HomeMy WebLinkAboutCT 73-24; Carlsbad Lake Community; Soils Report; 1973-07-30SOIL INYESTIGATION FOR THE PROPOSED . .. ( CARLSBAD LAKE COMMUNUYA
c
CARLSBAD, CALVORNN
for
2452 'E. Orangethorpe Covington Brothers
Fullerton, California 92634
WOODWARD-GIZIENSKI & ASSOCIATES Consulting Soil and Foundation Engineers and Geologist ..
(An Affiliate of Woodward-Clyde Consultants)
51010.15.22
TABLE OF CONTENTS
PAGE
TRANSMITTAL LETTER
SCOPE
-
.- FIELD INVESTIGATION
LABORATORY TESTS
SITE AND SOIL CONDITIONS
CONCLUSIONS AND RECOMMENDATIONS
LIMITATIONS
-
-
- FIGURE 1 - SITE PLAN
FIGURE 2 - LOG OF TEST BORING 1 - FIGURE 3 - LOG OF TEST BORING 2
FIGURE 4 - LOG OF TEST BORING 3
FIGURE 5 - LOGS OF TEST BORINGS 4 & 5
FIGURE 6 - LOG OF TEST BORING 6
FIGURE 7 - LOG OF TEST BORING 7
FIGURE 8 - LOGS OF TEST BORINGS 8 & 9
FIGURE 9 - LOGS OF TEST BORINGS 10 & 11
FIGURE 10,- LOGS OF TEST BORINGS 12 & 13
FIGURE 11 - LOG OF CUT SLOPE
FIGURE 12 - GRAIN SIZE DISTRIBUTION CURVES
FIGURE 13 - RESULTS OF CONFINED COMPRESSION TESTS
FIGURE 14 - FILL SUITABILITY TESTS
ATTACHMENT I - SPECIFICATIONS FOR CONTROLLED FILL
ATTACHMENT I1 - FILL SLOPES: STABILITY ANALYSIS
ATTACHMENT 111 - CUT SLOPE: STABILITY ANALYSIS
CONSULTING SOIL AND FOUNDATION ENGINEERS AND GEOLOGISTS
An uffiliote of Woodttiard - Clyde Corwultants
3467 Kultz Street
- California 92110
San Diego July 30, 1973
(714) 224-2911 Project No. 73-222
- Covington Brothers 2451 E. Orangethorpe
- Ful lerton, California 92634
. Attention: Mr. Mike Ryan
In accordance with your Purchase Order Number 15290 and our proposal dated June 4, 1973, we have conducted an investigation of the underlying soil conditions at the site of the proposed Carlsbad Lake Community subdivision in Carlsbad, California.
Results of our studies indicate that the site is suitable for the proposed construction. There are however, existing fills, porous soils, and cultivated soils existing on the site that will require special treatment during grading.
The accompanying report presents our conclusions and recomnendations, as well as the results of the subsurface exploration and the laboratory tests upon which these recomnendations are based.
The engineer assigned to this project'was Joseph G. Kocherhans of our firm.
WOODWARD-GIZIENSKI & ASSOCIATES
SFG/JGK/ls
(6)
- Project No. 73-222
- SCOPE
This report describes an investigation of the underlying soil and -
geological conditions at the site of the proposed Carlsbad Lake Community to
- be located east of Interstate 5 and south of Poinsettia Lane, in Carlsbad,
California. The purpose of the investigation is to determine the general
geology and subsurface conditions, including the presence and effect of
existing fills, loose or porous soils, and potentially expansive soils; the
embankment shrinkage factor; the relative stability of cut and fill slopes;
the availability of select fill materia1s;'recommendations regarding allowable
bearing pressures for design of foundations in natural undisturbed soil and
in compacted fill; the most suitable type and required depth of foundations.
for use at the site; and, the depth to water, if significant.
It is our understanding the development will consist of approximately
- 300 one to two-story wood-frame condominiums utilizing concrete slab-on-grade
construction. We also understand that a shallow lake will be excavated at
the central portion of the site. It is our further understanding that grading
will be performed in general, in accordance with the Tentative Tract 73-24
plan dated May 1973, prepared by Lawrence R. Williams, Tustin, California,
Consulting Civil Engineer.
FIELD INVESTIGATION
Thirteen test borings were made by a truck mounted, continuous
flight, 6-in. diameter power auger and one existing cut slope was logged at
the approximate locations shown on the Site Plan, Fig. 1. Field and sub-
surface exploration was done on July 5 and 7, 1973, under the supervision of
a staff engineer from our firm. Field logs were prepared by the engineer on
the basis of an inspection of the samples secured, the materials excavated,
and the soils exposed in the existing cut bank along Poinsettia Lane.
~- Project No. 73-222 Page 2
-.
~ The Logs of the Test Borings are shown on Figs. 2 through 10 and are
" based on an inspection of the samples taken, the laboratory test results
and field logs. Test Boring locations were plotted in the field on a Site
.- Plan entitled "Tentative Tract 73-24 Carlsbad Lake Community" dated May 1973,
and prepared by Lawrence R. Williams of Tustin, California.
LABORATORY TESTS
-
- The soils encountered were visually classified and evaluated with
respecto to strength, swelling and compressibility characteristics, dry
- density and moisture content. These classifications were substantiated by
moisture content and dry density, plasticity, grain size analysis, direct
shear and confined compression tests on representive samples of the soils.
Results of the moisture content, dry density, plasticity and direct shear
tests are shown at the corresponding sample location on the Log of Test
Borings. Results of the grain size analyses and confined compression tests
are shown on Figs. 12 and 13, respectively.
Fill suitability tests, including compaction, grain size analysis,
and direct shear tests have been performed on the probable fi 11 soils.
Results of the fill suitability tests were utilized to arrive at the conclusions
and recommendations contained herein and are presented on Fig. 14.
SITE AND SOIL CONDITIONS
The site is located south and east of the intersection of Interstate 5
and Poinsettia Lane and west of Bataquitos Lane in Carlsbad, California. The
site consists of a relatively flat north-south trending ancient "beach ridge"
sloping gently to the west with changes in elevation from approximately 150 ft
in the east down to approximately 110 ft near 1-5. A relatively steep
(approximately 2 to 1, horizontal to vertical) somewhat eroded slope exists
near the eastern boundary. The Tentative Tract Plan indicates that construction
WOODWARD GlZlENSKl & ASSOCIATES
oDIY11.lo mn UD -nm U" -0 OIOLOOI."
Project No. 73-222 Page 3
will be limited to the gently sloping western portion of the site. At the
time of our investigation the major portion of the site was under cultivation.
A row of large eucalyptus trees trending north-south exists in the north-
western portion of the site.
Results of the test borings made at the site indicate the presence
of the following materials which are described in their general order of
occurrence with depth and increasing geological age.
- Fill. Damp to moist, brown silty sand with a trace of clay.
The fill was encountered in the west-central portion of the site
in Boring 7 extending to a depth of 13 ft. Piles of loose fill
have been placed along the top of the ridge near the eastern
boundary of the site. Some rubble and organic materials were
observed in the scattered piles of fill in this area.
Topsoil. Loose to medium dense, generally porous, damp to
moist, dark brown silty sand. This material was encountered in
borings located .in the western portion of the site, Borings 1, 2, and
8 to 13, ranges from one to six ft in thickness. These topsoils
exhibit low potential expansibility characteristics.
Terrace Materials. Medium to very dense, damp, red brown to
grey brown silty to clayey sands. These materials were encountered
in all borings and extend to the depths explored, a maximum of 30 ft.
They comprise the basic formational soil at the site, and relatively
competent foundation material and exhibit a low potential for
expansion when wetted.
Below the fill found in Boring 7 about 4 ft of porous clayey sand
"old topsoil" was encountered.
No hard rock or ground water was encountered in the test borings
at the time of excavation.
Project No. 73-222 Page 4
CONCLUSIONS AND RECOMMENDATIONS
(1) It is our opinion no major soil conditions exist at the site
which would preclude the development of the proposed one to two-story
condominiums. The presence of existing fills, old porous topsoil, and loose
piles of trashy fill will require special treatment during grading.
(2) The ground which will receive fill and/or one and two-story
condominiums will have an adequate bearing value to safely support the
proposed loads when treated as described in the following paragraphs and
in the attached "Specifications for Controlled Fill". Footings for
residential structures placed on nonexpansive, non-porous native soils or
properly compacted nonexpansive fill soils may be designed for a soil
bearing pressure of 2000 psf (total dead plus live load) at a depth of 12
inches below rough lot grade. Footings should have a minimum width of
12 inches. The above soil bearing pressure may be increased by one-third
for loads that include wind or seismic forces.
(3) Cut and fill slopes having an inclination of 2:l (horizontal
to vertical) and maximum unsupported heights of less than 25 feet will in
our opinion have adequate safety factors against deep seated slope failures
if constructed in accordance with the plans and the attached "Specifications
for Controlled Fill". Typical stability calculations for cut and fill
slopes are attached for your information to support our conclusions.
(4) Results of our field investigation indicate that soils
expected to be used in fills are basically nonexpansive. Though no potential
expansive soils were encountered, it has been our experience, that thin
(1 to 2-ft) residual clayey soils could be encountered between the topsoils
and formational soils in localized areas. Should any potentially expansive
soils be encountered they should be excavated and spread and compacted in
Project No. 73-222 Page 5
fills below a depth of 2 ft below rough lot grade, Potentially expansive
soils, if encountered within 2 ft of finish grade in cut areas should
be undercut and be replaced with properly compacted nonexpansive soils
avai lab1 e on the site.
(5) Results of our field exploration indicate that all materials
encountered can be excavated with normal heavy grading equipment. No
extensive cemented zones nor hard rock are expected.
(6) In order to express a meaningful estimate of the embankment
’ shrinkage-swell factor, the results of laboratory compaction tests need
to be compared to the density in the natural state in borrow. We wish
to emphasize that variations in soil density in the natural state, as well
as in the fill, make calculated values of shrinkage at best very approximate.
A major factor is that relatively few tests are made of on-site materials
as compared to the mass of material moved during grading plus the insuffi-
cient knowledge regarding the actual densities in excess of minimum require-
ments to which the contractor will compact the fill. Based on the 1 imited
work done to date and considering the above factors the following shrinkage
values for preliminary estimating may be used: Topsoil, approximately
8% 2 2%; the underlying formational soils approximately - 2%; existing
loose fills, 10 to 20%.
+
(7) Our experience with soils similar to those encountered
on the site indicates that they could have relatively high permeability
rates. Therefore the water loss through seepage of the proposed lakes
could be high, could cause marshy areas at lower elevations, or could show
as slope seepage. It is therefore recomended that adequate steps be taken
to seal the lake areas or to intercept the seepage so that no harmful
effects result.
Project No. 73-222 Page 6
(8) Soils similar to those encountered on this site are subject
to extreme erosion by uncontrolled action of water. Therefore, it is
recomended that all cut and fill slopes be planted and be provided with
adequate surface drainage in accordance with the City of Carlsbad standards.
(9) It is recomended that loose and/or porous soils as well as
existing fill soils that are not removed by grading operations be excavated
or scarified, as required, replaced and compacted before fill or structures
are constructed. In general the loose and/or porous surface soils average
approximately 3 ft in thickness where encountered. The maximum thickness of
existing fill encountered was approximately 13 ft at Boring 7. Since the fill
soils on the site have the same general appearance as. the formational soils
and the area is used for plant growth, it is difficult to define exact limits
of existing fills for this report. The former erosional patterns are not
known by us, nor is the extent of filling to make grade for the present
farming operation. Because of these factors it is recommended that several
inspection pits be made with grading equipment at the time of grading in
proposed fill areas to ascertain the extent of existing fills.
(10) It is recommended that all existing potentially compressible
soils be excavated, as ,required, and compacted prior to placing fill soils
or structures. This reconmendation includes the area of porous old topsoil
in the vicinity of Boring 7. The excavation is expected to extend to
approximately 16 ft in depth (the depth to the base of the porous soils in
Boring 7). Since there has been some filling on the site in the past, the
actual extent of porous soils that will require treatment should be controlled
in the field by the soil engineer during grading upon visual examination of
the exposed soil.
Project No. 73-222 Page 7
-
(11) It is recommended that all grading operations be observed
- and compacted fills tested by Woodward-Gizienski & Associates. Organic
material and debris should not be permitted in compacted fill. A set of
"Specifications for Controlled Fill" is attached. The recomendations -
made as a part of this report shall become a part of the "Specifications
for Controlled Fill".
LIMITATIONS
The conclusions and recommendations made in this report are
based on the assumption that the soil and geological conditions do not
deviate appreciably from those disclosed by the test borings. If
variations are encountered during construction, we should be notified so
that we may make supplemental recommendations, if this should be required.
Evaluation and utilization of soil materials and geological
formations for support of structures includes investigation of the subsurface
conditions, analysis, formulation of recommendations, and inspection during
grading. The soil investigation is not completed until the soil engineer
has been able to examine the soil in excavations or cut slopes so that he
can make the necessary modifications, if needed. We emphasize the im-
portance of the soil engineer continuing his services through the inspection
of grading, including construction of fills, and foundation excavations.
Boring I
DD = 112 Medium dense to dense, danp, bravl
Medium dense to dense, damp, red- DD = 120 BC = 32 brown clayey sand (SC)
BC= 40
Bc=
E=
.
Very dense, danp, red-brow si1 ty
For Legend, see Fig. 3 LOG OF TEST BORING I
CARLSBAD LAKE COMMUNITY
WSULTIIIG SOIL S AND GEDLOGISTS
I
Boring 2
LEGEND
WC = Water Content in percent of dry weight.
DD = Dry Density in pcfo
BC = Number of blows by 140-1 b. hammer falling
30 inches to drive sampler 12 incheso
DS = Direct Shear Test Data: 6 = Angle of Apparent Friction in degrees.
C = Apparent Cohesion in psf.
(SH) = Group classification symbol in accordance with the
Unified Soil Classification System.
0
5
4 m
LL Q)
m
I
0
Y-
cn
L
'0
a 0 L a
3 0
Q) m
10
m
a
c 15
-
r 20 e
m n
a
25
30
Boring 3
For Legend, see Fig. 3 I LOG OF TEST BORING 3
CARLSBAD LAKE CCMMUNITY
WSULTIWG SOIL WD FOUWOATION EllGlllEERS AND GEOLOGISTS WXlDWARD - GIZIENSKI & ASSOCIATES
SUI Dl EO, CALI FORIIIA
DR. BY: GS I APPROX. SCALE: 1" 5' I m& NO: 73-222
CK'D 8Y:)th I DATE: 7/19/73 F[GlI& NO: I)
0
IO
15 I
0
15
Boring 4
Boring 5
Dense, damp, red-brm clayey sand
BC = 7.4
S1 ightly Porous
DS: = 29
BC =
BC =
e, damp, red-brm clayey sand _- S1 ightly Porous
WC= 6 2 ; .., DD = 117 -::
For Legend, see Fig. 3 I LOGS OF TEST BORINGS 4 & 5
CARLSBAD LAKE COMMUNITY
Boring 6
0
5
IO
13
For Legend, see Fig. 3 I LOG OF TEST BORING 6
CARLSBAO LAKE COMMUNITY
CollSULTlNG SOIL S AND GEOLOGISTS
0
5
IO
15
20
DD = 114 BC= 14
DD = 106 BC = 12
DD = 112 BC= 37
.: ...
DD = IIU BC= 29
,. ..
Be = 26 ..
For Legend, see Fig. 3
Boring 7
Damp, dark brown silty sand Fill
hp, red-brom silty sand Fill
Damp to mist, yellow-brm to red-brm silty fine sand
Fill
Medium dznse, damp, red-brown clayey
sand (SC) brous (Appears to be topsoil)
Medium dense, damp to mist, gray-
brown si 1 ty sand (34)
LOG OF TEST BORING 7
CARLSBAD LAKE COMMUNITY
0
5
IO
15
18
0-
5-
' IO -
15 -
Boring 8
Loose, damp, dark brow silty sand (SM)
Boring 9
Loose, moist, dark brm silty sand
urn dense, damp to moist, yellow- to red-brm clayey sand (SC)
LOGS OF TEST BORINGS 8 & 9
CARLSBAD LAKE COMJN ITY
I eOllSULTIWG SOIL WD FOUNDATION ENGINEERS AND GE0U)GISTS WXlDWARD - GIZIENSKI b ASSOCIATES
0
5
IO
15
0
5
IO
13
Boring IO
Medium dense, damp, 1 ight brcm silty
fine sand (a)
: kdium dense,tovery dense, danp,
red-brown clayey sand (SC)
Dense, damp, gray-brown si 1 ty sand
Bc= 37
Boring II
For Legend, see Fig. 3 LOGS OF TEST WRINGS 10 h I I
0
IO
i3 j
0
5
IO
15
Boring 12
, light brcwn silty
wc =
E... .. ..A kd i urn dense, damp, brown to red-
Boring 13
~=
Bc=
wc = DD = BC =
dim dense, damp, red-brm clayey
1 ' '1 sand (34) Very dense, damp, red-brown si Ity
BC= 70
For Legend, see Fig. 3 I LOGS OF TEST BORINGS 12 b 13
CARLSBAD LAKE COMMUNITY
Cut Slope I4
For Legend, see Fig. 3 LOG OF CUT SLOPE
CONSULTING SOIL &ID FOUNDATION ENGINEERS AND GEOLOGISTS
COBBLES GRAVEL I SAND
Coarse I Fine Ikrd Medium I Fine SILT and CLAY
Mesh Opening - ins. Sieve Sizes Hvdruneter Analysis I I I 1
0
IO
20
30
n w
4
p:
$-
0 p:
Wf
L
50E
k!
60
70
80
90
loo 50 10.0 5.0 I .o 0.1 405 0.01 0.005 awl 100
GRAIN SIZE IN MILLIMETERS
SAMPLE CLASSIFICATION AND SWL *LL *PI
. 3-2 Clavev sand fSCl - -
3-4 Silty sand (SH) - -
3- 6 Silty sand ISM) - -
4- I Clayey sand (SC) - -
*LL = Liquid Limit GRAIN SIZE DISTRIBUTION CURVES
*PI = Plasticity Index CARLSBAD LAKE COMMUNITY
WOODWARD - GIZIENSKI & ASSOCIATES
CONSULTING SOIL AND FOUNDATION ENGINEERS AND GEOLOGISTS SAN DIEGO. CALIFORNIA
OR. BY: GS IAPPROX. SCALE: - - - - IPROJ. NO: 73-222
CK'D BY: WIDATE: 7/23/73 IFIGURE NO: 12-
RESULTS OF CONFINED COMPRESSION TESTS
Initial
II 65
Final
:later
mtent
-
- - %
15
IU
I 3turation Pressure
PRESSURE - psf
* E of Initial kig
U.8
3.3
RESULTS OF COHF I NED COI4PRESS I ON TESTS
CARLSBAD LAKE CCMMUNITY I WOOCWARD - GlZlENSKl & ASSOCIATES
CONSULTING SOIL AND FOUNDATION ENGINEERS AND GEOLOGISTS SAM DIEGO. CALIFORNIA
DR. BY: GS I APPROX. SCALE: - - - -1 PROJ. NO: 73-222
CK'D W:m 1 DATE: 7/23/73 1 FIGURE NO: 13
IUO
I30
I 20
I IO
100
90
80
DIRECT SHEAR TEST DATA I 2 3
Dry Density, pcf 118 116
Initial Water Content. % 9 8
Final Water Content. % 13 15
Apparent Cohesion. psf 600 360
Apparent Friction Angle. 26 18
I00
0
v)
80
2 60
f
b
"ICAL AnALYSlS
3 t 410 w 200 3 t 410 w 200
Iwo I00 10 1.0 0.1 0.01 0.001
GRAIN SIZE IN MILLIMETERS
PLASTlClM CHARACTERISTICS I1 121 3
Liquid Limit, % - 22
Plasticity Index. % - 7 I
Classification by Unified Soil
Classificatim System SM SC I
I %ELL TEST DATA I _I 2 3
2.60 SPECIFIC GRAVITY
ZERO AIR VOIDS CURVES
NOTE: Specimen I = I - 3
Specinm 2 = 3 - 3
Specimen 3 =
IO 20 w
Initial Dry Density. pcf
~.
v -
Initial Water Content, % - -
Load. osf - -
LABORATORY WACTIOW EST
FILL SUITABILITY TESTS
LABORATORY WACTION
TEST METHOD: PSM 0-1 557-70T CARLSEAD LAKE COMMUNITY
WOODWARD - GIZIENSKI h ASSOCIATES
WSULTING SOIL ARD FWNDATIOH ENGINEERS AND GEOLOGISTS SIN DIEGO, CALIFORNIA O(L. ex: GS IAEPROX. SCALE: - - - - I PROJ. NO: 73-77')
CI'D BY:,MDATE: 7/23/73 I FIGURE NO: 1'4 .. 1
Project NO. 73-222 ATTACHMENT I Page 1 of 4
" .II.
- 111.
SPECIFICATIONS FOR CONTROLLED FILL
GENERAL
These specifications cover preparation of existing surfaces to receive fills; the type of soil suitable for use in fills; the control of com- paction and the methods of testing compacted fills. It shall be the Contractor's responsibility to place, spread, water and compact the fill in strict accordance with these specifications. A Soil Engineer shall be the Owner's representative to inspect the construction of fills. Exca- vation and the placing of fill shall be under the direct inspection of the Soil Engineer and he shall give written notice of conformance with the specifications upon completion of grading. Deviations from these specifications will be permitted only upon written authorization fron the Soil Engineer. A soil investigation has been made for this project; any recommendations made in the report of the soil investigation or subsequent reports shall become an addendum to these specifications.
SCOPE
The placement of controlled fill by the Contractor shall include all clearing and grubbing, removal of existing unsatisfactory material,
fill in the areas to be filled, and all other work necessary to complete preparation of the areas to be filled, spreading and compaction.of
the grading of the filled areas.
MATERIALS
1. Materials for compacted fill shall consist of any material imported or excavated from the cut areas that, i.n the opinion of the Soil Engineer, is suitable for use in constructing fills. The material shall contain no rocks or hard lumps greater than 6 inches in size and shall contain at least 40% of material smaller than 1/4 inch in size. No material of a' perishable, spongy, or otherwise improper nature shall be used in filling.
2. Material placed within 24 inches of rough lot grade shall be select material that contains no rocks or hard lumps greater than 6 inches in size and that swells less than 3% when compacted as hereinafter specified for compacted fill and when subjected to an axial pressure of 160 psf.
3. Representative samples of material to be used for fill shall be tested in the laboratory by the Soil Engineer in order to determine the maximum density;optimum moisture content and classification of the soil. In addition, the Soil Engineer shall determine the approximate bearing value of a recom- pacted, saturated sample by direct shear tests or other tests applicable to the particular soil.
4. During grading operations, soil types other than those analyzed in the report of the soil investigation may be encountered by the Contractor. The Soil Engineer shall be consulted to determine the suitability of these soils.
". . ..
" WOODWARD - GlZlENSWl 6 ASSOCIATES -- W M MU"IIO* uucrp UO UMOOISIl
Project No. 13-222 ATTACHMENT I Page 2 of 4
COMPACTED FILLS
1. General
(a) Unless otherwise specified, fill material shall be compacted by the Contractor while at a moisture content near the optimum moisture content and to a density that is not less than 90% of
01557-70T, or other density methods that will obtain equivalent the maximum density determined in accordance with ASTM Test No.
resul ts.
(b) Potentially expansive soils may be used in fills below a depth of 24 inches and shall be compacted at a moisture content greater than the optimum moisture content for the material.
2. Clearing and Preparing Areas to be Filled
be collected, piled and burned or otherwise disposed of by the Con- (a) All trees, brush, grass and other objectionable material shall
tractor so as to leave the areas that have been cleared with .a neat finished appearance free from unsightly debris.
(b) All vegetable matter and objectionable material shall be removed by the Contractor from the surface upon’which the fill is to be placed and any loose and porous soils shall be removed or compacted to the depth shown on the plans. The surface shall then be plowed or scarified to a minimum depth of 6 inches until the surface is free from uneven features that would tend to prevent uniform compaction by the equipment to be used.
(c) Where fills are constructed on hillsides or slopes, the slope of the original ground on which the fill is to be placed shall be stepped: or keyed by the Contractor as shown on the attached figure. The steps shall extend completely through the soil mantle and into the underlying formation materials.
scarified, it shall be disced or bladed by the Contractor until it is (d) After the foundation for the fill has been cleared, plowed or
uniform and free from clods, brought to the proper moisture content and compacted as specified for fill.
3. Placing, Spreadinq, and Compaction Fill Material
(a) The fill material shall be placed by the Contractor in layers that when compacted shall not exceed 6 inches. Each layer shall be spread evenly and shall be thoroughly mixed during the spreading to obtain uniformity of material in each layer.
(b) When the moisture content of the fill material is above that . specified by the Soil Engineer, the fill material shallbeerated by the Contractor by blading, mixing or other satisfactory methods until the moisture content is as specified.
-. .
Project No. 73-222. ATTACHMENT I Page 3 of 4
specified by tilc Scil Engineer, water shall be added by the Con- (c) When ;\- moisture content of the fill material is & that
tractor until the moisturp content is as specified.
(d) After each layer has been ;lzced, mixed and spread evenly, it shall be thoroughli. compacted by L4p Contractor to the specified density. Compaction shall be accomplisnc+ hy sheepsfoot rollers, vibratory roller, multiple-wheel pneumatic-i:rnd rollers or other
design that it will be able to compact the fill to the specified density. types of acceptable compacting equipment. Equipmen: shall be of such
Compaction shall be continuous over the entire area and the equipment
obtained throughout the entire fill. shall make sufficient trips to insure that the desired density has been
(e). Surface of fill slopes shall be compacted and there shall be no loose soil on the slopes. -
V. INSPECTION
- 1. Observations and compaction tests shall be made by 'the Soil Engineer
during the filling and compaction operations so that he can state his opinion that the fill was constructed in accordance with the specifications. - '2. The Soil Engineer shall make field density tests in accordance with ASTM Test No. D-1556-70.. Density tests shall be made in the compacted materials below the surface where the surface is disturbed. When these tests indicate that the density of any layer of fill or portion thereof is below the specified density, the particular layer or portions shall be reworked until the specified density has been obtained.
-
-
VI. PROTECTION OF WORK
1. During construction the contractor shall properly grade all excavated surfaces to provide positive drainage and prevent ponding of water.
or to finished work on the site. The Contractor shall take remedial .
He shall control surface water to avoid damage to adjoining properties.
measures to prevent erosion of freshly graded areas and until such time as permanent drainage and erosion con,trol measures have been installed.
2. After completion of grading and the Soil Engineer has finished his observations of the work, no further excavation or filling shall be done except under the observation of the Soil Engineer.
c
Project NO. 73-222 ATTACHMENT I
Page 4 of 4
cm sr mo mu mm
D
c c
U m
r I
Project N3. 73-222 ATTACHMENT r I
FILL SLOPES: STABILITY ANALYSIS
Assumptions :
(I) Maximum height of slopes, H =I 25 feet 2 :1 (3) Unit weight of soil,
(4) Apparent angle of internal friction, + = 26O y = 118 pcf
(5) Apparent cohesion, c = 600 psf
. (2) Maximum slope inciination,
~ (6) No seepage forces.
Reference:
~- (1) Janbu, N., "Stability Analysis of 'Slopes with Dimensionless Parameters", Harvard Soil Mechanics Series No. 46, 1954.
Analysis:
Safety Factor, F.S. = Ncf yH - C Where Ncf is the stability No.
for slopes with both c and 4.
~~ y H tan 4 - 118 X 25 X 0.487 = lcf = C 600 2.4 -
From Figure 3-1 of Reference: Ncf = 14 -
F.S. = 14 x 600 l"Z% = 2.85
OK for seismic
Project No. 73-222 ATTACHMENT I I I
CUT SLOPE: STABILITY ANALYSIS
. Assumptions :
- (1) Maximum height of slopes, H =. 25 feet
(2) Maximum slope inclination, 2 :1-
~ (3) Unit weight of soil, y .=113 pcf
(4) Apparent angle of internal friction, 9 = 290
(5) Apparent cohesion, c =320 psf
(6) No seepage forces.
- Analysis: ..
Safety Factor, F.S. = NCf Where Ncf is the stability NO.
for slopes with both c and +.
C - - YH
"cf = 113 x 25 x 0.554 -
320 -
From Figure 3-1 of Reference: Ncf = 19.5
- 19.5 x 320.
25 x 113 F.S. = = 2.2
- ..- OK for seismic
4.9