HomeMy WebLinkAboutTHE SAVOY - FDP230012 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT400 North Link Lane | Fort Collins, Colorado 80524
Telephone: 970-206-9455 Fax: 970-206-9441
GEOLOGIC AND PRELIMINARY
GEOTECHNICAL INVESTIGATION
THE SAVOY
FORT COLLINS, COLORADO
Prepared For:
MILESTONE DEVELOPMENT GROUP
1400 16TH Street, 6TH Floor
Denver, Colorado 80202
Attention: Carter Laing
Project No. FC10152-115
November 17, 2021
TABLE OF CONTENTS
SCOPE .................................................................................................................. 1
SUMMARY OF CONCLUSIONS ........................................................................... 1
SITE DESCRIPTION ............................................................................................. 2
SITE GEOLOGY .................................................................................................... 3
GEOLOGIC HAZARDS .......................................................................................... 3
Expansive Soils and Bedrock ............................................................................. 4
Seismicity ........................................................................................................... 5
Radioactivity ....................................................................................................... 5
FIELD AND LABORATORY INVESTIGATIONS .................................................... 6
SUBSURFACE CONDITIONS ............................................................................... 6
Natural Sand and Clay ....................................................................................... 7
Bedrock .............................................................................................................. 7
DEVELOPMENT RECOMMENDATIONS .............................................................. 8
Site Grading ....................................................................................................... 8
Sub-Excavation .................................................................................................. 8
Utility Construction ........................................................................................... 10
PRELIMINARY PAVEMENT RECOMMENDATIONS .......................................... 11
Subgrade Preparation ...................................................................................... 11
Preliminary Pavement Thickness Desig n ......................................................... 11
PRELIMINARY RECOMMENDATIONS FOR STRUCTURES ............................. 12
Foundations ..................................................................................................... 12
Slabs-on-Grade Floor Construction .................................................................. 12
Surface Drainage ............................................................................................. 13
General Design Considerations ........................................................................ 13
WATER SOLUBLE SULFATES ........................................................................... 14
RECOMMENDED FUTURE INVESTIGATIONS .................................................. 14
LIMITATIONS ...................................................................................................... 15
FIGURE 1 – LOCATIONS OF EXPLORATORY BORINGS
FIGURES 2 AND 3 – SUMMARY LOGS OF EXPLORATORY BORINGS
FIGURE 4 – CONCEPTUAL SUB-EXCAVATION PROFILE
APPENDIX A – LABORATORY TEST RESULTS
APPENDIX B – GUIDELINE SITE GRADING SPECIFICATIONS
APPENDIX C – GUIDLINE SUB-EXCAVATION SPECIFICATIONS
MILESTONE DEVELOPMENT GROUP 1
THE SAVOY
CTL | T PROJECT NO. FC10152-115
SCOPE
This report presents the results of our Geologic and Preliminary Geotechnical
Investigation. The purpose of our investigation was to identify geologic hazards that may
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 de scription of
subsoil, bedrock and groundwater conditions found in our exploratory borings, and
discussions of site development as influenced by geotechnical considerations.
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 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. No geologic or geotechnical conditions were identified
which would preclude development of this site. Expansive soils and bedrock,
regional issues of seismicity and radioactivity are the primary geologic
concerns pertaining to the development of the site .
2. The subsurface conditions encountered in our borings were variable across
the site. In general, the overburden soils encountered in our borings
consisted of 22 to 25 feet of clayey sand, sandy clay, and clean to slightly
clayey sand and gravel. Weathered claystone bedrock was encountered at
depths ranging from 22 to 24 feet below the existing ground surface to the
depths explored in four borings. Groundwater was encountered at depths
ranging from 20 to 24 feet below the existing ground surface. Groundwater
levels will not likely affect planned development at this site.
MILESTONE DEVELOPMENT GROUP 2
THE SAVOY
CTL | T PROJECT NO. FC10152-115
3. Swell-consolidation testing indicated generally non -expansive to moderate
swelling soils exist at anticipated foundation depths. High swelling soils were
generally encountered within the upper 5 feet of the overburden soils. We
anticipate shallow foundations such as post-tensioned slab (PTS)
foundations may be appropriate for the planned structures if placed on a 4-
foot sub-excavation. Deep foundations may be considered as a lower risk
alternative in areas where high swelling soils are encountered. Individual
soils and foundation investigations conducted for specific structures should
address procedures for mitigating problems associated with expansive soils
and bedrock.
4. Pavement subgrade mitigation for swell is likely over the majority of the site.
Mitigation may consist of moisture and/or chemical treatment of the subgrade
soils. A minimum of 12 inches of chemical treatment (fly ash or lime) should
be expected. Anticipated pavement thickness recommendations are provided
in this report.
5. Overall surface drainage should be designed to provide rapid run -off of
surface water away from the proposed struct ures. Water should not be
allowed to pond near the crest of slopes, on or adjacent to pavements, or
adjacent to structures. All permanent slopes should be re-vegetated to
reduce erosion.
6. Further investigations are required to make design recommendati ons for
foundations, floors, and pavements.
SITE DESCRIPTION
The site is located southeast of Le Fever Drive and Cinquefoil Lane in Fort Collins,
Colorado. At the time of our exploration the site was ungraded and undeveloped. The
8.29-acre parcel is generally in a plains area, and is primarily vegetated with natural
grasses and weeds. The site is relatively level. Multi-family residential complexes exist to
the west, south, and east of the site. A vacant grassland exists to the north of the site. No
water features or rock outcrops were noted on site. An irrigation canal trends roughly
northwest to southeast approximately 600 feet east of the site. Several reservoirs exist
approximately 1,200 feet east of the site. We understand the parcel is planned for
development of a multi-family apartment complex. A clubhouse is also planned.
Associated pavement areas will include parking and access drives. We anticipated
buildings will be wood and/or steel framed structures.
MILESTONE DEVELOPMENT GROUP 3
THE SAVOY
CTL | T PROJECT NO. FC10152-115
SITE GEOLOGY
The geology of the site was investigated through review of mapping by Colten et al
(Geologic map of the Boulder-Fort Collins-Greeley Area, Colorado, 1978). Geology was
further evaluated through review of conditions found in explorator y borings, and our
experience in the area. According to the referenced mapping, the site is characterized by
quaternary sediment underlain by the Pierre Shale unit (Kpu). Overburden soils were
judged to be quaternary sediment of eolian (Qe) origin underlain by lenses of alluvium
(Qpp).
EOLIUM (Qe)
Eolian deposits are wind-blown and typically contain varying fractions of clay, silt,
and fine sand. Problems associated with this unit can include collapsible soils, where silt
contents are high and swelling soils, where clay contents are high. Both of these potential
issues are more severe when the soils are dry. In this investigation, we did not encounter
collapsible soils, but expansive soils are present at this site.
PIERRE SHALE (Kpu)
The overburden soils are underlain by the upper shale member of the Pierre Shale
unit. This unit consists of gray concretionary silty shale.
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. Development plans are preliminary.
Planning should consider the geologic hazards discussed below. The hazards
require mitigation which could include avoidance, non-conflicting use or engineered design
and construction during site development. Geologic hazards at the site that need to be
addressed include expansive soils and bedrock, and regional issues of seismicity and
MILESTONE DEVELOPMENT GROUP 4
THE SAVOY
CTL | T PROJECT NO. FC10152-115
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.
Expansive Soils and Bedrock
Colorado is a challenging location to practice geotechnical engineering. The climate
is relatively dry, and the near-surface soils are typically dry and relatively stiff. These soils
and related sedimentary bedrock formations tend to react to changes in moisture
conditions. Some of the soils and bedrock swell as they increase in moisture and are called
expansive soils. Other soils can settle significantly upon wetting and are referred to as
collapsing soils. Most of the land available for development east of the Front Range is
underlain by expansive clay or claystone bedrock near the surface. The so ils that exhibit
collapse are more likely west of the continental divide; however, both types of soils occur all
over the state.
Covering the ground with houses, streets, driveways, patios, etc., coupled with lawn
irrigation and changing drainage pattern s, leads to an increase in subsurface moisture
conditions. As a result of this moisture fluctuation, some soil movement due to heave or
settlement is inevitable. There is risk that improvements will experience damage. It is
critical that precautions are taken to increase the chances that the foundations and slabs-
on-grade will perform satisfactorily. Engineered planning, design and construction of
grading, pavements, foundations, slabs-on-grade, and drainage can mitigate, but not
eliminate the effects of expansive and compressible soils.
The soils and bedrock at this site include clayey sand, sandy clay, and clean to
slightly clayey sand and gravel underlain by claystone bedrock. Approximately 15 percent
of the soils encountered are judged to be high swell risk. High swelling soils were primarily
encountered in the upper 5 feet of the o verburden soils. Problems associated with the
existence of expansive materials are typically mitigated through currently utilized foundation
and floor slab techniques. Individual soils and foundation investigations conducted for
specific structures should address procedures for mitigating problems associated with
expansive soils and bedrock.
MILESTONE DEVELOPMENT GROUP 5
THE SAVOY
CTL | T PROJECT NO. FC10152-115
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 ou r
understanding of the geology, the site classifies as a 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. Rad on 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 the se 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 may consist of sealing soil
gas entry areas and periodic ventila tion of below-grade spaces and perimeter drain
systems. It is relatively economical to provide for ventilatio n of perimeter drain systems or
under slab gravel layers at the time of construction, compared to retrofitting a structure after
construction. Radon rarely accumulates to significant levels in above-grade, heated and
ventilated spaces.
MILESTONE DEVELOPMENT GROUP 6
THE SAVOY
CTL | T PROJECT NO. FC10152-115
FIELD AND LABORATORY INVESTIGATIONS
Subsurface conditions were further investigated by drilling nine exploratory borings
at the approximate locations shown on Figure 1. The borings were drilled using a truck-
mounted drill rig and with 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 and field penetration resistance values are presented
in 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. Laboratory testing included
determination of moisture content and dry density, swell-consolidation characteristics,
Atterberg limits, particle-size analysis, and water-soluble sulfate content. Laboratory test
results are presented in Appendix A.
SUBSURFACE CONDITIONS
Subsurface conditions encountered in our borings were variable across the site. In
general, the overburden soils encountered in our borings consisted of 22 to 25 feet of
clayey sand, sandy clay, and clean to slightly clayey sand and gravel. Weathered claystone
bedrock was encountered at depths ranging from 22 to 24 feet below the existing ground
surface in four borings. Groundwater was encountered at depths ranging from 20 to 24 feet
below the existing ground surface. Groundwater levels will not likely affect planned
development at this site. A more detailed description of the subsurface conditions is
presented in our boring logs and laboratory testing.
MILESTONE DEVELOPMENT GROUP 7
THE SAVOY
CTL | T PROJECT NO. FC10152-115
TABLE 1: Summary of Swell Behavior by Soil Type
*Swell measured after wetting under the approximate weight of the overlying soils (overburden pressures).
Natural Sand and Clay
The soils encountered on this site included clayey sand, sandy clay, and clean to
slightly clayey sand and gravel. The thickness of soil was variable across the site, ranging
from about 22 feet to 25 feet. Field penetration resistance tests indicated the clay soils
classified as stiff to very stiff, and the granular soils classified as medium dense to very
dense. Nineteen samples of overburden soils were selected for swell-consolidation testing.
The results indicated 0.2 percent compression to 9.6 percent swell after wetting under
approximate overburden pressure. High swelling soils were encountered in the upper 5 feet
of the overburden soils. We anticipate most of the site will be considered to have low to
moderate risk of swell.
Bedrock
Weathered claystone bedrock was encountered in four of nine test holes. Bedrock
was encountered 22 to 24 feet below the existing ground surface and is generally shallower
towards the southeast edges of the site. Our experience indicates the Pierre Shale
formation can contain layers of expansive claystone that may be encountered during
design level investigations.
Soil Type Compression Range of Measured Swell (%)*
0 to <2 2 to <4 4 to <6 >6
Number of Samples and Percent
Sandy Clay 0 5 4 1 2
0% 42% 33% 8% 17%
Clayey Sand 2 5 0 0 0
28% 72% 0% 0% 0%
Overall Sample
Number 2 10 4 1 2
Overall Sample
Percent 15% 50% 20% 5% 10%
MILESTONE DEVELOPMENT GROUP 8
THE SAVOY
CTL | T PROJECT NO. FC10152-115
DEVELOPMENT RECOMMENDATIONS
Site Grading
At the time of this investigation, site grading plans were not available for review in
conjunction with this subsurface exploration program. It is important that deep fills (if
planned) be constructed as far in a dvance of surface construction as possible. It is our
experience that fill compacted in accordance with the compaction recommendations in this
report may settle about 1 percent of its height under its own weigh t. Most of this settlement
usually occurs during and soon after construction. Some additional settlement is possible
after development and landscape irrigation increases soil moisture. We recommend
delaying the construction of buildings underlain by deep f ills as long as possible to allow for
this settlement to occur. Delaying construction of structures up to one year where located
on deep fills is recommended.
The existing on-site soils are suitable for re-use as fill material provided debris or
deleterious organic materials are removed. Prior to fill placement, all trash and debris
should be removed from fill areas and properly disposed. Import fill should generally have
similar or better engineering properties as the onsite materials and should be approved by
CTL. 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.
Site grading fill should be placed in thin, loose lifts, moisture conditioned and
compacted. In areas of deep fill, we recommend higher compaction criteria to help reduce
settlement of the fill. The placement and compaction of fill should be observed, and density
tested during construction. Guideline site grading specifications are presented in Appendix
B.
Sub-Excavation
Expansive soils at this site generally consist of the upper 5 feet where soils are drier
in areas near the surface. A grading plan or cut/fill plan for the site was not available at the
MILESTONE DEVELOPMENT GROUP 9
THE SAVOY
CTL | T PROJECT NO. FC10152-115
time of this report. Drilled piers and structurally supported basement floors are normally
recommended for higher swelling sites. Sub-excavation is a ground improvement method
to reduce the potential swell and potentially allow for footing foundations and basement
slab-on-grade floors. A preliminary estimate of the depth of sub-excavation is 4 feet below
foundation bearing elevation. Site grading will impact how the sub-excavation is applied at
this site. We conservatively estimate that drilled pier foundations may be required for about
60 percent of the lots unless sub-excavation is conducted. Additional investigation is
recommended to better delineate the lots that merit and don’t merit sub-excavation, if this
approach is desired.
The bottom of the sub-excavated area should extend at least 5 feet laterally outside
the largest possible foundation footprints to ensure foundations are constructed over
moisture-conditioned fill. A conceptual sub-excavation profile is shown on Figure 4. We
recommend that a civil engineer create sub-excavation plans. The sub-excavation depth
and geometry should be verified by a surveyor prior to filling.
The excavation contractor should be chosen carefully to assure they have
experience with fill placement at over-optimum moisture and have the necessary
compaction equipment. The contractor should provide a construction disc to break down fill
materials and anticipate use of push-pull scraper operations and dozer assistance. The
operation will be relatively slow. In order for the procedure to be performed properly, close
contractor control of fill placement to specifications is required. Sub-excavation fill should
be moisture-conditioned between optimum and 3 percent above optimum moisture content
with an average test moisture content each day of at least 1.5 percent above optimum. Fill
should be compacted as recommended in Site Grading.
Special precautions should be taken for compaction of fill at corners, access ramps,
and along the perimeters of the s ub-excavation as large compaction equipment cannot
easily reach these areas. Our representative should observe placement procedures and
test compaction of the fill on a full-time basis. The swell of the moisture-conditioned fill
should be tested during and after the fill placement. Guideline sub-excavation grading
specifications are presented in Appendix C.
MILESTONE DEVELOPMENT GROUP 10
THE SAVOY
CTL | T PROJECT NO. FC10152-115
If the fill dries excessively prior to construction, it may be necessary to rework the
upper drier materials just prior to constructing foundations. We judge the fill should retain
adequate moisture for about two years and can check moisture conditions in each
excavation as construction progresses, if requested.
Sub-excavation and replacement with low swell fill will likely allow use of footing
foundations and enhance performance of slab-on-grade basement floor construction. Sub-
excavation will also enhance performance of concrete flatwork (driveways and sidewalks)
and pavements, potentially reducing warranty and maintenance costs
Utility Construction
We believe excavations for utility installation in the overburden soils can be
performed with conventional heavy-duty trenchers or large backhoes. Groundwater is not
anticipated in excavations. If groundwater is encountered during construction, dewatering
may be accomplished by sloping excavatio ns 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. Excavation slopes specified by OSHA are dependent upon soil types and
groundwater conditions encountered. Seepage and groundwater conditions in trenches
may downgrade the soil type. Contractors should identify the soils encountered in the
excavation 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. We
believe 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). The placement and compaction of fill and
backfill should be observed and tested by our firm during construction.
MILESTONE DEVELOPMENT GROUP 11
THE SAVOY
CTL | T PROJECT NO. FC10152-115
PRELIMINARY PAVEMENT RECOMMENDATIONS
Subgrade Preparation
Based on the borings, the near surface soils on this site will consist of sandy clay
and clayey sand. These soils will range from moderate to highly plastic and will provide
relatively poor subgrade support below the pavements. Mitigation for swelling soils is
typically required beneath roadways where the swell potential is greater than 2 percent.
Lime or fly ash stabilization of these soils will improve their subgrade support
characteristics, in addition to enhancing the workability of the clays and reducing water
infiltration into the underlying subgrade and the potential movements under the pavements.
Over-excavation can also be used to help mitigate swelling soils.
Preliminary Pavement Thickness Design
Preliminary guidelines for pavement systems on this site are provided. Final
pavement sections should be determined based on a design level geotechnical
investigation and anticipated frequency of load applications on the pavement during the
desired design life. Flexible hot mix asphalt (HMA) over aggregate base course (ABC) or
rigid Portland cement concrete (PCC) pavements can be used at this site for automobile
and light truck traffic use. Rigid pavements are recommended in any areas subject to heavy
truck traffic. We anticipate asphalt pavement sections for local residential streets will be on
the order of 4 to 5 inches thick over 6 inches of aggregate base course.
Portland cement concrete (PCC) pavement is recommended in areas subject to any
heavy truck traffic such as garbage pickup and/or dumpster trucks and any heavy delivery
trucks. We anticipate the use of 6 to 7 inches of PCC for general area pavements which
are not subject to truck traffic. Any areas subject to frequent heavy trucks should be
designed based on frequency and wheel loads. PCC pavements in this area are typically
reinforced due to the underlying active clays. Properly designed control joints and other
joints systems are required to control cracking and allow pavement movement.
MILESTONE DEVELOPMENT GROUP 12
THE SAVOY
CTL | T PROJECT NO. FC10152-115
PRELIMINARY RECOMMENDATIONS FOR STRUCTURES
The property is currently planned for construction of a multi-family apartment
complex. The following discussions are preliminary and are not intended for design or
construction. After grading is completed, a detailed soils and found ation investigation
should be performed. Recommendations provided here are general and for planning
purposes only.
Foundations
Our geologic and preliminary geotechnical investigation for this site indicates non-
expansive to moderate swelling soils exist at anticipated foundation elevations. Higher
swells were measured in the upper 5 feet of the overburden soils. Structures may likely be
founded on shallow foundations such as post-tensioned slab (PTS) foundations if a 4-foot
sub-excavation is used. This may reduce potential edge uplift and increase support
characteristics. Deep foundations may be recommended as a lower risk alternative. A
design level geotechnical investigation may identify potential hazards for specified areas
not indicated by our borings which may suggest the need for a deep foundation system.
Slabs-on-Grade Floor Construction
Slab-on-grade floors may be considered on low and some moderate risk sites where
potential heave is acceptable to builder s and homebuyers. Structurally supported floors
should be used on lots with high or very high risk of poor slab performance. Sub-excavation
may be used to reduce potential heave where moderate to high swelling soils are sub-
excavated and should allow wider use of slab-on-grade floors.
Structurally supported floor systems should be planned in areas where slab risk is judged
high or very high. Our firm also generally recommends structurally supported floors for
moderate (2 to less than 4 percent), high (4 to less than 6 percent) and very high (greater
than 6 percent) risk sites where walkout and garden level basements are planned. The
performance of garage floors, d riveways, sidewalks, and other surface flatwork may be
poor where expansive soils are present. Slab performance risk should be more thoroughly
defined during the design level soils and foundation investigation.
MILESTONE DEVELOPMENT GROUP 13
THE SAVOY
CTL | T PROJECT NO. FC10152-115
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 of pavements. We generally recommend slopes of at least
12 inches in the first 10 feet where practical in the landscaping areas surrounding
residences. There are practical limitations on achieving these slopes. 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.
Water can follow poorly compacted fill behind curb and gutter and in utility trenches.
This water can soften fill and undermine the performance of the roadways, flatwork, and
foundations. We recommend compactive effort be used in placement of all fill.
General Design Considerations
Exterior sidewalks and pavements supported above the on-site clays are subject to
post construction movement. Flat grades should be avoided to prevent possible ponding,
particularly next to the building due to soil movement. Positive grades away from the
buildings should be used for sidewalks and flatwork around the perimeter of the buildings in
order to reduce the possibility of lifting of th is flatwork, resulting in ponding next to the
structures. Where movement of the flatwork is objectionable, procedures recommended for
on-grade floor slabs should be considered.
Joints next to buildings should be thoroughly sealed to prevent the infiltration of
surface water. Where concrete pavement is used, joints should also be sealed to reduce
the infiltration of water. Since some post construction movement of pavement and flatwork
may occur, joints around the buildings should be periodically observed and resealed where
necessary.
MILESTONE DEVELOPMENT GROUP 14
THE SAVOY
CTL | T PROJECT NO. FC10152-115
Roof drains should be discharged well away from the structures, preferably by
closed pipe systems. Where roof drains are allowed to discharge on concrete flatwork or
pavement areas next to the structures, care should be taken to ensure the area is as water
tight as practical to eliminate the infiltration of this water next to the buildings.
WATER SOLUBLE SULFATES
Concrete that comes into contact with soils can be subject to sulfate attack. We
measured water-soluble sulfate concentrations in three samples from this site.
Concentrations were measured between below measurable limits and 0.01 percent.
Sulfate concentrations less than 0.1 percent indicate Class 0 exposure to sulfate attack for
concrete that comes into contact with the subsoils, 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 high-water
tables. 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. Review of final site grading plans by our firm;
2. Potential additional investigation to help determine extents of sub-excavation;
if considered.
3. Construction testing and observation for site development;
4. Subgrade investigation and pavement design after site grading is complete;
5. Design-level soils and foundation investigations after grading;
6. Construction testing and observation for residential building construction and
paving.
MILESTONE DEVELOPMENT GROUP 15
THE SAVOY
CTL | T PROJECT NO. FC10152-115
LIMITATIONS
Our exploratory borings were located to obtain preliminary subsoil data indicative of
conditions on this site. Although our borings were spaced to obtain a reasonably accurate
picture of subsurface conditions, 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 in the locality of this project. 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 understand ing of the
planned construction. If plans change or 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.
Hadi Al-Jassim, EIT R.B. "Chip" Leadbetter, III, P.E.
Staff Geotechnical Engineer Senior Geotechnical Engineer
Reviewed by: RBL
TH-1 TH-2
TH-6
TH-9TH-8
TH-7
TH-3 TH-4 TH-5
PRECISION DR BROOKFIELD DRCINQUEFOIL LNI-25KECHTER RD.LADY MOON DR.E. HARMONY RD.
SITE
ROCK CREEK
DR.
LEGEND:
INDICATES APPROXIMATE
LOCATION OF EXPLORATORY
BORING
TH-1
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL I T PROJECT NO. FC10152-115
FIGURE 1
Locations of
Exploratory
Borings
VICINITY MAP
(FORT COLLINS, COLORADO)
NOT TO SCALE
150'75'
APPROXIMATE
SCALE: 1" = 150'
0'
0
5
10
15
20
25
30
35
40
0
5
10
15
20
25
30
35
40
23/12
13/12
29/12
22/12
33/12
31/12
WC=8.6LL=35 PI=17-200=90
WC=9.4DD=116SW=2.1
WC=9.3DD=124SW=0.7
WC=8.6LL=35 PI=17-200=90
WC=9.4DD=116SW=2.1
WC=9.3DD=124SW=0.7
TH-1
17/12
13/12
20/12
25/12
50/6
WC=8.9DD=122SW=4.0SS=<0.01
WC=11.8DD=112SW=0.3
WC=8.9DD=122SW=4.0SS=<0.01
WC=11.8DD=112SW=0.3
TH-2
21/12
30/12
21/12
19/21
37/12
WC=11.0DD=118SW=1.7
WC=9.0DD=122SW=-0.1
WC=11.0DD=118SW=1.7
WC=9.0DD=122SW=-0.1
TH-3
26/12
23/12
31/12
14/12
20/12
28/12
WC=10.7LL=42 PI=24-200=79
WC=7.7DD=111SW=6.1
WC=15.7DD=115SW=1.7
WC=10.7LL=42 PI=24-200=79
WC=7.7DD=111SW=6.1
WC=15.7DD=115SW=1.7
TH-4
23/12
32/12
31/12
27/12
17/12
WC=6.1-200=41
WC=11.6DD=116SW=0.2
WC=6.1-200=41
WC=11.6DD=116SW=0.2
TH-5
Summary Logs of
Exploratory Borings
FIGURE 2 DEPTH - FEETDEPTH - FEETMILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
0
5
10
15
20
25
30
35
40
0
5
10
15
20
25
30
35
40
15/12
12/12
26/12
28/12
30/12
30/12
WC=7.8DD=91
SW=0.9SS=<0.01
WC=4.5LL=22 PI=11-200=32
WC=8.8DD=125SW=3.7
WC=3.5-200=10
WC=7.8DD=91
SW=0.9SS=<0.01
WC=4.5LL=22 PI=11-200=32
WC=8.8DD=125SW=3.7
WC=3.5-200=10
TH-6
20/12
14/12
18/12
20/12
24/12
WC=9.2DD=106SW=1.6
WC=17.5DD=112SW=-0.2
WC=9.2DD=106SW=1.6
WC=17.5DD=112SW=-0.2
TH-7
23/12
25/12
19/12
27/12
17/12
12/12
WC=7.0DD=127SW=9.6
WC=6.5DD=117SW=0.9
WC=11.2DD=115SW=3.4
WC=14.4DD=115SW=2.0
WC=7.0DD=127SW=9.6
WC=6.5DD=117SW=0.9
WC=11.2DD=115SW=3.4
WC=14.4DD=115SW=2.0
TH-8
11/12
16/12
19/12
16/12
18/12
WC=5.2DD=95SW=-5.3SS=0.010
WC=8.7DD=117SW=1.9
WC=5.2DD=95SW=-5.3SS=0.010
WC=8.7DD=117SW=1.9
TH-9
DEPTH - FEETDRIVE SAMPLE. THE SYMBOL 15/12 INDICATES 15 BLOWS OF A 140-POUND HAMMER FALLING
30 INCHES WERE REQUIRED TO DRIVE A 2.5-INCH O.D. SAMPLER 12 INCHES.
CLAY, SANDY, MOIST, STIFF TO VERY STIFF, BROWN (CL)
1.
NOTES:
THESE LOGS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS AND CONCLUSIONS IN THIS
REPORT.
WATER LEVEL MEASURED SEVERAL DAYS AFTER DRILLING.
SAND, CLAYEY, MOIST, MEDIUM DENSE TO DENSE, BROWN (SC)
3.
LEGEND:
SAND, GRAVELLY, MOIST, MEDIUM DENSE TO VERY DENSE, BROWN (SP, GP)
WEATHERED CLAYSTONE, SANDY, MOIST, M,EDIUM HARD, GRAY, BROWN
DEPTH - FEETWATER LEVEL MEASURED AT TIME OF DRILLING.
Summary Logs of
Exploratory Borings
THE BORINGS WERE DRILLED ON OCTOBER 21, 2021 USING 4-INCH DIAMETER
CONTINUOUS-FLIGHT AUGERS AND A TRUCK-MOUNTED DRILL RIG.
FIGURE 3
WC
DD
SW
-200
LL
PI
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 SOLUBLE SULFATE CONTENT (%).
2.
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
Conceptual
Sub-Excavation
Profile
FIGURE 4
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPENDIX A
LABORATORY TEST RESULTS
TABLE A-I: SUMMARY OF LABORATORY TEST RESULTS
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=116 PCF
From TH - 1 AT 9 FEET MOISTURE CONTENT=9.4 %
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=124 PCF
From TH - 1 AT 14 FEET MOISTURE CONTENT=9.3 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-1COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=122 PCF
From TH - 2 AT 4 FEET MOISTURE CONTENT=8.9 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-2
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
EXPANSION UNDER CONSTANT PRESSURE
DUE TO WETTING
0.1 1.0 10 100
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=112 PCF
From TH - 2 AT 14 FEET MOISTURE CONTENT=11.8 %
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=112 PCF
From TH - 2 AT 14 FEET MOISTURE CONTENT=11.8 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-3COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=118 PCF
From TH - 3 AT 9 FEET MOISTURE CONTENT=11.0 %
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=122 PCF
From TH - 3 AT 19 FEET MOISTURE CONTENT=9.0 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE
-
KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-4COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
-4
-3
-2
-1
0
1
2
3
ADDITIONAL COMPRESSION UNDER
CONSTANT PRESSURE DUE TO
WETTING
0.1 1.0 10 100
0.1 1.0 10 100
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=122 PCF
From TH - 3 AT 19 FEET MOISTURE CONTENT=9.0 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-5
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ADDITIONAL COMPRESSION UNDER
CONSTANT PRESSURE DUE TO WETTING
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=111 PCF
From TH - 4 AT 4 FEET MOISTURE CONTENT=7.7 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-6
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
8
EXPANSION UNDER CONSTANT PRESSURE
DUE TO WETTING
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=115 PCF
From TH - 4 AT 14 FEET MOISTURE CONTENT=15.7 %
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=116 PCF
From TH - 5 AT 19 FEET MOISTURE CONTENT=11.6 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-7COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=91 PCF
From TH - 6 AT 2 FEET MOISTURE CONTENT=7.8 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-8
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
EXPANSION UNDER CONSTANT PRESSURE
DUE TO WETTING
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=125 PCF
From TH - 6 AT 14 FEET MOISTURE CONTENT=8.8 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
EXPANSION UNDER CONSTANT PRESSURE
DUE TO WETTING
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=106 PCF
From TH - 7 AT 4 FEET MOISTURE CONTENT=9.2 %
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=112 PCF
From TH - 7 AT 19 FEET MOISTURE CONTENT=17.5 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-10COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
-4
-3
-2
-1
0
1
2
3
ADDITIONAL COMPRESSION UNDER
CONSTANT PRESSURE DUE TO
WETTING
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=127 PCF
From TH - 8 AT 2 FEET MOISTURE CONTENT=7.0 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-11
-3
-2
-1
0
1
2
3
4
5
6
7
8
9
10
11
12
EXPANSION UNDER CONSTANT PRESSURE
DUE TO WETTING
0.1 1.0 10 100
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=117 PCF
From TH - 8 AT 4 FEET MOISTURE CONTENT=6.5 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=115 PCF
From TH - 8 AT 9 FEET MOISTURE CONTENT=11.2 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSF
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-12COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
-3
-2
-1
0
1
2
3
4
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
0.1 1.0 10 100
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=115 PCF
From TH - 8 AT 14 FEET MOISTURE CONTENT=14.4 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-13
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
EXPANSION UNDER CONSTANT PRESSURE
DUE TO WETTING
0.1 1.0 10 100
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=117 PCF
From TH - 9 AT 9 FEET MOISTURE CONTENT=8.7 %
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-14
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
EXPANSION UNDER CONSTANT PRESSURE
DUE TO WETTING
0.1 1.0 10 100
PASSING WATER-
MOISTURE DRY LIQUID PLASTICITY APPLIED NO. 200 SOLUBLE
DEPTH CONTENT DENSITY LIMIT INDEX SWELL*PRESSURE SIEVE SULFATES
BORING (FEET)(%)(PCF)(%)(PSF)(%)(%)DESCRIPTION
TH-1 4 8.6 35 17 90 CLAY, SANDY (CL)
TH-1 9 9.4 116 2.1 1,100 CLAY, SANDY (CL)
TH-1 14 9.3 124 0.7 1,800 SAND, CLAYEY (SC)
TH-2 4 8.9 122 4.0 500 <0.01 CLAY, SANDY (CL)
TH-2 14 11.8 112 0.3 1,800 SAND, CLAYEY (SC)
TH-3 9 11.0 118 1.7 1,100 CLAY, SANDY (CL)
TH-3 19 9.0 122 -0.1 2,400 SAND, CLAYEY (SC)
TH-4 2 10.7 42 24 79 CLAY, SANDY (CL)
TH-4 4 7.7 111 6.1 500 CLAY, SANDY (CL)
TH-4 14 15.7 115 1.7 1,800 CLAY, SANDY (CL)
TH-5 9 6.1 41 SAND, CLAYEY (SC)
TH-5 19 11.6 116 0.2 2,400 SAND, CLAYEY (SC)
TH-6 2 7.8 91 0.9 200 <0.01 CLAY, SANDY (CL)
TH-6 9 4.5 22 11 32 SAND, CLAYEY (SC)
TH-6 14 8.8 125 3.7 1,800 CLAY, SANDY (CL)
TH-6 24 3.5 10 SAND (SP)
TH-7 4 9.2 106 1.6 500 CLAY, SANDY (CL)
TH-7 19 17.5 112 -0.2 2,400 SAND, CLAYEY (SC)
TH-8 2 7.0 127 9.6 200 CLAY, SANDY (CL)
TH-8 4 6.5 117 0.9 500 SAND, CLAYEY (SC)
TH-8 9 11.2 115 3.4 1,100 CLAY, SANDY (CL)
TH-8 14 14.4 115 2.0 1,800 CLAY, SANDY (CL)
TH-9 4 5.2 95 500 0.01 SAND (SP)
TH-9 9 8.7 117 1.9 1,100 CLAY, SANDY (CL)
SWELL TEST RESULTS*
TABLE A-I
SUMMARY OF LABORATORY TESTING
ATTERBERG LIMITS
Page 1 of 1
* NEGATIVE VALUE INDICATES COMPRESSION.
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL|T PROJECT NO. FC10152-115
APPENDIX B
GUIDELINE SITE GRADING SPECIFICATIONS
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTLT PROJECT NO. FC10152-115
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 an d 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 t he 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.
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTLT PROJECT NO. FC10152-115
Appendix B-2
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 opt imum 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
Overlot Grade
(feet)
Moisture Requirement
(% from optimum) Density Requirement
Clay 0 to 20 feet +1 to +4 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 no t possible to
obtain uniform moisture content by adding water on the fil l 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 Engin eer, 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.
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTLT PROJECT NO. FC10152-115
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 max imum 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 ap preciable 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.
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTLT PROJECT NO. FC10152-115
Appendix B-4
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 un til 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 repor ted 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.
APPENDIX C
GUIDELINE SITE GRADING SPECIFICATIONS
(SUB-EXCAVATION)
THE SAVOY
FORT COLLINS, COLORADO
Note: This guideline is intended for use with sub -excavation. If sub-excavation is not
selected, the guidelines in Appendix B should be followed.
C-1
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 materials that may be placed outside of the development boundaries.
2. GENERAL
The Soils Engineer shall be the Owners representative. The Soils Engineer shall
approve fill materials, method of placement, moisture content 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 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, (optimum
to 3 percent above optimum) and compacted to not less than 95 percent of maximum
density as determined in accordance with ASTM D 698.
6. FILL MATERIALS
Fill soils shall be free from vegetable matter or other deleterious substances and shall
not contain rocks 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, SP, GP, GC, and GM are acceptable.
Concrete, asphalt, and other deleterious materials or debris shall not be used as fill.
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
GUIDELINE SITE GRADING SPECIFICATIONS
(SUB-EXCAVATION)
The Savoy
Fort Collins, Colorado
C-2
7. MOISTURE CONTENT
Fill materials shall be moisture treated to within limits of optimum moisture content
specified in “Moisture Content and Density Criteria”. Sufficient laboratory compaction
tests shall be made to determine the optimum moisture content for the various soils
encountered in borrow areas or imported to the site.
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 will be required to
rake or disc the fill to provide uniform moisture content throughout the fill.
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 desire 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 MATERIALS
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 given in “Moisture Content and Density Criteria”. Fill
materials shall be placed such that the thickness of loose material does not exceed 8
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 Soils
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. MOISTURE CONTENT AND DENSITY CRITERIA
Fill material shall be substantially compacted to at least 95 percent of maximum ASTM D
698 (AASHTO T 99) dry density at optimum to 3 percent above optimum moisture
content. Additional criteria for acceptance are presented in DENSITY TESTS.
10. 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 the density or moisture content of any layer of fill or
portion thereof not within specifications, the particular layer or portion shall be reworked
until the required density or moisture content has been achieved.
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115
C-3
Allowable ranges of moisture content and density given in MOISTURE CONTENT AND
DENSITY CRITERIA are based on design considerations. The moisture shall be
controlled by the Contractor so that moisture content of the compacted earth fill, as
determined by tests performed by the Soils Engineer, shall be within the limits given.
The Soils Engineer will inform the Contractor when the placement moisture is less than
or exceeds the limits specified and the Contractor shall immediately make adjustments
in procedures as necessary to maintain placement moisture content within the specified
limits, to satisfy the following requirements.
A. Moisture
1. The average moisture content of material tested each day shall not be
less than 1.5 percent over optimum moisture content.
2. Material represented by samples tested having moisture lower than
optimum will be rejected. Such rejected materials shall be reworked until
moisture equal to or greater than 1 percent above optimum is achieved.
B. Density
1. The average dry density of material tested each day shall not be less than
95 percent of maximum ASTM D 698 dry density.
2. No more than 10 percent of the material represented by the samples
tested shall be at dry densities less than 95 percent of maximum ASTM D
698 dry density.
3. Material represented by samples tested having dry density less than 93
percent of maximum ASTM D 698 dry density will be rejected. Such
rejected materials shall be reworked until a dry density equal to or greater
than 95 percent of maximum ASTM D 698 dry density is obtained.
11. INSPECTION AND TESTING OF FILL
Inspection by the Soils Engineer shall be sufficient during the placement of fill and
compaction operations so that they can declare the fill was placed in general
conformance with specifications. All inspections necessary to test the placement of fill
and observe compaction operations will be at the expense of the Owner.
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 the moisture content
and density of previously placed materials are as specified.
13. 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.
MILESTONE DEVELOPMENT GROUP
THE SAVOY
CTL | T PROJECT NO. FC10152-115