HomeMy WebLinkAboutSANCTUARY ON THE GREEN - PDP190003 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT400 North Link Lane | Fort Collins, Colorado 80524
Telephone: 970-206-9455 Fax: 970-206-9441
PRELIMINARY
GEOTECHNICAL INVESTIGATION
SANCTUARY WEST
FORT COLLINS, COLORADO
Prepared For:
C & A COMPANIES
7991 Shaffer Parkway, Suite 200
Littleton, Colorado 80127
Attention: David Pretzler
Project No. FC08483-115
October 10, 2018
i
TABLE OF CONTENTS
SCOPE ....................................................................................................................... 1
SUMMARY OF CONCLUSIONS ............................................................................... 1
SITE DESCRIPTION ................................................................................................. 2
PROPOSED DEVELOPMENT .................................................................................. 3
SITE GEOLOGY ........................................................................................................ 3
GEOLOGIC HAZARDS .............................................................................................. 4
Shallow Groundwater ............................................................................................. 4
Expansive Soils and Bedrock................................................................................. 5
Seismicity................................................................................................................ 5
Radioactivity ........................................................................................................... 6
FIELD AND LABORATORY INVESTIGATIONS ....................................................... 7
SUBSURFACE CONDITIONS ................................................................................... 7
Groundwater ........................................................................................................... 8
PERCOLATION TESTS ............................................................................................ 9
DEVELOPMENT RECOMMENDATIONS ................................................................. 9
Site Grading ............................................................................................................ 9
Permanent Cut and Fill Slopes ............................................................................ 10
Utility Construction ................................................................................................ 10
Underdrain System ............................................................................................... 11
BUILDING CONSIDERATIONS .............................................................................. 12
Foundations .......................................................................................................... 13
Slabs-on-Grade and Basement Floor Construction ............................................. 13
Below-Grade Construction ................................................................................... 13
Surface Drainage ................................................................................................. 14
Water-Soluble Sulfates ........................................................................................ 14
RECOMMENDED FUTURE INVESTIGATIONS ..................................................... 15
LIMITATIONS ........................................................................................................... 15
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TABLE OF CONTENTS cont’d
FIGURE 1 - LOCATIONS OF EXPLORATORY BORINGS
FIGURE 2 AND 3 - SUMMARY LOGS OF EXPLORATORY BORINGS
FIGURE 4 – GROUNDWATER ELEVATION CONTOURS
FIGURE 5 – PERCOLATION LOCATIONS AND RATES
FIGURES 6 THROUGH 8 – SEWER UNDERDRAIN DETAILS
APPENDIX A – LABORATORY TEST RESULTS
APPENDIX B – GUIDELINE SITE GRADING SPECIFICATIONS
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SCOPE
This report presents the results of our Preliminary Geotechnical
Investigation for the Sanctuary West mixed housing development in Fort Collins,
Colorado. The purpose of our investigation was to identify geologic hazards that
may exist at the site and evaluate the subsurface conditions to assist in planning
and budgeting for the proposed development. The report includes descriptions
of site geology, our analysis of the impact of geologic conditions on site
development, a description of subsoil, bedrock and groundwater conditions
found in our exploratory borings, and discussions of site development as
influenced by geotechnical considerations. A Subgrade Investigation and
Pavement design report addressing proposed overlays and turning lanes along
Laporte Avenue and Taft Hill Road will be provided separately. The scope was
described in a Service Agreement (No. DN 17-0596R3) dated June 26, 2018.
This report was prepared based upon our understanding of the
development plans. The recommendations are considered preliminary and can
be used as guidelines for further planning of development and design of grading.
We should review final development and grading plans to determine if additional
investigation is merited, or if we need to revise our recommendations. Additional
investigations will be required to design building foundations, floor systems and
pavements. A summary of our findings and recommendations is presented
below. More detailed discussions of the data, analysis and recommendations
are presented in the report.
SUMMARY OF CONCLUSIONS
1. The site contains geologic hazards that should be mitigated during
planning and development. No geologic or geotechnical conditions
were identified which would preclude development of this site.
Shallow groundwater, expansive soils and bedrock, and regional
issues of seismicity and radioactivity are the primary geologic
concerns pertaining to the development of the site.
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2. The subsurface conditions encountered in our borings were
variable and consisted of interlayered sandy clay and clayey sand
overlying clean to clayey sand and gravel. Claystone bedrock was
encountered in nine borings at depths of 14 to 24½ feet.
3. Groundwater was encountered in all the borings during drilling at
depths of 5 to 19 feet. When measured a few days later,
groundwater was at depths of 2½ to 17 feet. We typically
recommend a minimum 3-feet separation between basement
foundation elements and groundwater. Grade would likely have to
be raised significantly to accommodate basement construction
throughout most of the site. Groundwater will likely be encountered
in some utilities and basement excavations. Further monitoring is
recommended.
4. We tested nineteen samples for swell-consolidation. Test results
indicated nil to 3.1 percent measured swell. The 3.1 percent swell
was measured on a sample of weathered claystone in TH-10. The
rest of the samples swelled 2.4 percent or less which is
characterized as low. We anticipate footing or pad-type foundations
will likely be appropriate for most structures.
5. Asphaltic pavement sections on the order of 5 to 6 inches for
streets, parking areas, and access drives are anticipated for
preliminary planning purposes. Higher volume pavement will likely
require thicker sections, on the order of 6 to 8 inches. Pavement
section recommendations for the turn lanes off Taft Hill Drive and
Laporte Avenue will be provided in a separate report.
6. Percolation tests were performed at six requested locations.
Percolation rates varied between 14 and greater than 240 minutes
per inch.
SITE DESCRIPTION
The site is northwest of the intersection of Laporte Avenue and Taft Hill
Road in Fort Collins, Colorado. Residential areas exist to the north, east, south
and west. The Little Cache la Poudre Ditch runs north to south through the
eastern section of the site. At the time of our investigation the site was mostly
undeveloped with some dirt paths and fenced areas. There is an old foundation
pad located near boring TH-11.
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The site is relatively flat with a general slope to the south. Ground cover
consisted of native grasses, weeds and trees.
PROPOSED DEVELOPMENT
We understand the parcel is planned for development of residential single
and multi-family homes and a senior living facility. The homes will be one to
three-story, wood-framed structures, with attached or detached garages,
founded over crawlspaces or basements. The senior living facility will be a two to
three-story wood-framed structure. Preliminary plans indicate site grading will be
generally limited to construction of access roads and building pads.
PREVIOUS INVESTIGATION
A Preliminary Geotechnical Investigation prepared by Terracon (Terracon
Project No. 20035190, dated December 15, 2003) and a Groundwater
Observation report (Terracon Project No. 20075075, dated September 27, 2007)
were provided. The data generated from these studies were reviewed in
preparation of this report.
SITE GEOLOGY
The geology of the site was investigated through review of mapping by
Ogden Tweto (Geologic Map of Colorado, 1979) and the U.S. Geological Survey.
Our geotechnical engineer for the project visited the site to assess whether field
conditions are consistent with the geologic mapping and reports, evaluate
specific site features and to look for other geologic concerns. Geology was
further evaluated through review of conditions found in exploratory borings, and
our experience in the area.
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According to the Geologic map of Boulder-Fort Collins-Greeley area and
the Tweto Geologic map, the site is predominantly underlain by sand and gravel
of the Slocum alluvium. The soils can contain layers of expansive clay. The
underlying bedrock includes claystone which is expansive.
GEOLOGIC HAZARDS
Our investigation identified several geologic hazards that must be
considered during the planning and development phases of this project. None of
the geologic hazards identified will preclude development of the property.
Geologic hazards which need to be addressed include shallow
groundwater, expansive clay and claystone bedrock and regional issues of
seismicity and radioactivity. The following sections discuss each of these
geologic hazards and associated development concerns. Mitigation concepts
are discussed below and in the DEVELOPMENT RECOMMENDATIONS section
of the report.
Shallow Groundwater
Groundwater was encountered in all borings during drilling at depths of 5
to 19 feet. When measured a few days later, groundwater was at depths of 2½ to
17 feet. Groundwater may rise due to site development and during extended
periods of flow in the Little Cache la Poudre ditch. Groundwater will fluctuate
seasonally. Our estimate of groundwater elevations is presented on Figure 4
along with measured depths to groundwater.
We typically recommend a minimum separation of 3 feet (preferably 5
feet) between basement excavations and groundwater. At current grade most of
the site is not suitable for normal depth basements or are marginal unless
dewatering systems are installed. Grading could be designed to raise the
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elevations in areas of shallow groundwater. Excavations near groundwater will
be wet and may require dewatering. Construction of underdrain systems with the
sanitary sewer trenches is a commonly employed method to mitigate the
accumulation of shallow groundwater after construction. The depth to
groundwater should be evaluated during further investigations at the site.
Foundation drains should be anticipated around basement areas and
crawl spaces where no basements are built. A gravel drainage layer and vapor
retarder will likely be necessary below slab-on-grade basement floors in portions
of the site. Drains should connect to a sump pit and pump or a gravity outlet.
Gravity outlets typically consist of pipes placed below sewer mains (i.e.
underdrains) that lead to an outfall. In lieu of a gravity outfall, another alternative
would be to outfall drains to a wet well where water can be removed with a
pump; maintenance should be expected with this option.
Expansive Soils and Bedrock
Some of the clay and claystone at this site are expansive. There is risk
that ground heave will damage pavements, slabs-on-grade, and foundations.
Engineered design of grading, pavements, foundations, slabs-on-grade, and
surface drainage can mitigate, but not eliminate, the effects of expansive soil and
bedrock. We judge the risk is low, and no mitigation such as sub-excavation is
merited.
Seismicity
This area, like most of central Colorado, is subject to a low degree of
seismic risk. No indications of recent movements of any of the faults in the
Larimer County area have been reported in the available geologic literature. As
in most areas of recognized low seismicity, the record of the past earthquake
activity in Colorado is somewhat incomplete.
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Based on the subsurface conditions encountered in our borings and our
understanding of the geology, the site classifies as Seismic Site Class D (2015
International Building Code). Only minor damage to relatively new, properly
designed and built buildings would be expected. Wind loads, not seismic
considerations, typically govern dynamic structural design in this area.
Radioactivity
It is normal in the Front Range of Colorado and nearby eastern plains to
measure radon gas in poorly ventilated spaces in contact with soil or bedrock.
Radon 222 gas is considered a health hazard and is one of several radioactive
products in the chain of the natural decay of uranium into stable lead.
Radioactive nuclides are common in the soils and sedimentary rocks underlying
the subject site. Because these sources exist on most sites, there is potential for
radon gas accumulation in poorly ventilated spaces. The amount of soil gas that
can accumulate is a function of many factors, including the radio-nuclide activity
of the soil and bedrock, construction methods and materials, pathways for soil
gas and existence of poorly-ventilated accumulation areas. It is difficult to predict
the concentration of radon gas in finished construction.
We recommend testing to evaluate radon levels after construction is
completed. If required, typical mitigation methods for residential construction
consist of sealing soil gas entry areas and ventilation of below-grade spaces and
perimeter drain systems. It is relatively economical to provide for ventilation of
perimeter drain systems or underslab gravel layers at the time of construction,
compared to retrofitting a structure after construction.
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FIELD AND LABORATORY INVESTIGATIONS
Subsurface conditions were investigated by drilling thirteen exploratory
borings at the approximate locations shown on Figure 1. Six percolation test
holes were also drilled; the approximate locations are presented on Figure 5.
The borings were drilled to a depth of 25 feet using a truck-mounted drill rig and
4-inch diameter, continuous-flight auger. Percolation holes were drilled using the
same truck-mounted drill rig, utilizing an 8-inch auger and drilling to depths of 24
to 36 inches. Our field representative observed drilling logged the soils found in
the borings and obtained samples. Summary logs of the soils found in the
borings and field penetration resistance values are presented on Figures 2 and
3.
Samples of soil and bedrock were obtained during drilling by driving a
modified California-type sampler (2.5-inch O.D.) into the subsoils and bedrock
using a 140-pound hammer falling 30 inches. Samples recovered from the test
holes were returned to our laboratory and visually classified by the geotechnical
engineer for the project. Laboratory testing included moisture content and dry
density, swell-consolidation, Atterberg limits, particle-size analysis, standard
Proctor compaction, unconfined compression and water-soluble sulfate content.
Laboratory test results are presented in Appendix A and summarized in Table A-
1.
SUBSURFACE CONDITIONS
The subsurface conditions encountered in our borings were variable. The
soils consisted of 6 to 25 feet of interlayered sandy clay and clayey sand
overlying 5 to 12 feet clean to clayey sand and gravel. The clay was medium stiff
to very stiff and the sand and gravel were loose to dense based on field
penetration resistance tests. Samples tested for swell-consolidation exhibited nil
to 2.4 percent swell with two samples in the upper 5 feet exhibiting greater than
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1.0 percent swell. Fines content (percent passing the No. 200 sieve) for the
interlayered materials was 12 to 82 percent. Atterberg limits tests indicated
moderate plasticity. One sample of the clay had an unconfined compressive
strength of 6,000 psf.
Claystone bedrock was encountered in nine borings from depths of 14 to
24½ feet to the depths explored. Samples of the claystone exhibited swell
potential of nil to 3.1 percent with one sample at 14 feet having swell greater
than 0.3 percent. One sample contained fines content of 97 percent and was
moderately plastic. Two samples of the claystone at 19 and 24 feet had
unconfined compressive strengths of 15,700 and 15,400 respectively.
Groundwater
Groundwater was encountered in all the borings during drilling at depths
of 5 to 19 feet. When measured a few days later groundwater was at depths of
2½ to 17 feet. Groundwater levels will fluctuate seasonally and will be influenced
by water in the Little Cache la Poudre irrigation ditch.
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PERCOLATION TESTS
Percolation testing was performed at six locations about the site. Results
are summarized in Table 1.
Table 1: Percolation Rates
Percolation Hole Number Percolation Rate (mpi)
P-1 >240
P-2 14
P-3 22
P-4 120
P-5 27
P-6 40
Site Average = 77 mpi
DEVELOPMENT RECOMMENDATIONS
The primary geotechnical concerns that we believe will influence
development and building performance are shallow groundwater and expansive
clay and bedrock. These concerns can be mitigated with proper planning,
engineering, design and construction. We believe there are no geotechnical
constraints that would preclude development. The following sections provide site
development recommendations.
Site Grading
We believe grading can be accomplished using conventional heavy-duty
construction equipment. The ground surface in areas to be filled should be
stripped of vegetation, scarified, and moisture conditioned to between optimum
and 3 percent above optimum moisture content for clay and within 2 percent of
optimum for sand, and compacted to at least 95 percent of standard Proctor
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maximum dry density (ASTM D 698). We anticipate stripping may require cuts of
at 6 to 12 inches for the majority of the site.
The properties of fill will affect the performance of foundations, slabs-on-
grade, utilities, pavements, flatwork and other improvements. If imported soil is
needed to achieve site grades, the material should be tested and approved by
our firm prior to importing to the site. The on-site soils are suitable for use as site
grading fill provided they are substantially free of debris, organics and other
deleterious materials. Fill should be placed in thin loose lifts, moisture
conditioned and compacted prior to placement of the next lift using the criteria
presented in the previous paragraph. The placement and compaction of site
grading fill should be observed and tested by our representative during
construction. Guideline grading specifications are presented in Appendix B.
Permanent Cut and Fill Slopes
We recommend permanent cut and fill slopes be designed with a
maximum inclination of 3:1 (horizontal to vertical). Where fills will be placed on
slopes exceeding 20 percent (5:1) the slope should be benched. Structures
should be set back from the top or bottom of cut and fill slopes. If site
constraints (property boundaries and streets) do not permit construction with
recommended slopes, we should be contacted to evaluate the subsurface soils
and steeper slopes.
Utility Construction
We believe excavations for utility installation can be performed with
conventional heavy-duty trenchers or large backhoes. Where groundwater is
encountered within a few feet of excavation bottom depths, dewatering can likely
be accomplished by sloping excavations to occasional sumps where water can
be removed by pumping. Where excavations extend well below groundwater, it
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is possible other means of dewatering, such as well points, may be necessary.
Utility trenches should be sloped or shored to meet local, State and
federal safety regulations. Based on our investigation, we anticipate the
interlayered sandy clay and clayey sand, and sand and gravel will classify as
Type C and the bedrock as Type B soil based on OSHA standards. Excavation
slopes specified by OSHA are dependent upon soil types and ground water
conditions encountered. Seepage and ground water conditions in trenches may
downgrade the soil type. These classifications are based on conditions found in
widely spaced borings and are preliminary. Contractors are required to identify
the soils encountered in excavations and refer to OSHA standards to determine
appropriate slopes. Excavations deeper than 20 feet should be designed by a
professional engineer.
Water and sewer lines are usually constructed beneath paved roads.
Compaction of trench backfill can have significant effect on the life and
serviceability of pavements. Trench backfill should be placed in thin, loose lifts,
and moisture conditioned and compacted to criteria in Site Grading. The
placement and compaction of fill and backfill should be observed and tested by
our firm during construction.
Underdrain System
Shallow groundwater is present below the site. With long-term
development and subsequent irrigation, groundwater may rise. We believe this
water should be controlled. The water could lead to frequent pumping of
basement foundation drains. Where feasible, we advocate use of an underdrain
system incorporated into the design of sanitary sewer systems to provide a
means to control water and allow gravity discharge from basement foundation
drains. It may not be practical to install underdrains at this site if a gravity
discharge is not available. It is possible a pumped system could be used, which
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would require long-term maintenance. If an underdrain system is not installed,
individual house foundation drains would discharge into sumps with pumps.
Sump discharge can result in ponding and recycling if slopes between lots are
not adequately graded. Problems with chronic ice or algae formation at
sidewalks have also been caused by sump discharge. Conceptual sewer
underdrain details are provided on Figures 6 through 8. If used, the underdrain
should be provided with clean-outs and be maintained. Drain outfalls should be
designed with a concrete head wall large enough to protect the pipe from
damage during maintenance.
Where feasible, the underdrain services should be installed deep enough
so that the lowest point of a basement foundation drain can be connected to the
underdrain service as a gravity outlet. For non-walkout basements, the low point
of the basement foundation drain may be about 2 to 3 feet deeper than the
foundation excavation. For buildings with walkout basements, the low point of the
basement foundation drain will be adjacent to the frost wall in the rear portion of
the basement. The foundation drain in a walkout basement would require a
deeper underdrain service for a gravity discharge and may not be practical. For
these conditions, we suggest the front portion of the foundation drain be
connected to the underdrain and a sump pit used for the rear portion.
BUILDING CONSIDERATIONS
The property is currently planned for residential construction. Our field
and laboratory data indicate the soil and bedrock conditions vary across the site.
The following discussions are preliminary and are not intended for design or
construction. After grading is completed, site-specific investigations should be
performed for each structure. This discussion is provided for planning purposes
only.
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Foundations
Our investigation indicates low swelling and non-expansive soils are
present at depths likely to influence foundations. We anticipate structures can
likely be founded on shallow, footing or pad foundations.
Slabs-on-Grade and Basement Floor Construction
Basement construction will be limited by shallow groundwater. The use of
slab-on-grade floors for basements should be limited to areas where risk of poor
performance is low or moderate. We believe most of the site will have low risk of
poor basement floor slab performance. Slab performance risk should be more
thoroughly defined during design level soils investigations.
Where residences are constructed with no basements on sites with
expansive soils, we recommend use of structurally supported floors in finished
living areas. Post-tensioned slab-on-grade foundations can also be considered.
Below-Grade Construction
Ground water was encountered during this investigation. To reduce the
risk of hydrostatic pressure developing on foundation walls, foundation drains will
be necessary around basement areas and around crawlspaces on structures
with no basement. We suggest foundation drains be tied to the sewer underdrain
system (if constructed). They may also discharge to sumps where water can be
removed by pumping. Foundation walls and grade beams should be designed to
withstand lateral earth pressures. The design pressure should be established
during design-level investigations.
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Surface Drainage
The performance of foundations will be influenced by surface drainage.
The ground surface around proposed structures should be shaped to provide
runoff of surface water away from the structure and off pavements. We
generally recommend slopes of at least 12 inches in the first 10 feet where
practical in the landscaping areas surrounding residences with basements, and 6
inches in 19 feet for structures without basements. There are practical
limitations on achieving these slopes. Irrigation should be minimized to control
wetting. Roof downspouts should discharge beyond the limits of foundation
backfill. Water should not be allowed to pond on or adjacent to pavements.
Proper control of surface runoff is also important to limit the erosion of surface
soils. Concentrated sheet flow should not be directed over unprotected slopes.
Water should not be allowed to pond at the crest of slopes. Permanent slopes
should be re-vegetated to reduce erosion.
Water-Soluble Sulfates
Concrete in contact with soil can be subject to sulfate attack. We
measured water-soluble sulfate concentrations in four samples from this site.
Concentrations were measured between 0.6 and 0.1 percent. Sulfate
concentrations less than 0.1 percent indicate Class 0 exposure to sulfate attack
according to the American Concrete Institute (ACI). For this level of sulfate
concentration, ACI indicates any type of cement can be used for concrete that
comes into contact with the subsoils. In our experience, superficial damage may
occur to the exposed surfaces of highly permeable concrete, even though sulfate
levels are relatively low. To control this risk and to resist freeze-thaw deterioration,
the water-to-cementitious material ratio should not exceed 0.50 for concrete in
contact with soils that are likely to stay moist due to surface drainage or shallow
groundwater. Concrete should be air entrained.
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RECOMMENDED FUTURE INVESTIGATIONS
Based on the results of this investigation and the proposed development, we
recommend the following investigations be performed:
1. Review of final site grading plans by our firm;
2. Groundwater investigation over one calendar year;
3. Construction testing and observation for site development;
4. Subgrade investigation and pavement design after site grading;
5. Design-level soil investigations after grading;
LIMITATIONS
Our exploratory borings were drilled at requested locations and should be
indicative of conditions on this site. Variations in the subsoils not indicated in our
borings are possible. We believe this investigation was conducted in a manner
consistent with that level of skill and care ordinarily used by members of the
profession currently practicing under similar conditions. No warranty, express or
implied, is made.
This report was prepared from data developed during our field exploration,
laboratory testing, engineering analysis and experience with similar conditions.
The recommendations contained in this report were based upon our
understanding of the planned construction. If plans will differ from the
assumptions presented herein, we should be contacted to review our
recommendations.
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If we can be of further service in discussing the contents of this report or
in the analysis of the development from the geotechnical point of view, please
call.
Very truly yours,
CTL | THOMPSON, INC.
Trace Krausse, EIT
Staff Geotechnical Engineer
Reviewed by:
Ronald M. McOmber, P.E.
Chairman, Senior Principal
Via email: david@cacompanies.com
TSK:RMM
TH-1
TH-2 TH-3
TH-4
TH-5
TH-8
TH-7
TH-6
TH-9
TH-10
TH-11
TH-12
TH-13
Taft Hill Road
Laporte Avenue
LEGEND:
INDICATES APPROXIMATE
LOCATION OF EXPLORATORY
BORING
APPROXIMATE PROPERTY
BOUNDARY
TH-1
W. VINE DR.
LAPORTE AVE.
N. SUNSET ST.
N. TAFT HILL RD.
SITE
FIGURE 1
Locations of
Exploratory Borings
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0 125' 250'
APPROXIMATE
SCALE: 1"=250'
VICINITY MAP
FORT COLLINS, CO
NOT TO SCALE
5,000
5,010
5,020
5,030
5,040
5,050
5,060
5,070
5,080
5,000
5,010
5,020
5,030
5,040
5,050
5,060
5,070
5,080
Summary Logs of
Exploratory Borings
ELEVATION - FEET
FIGURE 2
ELEVATION - FEET
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23/12
11/12
14/12
30/12
47/12
TH-1
El. 5079.5
WC=16.0
DD=105
SW=0.3
WC=13.8
DD=118
-200=30
WC=12.7
-200=22
WC=15.8
DD=113
-200=42
WC=12.8
DD=123
SW=2.4
20/12
12/12
29/12
25/12
50/9
TH-2
El. 5075.5
WC=9.7
-200=62
WC=19.7
DD=107
SW=0.8
SS=0.060
4,970
4,980
4,990
5,000
5,010
5,020
5,030
5,040
5,050
5,060
4,970
4,980
4,990
5,000
5,010
5,020
5,030
5,040
5,050
5,060
ELEVATION - FEET
FIGURE 3
ELEVATION - FEET
SAND, CLAYEY, MOIST TO WET, LOOSE TO MEDIUM DENSE, BROWN (SC)
2.
3.
CLAY, SANDY, WITH OCCASIONAL SAND, CLAYEY INTERLAYERS, MOIST TO WET, MEDIUM
STIFF TO VERY STIFF, BROWN, TAN, RUST (CL, SC)
THE BORINGS WERE DRILLED ON AUGUST 13 AND 14, 2018 USING 4-INCH DIAMETER
CONTINUOUS-FLIGHT AUGERS AND A TRUCK-MOUNTED DRILL RIG.
1.
LEGEND:
NOTES:
SAND AND GRAVEL, CLEAN TO CLAYEY, MOIST TO WET, LOOSE TO DENSE, BROWN, TAN,
GRAY (SP,SP-SC, SC, GP, GP-GC, GC)
WEATHERED CLAYSTONE, SANDY, MOIST, MEDIUM HARD, BROWN, GRAY, RUST
CLAYSTONE, SANDY, MOIST, HARD, BROWN, GRAY, RUST (BEDROCK)
BORING ELEVATIONS WERE SURVEYED BY A REPRESENTATIVE OF THE CLIENT.
THESE LOGS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS AND CONCLUSIONS IN
THIS REPORT.
4.
Summary Logs of
Exploratory Borings
WC
DD
SW
-200
LL
PI
UC
SS
-
-
-
-
-
-
-
-
INDICATES MOISTURE CONTENT (%).
TH-1
TH-2 TH-3
TH-4
TH-5
TH-8
TH-7
TH-6
TH-9
TH-10
TH-11
TH-12
TH-13
Taft Hill Road
Laporte Avenue
(12.5)
(9.0) (6.5)
(5.5)
(17.0)
(3.5)
(5.0)
(4.0)
(3.0)
(2.5)
(9.0)
(6.5)
(5.5)
LEGEND:
INDICATES APPROXIMATE
LOCATION OF EXPLORATORY
BORING
INDICATES ESTIMATED
GROUNDWATER CONTOUR
ELEVATION
INDICATES DEPTH TO
GROUNDWATER
TH-1
(6.5)
FIGURE 4
Approximate
Groundwater
Elevation Contours
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CTL I T PROJECT NO. FC08483-115
0 125' 250'
APPROXIMATE
SCALE: 1"=250'
>240 MPI
40 MPI
27 MPI
Taft Hill Road
Laporte Avenue
P-5
P-1
P-6
14 MPI
22 MPI
120 MPI
P-2
P-3
P-4
LEGEND:
INDICATES LOCATION OF
PERCOLATION HOLES
INDICATES PERCOLATION RATE IN
MINUTES PER INCH
TH-1
120 MPI
FIGURE 5
Locations of Percolation
Holes and Percolation Rates
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CTL I T PROJECT NO. FC08483-115
0 125' 250'
APPROXIMATE
SCALE: 1"=250'
FIGURE 6
Underdrain
Detail
Sewer
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CTL |T PROJECT NO. FC088483-115
Underdrain
Cutoff Wall
Detail
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CTL |T PROJECT NO. FC088483-115
FIGURE 7
FIGURE 8
Conceptual
Underdrain
Service Profile
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CTL |T PROJECT NO. FC088483-115
APPENDIX A
LABORATORY TEST RESULTS
TABLE A-1: SUMMARY OF LABORATORY TEST RESULTS
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 123 PCF
From TH - 1 AT 4 FEET MOISTURE CONTENT= 12.8 %
Sample of CLAYSTONE, SANDY DRY UNIT WEIGHT= 105 PCF
From TH - 1 AT 24 FEET MOISTURE CONTENT= 16.0 %
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CTL | T PROJECT NO. FC08483-115
APPLIED PRESSURE - KSF
APPLIED PRESSURE - KSF
COMPRESSION % EXPANSION
Swell Consolidation
Test Results FIGURE A-1
COMPRESSION % EXPANSION
-4
-3
-2
-1
0
1
2
3
EXPANUND SIONC ER ON ST A N T
P R E S SUDUE RE TO W ET T IN G
-4
-3
-2
-1
0
1
2
3
EXPANUN SIONDC ER ON ST AN T
PREESSUDUE RE TO W ET T IN G
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 107 PCF
From TH - 2 AT 9 FEET MOISTURE CONTENT= 19.7 %
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CTL | T PROJECT NO. FC08483-115
APPLIED PRESSURE - KSF
COMPRESSION % EXPANSION
Swell Consolidation
Test Results
FIGURE A-2
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
EXPANSIONUC NDER ONST ANT
P RE SS U R E D UE TO W ETTIN G
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 105 PCF
From TH - 3 AT 4 FEET MOISTURE CONTENT= 19.1 %
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CTL | T PROJECT NO. FC08483-115
APPLIED PRESSURE - KSF
COMPRESSION % EXPANSION
Swell Consolidation
Test Results
FIGURE A-3
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
N O MO V E MEN TWE DUE T O TTI N G
0.1 1.0 10 100
Sample of CLAYSTONE, SANDY DRY UNIT WEIGHT= 121 PCF
From TH - 3 AT 19 FEET MOISTURE CONTENT= 15.0 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 122 PCF
From TH - 4 AT 4 FEET MOISTURE CONTENT= 12.1 %
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APPLIED PRESSURE - KSF
APPLIED PRESSURE - KSF
COMPRESSION % EXPANSION
Swell Consolidation
Test Results FIGURE A-4
COMPRESSION % EXPANSION
-4
-3
-2
-1
0
1
2
3
EXPANUND SIONC ER ON ST A N T
P R E S SUDUE RE TO W ET T IN G
-4
-3
-2
-1
0
1
2
3
EXPANUN SIONDC ER ON ST AN T
PREESSUDUE RE TO W ET T IN G
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 100 PCF
From TH - 4 AT 9 FEET MOISTURE CONTENT= 28.4 %
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CTL | T PROJECT NO. FC08483-115
APPLIED PRESSURE - KSF
COMPRESSION % EXPANSION
Swell Consolidation
Test Results
FIGURE A-5
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
EXPANSIONUC NDER ONST ANT
P RE SS U R E D UE TO W ETTIN G
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 103 PCF
From TH - 5 AT 19 FEET MOISTURE CONTENT= 22.2 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 99 PCF
From TH - 6 AT 4 FEET MOISTURE CONTENT= 25.6 %
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CTL | T PROJECT NO. FC08483-115
APPLIED PRESSURE - KSF
APPLIED PRESSURE - KSF
COMPRESSION % EXPANSION
Swell Consolidation
Test Results FIGURE A-6
COMPRESSION % EXPANSION
-4
-3
-2
-1
0
1
2
3
EXPANUND SIONC ER ON ST A N T
P R E S SUDUE RE TO W ET T IN G
-4
-3
-2
-1
0
1
2
3
EXPANUN SIONDC ER ON ST AN T
PREESSUDUE RE TO W ET T IN G
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 109 PCF
From TH - 6 AT 19 FEET MOISTURE CONTENT= 20.9 %
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CTL | T PROJECT NO. FC08483-115
APPLIED PRESSURE - KSF
COMPRESSION % EXPANSION
Swell Consolidation
Test Results
FIGURE A-7
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
EXPANSIONUC NDER ONST ANT
P RE SS U R E D UE TO W ETTIN G
0.1 1.0 10 100
Sample of CLAYSTONE, SANDY DRY UNIT WEIGHT= 126 PCF
From TH - 9 AT 19 FEET MOISTURE CONTENT= 6.2 %
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CTL | T PROJECT NO. FC08483-115
APPLIED PRESSURE - KSF
COMPRESSION % EXPANSION
Swell Consolidation
Test Results
FIGURE A-8
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
EXPANSIONUC NDER ONST ANT
P RE SS U R E D UE TO W ETTIN G
0.1 1.0 10 100
Sample of CLAYSTONE, SANDY DRY UNIT WEIGHT= 120 PCF
From TH - 9 AT 24 FEET MOISTURE CONTENT= 17.5 %
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CTL | T PROJECT NO. FC08483-115
APPLIED PRESSURE - KSF
COMPRESSION % EXPANSION
Swell Consolidation
Test Results
FIGURE A-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
N O MO V E MEN TWE DUE T O TTI N G
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 110 PCF
From TH - 10 AT 4 FEET MOISTURE CONTENT= 19.5 %
Sample of CLAYSTONE, WEATHERED DRY UNIT WEIGHT= 98 PCF
From TH - 10 AT 14 FEET MOISTURE CONTENT= 26.6 %
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CTL | T PROJECT NO. FC08483-115
APPLIED PRESSURE - KSF
APPLIED PRESSURE - KSF
COMPRESSION % EXPANSION
Swell Consolidation
Test Results FIGURE A-10
COMPRESSION % EXPANSION
-4
-3
-2
-1
0
1
2
3
EXPANUND SIONC ER ON ST A N T
P R E S SUDUE RE TO W ET T IN G
-4
-3
-2
-1
0
1
2
3
EXPANUN SIONDC ER ON ST AN T
PREESSUDUE RE TO W ET T IN G
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 103 PCF
From TH - 12 AT 4 FEET MOISTURE CONTENT= 21.9 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 104 PCF
From TH - 13 AT 14 FEET MOISTURE CONTENT= 22.2 %
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CTL | T PROJECT NO. FC08483-115
APPLIED PRESSURE - KSF
APPLIED PRESSURE - KSF
COMPRESSION % EXPANSION
Swell Consolidation
Test Results FIGURE A-11
COMPRESSION % EXPANSION
-4
-3
-2
-1
0
1
2
3
EXPANUND SIONC ER ON ST A N T
P R E S SUDUE RE TO W ET T IN G
-4
-3
-2
-1
0
1
2
3
EXPANUN SIONDC ER ON ST AN T
PREESSUDUE RE TO W ET T IN G
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT= 98 PCF
From TH - 13 AT 19 FEET MOISTURE CONTENT= 25.4 %
C&A COMPANIES
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CTL | T PROJECT NO. FC08483-115
APPLIED PRESSURE - KSF
COMPRESSION % EXPANSION
Swell Consolidation
Test Results
FIGURE A-12
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
EXPANSIONUC NDER ONST ANT
P RE SS U R E D UE TO W ETTIN G
0.1 1.0 10 100
Sample of SAND, CLAYEY (SC) GRAVEL 4 % SAND 51
%
From S - 1 AT FEET SILT & CLAY 45 % LIQUID LIMIT 39
%
PLASTICITY INDEX 18 %
Sample of CLAY, SANDY (CL) GRAVEL 0 % SAND 23
%
From S - 2 AT FEET SILT & CLAY 77 % LIQUID LIMIT 43
%
PLASTICITY INDEX 23 %
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CTL | T PROJECT NO. FC08483-115
FIGURE A-13
Gradation
Test Results
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
127
5"
152
6"
200
8"
.001
45 MIN.
Sample of SAND, CLAYEY, SLIGHTLY GRAVELLY (SC) GRAVEL 8 % SAND 62
%
From TH - 1 AT 19 FEET SILT & CLAY 30 % LIQUID LIMIT %
PLASTICITY INDEX %
Sample of SAND, CLAYEY, GRAVELLY (SC) GRAVEL 27 % SAND 44
%
From TH - 9 AT 14 FEET SILT & CLAY 29 % LIQUID LIMIT %
PLASTICITY INDEX %
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CTL | T PROJECT NO. FC08483-115
FIGURE A-14
Gradation
Test Results
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
127
5"
152
6"
200
8"
.001
45 MIN.
0
10
Sample of SAND, CLAYEY, SLIGHTLY GRAVELLY (SC) GRAVEL 11 % SAND 77
%
From TH - 13 AT 9 FEET SILT & CLAY 12 % LIQUID LIMIT %
PLASTICITY INDEX %
Sample of GRAVEL % SAND %
From SILT & CLAY % LIQUID LIMIT %
PLASTICITY INDEX %
C&A COMPANIES
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CTL | T PROJECT NO. FC08483-115
FIGURE A-15
Gradation
Test Results
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
127
5"
152
6"
200
8"
.001
45 MIN.
0
10
20
#
LIQUID LIMIT %
PLASTICITY INDEX %
Location GRAVEL %
SAND %
Compaction Test Procedure ASTM D 698 SILT AND CLAY %
METHOD B
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PROJ. NO. FC08483.125
FIGURE A-16
SAND, CLAYEY
S-1 BULK COMPOSITE
45
51
Sample Description
Laboratory Moisture-
Density Test Results
95
100
105
110
115
120
125
130
135
140
0 5 10 15 20 25 30 35
MOISTURE CONTENT - % 1
DRY DENSITY - PCF
CURVE NUMBER
MAXIMUM DRY DENSITY
PCF
OPTIMUM MOISTURE CONTENT
% DRY WEIGHT
111
1
16
39
18
4
#
LIQUID LIMIT %
PLASTICITY INDEX 23 %
Location GRAVEL %
SAND %
Compaction Test Procedure ASTM D 698 SILT AND CLAY %
METHOD B
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PROJ. NO. FC08483-115
FIGURE A-17
CLAY, SANDY
S-2 BULK COMPOSITE
77
0
23
Sample Description 43
Laboratory Moisture-
Density Test Results
75
80
85
90
95
100
105
110
115
120
0 5 0.1 10 15 20 1.0 25 30 10 35
MOISTURE CONTENT - % 1
DRY DENSITY - PCF
C UR V E NU MB ER
M AXI MU M DRY D ENS IT Y
P CF
O PT IMU M MO IST UR E C ON TE NT
% DR Y W EI GH T
109
1
1 6
UNCONFINED PASSING WATER-
MOISTURE DRY LIQUID PLASTICITY APPLIED SWELL COMPRESSIVE NO. 200 SOLUBLE MAXIMUM OPTIMUM
DEPTH CONTENT DENSITY LIMIT INDEX SWELL* PRESSURE PRESSURE STRENGTH SIEVE SULFATES DENSITY MOISTURE
BORING (FEET) (%) (PCF) (%) (PSF) (PSF) (PSF) (%) (%) (PCF) (%) DESCRIPTION
S-1 0-4 8.6 39 18 45 111 16 SAND, CLAYEY (SC)
S-2 0-4 12.2 43 23 77 109 16 CLAY, SANDY (CL)
TH-1 4 12.8 123 2.4 500 CLAY, SANDY (CL)
TH-1 9 15.8 113 42 SAND, CLAYEY (SC)
TH-1 14 12.7 22 SAND, CLAYEY (SC)
TH-1 19 13.8 118 30 SAND, CLAYEY (SC)
TH-1 24 16.0 105 0.3 3,000 4,000 CLAYSTONE, SANDY
TH-2 4 9.7 62 CLAY, SANDY (CL)
TH-2 9 19.7 107 0.8 1,100 0.06 CLAY, SANDY (CL)
TH-2 24 18.4 101 15,400 CLAYSTONE, SANDY
TH-3 4 19.1 105 0.0 500 CLAY, SANDY (CL)
TH-3 19 15.0 121 0.2 2,400 CLAYSTONE, SANDY
TH-4 4 12.1 122 1.6 500 0.08 CLAY, SANDY (CL)
TH-4 9 28.4 100 0.2 1,100 CLAY, SANDY (CL)
TH-5 9 2.6 17 SAND, CLAYEY (SC)
TH-5 14 16.2 116 6,000 CLAY, SANDY (CL)
TH-5 19 22.2 103 0.1 2,400 CLAY, SANDY (CL)
TH-6 4 25.6 99 0.4 500 CLAY, SANDY (CL)
TH-6 19 20.9 109 1.0 2,400 CLAY, SANDY (CL)
TH-7 9 20.5 38 CLAY, SANDY (CL)
TH-8 4 16.0 117 34 0.08 SAND, CLAYEY (SC)
TH-9 4 23.0 104 39 19 82 CLAY, SANDY (CL)
TH-9 14 16.6 29 SAND, GRAVELLY (SP)
TH-9 19 6.2 126 0.2 2,400 3,300 CLAYSTONE, SANDY
TH-9 24 17.5 120 0.0 3,000 CLAYSTONE, SANDY
TH-10 4 19.5 110 0.7 500 1,300 CLAY, SANDY (CL)
TH-10 14 26.6 98 3.1 1,800 CLAYSTONE, WEATHERED
TH-10 19 17.6 114 15,700 CLAYSTONE, SANDY
TH-11 9 16.3 121 31 SAND, CLAYEY (SC)
TH-12 4 21.9 103 0.3 500 0.10 CLAY, SANDY (CL)
TH-12 24 15.5 120 45 23 97 CLAYSTONE, WEATHERED
TH-13 4 20.4 107 38 18 73 CLAY, SANDY (CL)
TH-13 9 11.0 12 SAND, CLAYEY (SC)
TH-13 14 22.2 104 0.4 1,800 2,900 CLAY, SANDY (CL)
TH-13 19 25.4 98 0.9 2,400 CLAY, SANDY (CL)
TH-13 14 22.2 104 0.4 1,800 2,900 CLAY, SANDY (CL)
TH-13 19 25.4 98 0.9 2,400 CLAY, SANDY (CL)
SWELL TEST RESULTS*
TABLE A-I
SUMMARY OF LABORATORY TESTING
ATTERBERG LIMITS STD. PROCTOR (ASTM D698)
Page 1 of 1
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CTL|T PROJECT NO. FC08483-115
APPENDIX B
GUIDELINE SITE GRADING SPECIFICATIONS
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CTL | T PROJECT NO. FC08453-115
Appendix B-1
GUIDELINE SITE GRADING SPECIFICATIONS
1. DESCRIPTION
This item shall consist of the excavation, transportation, placement and
compaction of materials from locations indicated on the plans, or staked by
the Engineer, as necessary to achieve preliminary street and overlot
elevations. These specifications shall also apply to compaction of excess cut
materials that may be placed outside of the development boundaries.
2. GENERAL
The Soils Engineer shall be the Owner's representative. The Soils Engineer
shall approve fill materials, method of placement, moisture contents and
percent compaction, and shall give written approval of the completed fill.
3. CLEARING JOB SITE
The Contractor shall remove all vegetation and debris before excavation or fill
placement is begun. The Contractor shall dispose of the cleared material to
provide the Owner with a clean, neat appearing job site. Cleared material
shall not be placed in areas to receive fill or where the material will support
structures of any kind.
4. SCARIFYING AREA TO BE FILLED
All topsoil and vegetable matter shall be removed from the ground surface
upon which fill is to be placed. The surface shall then be plowed or scarified
until the surface is free from ruts, hummocks or other uneven features, which
would prevent uniform compaction.
5. COMPACTING AREA TO BE FILLED
After the foundation for the fill has been cleared and scarified, it shall be
disked or bladed until it is free from large clods, brought to the proper moisture
content (0 to 3 percent above optimum moisture content for clays and within 2
percent of optimum moisture content for sands) and compacted to not less
than 95 percent of maximum dry density as determined in accordance with
ASTM D698.
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CTL | T PROJECT NO. FC08453-115
Appendix B-2
6. FILL MATERIALS
Fill soils shall be free from organics, debris or other deleterious substances,
and shall not contain rocks or lumps having a diameter greater than six (6)
inches. Fill materials shall be obtained from cut areas shown on the plans or
staked in the field by the Engineer.
On-site materials classifying as CL, CH, SC, SM, SW, SP, GP, GC and GM
are acceptable. Concrete, asphalt, organic matter and other deleterious
materials or debris shall not be used as fill.
7. MOISTURE CONTENT AND DENSITY
Fill material shall be moisture conditioned and compacted to the criteria in the
table, below. Maximum density and optimum moisture content shall be
determined from the appropriate Proctor compaction tests. Sufficient
laboratory compaction tests shall be made to determine the optimum moisture
content for the various soils encountered in borrow areas.
FILL COMPACTION AND MOISTURE REQUIREMENTS
Soil
Type
Depth from
Final Grade
(feet)
Moisture Requirement
(% from optimum)
Density Requirement
Clay
0 to 15 feet
0 to +3 95% of ASTM D 698
Sand -2 to +2 95% of ASTM D 698
The Contractor may be required to add moisture to the excavation materials in
the borrow area if, in the opinion of the Soils Engineer, it is not possible to
obtain uniform moisture content by adding water on the fill surface. The
Contractor may be required to rake or disc the fill soils to provide uniform
moisture content through the soils.
The application of water to embankment materials shall be made with any
type of watering equipment approved by the Soils Engineer, which will give the
desired results. Water jets from the spreader shall not be directed at the
embankment with such force that fill materials are washed out.
Should too much water be added to any part of the fill, such that the material
is too wet to permit the desired compaction from being obtained, rolling and all
work on that section of the fill shall be delayed until the material has been
allowed to dry to the required moisture content. The Contractor will be
permitted to rework wet material in an approved manner to hasten its drying.
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CTL | T PROJECT NO. FC08453-115
Appendix B-3
8. COMPACTION OF FILL AREAS
Selected fill material shall be placed and mixed in evenly spread layers. After
each fill layer has been placed, it shall be uniformly compacted to not less
than the specified percentage of maximum density. Fill shall be compacted to
the criteria above. At the option of the Soils Engineer, soils classifying as SW,
GP, GC, or GM may be compacted to 95 percent of maximum density as
determined in accordance with ASTM D 1557 or 70 percent relative density for
cohesionless sand soils. Fill materials shall be placed such that the thickness
of loose materials does not exceed 12 inches and the compacted lift thickness
does not exceed 6 inches.
Compaction as specified above, shall be obtained by the use of sheepsfoot
rollers, multiple-wheel pneumatic-tired rollers, or other equipment approved by
the Engineer for soils classifying as CL, CH, or SC. Granular fill shall be
compacted using vibratory equipment or other equipment approved by the
Soils Engineer. Compaction shall be accomplished while the fill material is at
the specified moisture content. Compaction of each layer shall be continuous
over the entire area. Compaction equipment shall make sufficient trips to
ensure that the required density is obtained.
9. COMPACTION OF SLOPES
Fill slopes shall be compacted by means of sheepsfoot rollers or other
suitable equipment. Compaction operations shall be continued until slopes
are stable, but not too dense for planting, and there is not appreciable amount
of loose soils on the slopes. Compaction of slopes may be done
progressively in increments of three to five feet (3' to 5') in height or after the
fill is brought to its total height. Permanent fill slopes shall not exceed 3:1
(horizontal to vertical).
10. PLACEMENT OF FILL ON NATURAL SLOPES
Where natural slopes are steeper than 20 percent in grade and the placement
of fill is required, benches shall be cut at the rate of one bench for each 5 feet
in height (minimum of two benches). Benches shall be at least 10 feet in
width. Larger bench widths may be required by the Engineer. Fill shall be
placed on completed benches as outlined within this specification.
11. DENSITY TESTS
Field density tests shall be made by the Soils Engineer at locations and
depths of his choosing. Where sheepsfoot rollers are used, the soil may be
disturbed to a depth of several inches. Density tests shall be taken in
compacted material below the disturbed surface. When density tests indicate
that the density or moisture content of any layer of fill or portion thereof is not
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CTL | T PROJECT NO. FC08453-115
Appendix B-4
within specification, the particular layer or portion shall be reworked until the
required density or moisture content has been achieved.
12. SEASONAL LIMITS
No fill material shall be placed, spread or rolled while it is frozen, thawing, or
during unfavorable weather conditions. When work is interrupted by heavy
precipitation, fill operations shall not be resumed until the Soils Engineer
indicates that the moisture content and density of previously placed materials
are as specified.
13. NOTICE REGARDING START OF GRADING
The Contractor shall submit notification to the Soils Engineer and Owner
advising them of the start of grading operations at least three (3) days in
advance of the starting date. Notification shall also be submitted at least 3
days in advance of any resumption dates when grading operations have been
stopped for any reason other than adverse weather conditions.
14. REPORTING OF FIELD DENSITY TESTS
Density tests made by the Soils Engineer, as specified under "Density Tests"
above, shall be submitted progressively to the Owner. Dry density, moisture
content, and percentage compaction shall be reported for each test taken.
15. DECLARATION REGARDING COMPLETED FILL
The Soils Engineer shall provide a written declaration stating that the site was
filled with acceptable materials and was placed in general accordance with the
specifications.
30
40
50
60
70
80
90
100
CLAY (PLASTIC) TO SILT (NON-PLASTIC)
SANDS
FINE MEDIUM COARSE
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR. 7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PERCENT PASSING
0
10
20
30
50
60
70
80
90
100
PERCENT RETAINED
40
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
127
5"
152
6"
200
8"
.001
45 MIN.
0
10
20
30
40
50
60
70
80
90
100
CLAY (PLASTIC) TO SILT (NON-PLASTIC)
SANDS
FINE MEDIUM COARSE
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR. 7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PERCENT PASSING
PERCENT RET A I NED
0
10
20
30
40
50
60
70
80
90
100
20
30
40
50
60
70
80
90
100
CLAY (PLASTIC) TO SILT (NON-PLASTIC)
SANDS
FINE MEDIUM COARSE
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR. 7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PERCENT PASSING
0
10
20
30
50
60
70
80
90
100
PERCENT RETAINED
40
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
127
5"
152
6"
200
8"
.001
45 MIN.
0
10
20
30
40
50
60
70
80
90
100
CLAY (PLASTIC) TO SILT (NON-PLASTIC)
SANDS
FINE MEDIUM COARSE
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR. 7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PERCENT PASSING
PERCENT RETAINED
0
10
20
30
40
50
60
70
80
90
100
0
10
20
30
40
50
60
70
80
90
100
CLAY (PLASTIC) TO SILT (NON-PLASTIC)
SANDS
FINE MEDIUM COARSE
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR. 7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PERCENT PASSING
0
10
20
30
50
60
70
80
90
100
PERCENT RETAINED
40
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
127
5"
152
6"
200
8"
.001
45 MIN.
0
10
20
30
40
50
60
70
80
90
100
CLAY (PLASTIC) TO SILT (NON-PLASTIC)
SANDS
FINE MEDIUM COARSE
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR. 7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PERCENT PASSING
PERCENT RETAINED
0
10
20
30
40
50
60
70
80
90
100
INDICATES DRY DENSITY (PCF).
INDICATES SWELL WHEN WETTED UNDER OVERBURDEN PRESSURE (%).
INDICATES PASSING NO. 200 SIEVE (%).
INDICATES LIQUID LIMIT.
INDICATES PLASTICITY INDEX.
INDICATES UNCONFINED COMPRESSIVE STRENGTH (PSF).
INDICATES SOLUBLE SULFATE CONTENT (%).
C&A COMPANIES
SANCTUARY WEST
CTL | T PROJECT NO. FC08483-115
DRIVE SAMPLE. THE SYMBOL 5/12 INDICATES 5 BLOWS OF A 140-POUND HAMMER
FALLING 30 INCHES WERE REQUIRED TO DRIVE A 2.5-INCH O.D. SAMPLER 12 INCHES.
WATER LEVEL MEASURED SEVERAL DAYS AFTER DRILLING.
WATER LEVEL MEASURED AT TIME OF DRILLING.
5/12
22/12
5/12
50/9
50/10
WC=23.0
DD=104
LL=39 PI=19
-200=82
WC=16.6
-200=29
WC=6.2
DD=126
SW=0.2
WC=17.5
DD=120
SW=0.0
TH-9
El. 5059.0
10/12
23/12
15/12
41/12
50/8
WC=19.5
DD=110
SW=0.7
WC=26.6
DD=98
SW=3.1
WC=17.6
DD=114
UC=15,688
TH-10
El. 5054.0
7/12
11/12
7/12
22/12
17/12
WC=16.3
DD=121
-200=31
TH-11
El. 5059.0
5/12
8/12
20/12
11/12
47/12
WC=21.9
DD=103
SW=0.3
SS=0.100
WC=15.5
DD=120
LL=45 PI=23
-200=97
TH-12
El. 5057.5
6/12
20/12
15/12
16/12
9/12
WC=20.4
DD=107
LL=38 PI=18
-200=73
WC=11.0
-200=12
WC=22.2
DD=104
SW=0.4
WC=25.4
DD=98
SW=0.9
TH-13
El. 5058.0
WC=18.4
DD=101
UC=15,350
4/12
12/12
36/12
50/9
50/10
TH-3
El. 5072.5
WC=15.0
DD=121
SW=0.2
WC=19.1
DD=105
SW=0.0
17/12
6/12
23/12
9/12
50/11
TH-4
El. 5066.5
WC=12.1
DD=122
SW=1.6
SS=0.080
WC=28.4
DD=100
SW=0.2
14/12
17/12
14/12
13/12
14/12
TH-5
El. 5078.5
WC=22.2
DD=103
SW=0.1
WC=16.2
DD=116
UC=5,959
WC=2.6
-200=17
7/12
23/12
4/12
17/12
17/12
TH-6
El. 5065.0
WC=25.6
DD=99
SW=0.4
WC=20.9
DD=109
SW=1.0
12/12
4/12
16/12
13/12
14/12
TH-7
El. 5062.5
WC=20.5
-200=38
3/12
11/12
23/12
17/12
21/12
TH-8
El. 5062.5
WC=16.0
DD=117
-200=34
SS=0.080