HomeMy WebLinkAboutCE-5662; Nine Lots Seaview Way-MSk Development Group; Nine lots Seaview Way; 1998-10-19NORTH COUNTY
COMPACTION
ENGINEERING, INC.
PRELIMINARY SOILS INVESTIGATION
FOR THE
PROPOSED NINE LOT RESIDENTIAL SUBDIVISION
3612SEAVIEWWAY
CARLSBAD, CALIFORNIA
PREPARED FOR:
MSK Development Group
5142 Avenida Encinas
Carlsbad, CA 92008
October 19, 1998
Project No. CE-5662
P.O. BOX 302002 * ESCONDIDO, CA 92030
(760)480-1116
t'*^urtfr>i$ffrfWt3yyiig^ •:*•••••
NORTH COC1MTY
COMPACTION
ENGINEERING, INC.October 19, 1998
Project No. CE-5662
MSK Development Group
5142 Avenida Encinas
Carlsbad, CA 92008
SUBJECT: Proposed Nine Lot Residential Subdivision
3612 Seaview Way
Carlsbad, California
In response to your request, we have performed a Preliminary Soils Investigation for the subject
project.
The purpose of our investigation was to evaluate the suitability of the site for the proposed
development and make recommendations with regard to site grading and foundation design.
Briefly, our investigation revealed the presence of compressible topsoils (old fill/plowed ground)
overlying the site from 2 feet to 4 feet in depth. In addition, soils possessing moderate expansion
potential were encountered on the western region of the property. However, it is our opinion, the
site is suitable for the proposed development, provided recommendations set forth in the attached
report are adhered to.
If you have any questions, please do not hesitate to contact us. This opportunity to be of service
is sincerely appreciated.
Respectfully submitted,
North County
COMPACTION ENGINEERING, INC.
Ronald K. Adams A.R. B
President Registered Civil Engineer
Geotechnical Engineer 0001
RKA:kla
cc: (3) submitted
(2) filed
P.O. BOX 302002 * ESCONDIDO, CA 92030
(760)480-1116
NORTH COUNTY
COMPACTION
ENGINEERING, INC,
TABLE OF CONTENTS
1. Purpose and Scope
2. Location and Description of Site
3. Field Investigation
4. Soil Conditions
5. Laboratory Soil Testing
6. Recommendations and Conclusions
A. Grading
B. Foundations
C. Slopes
D. Retaining Walls
E. Estimated Paving Section
F. Review of Grading Plan
7. Uncertainty and Limitations
Page
1
1
1
2
2
3
3
5
6
6
6
7
APPENDIX
Appendix A: Exploration Legend & Unified Soil Classification Chart
Plate No. One
Plate No. Two through Six
Plate No. Seven
Test Pit Location Plan
Exploration Logs
Tabulation of Test Results
Appendix B: Recommended Grading Specifications
S^«««^?*W^^^^^^^W .^-..x;,^.,. ^',n * ,,,7-Vv'.-^
NORTH COUNTY
COMPACTION
ENGINEERING, INC.
1. PURPOSE AND SCOPE
Project No. CE-5662
Page 1
The purpose of the investigation was to determine if the site is suitable for the proposed nine lot
residential subdivision.
The scope of the investigation was to:
A. Determine the physical properties and engineering characteristics of the
surface and subsurface soils.
*•
B. Provide design information with regard to grading, site preparation, and
foundation design of the proposed structure(s).
2. LOCATION AND DESCRIPTION OF SITE
The site is located at 3612 Seaview Way in the City of Carlsbad, California.
The 3.7 acre trapezoidal shaped property is bordered by single family dwellings to the north,
west, and south, and Maria Lane to the east. Seaview Drive dead-ends into the approximate
center of the south property line.
The east portion of the property is occupied by abandoned greenhouse structures and a single
family dwelling. The greenhouses and dwelling are supported upon shallow cut/fill building pads
that terrace downhill to the west. The depth of fill in the pad varies between 2 to 4 feet. A paved
driveway traversing from the end of Seaview Drive to the dwelling parallels the south property
line. An existing 2:1 cut slope constructed to an approximate height of 10 feet descends from the
east property line to existing grade. The westerly two-thirds of the property is predominately flat
and slopes gently downhill to the west and northwest. The total difference in elevation between
the southeast property corner and the northwest property corner is approximately 78 feet and
varies between 260 feet (MSL) and 338 feet (MSL).
Site vegetation on the westerly two-thirds of the property and around the greenhouses consists of
recently mowed native grasses. The dwelling is generally landscaped with lawns, trees, shrubs,
walkways, planters, etc.
3. FIELD INVESTIGATION
The field investigation was performed on October 1, 1998 and included an inspection of the site
and the excavation of five exploratory trenches, with a backhoe to depths of 10 feet. Location of
test pits are shown on the attached Plate No. One, entitled "Test Pit Location Plan".
NORTH COUNTY
COMPACTION
ENGINEERING, INC. B nPage 2
As excavation proceeded, representative bulk samples were collected. In place natural densities
and moisture contents were determined at different depths in the excavations and are included on
Plate No.'s Two through Six. Subsequent to obtaining soil samples, our exploratory excavations
were backfilled.
4. SOIL CONDITIONS
Loose surficial soils (silty-sands) consisting of old fill and/or plowed ground were found to be 2
feet, 2 feet, 3.5 feet, 2.5 feet, and 4 feet in depth in Test Pit No.'s One through Five, respectively.
Underlying native soils to depths explored were comprised of medium dense to dense clayey-
sands, sandy-clay, and silty-sands of the Coastal Terrace Deposit.
On-site soils encountered in Test Pit No. Five have an expansion index of 79 and are classified as
being 'moderate' in expansion potential. This area will receive fill if grading is performed as
planned. Therefore, if selective grading is performed to assure these soils remain a minimum of
48 inches below finish grade, we do not anticipate special design considerations with regard to
foundations. AH other soils encountered in Test Pit No.'s One through Four were found to have
an expansion index varying between 15 and 25 and are classified as being Very low' to 'low' in
expansion potential.
Groundwater was not encountered at the time of our investigation, nor did caving of exploratory
trenches occur. In addition, due to the dense nature of the underlying sandstone formation at the
site, it is our opinion, soil liquefaction is unlikely to occur in the event grading is performed in
accordance with the recommendations set forth in this report.
5. LABORATORY SOIL TESTING
All laboratory test were performed on typical soils in accordance with accepted test methods of
the American Society for Testing and Materials (ASTM).
Tests conducted include:
A). Optimum Moisture & Maximum Density (ASTM D-1557)
B). Direct Shear (Remold) (ASTM D-3080)
C). Sieve Analysis (ASTM D-421)
D). Field Density & Moisture (ASTM D-1556)
E). Expansion Potential (FHA Standard)
Test results are tabulated on the attached Plate No.'s Two through Seven, entitled "Exploration
Log" and "Tabulation of Test Results".
NORTH COUNTY
COMPACTIOM
ENGINEERING, IMC. D ,Page 3
6. RECOMMENDATIONS AND CONCLUSIONS
General
It is our understanding, the proposed dwellings will consist of wood frame construction utilizing
slab on grade foundations. Furthermore, Seaview Way will be extended into the subdivision.
In our opinion, the site is suitable for the proposed development. Recommendations presented in
this report should be incorporated into the planning, design, and construction phases of the
subject project.
6A. Grading
General
It is our understanding cut/fill earthwork construction will be performed to construct level
building pads to accommodate slab on grade construction. In addition, approximately 14,000
cubic yards of imported soils will be required to complete grading as planned. Furthermore, we
recommend grading be performed selectively to assure on-site expansive soils encountered in
Test Pit No. Five are placed a minimum of 48 inches below finish grade upon completion of
grading. In our opinion, due to the amount of imported soil required to complete grading, in
conjunction with the present vertical location of expansive soils, selective grading should be
nearly automatic.
All grading should be performed in accordance with the City of Carlsbad Grading Ordinance and
the Recommendations/Specifications presented in this report.
Subsequent to site demolition, loose surficial soils (plowed ground/old fill), as indicated on the •
attached Plate No's Two through Six, should be undercut or removed to firm native ground and
recompacted in accordance with the attached Appendix *B* entitled "Recommended Grading
Specifications". Firm native ground may be determined as undisturbed soil having an insitu
density of greater than ninety percent (90%) of maximum, dry density. We should be contacted to
document firm native ground is exposed and properly prepared prior to filling.
Prior to constructing fill slopes, shear keys should be excavated a minimum of 2 feet into firm
native ground, inclined back into slope, and have a minimum width of 15 feet. We should be
contacted to document keyways were properly constructed prior to placing fill.
Natural terrain steeper than an inclination of 5:1 (horizontal to vertical units), should be benched
(stair-stepped) to provide a stable bedding for subsequent fill. Sizing of benches should be
determined by the Soils Engineer or his representative during grading.
NORTH COC1MTY
COMPACTION
ENGINEERING, INC.Page 4
All fill soils generated from earthwork construction should be placed in conformance with the
attached Appendix 'B' entitled, "Recommended Grading Specifications".
Soils to be imported should be non-expansive (less than 2% swell) and granular by nature,
having strength parameters equal to or greater than the prevailing on-site soils. We should be
contacted to inspect an/or test imported soils prior to hauling then on-site to assure they will be
suitable for the proposed construction.»•
Particles of asphalt and concrete debris, having a diameter of greater than 6 inches, will not be
suitable fill material and should be separated from fines during grading and hauled off-site.
If encountered, leach lines and/or pipes should be removed. Concrete pipes may be crushed in
place. Trench lines should be recompacted in accordance with Appendix 'B*.
Proposed slopes to be retained have been tested for temporary stability in accordance with
guidelines presented by CAL-OSHA. Direct shear tests have been conducted and their results are
presented on attached Plate No. Seven. The results indicate a temporary slope constructed to a
height of 10 feet having a minimum slope ratio of 1:1 should be stable with relation to deep
seated failure for a period of 60 days. Should construction of walls lapse beyond the indicted
time, we should be contacted to update the site conditions. Furthermore, we should be contacted
to supervise backfill operations. Backfill materials should consist of non-expansive soils (having
a swell of less than 2%) placed at a width behind the wall equivalent to two-thirds of the retained
height. Crushed rock (1 inch minus), approved by this firm, may be an alternate method. All
walls should be provided with drains. Drains should consist of 4 inch perforated pipe surrounded
with crushed rock placed at a minimum of 1 cubic foot per lineal foot, and have a minimum fall
of one percent (1%). A Structural Engineer should be contacted for the design of a retaining
device.
It is highly probable the proposed structures will be traversed by a transition from cut to fill.
Therefore, to reduce structural damage occurring from foundations bearing on two different soil
types, the following measure should be employed:
It is recommended the cut side of the transitional areas be removed to a depth of 1 foot below the
bottom of the deepest proposed footing and brought back to grade with properly compacted fill.
This will allow the proposed structures to bear entirely on a compacted fill mat, thus reducing the
probability of differential settlement. The removal areas should extend under and a minimum of
5 feet beyond the proposed dwellings.
sw^?
NORTH COCINTY
COMPACTION
ENGINEERING, INC. D ePage 5
6B. Foundations
General
The following foundation recommendations are based on the assumption that soils possessing
'very low' to 'low' expansion potential will exist within 48 inches of finish grade upon
completion of grading. Therefore, conventional foundations may be utilized, provided the
aforementioned Grading Recommendations are adhered to.
For One-Story Construction:
Continuous footing having a minimum width of 12 inches and founded a minimum depth of 12
inches below lowest adjacent grade will have an allowable soil bearing pressure of 1500 pounds
per square foot.
For Two-Story Construction:
Continuous footings should have a minimum width of 15 inches and be founded a minimum
depth of 18 inches below lowest adjacent grade.
Isolated square footings having a diameter of 18 inches and founded a minimum depth of 18
inches below lowest adjacent grade will have an allowable soil bearing pressure of 1500 pounds
per square foot.
All continuous footings are to be reinforced with one #4 bar top and bottom. Steel should be
positioned 3 inches above bottom of footing and 3 inches below top of footing.
Slabs should be a minimum of 4 inches thick and reinforced with 6 X 6, w 1.4 X w 1.4 welded
wire mesh or #3 bars on 18 inch centers, both ways. Reinforcement should be placed near the
center of the slab and extended through joints to provide a tension tie with perimeter footings.
Welded wire mesh is a UBC approved method when properly placed. However, it is the past
experience of this firm , wire mesh usually ends up in or below the.bottom of the slab. Therefore,
it is our opinion. #3 bars placed on 18 inch centers is a more effective method with regard to
concrete slab reinforcement.
Slab underlayment should consist of 4 inches of washed concrete sand with a visqueen moisture
barrier installed at mid-point of sand (2 inches sand, visqueen, 2 inches sand). Sand should be
tested in accordance with ASTM D-2419 to insure a minimum sand equivalent of 3.0.
Foundation set-backs from top of slopes should be a minimum of 8 feet. If this cannot be
achieved, footings.near or on adjacent slopes should be founded at a depth such that the
horizontal distance from the bottom outside edge of footing to the face of the slope is a minimum
of 8 feet.
NORTH COCINTY
COMPACTION
ENGINEERING, INC.
6C. Slopes
Page 6
Cut and compacted fill slopes constructed to maximum heights of 25 feet with maximum slope
ratios of 2:1 (horizontal to vertical units) will be stable with relation to deep seated failure,
provided they are properly maintained. During grading, positive drainage away from top of
slopes should be provided. Subsequent to completion of grading, slopes should be planted as
soon as possible with light groundcover indigenous to the area, A slope stability analysis was
performed utilizing 'Taylor's Charts' for cut and compacted fill slopes and a safety factor of 1.5.
6D. Retaining Walls
For static conditions, the prevailing soils will have an allowable equivalent passive fluid pressure
of 288 psf, increasing 288 psf per foot in depth. Allowable pressures assume walls are backfilled
with a non-expansive sand a distance behind the wall equivalent to two-thirds the retained height.
Allowable active pressures may be assumed to be equivalent to the pressure of a fluid weighing
47 pcf for unrestrained walls. These values assume a vertical, smooth wall, and a level, drained
backfill. Should these conditions not be met, we should be contacted for new values.
Allowable active pressures for restrained walls may be assumed to be equivalent to the pressure
of a fluid weighing 47 pcf, plus an additional uniform lateral pressure of 8H. H=height of
retained soils above top of wall footing in vertical feet.
Allowable active pressures for retaining walls with 2:1 inclinations of sloping surcharge may be
assumed to be equivalent to a pressure of fluid weighing 67 pcf.
The coefficient of friction of concrete to soil may be assumed to be .31 for resistance to
horizontal movement.
6E. Estimated Paving Section
Structural section for asphaltic paving for the proposed extension of Seaview Way and driveways
are based on an estimated R-Value of 30. The following section is provided for bid purposes
only. Actual sections should be determined subsequent to completion of grading operations.
Assumed Traffic Index = 4.5
(Residential Cul De Sac)
(Extension of Seaview Way)
3 inches of asphaltic paving on
4 inches of select base coarse on
6 inches of recompacted native subgrade.
NORTH COCJNTY
COMPACTION
ENGINEERING, INC. D nPage 7
All materials and construction for asphaltic paving and base should conform to the Standard
Specifications of the State of California Business and Transportation Agency, Department of
Transportation, Sections 39 and 26, respectively. Class II base material should have a minimum
R-Value of 78 and a sand equivalent of 30. All materials should be compacted to a minimum of
ninety-five percent (95%).
Rigid Concrete Paving:
(private driveways)»•
5 inches of concrete reinforced with #3 bars on 18 inch center, both ways, on
4 inches of Class II base material on
6 inches of recompacted native subgrade soil.
NOTE: All concrete should have a minimum compressive strength of 3250 psi. All subgrade and
base materials should be compacted to a minimum of ninety-five percent (95%).
6F. Review of Grading Plan
Approved site and grading plans were not available at the time of our investigation. Therefore,
upon their completion, we should review them to assure compliance with the recommendations
presented in this report.
Preliminary Plans used during our investigation were prepared by Buccola Engineering, Inc. and
were not dated.
7. UNCERTAINTY AND LIMITATIONS
Surface and subsurface soils are assumed to be uniform. Therefore, should soils encountered
during construction differ from those presented in this report, we should be contacted to provide
their engineering properties.
It is the responsibility of the owner and contractor to carry out recommendations set forth in this
report.
During our investigation of the subject site, evidence of faulting was not encountered.
Subsequent to review of available geologic literature, we feel any faulting in the vicinity of the
site may be classified as inactive. However, it should be noted that San Diego County is located
in a high seismic area with regard to earthquake. Earthquake proof projects are economically
unfeasible. Therefore, damage as a result of earthquake is probable and we assume no liability.
NORTH COCJNTY
COMPACTION
ENGINEERING, INC.
PageS
We assume the on-site safety of our personnel only. We cannot assume liability of personnel
other than our own. It is the responsibility of the owner and contractor to insure construction
operations are conducted in a safe manner and in conformance with regulations governed by
CAL-OSHA and/or local agencies.
Should you have any questions, please do not hesitate to contact us. This opportunity to be of
service is sincerely appreciated.
Respectfully submitted,
North County
COMPACTION ENGINEERING, INC.
Ronald K. Adams
President
A.R. Barry
Registered Civil Engineer
Geotechnical Engineer 0001
RKA:kla
cc: (3) submitted
(2) filed
NORTH COUNTY
COMPACTION
ENGINEERING, INC.
EXPLORATION LEGEND
UNIFIED SOIL CLASSIFICATION CHART
SOIL DESCRIPTION
I. COARSE GRAINED: More than
half of material is larger than
No. 200 sieve size.
GRAVELS CLEAN GRAVELS
More than half of coarse fraction
is larger than No. 4 sieve size, but
smaller than 3".
GRAVELS WITH FINES
(Appreciable amount of fines)
SANDS CLEAN SANDS
More than half of coarse fraction
is smaller than No. 4 sieve size. -
SANDS WITH FINES
(appreciable amount of fines)
II. FINE GRAINED: More than half
of material is smaller than No.200
sieve size.
SILTS AND CLAYS
Liquid Limit
less than 50
SILTS AND CLAYS
Liquid Limit
greater than 50
HIGHLY ORGANIC SOILS
GROUP SYMBOL
GW
GP
GM
GC
SW
SP
SM
SC
TYPICAL NAMES
ML
CL
OL
MH
CH
OH
PT
Well graded gravels, gravel-sand
mixtures, little or no fines
Poorly graded gravels, gravel sand
mixtures, little or no fines.
Silty gravels, poorly graded gravel-
sand-silt mixtures.
Clayey gravels, poorly graded
gravel-sand, clay mixtures
Well graded sand, gravely sands,
little or no fines.
Poorly graded sands, gravely sands,
little or no fines.
Silty sands, poorly graded sand and
silt mixtures.
Clayey sands, poorly graded sand
and clay mixtures.
Inorganic silts and very fine sands,
rock flour, sandy silt or clayey-
silt-sand mixtures with slight
plasticity.
Inorganic clays of low to medium
plasticity, gravely clays, lean clays,
Organic silts and organic silty clays
of low plasticity.
Inorganic silts, micaceous or
diatomaceous find sandy or silty
soils, elastic silts.
Inorganic clays of high plasticity,
fat clays.
Organic days of medium to high
plasticity.
Peat and other highly organic soils.
US - Undisturbed, driven ring sample or tube sample
CK - Undisturbed chunk sample
BG - Bulk sample
V - Water level at time of excavation or as indicated
APPENDIX 'A'
NORTH C'' MNTY COMPACTION ENGINEERING, INC.
SOiL TESTING & INSPECTION SERVICES
TEST PIT LOCATION PLAN
PROPOSED NINE LOT SUBDIVISION
SEAVIEW WAY
CARLSBAD, CALIFORNIA Approx. Scale
1" - 75'
PROJECT NO. CE-5662 PLATE NO.ONE
NORTH COUNTY
COMPACTION
ENGINEERING, INC.
EXPLORATION LOG
PROJECT NAME: SEA VIEW WY. CARLSBAD DATE LOGGED: 10/01/98
ELEVATION:290 MSL TEST PIT NO. ONE
Depth
(Feet)
1-
2-
3-
4-
5-
6-
7-
8-
9-
Sample
Type
CK
BG
Dry
Density
(pcf)
118.4
Moisture
Content
(%)
10.0
Passing
#200
Sieve
21.4
Sample
Depth
4'
Soil
Class
SM
SM
sc
Description & Remarks
BROWN, DRY LOOSE SILTY-SAND.
(PLOWED GROUND)
(REMOVE & RECOMPACT)
fVERY LOW EXPANSION
BROWN RED, HUMID, MEDIUM
DENSE SILTY-SAND.
(FIRM NATIVE)
(VERY LOW EXPANSION)
ORANGE BROWN, MOIST, MEDIUM
DENSE SLIGHTLY CLAYEY-SAND.
(LOW EXPANSION)
(BECOMES MORE SANDY W/DEPTH)
BOTTOM OF TEST PIT.
PROJECT NO.CE-5662 PLATE NO..TWO
NORTH COUNTY
COMPACTION
ENGINEERING, INC.
EXPLORATION LOG
PROJECT NAME: SKA VIEW WY. CARLSBAD DATE LOGGED: 10/01/98
ELEVATION:312MSL TEST PIT NO. TWO
Depth
(Feet)
1-
2-
3-
4-
5-
6-
7-
8-
9-
10-
Sampie
Type
BG
CK
Dry
Density
(pcf)
117.0
Moisture
Content
(%)
10.1
Passing
#200
Sieve
29.9
Sample
Depth
51
Soil
Class
SM
SM
Description & Remarks
BROWN, DRY LOOSE S1LTY-SAND.
(PLOWED GROUND)
(REMOVE & RECOMPACT)
(VERY LOW EXPANSION
ORANGE BROWN, MOIST, DENSE
SILTY-SAND.
(FIRM NATIVE)
(CLAY TINT)
(VERY LOW EXPANSION)
BOTTOM OF TEST PIT.
PROJECT NO.CE-5662 PLATE NO.THREE
NORTH COCINTY
COMPACTION
ENGINEERING, INC.
EXPLORATION LOG
PROJECT NAME: SEAVIEW WY. CARLSBAD DATE LOGGED: 10/01/98
ELEVATION:308 MSL TEST PIT NO. THREE
Depth
(Feet)
1-
2-
3-
4-
5-
6-
7-
S ample
Type
Dry
Density
(pcO
Moisture
Content
(%)
Passing
#200
Sieve
Sample
Depth
Soil
Class
SM
SM
Description & Remarks
BROWN, DRY LOOSE SILTY-SAND.
(PLOWED GROUND)
(REMOVE & RECOMPACT)
(VERY LOW EXPANSION)
ORANGE BROWN, HUMID, DENSE
SILTY-SAND.
(FIRM NATIVE)
(VERY LOW EXPANSION)
BOTTOM OF TEST PIT.
PROJECT NO.CE-5662 PLATE NO.FOUR
NORTH COUNTY
COMPACTION
ENGINEERING, INC.
EXPLORATION LOG
PROJECT NAME: SEAVIEW WY. CARLSBAD DATE LOGGED: 10/01/98
ELEVATION:286 MSL TEST PIT NO. FOUR
Depth
(Feet)
1-
2-
3-
4-
5-
6-
7-
8-
Sample
Type
CK
Dry
Density
(pcO
120.6
Moisture
Content
(%)
10.9
Passing
#200
Sieve
Sample
Depth
5'
Soil
Class
SM
SC
Description & Remarks
BROWN, HUMID, LOOSE SILTY-SAND
(PLOWED GROUND)
(REMOVE & RECOMPACT)
(VERY LOW EXPANSION)
ORANGE BROWN, MEDIUM DENSE
HUMID TO MOIST, SLIGHTLY
CLAYEY-SAND.
(FIRM NATIVE)
(VERY LOW EXPANSION)
BOTTOM OF TEST PIT.
PROJECT NO.CE-5662 PLATE NO.FIVE
V^^tf^l^s^^^-\'^^^ •
MORTH COUNTY
COMPACTION
ENGINEERING, INC.
EXPLORATION LOG
PROJECT NAME: SEAVIEW WY. CARLSBAD DATE LOGGED: 10/01/98
ELEVATION:274 MSL TEST PIT NO. FIVE
Depth
(Feet)
1-
2-
3-
4-
5-
6-
7-
8-
S ample
Type
BG
Dry
Density
(pcf)
Moisture
Content
(%)
Passing
#200
Sieve
53.1
Sample
Depth
6'
Soil
Class
SM
SM
CL
Description & Remarks
BROWN, DRY, LOOSE SILTY-SAND.
(OLD FILL/ PLOWED GROUND)
(VERY LOW EXPANSION)
BROWN RED, HUMID, SILTY-SAND.
(FIRM NATIVE)
ORANGE BROWN, MOIST, MEDIUM
DENSE SANDY-CLAY.
(MODERATE EXPANSION)
(NOT TO BE PLACED WITHIN 48
INCHES OF FINISH GRADE)
BOTTOM OF TEST PIT.
PROJECT NO.CE-5662 PLATE NO.SIX
NORTH COUNTY
COMPACTION
ENGINEERING, INC.
TABULATION OF TEST RESULTS
OPTIMUM MOISTURE/MAXIMUM DENSITY
SOIL DESCRIPTION TYPE
Orange Brown Clayey-Sand PI @4'
Orange Brown Silty-Sand
(Clay Tint) P2@5'
Orange Brown Silty-Sandy-
Clay P5@6'
MAX. DRY DENSITY
(LB. CU.
131.0
129.7
111.5
OPT. MOISTURE
(% DRY WT1
11.2
10.3
16.2
EXPANSION POTENTIAL
SAMPLE NO.
CONDITION
INITIAL MOISTURE (%)
AIR DRY MOISTURE (%)
FINAL MOISTURE (%)
DRY DENSITY (PCF)
LOAD (PSF)
SWELL (%)
EXPANSION INDEX
Pl@4'
Remold 90%
10.6
05.1
17.3
117.9
150 '
2.5
25
P2@5T
Remold 90%
10.8
07.1
16.1
116.7
150
1.5
15
P5@6'
Remold 90%
16.1
10.9
30.2
100.4
150
7.9
79
DIRECT SHEAR
SAMPLE NO. PI @4' P2 @ 5'
CONDITION Remold 90% Remold 90%
ANGLE INTERNAL FRICTION 28 25
COHESION INTERCEPT (PCF) 130 210
PROJECT NO. CE-5662
PLATE NO. SEVEN
NORTH COUNTY
COMPACTION
ENGINEERING, INC
RECOMMENDED GRADING SPECIFICATIONS
(General Provisions)
1. INTENT
The intent of these specifications is to provide procedures in accordance with current standard
practices regarding clearing, compacting natural ground, preparing areas to receive fill, and
placing and compacting of fill soil to the lines , grades, and slopes delineated on the project
plans. Recommendations set forth in the attached "Preliminary Soils Investigation" report or
special provisions are a part of the "Recommended Grading Specifications" and shall supercede
the provisions contained hereinafter in case of conflict.
2. INSPECTION & TESTING
A qualified Soils Engineer shall be employed to inspect and test the earthwork in accordance
with these specification and the accepted plans. It will be necessary that the Soils Engineer or his
representative be allowed to provide adequate inspection so that he may certify that the work was
or was not accomplished as specified or indicated. It shall be the responsibility of the contractor
to assist the Soils Engineer and to keep him appraised of work schedules, changes, new
information and dates, and new unforeseen soils conditions so that he may make these
certifications.
If substandard conditions (questionable soils, adverse weather, poor moisture control, inadequate
compaction, etc.) Are encountered, the Soils Engineer will be empowered to either stop
construction until conditions are remedied or recommend rejection of the work.
Soil tests used to determine the degree of compaction will be performed in accordance with the
following American Society for Testing and Materials (ASTM) test methods:
*Maximum Density & Optimum Moisture Content (ASTM D-1557-78)
* Density of Soil In-Place (ASTM D-1556 or ASTM D-2922 & 3017)
3. MATERIALS
Those soils used as fill will have a minimum of forty percent (40%) passing a #4 sieve. They will
be free of vegetable matter or other deleterious substances and contain no rock over 6 inches in
size. Should unsuitable material be encountered, the Soils Engineer will be contacted to provide
recommendations.
APPENDIX 'B'
> i.i&&i$ia4f#4<'JfWB?*t<tf ^i!***-? *t ••
NORTH COtiriTY
COMPACTION
ENGINEERING, INC.
4. PLACING AND SPREADING OF FILL
The selected fill material shall be placed in layers which when compacted will not exceed 6
inches in thickness.
Each layer shall be spread evenly and shall be thoroughly blade mixed during the spreading to
insure uniformity of material in each layer.
When moisture content of the fill material is below that recommended by the Soils Engineer,
water shall then be added until the moisture content is as specified to assure thorough bonding
during the compacting process.
When the moisture content of the fill materials is above that recommended by the Soils Engineer,
the fill material shall be aerated by blading or other satisfactory methods until the moisture
content is as specified.
5. COMPACTION
After each layer has been placed, mixed, and spread evenly, it shall be thoroughly compacted to
not less than ninety percent (90%) relative compaction. Compaction shall be by sheepsfoot
rollers multiple-wheel pneumatic tired rollers or other types of rollers.
Rolling shall be accomplished while the fill material is at the specified moisture content. Rolling
each layer shall be continuous over it's entire area and the roller shall make sufficient trips to
insure that the desired density has been obtained.
The fill operation shall be continued in 6 inch compacted layers, or as specified above, until the
fill has been brought to the finished slopes and grades shown on the project plans.
6. WALL BACKFILL
Backfill soils should consist of non-expansive sand, Compaction should be achieved with light
hand-held pneumatic tampers to avoid over compaction and hence cause structural damage. Wall
backfill should be compacted to a minimum of ninety percent (90%) of maximum density.
7. TRENCH BACKFILL
All trench backfill located within structural areas should be compacted to a minimum of ninety
percent (90%) of maximum density.
APPENDIX *