved offsite borrow area.
5. Based on our laboratory test results and our experience with the soil types on
the subject site, the soils will experience settlement in the magnitude of less
than 0.5 inch under a structural load of 2500 pounds per square foot.
6. The active earth pressure (to be utilized in the design of walls, et cetera), shall
be based on the following formula and surrrnarized laboratory test results. This
xtive pressure is for level backfill.
w = unit weight of soil = 110 pounds per cubic foot,
h = depth of foundation or footing into ground (feet),
0 = angle of repose of soil (Angle of Internal Friction) = 35 degrees.
Pa(Maximum) = w (1 - *in 0) e2 , (1 + sin 0)
Heli-Hangar
30 October 1960
job No. 8O-1580
Page 8
we = w (1 - sin 0) .
(1 + sin 8)
Therefore,
P,(Maximum) WelJ
=2
we = (110) m = 30 pounds per cubic foot. + .
Thus, the active earth pressure (at any depth) shall be based on an Equivalent
Fluid Pressure of 3O pounds per cubic foot.
7. The passive earth pressure of the encountered natural-ground soils (to be used
for design of building foundations and footings to resist the lateral forces) is
based on the Kankine Formula and laboratorv test results as follow.:
Pp(Maximum) = l/2 wh2 (1 + sin 0)
(1 - sin 0)
% *
where,
P = ‘passive’ earth pressure (pounds per square foot),
w = unit weight of soil = 110 pounds per cubic foot,
h = depth of foundation or footing into ground (feet),
0 = angle of repose of soil (Angle of Internal Friction) = 35 degrees.
we = Equivalent Fluid Pressure = w (1 + sin 8) .
(1 - sin 0)
Heli-Hangar
w October 1980
Job No. 80-1580
Page 9
Therefore,
we = (110) 11 + O-57) = 402 pounds per cubic foot.
(1 - 0.57)
The passive earth pressure (at any depth) shall then be based on an Equivalent
Fluid Pressure of 402 pounds per cubic foot.
a. A Coefficient of Friction of 0.4 times the dead load may be used between the
bearing soils and concrete wall foundations or structure foundations and floor
slabs.
9. The compacted fill soils that occur within five (5) feet of the face of the fill
slopes will possess poor lateral stability, even though the/ have been corn-
pacted. Proposed structures and other improvements (such as walls, fences,
sidewalks, driveways, asphalt paving, et cetera), that are located within five (5)
feet of the face of compacted fill slopes, could suffer differential movement as a
result of the poor lateral stability of these soils.
10. Foundations and footings of proposed structures, walls, et cetera, when found-
ed five (5) feet and further away from the top of compacted fill slop-es, may be
of standard design in conformance with the recommended soil-bearing value. If
the proposed foundations and footings are located closer than five (5) feet
inside the top of compacted fill slopes, they shall be deepened to one (1) foot
below a line beginning at a point five (5) feet horizontally inside the fill stopes
and projected, outward and downward, parallel to the face of the fill slope (see
Figure No. V).
11. It is recommended that continuous footings be reinforced with at least one (1)
NO. 4 steel bar, extending a minimum distance of 15 feet to either side of day-
light areas. The steel reinforcement will help to prevent damage due to minor
differential settlement between the compacted fill soils and the more-dense,
natural-ground soils.
Heli-Hangar Job No. 80-1580
30 October 1980 Page 10
12.
13.
14.
15.
16.
17.
The proposed hangar building is located five (5) feet from the top of a cut
slope, constructed at a ratio of 0.5 horizontal to 1.0 vertical. The proposed
structure may be designed with a standard-type foundation at a distance of five
(5) feet and further from the top of the cut slope. Should plans be modified
and the proposed structure encroach closer than five (5) feet from the top of
cut slope, then our firm shall be contacted for special foundation recommenda-
tions.
It is recommended that all compacted fill slopes and natural cut slopes be
planted with an erosion-resistant plant, in conformance with the requirements
of the County of San Diego.
Planter areas and planter boxes shall be sloped to drain away from the founda-
tions, footings and floor slabs. Planter boxes shall be constructed with a sub-
surface drain, installed in gravel, with the direction of subsurface and surface
flow away from the foundations, footings and floor slabs, to an adequate drain-
age facility.
The existing debris and vegetation observed on the site must be removed prior
to the preparation of building pads and/or areas to receive structural improve-
ments.
Existing topsoils, which will not be removed during the future grading opera-
tion, shall be scarified (in place) to a depth of 12 inches, watered to optimum
requirements, and shall then be compacted to at least 9~ percent of Maximum
Dry Density.
Any septic tanks, subsurface disposal systems, wells, et cetera, which might be
discovered on the site, shall be removed and properly backfilled with approved
onsite or imported fill soils, and shall then be compacted to at least 90 percent
of Maximum Dry Density.
Heli-Hangar Job No. 80-1580
30 October 1980 Page 11
18.
19.
20.
Any backfill soils placed in utility trenches, or behind retaining walls, which
support structures and other improvements (such as patios, sidewalks, drive-
ways, pavements, et cetera), other than landscaping, shall be compacted to at
least 90 percent of Maximum Dry Density.
It is our opinion that natural-groun.d cut slopes and compacted fill slopes of
maximum inclinations of l.!Ghorizontal-to-l&-vertical shall be stable and free
from deep-seated failures for slopes not exceeding 15 feet in. height.
Adequate measures shall be taken to properly finish-grade the site after the
structures and other improvements are in place. Drainage waters from this site
and adjacent properties are to be directed away from foundations, floor slabs
and footings, onto the natural drainage direction for this area or into properly
designed and approved drainage facilities. Proper subsurface and surface drain-
age will ensure that no waters will seek the level of the bearing soils under the
foundations, footings and floor slabs. Failure to observe this recommendation
could result in uplift or undermining and differential settlement of the structure
or other imorovements on the site.
Ceotechnicai Exploration, Inc. will assume no liability for damage to structures
which is attributable to poor drainage.
GRADING NOTES
Any required grading operations shall be performed in accordance with the general re-
quirements of the County of San Diego Grading Ordinance, under the supervision of a
qualified soils engineer or supervised field soils technician.
It is the responsibility of the Owner and/or Developer to ensure that the recommenda-
tions summarized in this report are carried out in the field operations.
Heli-Hangar
30 October 1980
LIMITATIONS
Job No. 80-1580
Page 12
Our conclusions and recommendations have been based on all available data obtained
from our field investigation and laboratory analysis, as well as our experience with the
soils and formational materials located in this portion of San Diego County. Of
necessity, we must assume a certain degree of continuity between exploratory excava-
tions and/or natural exposures. It is, therefore, necessary that all observations,
conclusions and recommendations be verified at the time grading operations begin, or
when footing excavations are placed. In the event discrepancies are noted, we should
be notified immediately so that an inspection can be made and additional recommenda-
tions issued, if required.
This report should be considered valid for a period of three (3) years, and is subject to
review by our firm following that time. If significant modifications are made to the
building and/or grading plans, especially with respect to the height and location of cot
and fill slopes and the height and location of proposed structures, this report must be
presented to us for iwnediate review and possible revision.
The firm of Gotechnical Exploration, Inc. shall not be held responsible for changes to
the physical condition of the property, such as addition of fill soils or changing
drainage patterns, which occur subsequent to issuance of this report.
Once again, should any questions arise concerning this report, please do not hesitate
to contact US. Reference to our Job No. 80-1580 will expedite response to your
inquiries.
Respectfully submitted,
CEOTECFWICAL EXfWRATI@l, INC.
a Monte, K.C.E. 25241
RJS/CWL:med
Enclosures
cc: Addressee (5)
Log of Test Trenches
.I
i
.
Soil Dercrlption
(Unlfled Soil Classlflcatlon)
Trench No. 1 . . : , Looser medium dense, damp, brown, fine . . sand : (SP)
-a Medium dense, damp,,mottled brown and tan, silty 116 11.1 t6.0
: clayey sand. (SC) .
. & Medium dense to dense, damp, mottled, light brown 105* 6.0k 88 '
-.@
and gray-brown, fine sand.
120 a.7
(SP)
. . . .
Trench No. 2
. . .
_ ' _; ! ,I. Poor to moderately compacted, dry, dark brown and
. brown, fine to medium sand and silty fine sand.
I!‘, !I FILL
: : Medium dense, dry, dark bro&, fine to medium sand
- :.. TOPSOIL
\. >'
-;p: Medium dense to dense, damp, dark brown, silty 118 10.1 +5.5
clayey fine sand.
\ ..' TOPSOIL
1 Bag Sample ‘In-Place Density
1 Undisturbed Sample “In-Place Moisture
JobNo. 80-1580
Figure No. I Ia
Log of Test Trenches
Soil Description
(Unilied Soil Classllicallon)
7 : . . I _I ! ! I’
:o;:, ‘,i I_ .’
k
1.1, .;‘p .\ _, \ : . . : . .
'rench No. 3
Moderately compacted, damp, mixed tan, brown and
dark brown silty clayey sands and fine to medium
sands.
FILL (SC-SP)
Medium~dense, damp, dark brown, silty clayey
fine to medium sand.
TOPSOIL (SC)
Medium dense, damp, gray-brown, fine sand.
FORMATION (SP)
-
106s
104*
) Bag Sample
I
‘In-Place Density
1 Undisturbed Sample “In-Place Moisture
Job No. 80-1580
Figure No. IIb
Log of Test Trenches
Soil Description
(Unified Soil Classllicatlon)
Trw& Nn 4 . -...
I _ . . . . . . It It .I > - - 1.1’. .
. . Moderately compacted, damp, intermixed, dark brown,
tan, green-gray, fine to medium sands, silty sands, ,24
fine sand, some asphalt and concrete debris. 7 8
107* 5:1* 86 .
j.. .' I.1
i . ' 1.1' FILL
I . _: .
3 .;;i
II.
a-: I..
. .
ID .:
il..'..,
. .
1 Bag Sample 'In-Place Density
3 Undisturbed Sample “In-Place Moisture
1
Job No. 80-1580
Figure No. 11~
Log of Test Trenches
. .
Soil Description
(Unified Soil Classification)
Trench No. 5
.,'I (
I' .
JI. . 11:. Poor to moderately compacted, damp, tan, silty
sand and fine sand.
3 m-d., FILL lOO* 6.0* 83
.',I.(!(
I--.
.
j
d Poor to moderately compacted, damp, green-brown,
j- '. fine to medium sand, little asphalt debris.
b . 7' . .
3.' .t'
3. 0. 7
J
9 Bag Sample
3
‘In-Place Density
Undisturbed Sample “In-Place Moisture
4
Job No. 8O-J58D
Figure No. IId
140
I30
I20
IO
00
¶O
so
FILL SUITABILITY TESTS
DIRECT YEAR TEST DATA I 2 3
APPARENT COHESION (pafl 1300 I
APPARENT FRICTION ANGLE I 35 1
MECHANICAL ANALYSIS
I I I I I I I 0’ I I II
1000 100 IO 1.0 0.1 0.01 0.001 GRPIN SIZE IN MILLIMETERS - L OGEi 3 -
SIL .T l CL - - -
MAXIMUM DRY ,2.70
DENSITY (pcf) 117 120 SPECIFIC GRAVITY
OPTIMUM MOISTURE
CONTENT (%) 11.1 8.7
=?l!3i 7.8 124 2.60 2.50
I!/! I
I I I I I I t TX
MOISTURE CONTENT %
~~_ dZE.50 AIR VOIDS CURVES
0 10 20 30 40
._~ ___._ _- ..-.- LABOKATOKY COMI’AC I IUN I t5 -.-.. V_^ T
SOIL TYPE SOIL CLASSIFICATION ““,‘;y ‘“,‘;.c” DEPTH
1~ Tan, clayey sand 1 2'
2 Brown, fine sand 1 5'
3 Brown, fine to medium sand 4 3.5'
.AY 7
JOB NO: 80-1580
FIGURE NO III
Proposed Structure
Concrete
/
Floor Slab
\ / Top of Compacted Fill Slope a i k, 7 0; _ 1 ')1
(J!einforcoment of Foundations and
Slabs following the Ret-
omandations of the Architect
or
Compacted Fill Slope
(Maximum Inclination 1.5:l.O)
mpacted Fill
-. Conkrete Foundat - 5~ 7 -~ -- - 1. L%5'1=4 -- - -
TYPICAL SXCTION
(Showing Proposed Foundation Located Within Five Feet of Top of Ccmpacted Fill Slcpe)
TOTAL DEPTH OF FOOTING
PISTANCiX FRO)!
TOP OF SLOPE
-
0
1’
2' -
3’ -
L.*
i
1.5 : 1.0 Fill Slops
52 "
IA"
36”
28"
20"
2.0 : 1.0 Fill Slops
l&2"
36"
30”
2L"
18"
Job No. go-1580
Figure No.1~
APPENDIX A
UNIFIED SOIL CLASSIFICATION CHART
SOIL DESCRIPTION
COARSE-GRAINED
More Ihan half of material Is larger than a No. 200 sieve
GRAVELS. CLEAN GRAVELS
More lhan half of coarse fraction is larger than GW Well-graded gravels. gravel and sand mix-
No. 4 sieve size, but smaller than 3” tures. little or no fines.
GP Poorly graded gravels, gravel and sand mix-
tures. little or no fines.
GRAVELS WITH FINES
(appreciable amount)
GM Silty gravels. poorly graded gravel-sand-silt
mixtures.
GC Clay gravels, poorly graded gravel-sand-silt
mixtures.
SANDS, CLEAN SANDS SW Well-graded sand, gravelly sands. little or no
More than half of coarse fraction is smaller than a no fines.
No. 4 sieve. SP Poorly graded sands, gravelly sands, little or
no fines.
SANDS WITH FINES
(appreciable amount)
SM Silty sands, poorly graded sand and silty
mixtures.
SC Clayey sands, poorly graded sand and clay
mixtures.
FINE-GRAINED
More than half of malerlal is smeller than a No. 200 sieve
SILTS AND CLAYS ML Inorganic silts and very fine sands, rock flour.
sandy silt and clayey-silt sand mixtures with
a slight plasticity.
Liquid Limit Less Than 50 CL Inorganic clays of low to medium plasticity,
gravelly clays, sandy clays, silty clays. clean
clays.
OL Organic silts and organic silty clays of low
plasticity.
MH Inorganic silts, micaceous or diatomaceous
fine sandy or silty soils. elastic silts.
Liquid.Limit Greater Than 50
HIGHLY ORGANIC SOILS
CH Inorganic clays of high plasticity, fat clays.
OH Organic clays of medium to high plasticity.
PT Peat and other highly organic soils.
APPENDIX B
GRADING SPECIFICATIONS
General
The intent of this item is to properly establish procedures for: cleaning and compacting natural ground. pre-
parlng areas to be filled, and placing and compacting fill material to the grades and slopes as shown on the
Gradmg Plans
Clearing
All vegetation, brush and debris shall be removed, piled and burned. orotherwisedisposed of. to give the sur-
lace a neat and finished appearance.
Compacting Natural Ground
After clearing, the natural ground shall be scarified to a depth of at least 12 inches. watered to optimum
reqturements and compacted to not less than 90 percent of maximum dry density. according to A.S.T.M. Test
Method D-1557. in a four-inch diameter, cylindrical mold of 1/3Oth-cubic-foot volume. Field density tests shall
be taken in the natural ground in accordance with A.S.T.M. Test Method D-1556.
Fill Materials
Materials for the fill shall be approved by the soils engineer and shall be free from organic matter and other
deleterious substances. In the event that expanswe materials are encountered within three feet of finished
grade, they shall either be entirely removed or thoroughly mixed with good, granular mate&l before ihcorpo-
ratmg them m fills No footing shall be allowed to bear on soils which, in the opmion of the soils engmeer. are
“. + detrlmentally expansive--unless deslgned for this clayey condition
Placing and Compacting Fill Material
After preparing the areas to be filled, the fill materials shall be placed in layers not to exceed six mches m a compacted thickness~ Each layer shall be watered to optimum requirements and compacted to not lessthan 90
percent of maximum dry density in accordance with A.S.T.M. Test Method D-1557. Compaction of the fill shall
then proceed in the specified manner to the grades as shown on the approved plans.
When the slope ratio of the original ground is steeper than five-horizontal-to-one-vertical, the onginal
ground shall be benched. Ground slopes flatter than five-horizontal-to-one-vertical shall be benched when
considered necessary by the soils engineer. Fill slopes shall be compacted by means of a sheepsfoot roller, or
other sultable equipment. Slope compaction shall be continued until the slopes are stable but not too dense for
planrIng.
Field density tests shall be taken when considered necessary by the soils engineer in accordance wth
A.S.T.M. Test Method D-1556 and shall be made not exceeding two feet in vertical height providing each layer is
tested.
Supervision
Continuous supervwon of the 1111 shall be made by the representatwe of Geofechnical Explorafion. Inc..
during the gradmg operalIon so that he can certrfy that the fill was placed m accordance with these
speclflctlons~
Season Limits
No fill material shall be placed, spread or rolled during unfavorable weather conditions. When the work IS
Interrupted by heavy rains. the filling operation shall not be resumed until field tests lndlcate that the moisture
conlenl and density of the fill are as prewously speclfled~