HomeMy WebLinkAboutSONDERS VILLAGE - PDP230012 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT
400 North Link Lane | Fort Collins, Colorado 80524
Telephone: 970-206-9455 Fax: 970-206-9441
PRELIMINARY GEOTECHNICAL INVESTIGATION
WATER’S EDGE EAST
NORTHEAST OF RICHARDS LAKE
ROAD AND TURNBERRY ROAD
FORT COLLINS, COLORADO
Prepared For:
WATERS’ EDGE DEVELOPMENTS, INC.
c/o ACTUAL DEVELOPMENTS, INC.
5935 South Zang Street, Suite 230
Littleton, Colorado 80127
Attention: Joe Knopinski
Project No. FC08010.003-115
October 19, 2018
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TABLE OF CONTENTS
SCOPE ....................................................................................................................... 1
SUMMARY OF CONCLUSIONS ............................................................................... 1
SITE DESCRIPTION ................................................................................................. 2
PROPOSED DEVELOPMENT .................................................................................. 3
SITE GEOLOGY ........................................................................................................ 4
GEOLOGIC HAZARDS .............................................................................................. 4
Expansive Soils ...................................................................................................... 4
Hard Bedrock and Difficult Excavation................................................................... 5
Groundwater ........................................................................................................... 5
Seismicity................................................................................................................ 5
Radioactivity ........................................................................................................... 6
SUBSURFACE CONDITIONS ................................................................................... 6
Natural Sandy Clay ................................................................................................. 7
Existing Fill ............................................................................................................. 7
DEVELOPMENT RECOMMENDATIONS ................................................................. 7
Site Grading ............................................................................................................ 8
Imported Fill ............................................................................................................ 8
Permanent Cut and Fill Slopes .............................................................................. 9
Utility Construction .................................................................................................. 9
Underdrain ............................................................................................................ 10
PAVEMENTS ........................................................................................................... 10
Subgrade Preparation .......................................................................................... 10
Slabs-on-Grade and Basement Floor Construction ............................................. 12
Below-Grade Construction ................................................................................... 12
Surface Drainage ................................................................................................. 13
CONCRETE ............................................................................................................. 13
RECOMMENDED FUTURE INVESTIGATIONS ..................................................... 13
LIMITATIONS ........................................................................................................... 14
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TABLE OF CONTENTS cont’d
FIGURE 1 – LOCATIONS OF EXPLORATORY BORINGS
FIGURE 2 – SEWER UNDERDRAIN DETAIL
FIGURE 3 – UNDERDRAIN CUTOFF WALL DETAIL
FIGURE 4 – CONCEPTUAL UNDERDRAIN SERVICE PROFILE
APPENDIX A – SUMMARY LOGS OF EXPLORATORY BORINGS
APPENDIX B – LABORATORY TEST RESULTS
APPENDIX C – GUIDELINE SITE GRADING SPECIFICATIONS
APPENDIX D – OVER-EXCAVATION SPECIFICATIONS
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 1
SCOPE
This report presents the results of our Preliminary Geotechnical Investigation for
Water’s Edge East in Fort Collins, Colorado (Fig. 1). The purpose of our investigation
was to identify geologic hazards and geotechnical concerns which exist at the site and to
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 ground
water conditions found in our exploratory borings, recommendations for site development
and a discussion of anticipated foundation and floor systems. The scope was described
in a Service Agreement dated April 18, 2018 (DN-18-0213).
This report was prepared based upon our understanding of the planned
development. The recommendations can be used for planning of development and
design of grading. We should review 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 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. Expansive soils are the primary geotechnical
concern. No geologic or geotechnical conditions were identified which
would preclude development of this site.
2. The subsurface conditions encountered in our borings consisted of 17 to
30 feet of sandy clay. In two borings, the sandy clay was underlain by
clayey sand. The clay was underlain by weathered claystone bedrock at a
depth of 27 feet in one boring. Groundwater was encountered at depths
ranging from 16 to 29 feet below the existing ground surface in seven
borings.
3. The clay soils are expansive. Most samples compressed slightly or
swelled less than 2 percent when wetted. Three samples swelled more
than 4 percent. There was no clear trend for the locations and depths of
the higher swelling samples. The range of calculated potential ground
heave is 2.2 to 3.9 inches. The range of calculated potential heave at 7
feet (typical basement depth) from current grades is <0.5 to 2.6 inches.
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 2
4. The data indicate that footing foundations designed to maintain minimum
deadload will be suitable for most structures. It may be necessary to
extend all footings to basement level, or to remove and replace expansive
soils as moisture-treated fill in some areas (over-excavation).
5. Structurally supported floors should be planned for all non-basement,
finished living areas unless post-tensioned slab-on-grade foundations are
used. It appears risk of poor performance of slab-on-grade basement
floors will be low for most of the site.
6. Preliminary data suggest that local residential streets will likely require
swell mitigation by moisture treatment or fly ash application. A design-level
subgrade investigation and pavement design should be performed after
grading is complete.
7. Asphaltic pavement sections on the order of 5 to 6 inches for local streets
are anticipated for preliminary planning purposes. Higher traffic volumes
will likely require thicker sections, on the order of 6 to 8 inches. Chemical
stabilization of clay subgrade will likely be required.
8. Control of surface and subsurface drainage will be critical to the
performance of foundations, slabs-on-grade and pavements. Overall
surface drainage should be designed to provide rapid runoff of surface
water away from structures, and off of pavements and flatwork.
SITE DESCRIPTION
The site is located north of Richards Lake Road and East of Turnberry Road in
Fort Collins, Colorado (Fig. 1). It is partially bordered by an existing subdivision located
at the northeast corner of the intersection of Richards Lake Road and Turnberry Road.
The adjacent sites to the east, north and west are vacant. Most of the site slopes
gradually south and east. Small, local ridges and valleys are present. Topography is most
variable in the portion of the site east of the existing subdivision. In this portion of the site,
a pile of apparent fill is present. An apparent storm water detention area is south of the fill
pile. Based upon our review of historical aerial photos, the previous land use was
agricultural, and the fill was generated during site grading activities in the adjacent
subdivision between 2003 and 2009.
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 3
PROPOSED DEVELOPMENT
We understand the parcel is planned for development of attached and detached
single-family residences, assisted living facilities, a community center, commercial center
and park. Development plans are preliminary. Grading plans are not available. The
project will be accessed via paved streets and serviced by buried utilities. We assume
the residences will be 1 to 2-story, wood frame structures with basements. . The
assisted living community center and commercial buildings will likely be one-story.
PREVIOUS INVESTIGATIONS
We conducted Preliminary Geotechnical Investigations for phases of Water’s
Edge Second Filing located west of Turnberry Road. We drilled a total of 51 borings
(Project Nos. FC08010.001-115 and FC08010.002-115). Bedrock was shallower than
found at this site, and moderate to highly expansive soils were more prevalent.
FIELD AND LABORATORY INVESTIGATIONS
We investigated subsurface conditions by drilling fourteen exploratory borings at
the locations shown on Figure 1. The holes were drilled using a truck-mounted drill rig
and 4-inch diameter, continuous-flight auger. Our field representative observed drilling,
logged the soils found in the borings and obtained samples. Summary logs of the soils
found in the borings are presented in Appendix A.
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 25 to 30 feet using
a 140-pound hammer falling 30 inches. Samples recovered from the test holes were
returned to our laboratory and visually classified by our engineer. Laboratory testing
included moisture content and dry density, swell-consolidation, Atterberg limits, particle-
size analysis, and water-soluble sulfate content. Laboratory test results are presented in
Appendix B.
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 4
SITE GEOLOGY
The geology of the site was investigated through review of mapping by W.A.
Braddock and J.C. Cole (Preliminary geologic map of the Greeley 1-degree x 2-degree
quadrangle, Colorado and Wyoming, 1979). The map indicates the site is underlain by
eolian (wind-blown) soil. The upper Pierre Shale formation is mapped west of the site and
lays beneath the windblown soil.
GEOLOGIC HAZARDS
Our investigation identified several geologic hazards that must be considered
during the planning and development phases of this project. Expansive soils are the
primary hazard. None of the geologic hazards identified will preclude development of the
property. No economically valuable extractable minerals are known to occur in the
immediate area of the site. The regional concerns of seismicity and radioactivity should
also be considered.
Expansive Soils
The soils at this site include expansive clay and claystone bedrock. Bedrock was
encountered at a depth of 27 feet in only one boring and is not likely to affect the project
development. There is risk that ground heave will damage pavements, slabs-on-grade,
and foundations. Engineered design of grading, pavements, foundations, slabs and
drainage can mitigate but not eliminate the effects of expansive soils and bedrock. Most
clay samples compressed slightly or swelled less than 2 percent when wetted. Three
samples swelled more than 4 percent. There was no clear trend for the locations and
depths of the higher swelling samples. We used the results of swell tests to evaluate the
potential future heave of the soil and bedrock. The analysis involves dividing the soil
profile into layers and modeling the swell characteristics of each layer from
representative tests. Based on the swell-consolidation test results and our experience,
we have estimated the potential heave at ground and basement-level, and risk at each
boring location as shown in Table B-II. The estimates were based upon 24 feet of wetting
below existing grade. Site grading will affect potential heave.
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 5
Hard Bedrock and Difficult Excavation
Layers of cemented sandstone were not encountered during this investigation but
were encountered in several borings at sites to the west. Significant cuts may reduce
depth to bedrock to an extent where excavations into bedrock would be required. The
bedrock may be relatively difficult to excavate. While not strictly considered a geologic
hazard, difficult excavation may be encountered.
Groundwater
Groundwater was encountered in seven borings at depths of 16 to 29 feet. We
do not expect current groundwater levels will affect development and building
construction unless significate cuts occur during grading.
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.
Based on the subsurface conditions encountered in our borings and our
understanding of the geology, we judge the site classifies as a Seismic Site Class D
(2015 International Residential Code, Section 1613.5.2). 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. If seismic site
class is critical to building design, we can provide a proposal for services to determine
the site class based on a geophysical study.
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 6
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. The only reliable method
to determine the concentration of radon is to perform testing after construction.
If required, typical mitigation methods may consist of sealing soil gas entry areas
and periodic 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.
Erosion
Erosion potential is considered low. The potential will increase during
construction but should return to pre-construction rates or less if proper grading
practices, surface drainage, and re-vegetation efforts are implemented.
SUBSURFACE CONDITIONS
Subsurface conditions encountered in the borings included approximately 17 to
30 feet of sandy clay. In two borings, the sandy clay was underlain by clayey sand. The
clay was underlain by weathered claystone bedrock at a depth of 27 feet in one boring,
Groundwater was encountered at depths ranging from 16 to 29 feet in seven borings.
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 7
Natural Sandy Clay
Field penetration resistance tests indicated the sandy clay was medium-stiff to
very stiff. Thirty samples of the sandy clay were selected for swell-consolidation testing.
The results are summarized in Table A. Three samples swelled more than 4 percent
Table A
Summary of Swell Test Results
Soil Type Measured Swell*
Compression 0 to <2% 2 to <4% 4 to <6% >= 6%
Sandy Clay 5 16 6 2 1
Clayey Sand 1 0 1 0 0
Claystone 0 1 0 0 0
Total 6 17 7 2 1
* Swell measured after wetting under overburden pressure
Existing Fill
Existing fill was not encountered in our borings during this investigation. There
are existing stockpiles on site. We recommend all existing fill be removed and replaced
as compacted fill.
DEVELOPMENT RECOMMENDATIONS
We believe the primary geotechnical factor that will influence site development
and residence performance is expansive soil. This concern can be mitigated with proper
planning, engineering, design and construction. We believe there are no geologic or
geotechnical constraints that would preclude development. The data indicate that footing
foundations designed to maintain minimum deadload will be suitable for most structures.
It may be necessary to extend all footings to basement level, or to remove and replace
expansive soils as moisture-treated fill in some areas (over-excavation) in order to use
footing foundations and reduce risk of poor performance of slab-on-grade floors. Mass
over-excavation does not appear merited because the occurrence of high swelling clay is
erratic.
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 8
Excavations should be sloped or shored to meet local, State and federal safety
regulations. W e anticipate the clay will classify as Type B soil based on OSHA
standards. These classifications are based on widely spaced borings. Excavation
slopes specified by OSHA are dependent upon soil types and ground water conditions
encountered. Seepage and groundwater conditions in excavations may downgrade the
soil type. The contractor’s “competent person” is required to identify the soils
encountered in excavations and refer to OSHA standards to determine appropriate
slopes. Stockpiles of soils and equipment should not be placed within a horizontal
distance equal to one-half the excavation depth from the edge of the excavation.
Excavations deeper than 20 feet should be designed by a professional engineer.
Site Grading
Site grading plans are not available. The on-site soils are suitable for re-use as fill
material provided debris or deleterious organic materials are removed. The ground
surface in areas to be filled should be stripped of vegetation, topsoil and other
deleterious materials, scarified to a depth of at least 8 inches, moisture conditioned and
compacted as recommended below. The depth of topsoil is not anticipated to be more
than 2 to 4 inches in most areas.
Site grading fill should be placed in thin, loose lifts, moisture conditioned and
compacted. In areas of deep fill (if any), we recommend higher compaction criteria to
help reduce settlement. Compaction and moisture requirements are presented in
Appendix C. The placement and compaction of fill should be observed, and density
tested during construction. Guideline site grading specifications are presented in
Appendix C.
Imported Fill
At the time of our investigation, a large fill pile was present at the site. We judge
this material is the result of on-site or nearby grading and excavation, due to the similarity
between stockpiles and the native sandy clay soils encountered in the investigation. It is
anticipated this material will be the primary borrow source for fill operations. This material
is suitable, provided organic and deleterious materials are removed before placement
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 9
and compaction. If import material is required, samples from each source should be
provided for our review.
Permanent Cut and Fill Slopes
We recommend permanent cut and fill slopes be designed with a maximum
inclination of 3:1 (horizontal to vertical); 4:1 slopes are preferable to help control erosion.
If 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 in the overburden soils can be
performed with conventional heavy-duty trenchers or large backhoes. If deep cuts are
planned, rock excavation techniques may be required. If ground water is encountered
during construction, dewatering may be accomplished by sloping excavations to
occasional sumps where water can be removed by pumping. Utility trenches should be
sloped or shored to meet local, State and federal safety regulations as discussed in
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
to between optimum and 3 percent above optimum content for clay soils and within 2
percent of optimum moisture content for sand. Trench backfill should be compacted to
at least 95 percent of maximum dry density (ASTM D 698). We do not recommend
compaction using a sheepsfoot attachment on a backhoe. Special attention should be
paid to backfill placed adjacent to manholes as we have seen instances where excessive
settlement has occurred. Improvements placed over backfill should be designed to
accommodate movement. The placement and compaction of fill and backfill should be
observed and tested by our firm during construction.
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 10
Underdrain
Based on existing groundwater levels measured during this investigation, an
underdrain system below or adjacent to sanitary sewer mains and services (a.k.a. area
drain) is not required. We advocate underdrains because they provide a gravity outlet for
foundation drains and may help control post-construction wetting. If used, the underdrain
should consist of 0.75 to 1.5-inch clean, free draining gravel surrounding a perforated
PVC pipe (Figure 2). We believe use of perforated pipe below sanitary sewer mains is
the most effective approach; Fort Collins may require solid pipe below streets. The line
should consist of rigid PVC pipe placed at a grade of at least 0.5 percent. A positive
cutoff (concrete) should be constructed around the sewer pipe and underdrain pipe
immediately downstream of the point where the underdrain pipe leaves the sewer trench
(Figure 3). Solid pipe should be used down gradient of this cutoff wall. The underdrain
should be installed with clean-outs. To reduce the risk of cross-connecting sewer and
underdrain services, we recommend using a 4-inch diameter pipe for sewer services and
a 3-inch diameter pipe for the underdrain services.
Where feasible, the underdrain services should be installed deep enough so that
the lowest point of the basement foundation drain can be connected to the underdrain
service as a gravity outlet (Figure 4). For non-walkout basements, the low point of the
basement foundation drain may be about 2 to 3 feet deeper than foundation excavations.
For buildings with walkout basements, the low point of the basement foundation drain will
be below the frost stem 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.
PAVEMENTS
Subgrade Preparation
Our investigation indicates the near surface soils will consist of sandy clay with an
AASHTO classification of A-6. These soils are expected to be moderately plastic and will
provide relatively poor subgrade support below the pavements. The City of Fort Collins
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 11
typically requires lime or fly ash stabilization of these soils to improve their subgrade
support characteristics and reduce potential expansion.
Pavement subgrades should be prepared by scarifying to depths of 6 to 8 inches
followed by mixing with fly ash or lime. Our experience suggests 8 to 10 percent fly ash
treatment will be required as determined by the dry weight of the soil, or 5 to 7 percent
lime. Deeper application of fly ash or lime, or subgrade over-excavation and moisture-
treatment may be used to further attenuate swelling in the subgrade. Site specific testing
should be performed to determine the percent admixture for the various development
areas of the site. The stabilized subgrades should be compacted to a minimum density
of 95 percent of the maximum density determined by ASTM D 698 in a moisture range of
+3 to +6 percent of the lime/soil mixture optimum moisture content.
We anticipate asphalt pavement sections for local residential streets will be on
the order of 5 to 6 inches thick. Collectors and other higher volume pavement will likely
require thicker pavement sections, estimated on the order 6 to 8 inches. A subgrade
investigation and pavement design should be performed after site grading.
BUILDING CONSTRUCTION CONSIDERATIONS
The following discussions are preliminary and are not intended for design or
construction. After grading is completed, design-level investigations should be performed
on a building-specific basis.
Foundations
Footing foundations may be used for sites where low swelling soil is present
within depths likely to influence performance of foundations. Where moderate to high
swelling clay is present, drilled piers or another deep foundation system will be merited to
control risk of heave. Long (25 to 35 feet) drilled piers should be anticipated unless over-
excavation is performed. We judge most of the site will be suitable for use of footing
foundations designed to maintain minimum deadload. It may be necessary to extend
footings to basement level or perform over-excavation in some areas. Post-tensioned,
slab-on-grade foundations may also be considered.
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 12
Slabs-on-Grade and Basement Floor Construction
Use of structurally supported floors should be anticipated for non-basement,
finished living areas in residences. The use of slab-on-grade floors for basements
should be limited to areas where risk of poor performance is low or moderate. W e
believe most of the site will be rated with low risk of poor basement slab performance.
Structurally supported floor systems should be planned in all non-basement finished
living areas and in basements where slab risk is judged high or very high. Our firm also
generally recommends structurally supported basement floors for moderate, high and
very high-risk sites where walkout and garden level basements are planned. Slab
performance risk should be more thoroughly defined during the design level soils and
foundation investigation.
Slab-on-grade floors are typically used for commercial buildings. It may be
necessary to over-excavate a portion of the soils below these floors to reduce potential
movement.
Below-Grade Construction
Ground water was encountered during this investigation at depths of 16 to 29 feet
in most borings. With long-term development and associated landscaping, groundwater
may rise. To reduce the risk of hydrostatic pressure developing on foundation walls,
foundation drains will be necessary around the lowest below-grade areas of all
residences. We suggest foundation drains be tied to the sewer underdrain system. They
may also discharge to sumps where water can be removed by pumping. In our opinion,
underdrain systems offer more comprehensive control of ground water and better
mitigate impacts of ground water and swelling soils on foundations, slabs and
pavements. Foundation walls and grade beams should be designed to withstand lateral
earth pressures. The design pressure should be established during design-level soils
investigations.
Foundation drains are not typically used for commercial structures with no below-
grade floors. Installation of the drains may help reduce excessive wetting of soils
supporting foundations and floors.
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 13
Surface Drainage
The performance of foundations will be influenced by surface drainage. The
ground surface around proposed residences 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. There are practical limitations on achieving
these slopes. Minimum slopes of 5 percent should be designed and installed in
landscaped areas around structures with no basement. Irrigation should be minimized to
control wetting. Roof downspouts should discharge beyond the limits of 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. 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.
CONCRETE
Concrete in contact with soils can be subject to sulfate attack. We measured
water-soluble sulfate concentrations in five samples from this site. Concentrations were
less than 0.01 percent to 0.31 percent, with four samples having sulfate concentrations
less than 0.1 percent. We judge the it is likely that no special cement requirements will
be merited.
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. Concrete should be air
entrained.
RECOMMENDED FUTURE INVESTIGATIONS
Based on the results of this investigation and the proposed development, we
recommend the following investigations be performed:
1. Design-level soils investigations after grading;
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 14
2. Subgrade investigation and pavement design after site;
3. Construction testing and observation for site development and building
construction.
LIMITATIONS
Our exploratory borings were located to obtain preliminary subsoil data indicative
of conditions on this site. Variations in the subsoils not indicated in our borings are
always 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.
If we can be of further service in discussing the contents of this report or in the
analysis of the building and pavement from the geotechnical point of view, please call.
Very truly yours,
CTL | THOMPSON, INC.
Taylor H. Ray, EI
Staff Geotechnical Engineer
Reviewed by:
Ronald M. McOmber, P.E.
Chairman, Senior Principal
THR:RMM
Via email: joe@actuallp.com
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TH-13Turnberry RoadRichards Lake Road TERRY LAKE RDHWY 287
COUNTRY CLUB RD
RICHARDS LAKE RD
E DOUGLAS RD
TURNBERRY RD
SITE
LEGEND:
INDICATES APPROXIMATE
LOCATION OF EXPLORATORY
BORING
TH-1
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL I T PROJECT NO. FC08010.003-115
FIGURE 1
Locations of
Exploratory
Borings
VICINITY MAP
(FT. COLLINS, CO)
NOT TO SCALE
1,000'500'
APPROXIMATE
SCALE: 1" = 1,000'
0'
FIGURE 2
Underdrain
Detail
Sewer
CTL\T Project No. FC08010.003-115
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
FIGURE 3
Underdrain
Cutoff Wall
DetailCTL\T Project No. FC08010.003-115
WATERS' EDGE DEVELOPMENT, INC.
WATERS' EDGE EAST
FIGURE 4
Conceptual
Underdrain
Service ProfileCTL\T Project No. FC08010.003-115
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
APPENDIX A
LOGS OF EXPLORATORY BORINGS
4,990
5,000
5,010
5,020
5,030
5,040
5,050
5,060
5,070
5,000
5,010
5,020
5,030
5,040
5,050
5,060
5,070
23/12
21/12
22/12
19/12
16/12
18/12
WC=13.5DD=115SW=7.2
WC=15.1DD=115SW=0.7
WC=15.9DD=116SW=0.0
WC=13.5DD=115SW=7.2
WC=15.1DD=115SW=0.7
WC=15.9DD=116SW=0.0
TH-1
El. 5063.8
14/12
14/12
9/12
9/12
12/12
9/12
WC=8.5DD=116SW=3.2SS=0.080
WC=20.7DD=106SW=0.0
WC=8.5DD=116SW=3.2SS=0.080
WC=20.7DD=106SW=0.0
TH-2
El. 5055.9
14/12
28/12
17/12
11/12
16/12
13/12
WC=8.9DD=116-200=60UC=15,600
WC=13.7DD=103SW=-0.3
WC=19.9DD=106SW=0.7
WC=8.9DD=116-200=60UC=15,600
WC=13.7DD=103SW=-0.3
WC=19.9DD=106SW=0.7
TH-3
El. 5062.3
23/12
26/12
25/12
14/12
17/12
19/12
WC=11.2DD=120SW=4.7
WC=21.7DD=104SW=-0.2
WC=22.1DD=101SW=-0.2
WC=11.2DD=120SW=4.7
WC=21.7DD=104SW=-0.2
WC=22.1DD=101SW=-0.2
TH-4
El. 5049.8
14/12
27/12
14/12
12/12
14/12
10/12
WC=9.6DD=106SW=2.4
WC=12.1DD=116SW=1.1SS=<0.01
WC=13.2DD=114SW=0.0
WC=9.6DD=106SW=2.4
WC=12.1DD=116SW=1.1SS=<0.01
WC=13.2DD=114SW=0.0
TH-5
El. 5059.7
ELEVATION - FEETELEVATION - FEET4,990
Summary Logs of
Exploratory Borings
FIGURE A-1WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
4,990
5,000
5,010
5,020
5,030
5,040
5,050
5,060
5,070
5,000
5,010
5,020
5,030
5,040
5,050
5,060
5,070
15/12
19/12
18/12
24/12
15/12
27/12
WC=7.1DD=103SW=1.0
WC=0.0DD=121LL=32 PI=15-200=61
WC=9.4DD=110SW=0.7
WC=7.1DD=103SW=1.0
WC=0.0DD=121LL=32 PI=15-200=61
WC=9.4DD=110SW=0.7
TH-6
El. 5060.5
22/12
20/12
27/12
30/12
26/12
WC=9.0DD=113SW=2.2
WC=8.8DD=116SW=1.1
WC=9.0DD=113SW=2.2
WC=8.8DD=116SW=1.1
TH-7
El. 5050.8
15/12
16/12
13/12
17/12
12/12
46/12
WC=6.2DD=110SW=1.2SS=<0.01
WC=12.5DD=116SW=-0.2
WC=17.5DD=110SW=0.1
WC=6.2DD=110SW=1.2SS=<0.01
WC=12.5DD=116SW=-0.2
WC=17.5DD=110SW=0.1
TH-8
El. 5055.7
26/12
18/12
26/12
23/12
20/12
WC=12.9DD=119SW=4.2
WC=15.4DD=114SW=0.2
WC=12.9DD=119SW=4.2
WC=15.4DD=114SW=0.2
TH-9
El. 5045.0
12/12
18/12
26/12
26/12
28/12
21/12
WC=8.0DD=110SW=2.0
WC=8.2DD=118SW=2.3
WC=8.0DD=110SW=2.0
WC=8.2DD=118SW=2.3
TH-10
El. 5048.5
ELEVATION - FEETELEVATION - FEET4,990
Summary Logs of
Exploratory Borings
FIGURE A-2WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
4,980
4,990
5,000
5,010
5,020
5,030
5,040
5,050
5,060
5,070
4,980
4,990
5,000
5,010
5,020
5,030
5,040
5,050
5,060
5,070
9/12
6/12
11/12
20/12
21/12
14/12
WC=9.8DD=107-200=52UC=6,680
WC=10.7DD=103SW=-0.4SS=0.310
WC=13.9DD=117SW=-0.1
WC=9.8DD=107-200=52UC=6,680
WC=10.7DD=103SW=-0.4SS=0.310
WC=13.9DD=117SW=-0.1
TH-11
El. 5040.4
16/12
19/12
29/12
28/12
35/12
WC=6.9DD=117SW=3.5
WC=8.2DD=119SW=1.8
WC=9.2DD=120SW=0.3
WC=6.9DD=117SW=3.5
WC=8.2DD=119SW=1.8
WC=9.2DD=120SW=0.3
TH-12
El. 5047.1
25/12
24/12
12/12
15/12
10/12
WC=10.8DD=118SW=1.5
WC=18.8DD=109LL=33 PI=15-200=68
WC=17.5DD=112SW=0.0
WC=10.8DD=118SW=1.5
WC=18.8DD=109LL=33 PI=15-200=68
WC=17.5DD=112SW=0.0
TH-13
El. 5025.9
27/12
30/12
28/12
20/12
16/12
12/12
WC=6.4DD=114SW=2.4SS=<0.01
WC=8.3DD=110SW=0.7
WC=6.4DD=114SW=2.4SS=<0.01
WC=8.3DD=110SW=0.7
TH-14
El. 5035.2
ELEVATION - FEETFIGURE A-3
DRIVE SAMPLE. THE SYMBOL 9/12 INDICATES 9 BLOWS OF A 140-POUND HAMMER
FALLING 30 INCHES WERE REQUIRED TO DRIVE A 2.5-INCH O.D. SAMPLER 12 INCHES.ELEVATION - FEETWATER LEVEL MEASURED SEVERAL DAYS AFTER DRILLING.
CLAY, SANDY, MOIST TO WET, MEDIUM STIFF TO VERY STIFF, BROWN, DARK BROWN,
TAN, GRAY, RUST (CL)
2.
FILL, CLAY, SANDY, MOIST, BROWN
THE BORINGS WERE DRILLED ON JULY 24 AND 27, 2018 USING 4-INCH DIAMETER
CONTINUOUS-FLIGHT AUGERS AND A TRUCK-MOUNTED DRILL RIG.
1.
LEGEND:
NOTES:
SAND, CLAYEY, MOIST TO WET, MEDIUM DENSE, BROWN, GRAY, TAN (SC)
WEATHERED CLAYSTONE, SANDY, MOIST, MEDIUM HARD, BROWN, GRAY, RUST
WATER LEVEL MEASURED AT TIME OF DRILLING.
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 (%).
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 (%).
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
3.THE BORING ELEVATIONS WERE PROVIDED BY ASPEN ENGINEERING.
APPENDIX B
LABORATORY TEST RESULTS
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=115 PCF
From TH - 1 AT 2 FEET MOISTURE CONTENT=13.5 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-1
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
8
9
ANTONSTNDER CUNOSIANXPE
ETTINUE TO WDRU GESSREP
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=115 PCF
From TH - 1 AT 9 FEET MOISTURE CONTENT=15.1 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=116 PCF
From TH - 1 AT 19 FEET MOISTURE CONTENT=15.9 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-2COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNASTONER CSION UNDNAPXE
GINTTO WRE DUESU ETSERP
-4
-3
-2
-1
0
1
2
3
GINTEWETOTDUEEMENTNO MOV
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=116 PCF
From TH - 2 AT 4 FEET MOISTURE CONTENT=8.5 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=106 PCF
From TH - 2 AT 14 FEET MOISTURE CONTENT=20.7 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-3COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNASTONER CSION UNDNAPXE
GINTTO WRE DUESU ETSERP
-4
-3
-2
-1
0
1
2
3
GINTEWETOTDUEEMENTNO MOV
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=103 PCF
From TH - 3 AT 9 FEET MOISTURE CONTENT=13.7 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=106 PCF
From TH - 3 AT 19 FEET MOISTURE CONTENT=19.9 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-4COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
ONSSIMPRENAL COOIITDDA
EUDRECONSTARSURESNT PEDNU
TINGWETTO
-4
-3
-2
-1
0
1
2
3
TANSTONER CDSION UNNAPEX
INTETWTORE DUEEPRESSU G
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=120 PCF
From TH - 4 AT 4 FEET MOISTURE CONTENT=11.2 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-5
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTONSTNDER CUNOSIANXPE
ETTINUE TO WDRU GESSREP
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=104 PCF
From TH - 4 AT 14 FEET MOISTURE CONTENT=21.7 %
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=101 PCF
From TH - 4 AT 24 FEET MOISTURE CONTENT=22.1 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-6COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
ONSSIMPRENAL COOIITDDA
EUDRECONSTARSURESNT PEDNU
TINGWETTO
-4
-3
-2
-1
0
1
2
3
ONSSIMPREONAL COIITDDA
EUDRERESNT PCONSTAUN SURED
TINGTO WET
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=106 PCF
From TH - 5 AT 2 FEET MOISTURE CONTENT=9.6 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=116 PCF
From TH - 5 AT 9 FEET MOISTURE CONTENT=12.1 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-7COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNASTONER CSION UNDNAPXE
GINTTO WRE DUESU ETSERP
-4
-3
-2
-1
0
1
2
3
TANSTONER CDSION UNNAPEX
INTETWTORE DUEEPRESSU G
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=114 PCF
From TH - 5 AT 19 FEET MOISTURE CONTENT=13.2 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=103 PCF
From TH - 6 AT 4 FEET MOISTURE CONTENT=7.1 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-8COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
GNTIEWETODUE TEMENTMOVON
-4
-3
-2
-1
0
1
2
3
TANSTONER CDSION UNNAPEX
INTETWRE DUEE TOPRESSU G
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=110 PCF
From TH - 6 AT 14 FEET MOISTURE CONTENT=9.4 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=113 PCF
From TH - 7 AT 9 FEET MOISTURE CONTENT=9.0 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-9COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNASTONER CSION UNDNAPXE
GINTTO WRE DUESU ETSERP
-4
-3
-2
-1
0
1
2
3
TANSTONER CDSION UNNAPEX
INTETWTORE DUEEPRESSU G
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=116 PCF
From TH - 7 AT 19 FEET MOISTURE CONTENT=8.8 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=110 PCF
From TH - 8 AT 4 FEET MOISTURE CONTENT=6.2 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-10COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNASTONER CSION UNDNAPXE
GINTTO WRE DUESU ETSERP
-4
-3
-2
-1
0
1
2
3
TANSTONER CDSION UNNAPEX
INTETWTORE DUEEPRESSU G
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=116 PCF
From TH - 8 AT 14 FEET MOISTURE CONTENT=12.5 %
Sample of CLAYSTONE, WEATHERED DRY UNIT WEIGHT=110 PCF
From TH - 8 AT 29 FEET MOISTURE CONTENT=17.5 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-11COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
ONSSIMPRENAL COOIITDDA
EUDRECONSTARSURESNT PEDNU
TINGWETTO
-4
-3
-2
-1
0
1
2
3
TANSTONER CDSION UNNAPEX
INTETWTORE DUEEPRESSU G
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=119 PCF
From TH - 9 AT 9 FEET MOISTURE CONTENT=12.9 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-12
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTONSTNDER CUNOSIANXPE
ETTINUE TO WDRU GESSREP
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=114 PCF
From TH - 9 AT 19 FEET MOISTURE CONTENT=15.4 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=110 PCF
From TH - 10 AT 4 FEET MOISTURE CONTENT=8.0 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-13COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNASTONER CSION UNDNAPXE
GINTTO WRE DUESU ETSERP
-4
-3
-2
-1
0
1
2
3
TANSTONER CDSION UNNAPEX
INTETWTORE DUEEPRESSU G
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=118 PCF
From TH - 10 AT 14 FEET MOISTURE CONTENT=8.2 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=103 PCF
From TH - 11 AT 9 FEET MOISTURE CONTENT=10.7 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-14COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNASTONER CSION UNDNAPXE
GINTTO WRE DUESU ETSERP
-4
-3
-2
-1
0
1
2
3
ONSSIMPREONAL COIITDDA
EUDRERESNT PCONSTAUN SURED
TINGTO WET
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=117 PCF
From TH - 11 AT 19 FEET MOISTURE CONTENT=13.9 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-15
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
RDEUNSIONSCOMPRELANOITIDDA
GNTIRESSURPTAETWTODUEENSTONC
0.1 1.0 10 100
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=117 PCF
From TH - 12 AT 4 FEET MOISTURE CONTENT=6.9 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-16
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTONSTNDER CUNOSIANXPE
ETTINUE TO WDRU GESSREP
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=119 PCF
From TH - 12 AT 14 FEET MOISTURE CONTENT=8.2 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=120 PCF
From TH - 12 AT 24 FEET MOISTURE CONTENT=9.2 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-17COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNASTONER CSION UNDNAPXE
GINTTO WRE DUESU ETSERP
-4
-3
-2
-1
0
1
2
3
TANSTONER CDSION UNNAPEX
INTETWTORE DUEEPRESSU G
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=118 PCF
From TH - 13 AT 9 FEET MOISTURE CONTENT=10.8 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=112 PCF
From TH - 13 AT 19 FEET MOISTURE CONTENT=17.5 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-18COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNASTONER CSION UNDNAPXE
GINTTO WRE DUESU ETSERP
-4
-3
-2
-1
0
1
2
3
GINTEWETOTDUEEMENTNO MOV
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=114 PCF
From TH - 14 AT 2 FEET MOISTURE CONTENT=6.4 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=110 PCF
From TH - 14 AT 14 FEET MOISTURE CONTENT=8.3 %
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL | T PROJECT NO. FC08010.003-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE B-19COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNASTONER CSION UNDNAPXE
GINTTO WRE DUESU ETSERP
-4
-3
-2
-1
0
1
2
3
TANSTONER CDSION UNNAPEX
INTETWTORE DUEEPRESSU G
0.1 1.0 10 100
0.1 1.0 10 100
UNCONFINED PASSING WATER-
MOISTURE DRY LIQUID PLASTICITY APPLIED COMPRESSIVE NO. 200 SOLUBLE
DEPTH CONTENT DENSITY LIMIT INDEX SWELL*PRESSURE STRENGTH SIEVE SULFATES
BORING (FEET)(%)(PCF)(%)(PSF)(PSF)(%)(%)DESCRIPTION
TH-1 2 13.5 115 7.2 500 CLAY, SANDY (CL)
TH-1 9 15.1 115 0.7 1,100 CLAY, SANDY (CL)
TH-1 19 15.9 116 0.0 2,400 CLAY, SANDY (CL)
TH-2 4 8.5 116 3.2 500 0.08 CLAY, SANDY (CL)
TH-2 14 20.7 106 0.0 1,800 CLAY, SANDY (CL)
TH-3 4 8.9 116 15,648 60 CLAY, SANDY (CL)
TH-3 9 13.7 103 -0.3 1,100 CLAY, SANDY (CL)
TH-3 19 19.9 106 0.7 2,400 CLAY, SANDY (CL)
TH-4 4 11.2 120 4.7 500 CLAY, SANDY (CL)
TH-4 14 21.7 104 -0.2 1,800 CLAY, SANDY (CL)
TH-4 24 22.1 101 -0.2 3,000 SAND, CLAYEY (SC)
TH-5 2 9.6 106 2.4 500 CLAY, SANDY (CL)
TH-5 9 12.1 116 1.1 1,100 <0.01 CLAY, SANDY (CL)
TH-5 19 13.2 114 0.0 2,400 CLAY, SANDY (CL)
TH-6 4 7.1 103 1.0 500 CLAY, SANDY (CL)
TH-6 9 0.0 121 32 15 61 CLAY, SANDY (CL)
TH-6 14 9.4 110 0.7 1,800 CLAY, SANDY (CL)
TH-7 9 9.0 113 2.2 1,100 CLAY, SANDY (CL)
TH-7 19 8.8 116 1.1 2,400 CLAY, SANDY (CL)
TH-8 4 6.2 110 1.2 500 <0.01 CLAY, SANDY (CL)
TH-8 14 12.5 116 -0.2 1,800 CLAY, SANDY (CL)
TH-8 29 17.5 110 0.1 3,000 CLAYSTONE, WEATHERED
TH-9 9 12.9 119 4.2 1,100 CLAY, SANDY (CL)
TH-9 19 15.4 114 0.2 2,400 CLAY, SANDY (CL)
TH-10 4 8.0 110 2.0 500 CLAY, SANDY (CL)
TH-10 14 8.2 118 2.3 1,800 CLAY, SANDY (CL)
TH-11 4 9.8 107 6,680 52 CLAY, SANDY (CL)
TH-11 9 10.7 103 -0.4 1,100 0.31 CLAY, SANDY (CL)
TH-11 19 13.9 117 -0.1 2,400 CLAY, SANDY (CL)
TH-12 4 6.9 117 3.5 500 SAND, CLAYEY (SC)
SWELL TEST RESULTS*
TABLE B-I
SUMMARY OF LABORATORY TESTING
ATTERBERG LIMITS
Page 1 of 2
* NEGATIVE VALUE INDICATES COMPRESSION.
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL|T PROJECT NO. FC08010.003-115
UNCONFINED PASSING WATER-
MOISTURE DRY LIQUID PLASTICITY APPLIED COMPRESSIVE NO. 200 SOLUBLE
DEPTH CONTENT DENSITY LIMIT INDEX SWELL*PRESSURE STRENGTH SIEVE SULFATES
BORING (FEET)(%)(PCF)(%)(PSF)(PSF)(%)(%)DESCRIPTION
SWELL TEST RESULTS*
TABLE B-I
SUMMARY OF LABORATORY TESTING
ATTERBERG LIMITS
TH-12 14 8.2 119 1.8 1,800 CLAY, SANDY (CL)
TH-12 24 9.2 120 0.3 3,000 CLAY, SANDY (CL)
TH-13 9 10.8 118 1.5 1,100 CLAY, SANDY (CL)
TH-13 14 18.8 109 33 15 68 CLAY, SANDY (CL)
TH-13 19 17.5 112 0.0 2,400 CLAY, SANDY (CL)
TH-14 2 6.4 114 2.4 500 <0.01 CLAY, SANDY (CL)
TH-14 14 8.3 110 0.7 1,800 CLAY, SANDY (CL)
Page 2 of 2
* NEGATIVE VALUE INDICATES COMPRESSION.
WATERS' EDGE DEVELOPMENTS, INC.
WATERS' EDGE EAST
CTL|T PROJECT NO. FC08010.003-115
TABLE B-II: HEAVE ESTIMATES
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115 TABLE B-II
The slab risk assessment is preliminary. Site grading will affect potential heave.
Boring
Basement Slab
Performance
Risk*
Total Heave Estimate (Inches)
Ground Surface Basement Level
TH-1 Low 3.5 0.5
TH-2 Low 2.2 <0.5
TH-3 Low 3.9 1.1
TH-4 Low 3.4 0.6
TH-5 Low 2.2 0.8
TH-6 Low 3.6 1.6
TH-7 Moderate 3.6 2.4
TH-8 Low 2.4 1.4
TH-9 Moderate 3.5 2.6
TH-10 Low 3.7 2.2
TH-11 Low 2.3 0.6
TH-12 Low 3.7 1.7
TH-13 Low 3.2 1.4
TH-14 Low 2.5 1.1
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115
APPENDIX C
GUIDELINE SITE GRADING SPECIFICATIONS
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115
Appendix C-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.
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.
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115
Appendix C-2
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 20 feet
0 to +3 95% of ASTM D 698
Sand -2 to +2 95% of ASTM D 698
Clay Greater than 20
feet
-2 to +1 98% of ASTM D 698
Sand -2 to +1 95% of ASTM D 1557
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.
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.
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115
Appendix C-3
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 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.
WATERS’ EDGE DEVELOPMENTS, INC
WATER’S EDGE EAST
CTLT PROJECT NO. FC08010.003-115
Appendix C-4
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.
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