HomeMy WebLinkAboutTHE SAVOY - FDP230012 - SUBMITTAL DOCUMENTS - ROUND 2 - GEOTECHNICAL (SOILS) REPORT
CTL|Thompson, Inc.
Denver, Fort Collins, Colorado Springs, Glenwood Springs, Pueblo, Summit County – Colorado
Cheyenne, Wyoming and Bozeman, Montana
The Savoy
Proposed Multi-Family Residential Community
Fort Collins, Colorado
Prepared for:
Milestone Development Group, LLC
1400 16th Street 6th Floor
Denver, Colorado 80202-1473
Attention:
Carter Laing
Project No. FC10774.000-120
May 9, 2023
SOIL AND FOUNDATION INVESTIGATION
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTLT PROJECT NO. FC10774.000-120
Table of Contents
Scope 1
Summary Of Conclusions 1
Site Description 2
Proposed Construction 4
Investigation 4
Subsurface Conditions 4
Overburden Soils 5
Bedrock 5
Groundwater 5
Geologic Hazards 6
Seismicity 7
Site Development 8
Fill Placement 8
Excavations 9
Over-Excavation 9
Foundations 11
Post-Tensioned Slab-On-Grade (PTS) 11
Footings with Minimum Dead Load 13
Floor Systems and Slab-On-Grade Floors 14
Slab Performance Risk 14
Structurally Supported Floors 14
Porches, Decks and Patios 15
Garage Slabs and Exterior Flatwork 16
Below-Grade Walls 17
Backfill Compaction 17
Pool and Pool Deck 18
Subsurface Drains and Surface Drainage 21
Pavements 21
Pavement Selection 22
Subgrade and Pavement Materials and Construction 22
Pavement Maintenance 23
Concrete 23
Construction Observations 24
Geotechnical Risk 25
Limitations 25
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FIGURE 1 – LOCATIONS OF EXPLORATORY BORINGS
FIGURES 2 THROUGH 5 – SUMMARY LOGS OF EXPLORATORY BORINGS
APPENDIX A – RESULTS OF LABORATORY TESTING
Table A-I – Summary of Laboratory Test Results
APPENDIX B – SLAB PERFORMANCE RISK EVALUATION, INSTALLATION, AND
MAINTENANCE
APPENDIX C – SURFACE DRAINAGE, IRRIGATION AND MAINTENANCE
APPENDIX D – SAMPLE SITE GRADING SPECIFICATIONS
APPENDIX E – PAVEMENT CONSTRUCTION RECOMMENDATIONS
APPENDIX F – PAVEMENT MAINTENANCE PROGRAM
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
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Scope
This report presents the results of our Soils and Foundation Investigation for a development
that includes eight proposed multi-family structures, clubhouse, and ancillary structures, located
northeast of Cinquefoil Lane and Precision Drive in Fort Collins, Colorado (Figure 1). The purpose
of our investigation was to evaluate the subsurface conditions in order to provide geotechnical
design and construction recommendations for the proposed development. The scope was
described in our Service Agreement (Proposal No. FC-23-0117) dated March 16, 2023.
This report was prepared from data developed during field exploration, laboratory testing,
engineering analysis, and experience with similar conditions. It includes our opinions and
recommendations for design criteria and construction details for foundations and floor systems,
slabs-on-grade, lateral earth loads, and drainage precautions. The report was prepared for the
exclusive use of Milestone Development Group, LLC and their development team, in design and
construction of multi-family structures in the referenced development. Other types of construction
may require revision of this report and the recommended design criteria. A brief summary of our
conclusions and recommendations follows. Detailed design criteria are presented within the
report.
Summary Of Conclusions
1. Soils encountered in our borings consisted of 10 to 25 feet of sandy clay and clayey
sand. Interbedded claystone and sandstone bedrock was encountered at depths
of 23 and 24 feet below the existing ground surface to the depths explored in two
borings.
2. Groundwater was measured at a depth 23 feet in one boring during drilling. When
measured several days later, groundwater was encountered at a depth of 23 feet
in one boring.
3. The presence of expansive soils and bedrock constitutes a geologic hazard. There
is risk that slabs-on-grade and foundations will heave or settle and be damaged.
We judge the risk is moderate to high. We believe the recommendations
presented in this report will help to control risk of damage; they will not eliminate
that risk. Slabs-on-grade and, in some instances, foundations may be damaged.
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4. Post tension slabs and footing foundations designed to maintain a minimum dead
load placed on natural, undisturbed soil and/or properly compacted fill are
considered appropriate for the site provided foundations are constructed on a
moisture treated soil layer. Design and construction criteria for foundations are
presented in the report.
5. The risk of poor slab performance is rated moderate to high for the lots included.
If the risk of potential movements can be tolerated, a post-tensioned slab can help
reduce the potential for foundation movements if constructed on a 6-foot-thick
compacted soil mat (over-excavation). Alternatively, as a higher risk option, slab-
on-grade floors can be constructed on a minimum 10-foot-thick compacted soil mat
(over-excavation). Pavements and other exterior flatwork will be slabs-on-grade
and may heave or settle and crack.
6. Surface drainage should be designed, constructed, and maintained to provide
rapid removal of surface runoff away from the proposed structures. Conservative
irrigation practices should be followed to avoid excessive wetting.
7. The design and construction criteria for foundations and floor system alternatives
in this report were compiled with the expectation that all other recommendations
presented related to surface and subsurface drainage, landscaping irrigation,
backfill compaction, etc. will be incorporated into the project and that property
manager will maintain the structures, use prudent irrigation practices, and maintain
surface drainage. It is critical that all recommendations in this report are followed.
Site Description
The Savoy development is located northeast of Cinquefoil Lane and Precision Drive in
Fort Collins, Colorado (Figure 1). During the time of our investigation, overlot grading was not
started. The lot slopes down gradually to the east. A creek flows to the east of the site.
Groundcover consisted of natural grasses and weeds.
A review of Google Earth historical aerial photography was performed. Based on the
available imagery, the site appears to have been primarily used for agricultural purposes prior to
2000. Starting around 2000, the site appears to be used for a variety of activities. It is clear that
fill was brought to the site but may have simply been soil and equipment storage for nearby
development. Construction should anticipate the potential for import fill to exist on the site. In
addition, other unknown temporary site development is evident on the site. Examples of Google
Earth imagery for the site are presented below.
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Google Earth historical aerial photography
2005 1999
2012 2016
2021
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Proposed Construction
The proposed multi-family development is anticipated to be wood or steel-framed, one to
three-story structures. The buildings are not currently planned to incorporate below grade
construction. We understand post tensioned foundations are preferred for the foundations. The
structures may have partial brick or stone veneer on the exterior. Foundation loads are expected
to vary between 1,000 and 3,000 pounds per lineal foot of foundation wall, with individual column
loads of 25 kips or less. We anticipate excavations of up to 3 feet will be required for frost-
protected, slab-on-grade level construction. Over-excavation (if used) will be an additional 3 to 7
feet. Final grading and landscaping will result in slightly greater depth of backfill.
Investigation
The field investigation included drilling 32 borings for the multi-family structures,
clubhouse, ancillary facilities, and parking lots. The borings were drilled to depths of
approximately 10 feet and 25 feet using 4-inch diameter continuous-flight augers, and a truck-
mounted drill. Drilling was observed by our field representative who logged the soils and bedrock.
Summary logs of the borings, including results of field penetration resistance tests, are presented
on Figures 2 through 5.
Soil and bedrock samples obtained during drilling were returned to our laboratory and
visually examined by our geotechnical engineer. Laboratory testing was assigned and included
moisture content, dry density, swell-consolidation, soil suction, particle-size analysis, Atterberg
limits, and water-soluble sulfate tests. Swell-consolidation test samples were wetted at a confining
pressure which approximated the weight of overlying soils (overburden pressures). Results of the
laboratory tests are presented in Appendix A and summarized in Table A-I.
Subsurface Conditions
Soils encountered in our borings generally consisted of 10 to 25 feet of sandy clays and
clayey sands. Interbedded claystone and sandstone bedrock was encountered from depths of
23 and 24 feet below the existing ground surface to the depths explored in borings TH-21 and
TH-26. Groundwater was measured at a depth of 23 feet in boring TH-21 during drilling. When
measured several days later, groundwater was encountered at a depth of 23 feet in boring TH-
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13. Expansive soils were identified at this site. A summary of the swell testing results is presented
in the table below. Further descriptions of the subsurface conditions are presented on our boring
logs (Figures 2 through 5) and in our laboratory test results (Appendix A).
TABLE A
SUMMARY OF SWELL TEST RESULTS
Soil Type Compression Range of Measured Swell (%)*
0 to <2 2 to <4 4 to <6 6
Number of Samples and Percent
Sand 0 1 0 0 0
0% 100% 0% 0% 0%
Clay 4 17 8 6 1
11% 47% 22% 17% 3%
Interbedded Bedrock 0 1 0 0 0
0% 100% 0% 0% 0%
Overall Sample Number 4 19 8 6 1
Overall Percent 11% 50% 21% 16% 3%
* Swell measured after wetting under the approximate weight of the overlying soils (overburden pressures).
Overburden Soils
Sandy clays and clayey sands were generally encountered to a depth explored of about 25
feet. The clay was medium stiff to very stiff and slightly moist to moist. Thirty-six samples of the
clay exhibited consolidations of 0.2 to 3.1 percent and swells of 0.0 to 9.6 percent.
Bedrock
Interbedded claystone and sandstone bedrock was encountered in two of the borings
underlying the natural soils, at depths of 23 to 24 feet. The bedrock was hard. One sample of the
bedrock exhibited a swell of 1.0 percent.
Groundwater
Groundwater was measured at a depth of 23 feet in boring TH-21 during drilling. When
measured several days later, groundwater was encountered at a depth of 23 feet in boring TH-
13. Groundwater levels are expected to fluctuate seasonally. Groundwater is not expected to
affect below-grade construction at the site.
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Geologic Hazards
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 soils 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 patterns, leads to an increase in subsurface moisture conditions.
As a result, some soil movement is inevitable. It is critical that all recommendations in this report
are followed to increase the chances that the foundations and slabs-on-grade will perform
satisfactorily. After construction, property manager must assume responsibility for maintaining the
structure and use appropriate practices regarding drainage and landscaping.
Expansive soils and bedrock are present at this site. The presence of expansive soils and
bedrock, collectively referred to as expansive or swelling soils, constitutes a geologic hazard.
There is risk that ground heave or settlement will damage slabs-on-grade and foundations. The
risks associated with swelling and compressible soils can be mitigated, but not eliminated by
careful design, construction, and maintenance procedures.
We believe the recommendations in this report will help control risk of foundation and/or
slab damage; they will not eliminate that risk. The builder and property manager should
understand that slabs-on-grade and, in some instances, foundations may be affected. Property
manager maintenance will be required to control risk. We recommend the builder provide a
booklet to the property manager that describes swelling soils and includes recommendations for
care and maintenance of structures constructed on expansive soils. Colorado Geological Survey
Special Publication 431 was designed to provide this information.
1“A Guide to Swelling Soils for Colorado Homebuyers and Homeowners,” Second Edition Revised and Updated by David
C. Noe, Colorado Geological Survey, Department of Natural Resources, Denver, Colorado, 2007.
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Seismicity
According to the USGS, Colorado’s Front Range and eastern plains are considered low
seismic hazard zones. The earthquake hazard exhibits higher risk in western Colorado compared
to other parts of the state. The Colorado Front Range area has experienced earthquakes within
the past 100 years, shown to be related to deep drilling, liquid injection, and oil/gas extraction.
Naturally occurring earthquakes along faults due to tectonic shifts are rare in this area.
The soil and bedrock at this site are not expected to respond unusually to seismic activity.
The 2021 International Building Code (Section 16.13.2.2) defers the estimation of Seismic Site
Classification to ASCE7-22, a structural engineering publication. The table below summarizes
ASCE7-22 Site Classification Criteria.
ASCE7-22 SITE CLASSIFICATION CRITERIA
Seismic Site Class 𝑣̅𝑠, Calculated Using Measured or Estimated
Shear Wave Velocity Profile (ft/s)
A. Hard Rock >5,000
B. Medium Hard Rock >3,000 to 5,000
BC. Soft Rock >2,100 to 3,000
C. Very Dense Sand or Hard Clay >1,450 to 2,100
CD. Dense Sand or Very Stiff Clay >1,000 to 1,450
D. Medium Dense Sand or Stiff Clay >700 to 1,000
DE. Loose Sand or Medium Stiff Clay >500 to 700
E. Very Loose Sand or Soft Clay ≥500
F. Soils requiring Site Response Analysis See Section 20.2.1
Based on the results of our investigation, the reduced, empirically estimated average
shear wave velocity values for the upper 100 feet range between 1,000 and 1,500 feet per second.
We judge a Seismic Site Classification of CD. The field penetration test results along with the
empirical estimates imply that shear-wave velocity seismic tests to directly measure 𝒗̅𝒔 could
result in a better Seismic Site Classification. The subsurface conditions indicate low susceptibility
to liquefaction from a materials and groundwater perspective.
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Site Development
Fill Placement
The existing onsite soils are generally suitable for re-use as new fill from a geotechnical
standpoint, provided debris or deleterious organic materials are removed. In general, import fill
should meet or exceed the engineering qualities of the onsite soils. In addition, particles larger
than 3 inches should be broken down or removed. If import material is used, it should be tested
and evaluated for approval by CTL|Thompson.
Prior to fill placement, debris, organics/vegetation and deleterious materials should be
substantially removed from areas to receive fill. The surface should be scarified to a depth of at
least 8 inches, moisture conditioned and compacted to the criteria below. Subsequent fill should
be placed in thin (8 inches or less) loose lifts, moisture conditioned, and compacted. Fill should
be compacted to a dry density of at least 95 percent of standard Proctor maximum dry density
(ASTM D 698, AASHTO T 99). Fill depths greater than 15 feet should be evaluated by CTL|T to
recommend appropriate compaction specifications. Sand soils used as fill should be moistened
to within 2 percent of optimum moisture content. Clay soils should be moistened between
optimum and 3 percent above optimum moisture content. The fill should be moisture-conditioned,
placed in thin, loose lifts (8 inches or less) and compacted as described above. We should
observe placement and compaction of fill during construction. Fill placement and compaction
should not be conducted when fill material is frozen. CTL|Thompson should observe placement
and compaction of fill during construction.
Existing fill was not encountered in our borings but appears on historical aerial
photography. Fill areas may be encountered during site development. The fill is of unknown
origin and age. The fill presents a risk of settlement or heave to improvements constructed on
the fill. We recommend any fill encountered during construction be removed, moisture treated if
necessary, and compacted. This procedure should remove the existing fill and provide more
uniform support for improvements.
Site grading in areas of landscaping where no future improvements are planned can be
placed at a dry density of at least 90 percent of standard Proctor maximum dry density (ASTM D
698, AASHTO T 99). Example site grading specifications are presented in Appendix D.
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Water and sewer lines are often constructed beneath areas where improvements are
planned. Compaction of trench backfill can have a significant effect on the life and serviceability
overlying structures. We recommend trench backfill be moisture conditioned and compacted as
described above. Placement and compaction of backfill should be observed and tested by a
representative of our firm during construction.
Excavations
We believe the soil and bedrock penetrated in our exploratory borings can generally be
excavated with conventional, heavy-duty excavation equipment. Excavations should be sloped or
shored to meet local, State, and Federal safety regulations. Excavation slopes specified by OSHA
are dependent upon types of soil and groundwater conditions encountered. The contractor’s
“competent person” is responsible to identify the soils and/or rock encountered in excavations
and refer to OSHA standards to determine appropriate slopes and safety measures. Based on
our investigation and OSHA standards, we believe the overburden soils may classify as Type B
and C soils.
Type B soils require a maximum slope inclination of 1:1 (horizontal:vertical) in dry
conditions. Type C soils require a maximum slope inclination of 1.5:1 in dry conditions.
Stockpiles of soils, rock, equipment, or other items should not be placed within a horizontal
distance equal to one-half the excavation depth, from the edge of excavation. Excavations deeper
than 20 feet should be braced, or a professional engineer should design the slopes.
Wind and water erosion is more likely with disturbed conditions expected during
construction and may need to be addressed due to municipal regulation. The erosion potential
will decrease after construction if proper grading practices, surface drainage design and re-
vegetation efforts are implemented.
Over-Excavation
We conducted swell-consolidation testing to provide a basis for calculating potential soil
heave at this site. Relatively higher swelling clay materials predominate. Potential ground heave
could be as much as 5 inches with typical post-construction wetting. Without mitigation, drilled
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pier foundations and structurally supported floors would be required. If shallow footing or post
tensioned slab foundations are desired, we recommend over-excavating to a uniform depth of at
least 6 feet below post tensioned foundations, and at least 10 feet below spread footing
foundations, to reduce potential heave to acceptable levels and provide more uniform support
conditions. Moisture conditioning of soil below foundations and floors will reduce, but not
eliminate, the risk of movement.
The existing soils are suitable for re-use as new fill from a geotechnical standpoint,
provided it is moisture conditioned and compacted. Over-excavation should extend at least 6 feet
outside the lateral extent of foundations. Provided that the over-excavation fill is low swelling, we
estimate potential movements of about 1-inch or less are probable provided excessive wetting
does not occur. Differential movements should also be substantially reduced, as the fill is
expected to act as a buffer or cushion, and distribute heave more evenly, should it occur.
In order for the over-excavation procedure to be performed properly, close control of fill
placement to specifications is required. Over-excavation fill should be placed to the criteria
presented in Fill Placement. Our field representative should observe and test compaction of fill
during placement.
Over-excavation has been used along the Colorado Front Range area with satisfactory
performance for the large majority of the sites where this ground modification method has been
completed. We have seen isolated instances where settlement of over-excavation fill has led to
damage to buildings supported on shallow foundations. In most cases, the settlement was caused
by wetting associated with poor surface drainage and/or poorly compacted fill placed at the
horizontal limits of the over-excavation. Special precautions should be taken for compaction of fill
at corners, access ramps, and edges of the over-excavation due to equipment access constraints.
The contractor should have the appropriate equipment to reach and compact these areas.
The excavation contractor should be chosen based on experience with over-excavation
and processing high moisture content clay fills and have the necessary mixing and compaction
equipment. The contractor should provide a construction disc to break down fill materials. The
operation will be relatively slow. Soil and bedrock clods should be broken down to about 3 inches
or less. The excavation slopes should meet OSHA, local, State, and Federal safety standards.
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We recommend at least 2 feet of over-excavation, moisture-conditioning and re-
compaction below pavements to reduce potential heave and improve performance. The over-
excavation can be extended beneath the adjacent sidewalks and improvements, if desired.
Deeper over-excavation below pavements can be considered for better performance.
Foundations
Our investigation indicates expansive soils were encountered at depths where they are
likely to affect foundation performance. Post-tensioned foundations are understood to be the
preferred foundation option. However, there will be other ancillary foundations that will be
supported on shallow foundations or other systems. Post-tensioned slabs and/or footing
foundations should not be constructed on native soils unless the soil has been moisture treated
to address the swell potential (see Over-Excavation).
Design criteria for post-tensioned slabs and footing foundations developed from analysis
of field and laboratory data and our experience are presented below. The builder and structural
engineer should also consider design and construction details established by the structural
warrantor (if any) that may impose additional design and installation requirements.
Post-Tensioned Slab-On-Grade (PTS)
PTS foundation design is based on a method developed by the Post-Tensioning Institute
(PTI) and is outlined in PTI’s third edition of Design of Post-Tensioned Slabs-On-Ground (2004
with 2008 Supplement). Various climate and relevant soil factors are required to evaluate the PTI
design criteria. These include Thornthwaite Moisture Index (Im), suction compression index (γh),
unsaturated diffusion coefficient (α), depth of probable moisture variation, initial and final soil
suction profiles, and percent clay fraction and predominant clay mineral. In the project area, Im is
about -25.
The PTS foundation design method is based on the potential differential movement of the
slab edges (ym) over a specified edge distance (em). Further, the PTI design method, evaluates
two mechanisms of soil movement (edge lift and center lift) based on assumptions that wetting
and drying of the foundation soils are primarily affected by seasonal climate changes. In the 2004
design manual, PTI recommends evaluating movements for a minimum depth of wetting of 9 feet
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below the ground surface. This value can be reasonable for a seasonal moisture variation;
however, our experience indicates the foundation soils will normally undergo an increase in
moisture due to covering the ground surface with buildings and flatwork, coupled with the
introduction of landscape irrigation around the buildings. Based on our experience and the
subsurface conditions at the site, the depth of wetting can be about 15 to 20 feet or more below
the ground surface.
The wetting may not penetrate this deep; however, we believe it is a reasonable design
assumption when evaluating the edge lift for this site. For the deeper depths of wetting, ground
movements can be estimated based on swell or suction profiles, or using a computer program
(such as “VOLFLO” by Geostructural Tool Kit, Inc.). The PTI design method does not predict soil
movement caused by site conditions such as excessive irrigation or poor surface drainage that
may lead to differential foundation movement in excess of the movements estimated by the PTI
design method. These conditions may also increase the edge moisture variation distance above
the design values provided in the PTI manual.
Considering the limitations of the current PTI design method, we believe a conservative
approach with reasonable engineering judgement is merited in PTS foundation design. Design
criteria for PTS foundations are presented below. Criteria were developed from analysis of field
and laboratory data, the PTS design method outlined in PTI’s third edition of Design and
Construction of Post-Tensioned Slabs-On-Ground (2004 with 2008 Supplement), and our
experience.
1. PTS foundations should be constructed on new moisture-conditioned and
compacted over-excavation fill. If fill/backfill or soft/loose soils or relatively dry soils
are exposed in footing excavations or are the result of the excavation/forming
process, these soils should be removed and recompacted.
2. PTS foundations should be designed for a maximum allowable soil pressure of
3,000 psf.
3. For design of uniform thickness PTS foundations or point loads, a modulus of
subgrade reaction (Ks) of 75 pci can be used.
4. A differential soil movement (ym) of 0.6 inches for the edge lift condition and -0.55
inches for the center lift condition can be used.
5. An edge moisture variation distance (em) of 4.5 feet for the edge lift condition and
9 feet for the center lift condition can be used.
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6. The above-grade construction, such as framing, drywall, brick and stucco should
be considered when determining the appropriate slab stiffness. We are aware of
situations where minor differential slab movement has caused distress to finish
materials. One way to enhance performance would be to place reinforcing steel in
the bottoms of stiffening beams. The structural engineer should evaluate the merits
of this approach, as well as other potential alternatives to reduce damage to finish
materials. The slab stiffness should be evaluated per section 6.10 of the PTI 2008
Supplement as it relates to different superstructure materials.
7. Stiffening beams and edge beams may be poured “neat” into excavated trenches.
Soil may cave or slough during trench excavation for the stiffening beams.
Disturbed soil should be removed from trench bottoms prior to placement of
concrete. Formwork or other methods may be required for proper stiffening beam
installation.
8. Exterior stiffening beams should be protected from frost action. Normally 2.5 feet
of frost cover is assumed in the area. If exterior patios are incorporated into the
PTS, we believe the stiffening beams around the patios should be as deep as
those around the building exterior to increase the likelihood they will perfor m
similarly to the rest of the PTS.
9. For slab tensioning design, a coefficient of friction value of 0.75 or 1.0 can be
assumed for slabs on polyethylene sheeting or a sand layer, respectively. A
coefficient of friction of 2.0 should be used for slabs on clay soils. We believe use
of polyethylene is preferable because it serves as a vapor retarder which helps to
control moisture migration up through the slabs.
10. A representative of our firm should observe the completed excavations. A
representative of the structural engineer or our firm should observe the placement
of the reinforcing tendons and any mild reinforcement prior to pouring the slabs
and beams, and observe the tendon stressing.
Footings with Minimum Dead Load
1. The footing foundation should bear on properly compacted fill (see Over-
Excavation). Where soils are loosened during excavation or in the footing forming
process the soils should be removed or compacted to at least 95 percent of
standard Proctor maximum dry density (ASTM D 698, AASHTO T 99) between
optimum and 3 percent above optimum moisture content, prior to placing concrete.
Excavation backfill placed below foundations should be compacted using the same
specifications.
2. Footings should be designed for a net allowable soil pressure of 3,000 pounds per
square foot (psf) and a minimum dead load pressure of 1,000 psf. The soil
pressure can be increased 33 percent for transient loads such as wind or seismic
loads.
3. We anticipate footings designed using the soil pressure recommended above
could experience 1-inch of movement. Differential movement of ½-inch should be
considered in the design.
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4. If interrupted footings are necessary to maintain the specified dead load, a 4-inch
void should be provided below grade beams or foundation walls, between the
pads.
5. Footings should have a minimum width of 12 inches. Foundations for isolated
columns should have minimum dimensions of 16 inches by 16 inches. Larger
sizes may be required depending upon the loads and structural system used.
6. Foundation walls should be well reinforced both top and bottom. We recommend
reinforcement sufficient to span an unsupported distance of at least 10 feet or the
distance between pads whichever is greater. Reinforcement should be designed
by the structural engineer.
7. Exterior footings must be protected from frost action per local building codes.
Normally, 30 inches of cover over footings is assumed in the area for frost
protection.
8. The completed foundation excavations should be observed by a representative of
our firm prior to placing the forms to verify subsurface conditions are as anticipated
from our borings. Our representative should also observe the placement and test
compaction of new fill placed for foundation subgrade (if merited).
Floor Systems and Slab-On-Grade Floors
Slab Performance Risk
Based on our heave calculations, the subsurface conditions found in our borings, and our
experience with construction and performance, we judge that the risk of poor slab-on-grade
performance at this site is moderate to high. Our experience indicates that slab performance is
generally satisfactory on moderate risk sites if a layer of moisture conditioned soil is provided
beneath (see Over-Excavation). If the moisture conditioned soil layer is provided, slab heave of 1
to 2 inches is considered “normal” for these sites; more or less heave can occur. If floor
movements cannot be tolerated, a structurally supported floor system should be installed. A more
detailed discussion of slab-on-grade performance risk and construction recommendations is
provided in Appendix B.
Structurally Supported Floors
Structural floors should be used in finished living areas if floor movement and cracking are
unacceptable. A structural floor is supported by the foundation system. There are design and
construction issues associated with structural floors that must be considered, such as ventilation
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and lateral loads. Where structurally supported floors are installed, the required air space
depends on the materials used to construct the floor and the expansion potential of the underlying
soils. Building codes require a clear space of 18 inches above exposed earth if untreated wood
floor components are used. Where other floor support materials are used, a minimum clear space
of 12 inches should be maintained. This minimum clear space should be maintained between
any point on the underside of the floor system (including beams and floor drain traps) and the
surface of the exposed earth.
Where structurally supported floors are used, utility connections, including water, gas, air
duct and exhaust stack connections to floor supported appliances, should be capable of absorbing
some deflection of the floor. Plumbing that passes through the floor should ideally be hung from
the underside of the structural floor and not lain on the bottom of the excavation. This
configuration may not be achievable for some parts of the installation. It is prudent to maintain
the minimum clear space below all plumbing lines. If trenching below the lines is necessary, we
recommend sloping these trenches so they discharge to the foundation drains.
Control of humidity in crawlspaces is important for indoor air quality and performance of
wood floor systems. We believe the best current practices to control humidity involve the use of
a vapor retarder (10-mil minimum), placed on the exposed soils below accessible sub-floor areas.
The vapor retarder should be sealed at joints and attached to concrete foundation elements. If
desired, we can provide designs for ventilation systems that can be installed in association with
a vapor retarder, to improve control of humidity in crawlspace areas. The Moisture Management
Task Force of Metro Denver2 has compiled additional discussion and recommendations regarding
best practices for the control of humidity in below-grade, under-floor spaces.
Porches, Decks and Patios
Porches or decks with overhanging roofs that are integral with the structure such that
excessive foundation movement cannot be tolerated, should be constructed with the same
foundation type as the house. Simple decks, that are not integral with the structure and can
tolerate foundation movement, can be constructed with less substantial foundations. A short pier
2 “Guidelines for Design and Construction of New Homes with Below-Grade Under-Floor Spaces,” Moisture Management Task
Force, October 30, 2003.
MILESTONE DEVELOPMENT GROUP, LLC
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16
or footing bottomed at least 3 feet below grade can be used if movement is acceptable. Use of
8-foot to 10-foot piers can reduce potential movement. Footings or short piers should not be
bottomed in wall backfill or undocumented fill due to risk of settlement. The inner edge of the
deck may be constructed on haunches or steel angles bolted to the foundation walls and detailed
such that movement of the deck foundation will not cause distress to the structure. We suggest
use of adjustable bracket-type connections or other details between foundations and deck posts
so the posts can be trimmed or adjusted if movement occurs.
Porches, patio slabs, and other exterior flatwork should be isolated from the structures.
Porch slabs can be constructed to reduce the likelihood that settlement or heave will affect the
slabs. One approach (for smaller porches located over backfill zones) is to place loose backfill
under a structurally supported slab. This fill will more likely settle than swell, and can thus
accommodate some heave of the underlying soils. A lower risk approach is to construct the porch
slab over void-forming materials. Conditions should allow the void-forming materials to soften
quickly after construction to reduce the risk of transmitting ground heave to the porch slab. Wax
or plastic-coated void boxes should not be used unless provisions are made to allow water to
penetrate into the boxes.
Garage Slabs and Exterior Flatwork
Garage floors, pavements, and sidewalks are normally constructed as slabs-on-grade.
Performance of conventional slabs on expansive soils is erratic. Various properties of the soils
and environmental conditions influence magnitude of movement and other performance.
Increases in the moisture content in these soils will cause heaving and may result in cracking of
slabs-on-grade. The performance of garage and driveway slabs-on-grade can be improved by
placing these structures over at least 6 feet of over-excavated, moisture conditioned and
recompacted fill. Deeper moisture treatment will further lower the risk of movement. Backfill
below slabs should be moisture conditioned and compacted to reduce settlement, as discussed
in Backfill Compaction. Driveways and exterior slabs founded on the backfill may settle and crack
if the backfill is not properly moisture treated and compacted. Where slabs-on-grade are used,
we recommend adherence to the precautions for slab-on-grade construction that are included in
Appendix B.
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Below-Grade Walls
Below grade and/or foundation walls and grade beams that extend below grade should be
designed for lateral earth pressures where backfill is not present to about the same extent on both
sides of the wall. Many factors affect the value of the design lateral earth pressure. These factors
include, but are not limited to, the type, compaction, slope and drainage of the backfill, and the
rigidity of the wall against rotation and deflection. For a very rigid wall where negligible or very
little deflection will occur, an "at-rest" lateral earth pressure should be used in design. For walls
that can deflect or rotate 0.5 to 1 percent of the wall height (depending upon the backfill types),
lower "active" lateral earth pressures are appropriate. Our experience indicates below grade walls
can deflect or rotate slightly under normal design loads and that this deflection results in
satisfactory wall performance. Thus, the earth pressure on the walls will likely be between the
"active" and "at-rest" conditions.
If on-site soils are used as backfill and the backfill is not saturated, we recommend design
of below grade walls at this site using an equivalent fluid density of at least 55 pounds per cubic
foot (pcf). This value assumes deflection; some minor cracking of walls may occur. If very little
wall deflection is desired, higher design density may be appropriate. The structural engineer
should also consider site-specific grade restrictions and the effects of large openings on the
behavior of the walls.
Backfill Compaction
Settlement of foundation wall and utility trench backfill can cause damage to concrete
flatwork and/or result in poor drainage conditions. Compaction of backfill can reduce settlement.
Attempts to compact backfill near foundations to a high degree can damage foundation walls and
may increase lateral pressures on the foundation walls. The potential for cracking of a foundation
wall can vary widely based on many factors including the degree of compaction achieved, the
weight and type of compaction equipment utilized, the structural design of the wall, the strength
of the concrete at the time of backfill compaction, and the presence of temporary or permanent
bracing.
MILESTONE DEVELOPMENT GROUP, LLC
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Proper moisture conditioning of backfill is as important as compaction because settlement
commonly occurs in response to wetting. The addition of water complicates the backfill process,
especially during cold weather. Frozen soils are not considered suitable for use as backfill
because excessive settlement can result when the frozen materials thaw.
Precautions should be taken when backfilling against a below grade wall. Temporary
bracing of comparatively long, straight sections of foundation walls should be used to limit damage
to walls during the compaction process. Waiting at least seven days after the walls are placed to
allow the concrete to gain strength can also reduce the risk of damage. Compaction of fill placed
beneath and next to window wells, counterforts, and grade beams may be difficult to achieve
without damaging these building elements. Proper moisture conditioning of the fill prior to
placement in these areas will help reduce potential settlement.
Ideally, drainage swales should not be located over the backfill zone (including excavation
ramps), as this can increase the amount of water infiltration into the backfill and cause excessive
settlement. Swales should be designed to be a minimum of at least 5 feet from the foundation to
help reduce water infiltration. Irrigated vegetation, sump pump discharge pipes, sprinkler valve
boxes, and roof downspout terminations should also be at least 5 feet from the foundation.
Pool and Pool Deck
Our investigation indicates that the bottom of the swimming pool, as well as flatwork
around the pool, will bear on natural sandy clays. The soils in these areas exhibited high
measured swell, and as such, pose a high risk of damaging the pools and/or decks in the event
they swell due to increases in moisture content. Reinforced concrete or “gunite/shot-crete” type
pools tend to be brittle and may be more susceptible to cracking due to shrinkage and/or
movement of the foundation soils. We recommend the following alternatives to reduce the risk of
damage due to these types of movements.
1. The pool could be constructed using standard pool construction techniques. The
pool and the lightly loaded slabs, such as decking around the pool, will exhibit
differential movement if the supporting soils become wetted. We do not
recommend that this scenario be considered.
2. The pool could be constructed using a thick waterproof barrier, such as a pond
liner. The liner should extend beneath the pool and decking. Additionally, a
thickness of washed gravel should be placed atop the liner, with a sump area, to
MILESTONE DEVELOPMENT GROUP, LLC
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allow water to be collected and disposed of by pumping. The pool and decking
would then be carefully constructed atop these improvements. Please note that
success of this scenario depends upon total control of all water sources. If any
water gets beneath the liner, the system is defeated and the same level of damage
as in scenario #1 can be expected.
3. The pool could be constructed atop a structural slab supported by drilled pier,
which support the pool above the potentially expansive soils. Additionally, the
decking could be designed as structural slabs, with air space below. Although this
is a relatively expensive option, the pool and decking can be almost totally isolated
from the soil and the risk of damage substantially reduced.
Founding the pool on a drilled pier foundation system is the least risky construction
technique. However, the other development structures/features will be supported on a layer of
moisture stabilized soil (over-excavation). This is a reasonable approach for the pool as well if
some risk is acceptable. In addition, we recommend that the following construction techniques
be utilized to help prevent secondary damage that could be caused by slab movement.
1. Separate slabs from the foundation elements with a slip joint. A slip joint should
be used around the perimeter of the slab and adjacent to any other structural
elements.
2. Moderately reinforce slabs with reinforcement continuous through interior slab
joints. Slab joints must be provided to control the cracking. The floor joint grid
should be designed to allow no more than 200 square feet of continuous slab.
3. Any pipes rising through the slab should be provided with flexible couplings or
other means to allow substantial movement without damage to the piping. Any
ducts connecting to equipment founded on the slab should be equipped with
flexible or crushable connections to allow for some slab movement.
4. Equipment and other building appurtenances constructed on the slab should be
constructed so that slab movement will not cause damage.
Prior to pouring any slab it is essential that all debris, topsoil, and organic materials be
removed and all loose fill either removed or compacted as described in the Fill Placement section
of this report. If any fill is required beneath the proposed slab, we recommend using a granular
fill compacted in 8-inch maximum lifts to the standard referenced above.
Pool walls should be designed for lateral earth pressures. Many factors affect the value
of the design lateral earth pressure. These factors include, but are not limited to the type,
compaction, slope and drainage of the backfill, and the rigidity of the wall against rotation and
MILESTONE DEVELOPMENT GROUP, LLC
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deflection. For a very rigid wall where negligible or very little deflection will occur such as a pool,
an "at-rest" lateral earth pressure of 75 pcf should be used in design. This “at-rest” value assumes
some minor cracking of walls may occur. If very little wall deflection is desired, a higher design
density may be appropriate.
We recommend that a gravel blanket be provided beneath the pool for drainage
purposes. The gravel blanket material should consist of 3/8" to 3/4" washed or crushed rock with
a maximum of 5% passing a #200 sieve. Drains which are to discharge downslope by means of
gravity (daylighted) should either be connected to a sump pit or have a cleanout installed to
facilitate monitoring and maintenance. A liner is recommended between the pool and the drain
to collect leaks and protect the soil supporting the pool. The discharge area should be protected
from damage due to animal activity, vegetation, and traffic. The discharge area should be placed
so that it does not interfere with adjacent properties.
Conceptual Pool Drain Monitoring Pipe
It is important to note that the long-term stability of the pool and decking depend on the
site grading and drainage being properly implemented, to assure that wetting of the bearing and
slab-subgrade soils is prevented.
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
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Subsurface Drains and Surface Drainage
No below grade areas are planned for the buildings. For this condition, perimeter drains
are not usually constructed. If any portion of a floor will be below exterior grade, or a crawl space
is planned, we should be contacted to provide recommendations for foundation drains.
Proper design, construction, and maintenance of surface drainage are critical to the
satisfactory performance of foundations, slabs-on-grade, and other improvements. Landscaping
and irrigation practices will also affect performance. Appendix C contains our recommendations
for surface drainage, irrigation, and maintenance.
Pavements
The project will include a paved parking lot and access drives. Additionally, a public road
(Le Fever Drive) will be constructed along the northern border of the site. This report presents
pavement sections for the interior pavements and a preliminary pavement section for Le Fever
Drive. Per the requirements of the city, public road pavement section design cannot be performed
until utilities beneath the road and rough grading are complete. CTL|T is able to provide the
design level roadway report at that time.
The performance of pavements is dependent upon the characteristics of the subgrade
soil, traffic loading and frequency, climatic conditions, drainage, and pavement materials. We
drilled 6 exploratory borings and conducted laboratory tests to characterize the subgrade soils,
which consisted of sandy clays. The subgrade soils classified as A-6 and A-7-6 soils in
accordance with AASHTO procedures. The subgrade soil will likely provide fair to poor support
for new pavement. If fill is needed, we have assumed it will be soils with similar or better
characteristics.
Flexible hot mix asphalt (HMA) over aggregate base course (ABC) is likely planned for
interior pavement areas. Rigid Portland cement concrete (PCC) pavement should be used for
trash enclosure areas and where the pavement will be subjected to frequent turning of heavy
vehicles. Our designs are based on the AASHTO design method and our experience. Using the
criteria discussed above we recommend the minimum pavement sections provided in the
following table.
MILESTONE DEVELOPMENT GROUP, LLC
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RECOMMENDED PAVEMENT SECTIONS
Classification
Hot Mix Asphalt (HMA)
+ Aggregate Base
Course (ABC)
+ Moisture Treated
Subgrade (MTS)
Portland Cement
Concrete (PCC)
+ Moisture Treated
Subgrade (MTS)
Parking Area
4" HMA
+ 6" ABC
+ 24” MTS
5" PCC
+ 24” MTS
Access Drives /
Heavy Traffic
Areas
5" HMA
+ 6" ABC
+ 24” MTS
6" PCC
+ 24” MTS
Trash Enclosures - 6" PCC
+ 24” MTS
Preliminary
Recommendation
for Le Fever Dr.
5" HMA
+ 8" ABC
+ 24” MTS
6" PCC
+ 24” MTS
Pavement Selection
Composite HMA/ABC pavement over a stable subgrade is expected to perform well at this
site based on the recommendations provided. HMA provides a stiff, stable pavement to withstand
heavy loading and will provide a good fatigue resistant pavement. However, HMA does not
perform well when subjected to point loads in areas where heavy trucks turn and maneuver at
slow speeds. PCC pavement is expected to perform well in this area; PCC pavement has better
performance in freeze-thaw conditions and should require less long-term maintenance than HMA
pavement. The PCC pavement for trash enclosures should extend out to areas where trash
trucks park to lift and empty dumpsters.
Subgrade and Pavement Materials and Construction
The design of a pavement system is as much a function of the quality of the paving
materials and construction as the support characteristics of the subgrade. The construction
materials are assumed to possess sufficient quality as reflected by the strength factors used in
our design calculations. Moisture treatment criteria and additional criteria for materials and
construction requirements are presented in Appendix E.
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
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Pavement Maintenance
Routine maintenance, such as sealing and repair of cracks, is necessary to achieve the
long-term life of a pavement system. We recommend a preventive maintenance program be
developed and followed for all pavement systems to assure the design life can be realized.
Choosing to defer maintenance usually results in accelerated deterioration leading to higher future
maintenance costs, and/or repair. A recommended maintenance program is outlined in Appendix
F.
Excavation of completed pavement for utility construction or repair can destroy the
integrity of the pavement and result in a severe decrease in serviceability. To restore the
pavement top original serviceability, careful backfill compaction before repaving is necessary.
Concrete
Concrete in contact with soil can be subject to sulfate attack. We measured water-soluble
sulfate concentrations in eight samples at 0.05 percent to less than measurable limits (<0.01%).
As indicated in our tests and ACI 332-20, the sulfate exposure class is Not Applicable or RS0.
SULFATE EXPOSURE CLASSES PER ACI 332-20
Exposure Classes
Water-Soluble Sulfate (SO4)
in Soil A
(%)
Not Applicable RS0 < 0.10
Moderate RS1 0.10 to 0.20
Severe RS2 0.20 to 2.00
Very Severe RS3 > 2.00
A) Percent sulfate by mass in soil determined by ASTM C1580
For this level of sulfate concentration, ACI 332-20 Code Requirements for Residential
Concrete indicates there are no cement type requirements for sulfate resistance as indicated in
the table below.
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
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CONCRETE DESIGN REQUIREMENTS FOR SULFATE EXPOSURE PER ACI 332-20
Exposure
Class
Maximum
Water/
Cement
Ratio
Minimum
Compressive
Strength A
(psi)
Cementitious Material Types B
Calcium
Chloride
Admixtures
ASTM
C150/
C150M
ASTM
C595/
C595M
ASTM
C1157/
C1157M
RS0 N/A 2500 No Type
Restrictions
No Type
Restrictions
No
Type
Restrictions
No
Restrictions
RS1 0.50 2500 II
Type with
(MS)
Designation
MS No
Restrictions
RS2 0.45 3000 V C
Type with
(HS)
Designation
HS Not
Permitted
RS3 0.45 3000
V + Pozzolan
or Slag
Cement D
Type with
(HS)
Designation
plus Pozzolan
or Slag
Cement E
HS +
Pozzolan or
Slag Cement
E
Not
Permitted
A) Concrete compressive strength specified shall be based on 28 -day tests per ASTM C39/C39M
B) Alternate combinations of cementitious materials of those listed in ACI 332 -20 Table 5.4.2 shall be permitted
when tested for sulfate resistance meeting the criteria in section 5.5.
C) Other available types of cement such as Type III or Type I are permitted in Exposure Classes RS1 or RS2 if
the C3A contents are less than 8 or 5 percent, respectively.
D) The amount of the specific source of pozzolan or slag to be used shall not be less than the amount that has
been determined by service record to improve sulfate resistance when used in concrete containing Type V
cement. Alternatively, the amount of the specific source of the pozzolan or slab to be used shall not be less
than the amount tested in accordance with ASTM C1012/C1012M and meeting the criteria in section 5.5.1 of
ACI 332-20.
E) Water-soluble chloride ion content that is contributed from the ingredients including water aggregates,
cementitious materials, and admixtures shall be determined on the concrete mixture ASTM C1218/C1218M
between 29 and 42 days.
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 materials 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 have a total air content of 6 percent ± 1.5 percent. We advocate damp-proofing
of all foundation walls and grade beams in contact with the subsoils (including the inside and
outside faces of garage and crawl space grade beams).
Construction Observations
This project will involve many activities that should be monitored during the construction
phase by a geotechnical engineering firm. To provide continuity between design and construction,
CTL|Thompson, Inc. should provide these services. Other observations are recommended to
review general conformance with design plans. If another firm is selected to provide these
MILESTONE DEVELOPMENT GROUP, LLC
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services, they must accept responsibility to evaluate whether conditions exposed during
construction are consistent with findings in this report and whether design recommendations
remain appropriate. When construction schedules and quantities are defined, we can develop an
appropriate scope of services and budget for construction observation and materials testing.
Geotechnical Risk
The concept of risk is an important aspect with any geotechnical evaluation, primarily
because the methods used to develop geotechnical recommendations do not comprise an exact
science. We never have complete knowledge of subsurface conditions. Our analysis must be
tempered with engineering judgment and experience. Therefore, the recommendations presented
in any geotechnical evaluation should not be considered risk-free. Our recommendations
represent our judgment of those measures that are necessary to increase the chances that the
structures and improvements will perform satisfactorily. It is critical that all recommendations in
this report are followed during construction. Owners or property managers must assume
responsibility for maintaining the structures and use appropriate practices regarding drainage and
landscaping. Improvements after construction, such as construction of additions, retaining walls,
landscaping, and exterior flatwork, should be completed in accordance with recommendations
provided in this report and may require additional soil investigation and consultation.
Limitations
This report has been prepared for the exclusive use of Milestone Development Group,
LLC for the purpose of providing geotechnical design and construction criteria for the proposed
project. The information, conclusions, and recommendations presented herein are based upon
consideration of many factors including, but not limited to, the type of structures proposed, the
geologic setting, and the subsurface conditions encountered. The conclusions and
recommendations contained in the report are not valid for use by others. Standards of practice
evolve in the area of geotechnical engineering. The recommendations provided are appropriate
for about three years. If the proposed structures are not constructed within about three years, we
should be contacted to determine if we should update this report.
MILESTONE DEVELOPMENT GROUP, LLC
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Borings were drilled across the project site for this investigation to obtain a reasonably
accurate picture of the subsurface conditions. Variations in the subsurface conditions not
indicated by our borings are possible. A representative of our firm should observe foundation
excavations to confirm the exposed materials are as anticipated from our borings. We should
also test compaction of fill if over-excavation is used.
We believe this investigation was conducted with that level of skill and care ordinarily used
by geotechnical engineers practicing in this area at this time. No warranty, express or implied, is
made. If we can be of further service in discussing the contents of this report or in the analysis of
the influence of subsurface conditions on design of the structures, please call.
CTLTHOMPSON, INC.
R.B. “Chip” Leadbetter, III, PE Trace Krausse, EI
Senior Engineer Project Geotechnical Engineer
TH-14
TH-15
TH-16
TH-17TH-18
TH-19
TH-20
TH-21
TH-22
P-4
TH-24
TH-26
TH-25
P-1 P-2 TH-12
TH-13
TH-11
TH-10
TH-9P-3
TH-23
TH-6TH-4
TH-3
TH-2
TH-1
P-5
TH-5 TH-7
P-6
TH-8
Precision Dr.Cinquefoil Ln.Brookfield Dr.Le Fever Dr.
LEGEND:
INDICATES APPROXIMATE
LOCATION OF EXPLORATORY
BORING
INDICATES APPROXIMATE
LOCATION OF EXPLORATORY
PAVEMENT BORING
TH-1
P-1
E Harmony Rd.Strauss Cabin Rd.Rock Creek Dr.Lady Moon Dr.Precision Dr.
Site
FIGURE 1
Locations of
Exploratory Borings
0 100'50'
APPROXIMATE
SCALE: 1"=100'
VICINITY MAP
(FORT COLLINS, COLORADO)
AREA
NOT TO SCALE
MILESTONE DEVELOPMENT GROUP, LLC
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0
5
10
15
20
25
30
35
40
0
5
10
15
20
25
30
35
40
23/12
25/12
26/12
WC=5.9DD=108SW=0.3SS=0.030
WC=6.5LL=32 PI=16-200=41
WC=5.9DD=108SW=0.3SS=0.030
WC=6.5LL=32 PI=16-200=41
P-1
28/12
21/12
41/12
WC=8.0LL=37 PI=20-200=68
WC=5.8DD=114SW=0.4SS=0.030
WC=8.0LL=37 PI=20-200=68
WC=5.8DD=114SW=0.4SS=0.030
P-2
23/12
23/12
27/12
WC=8.2DD=96SW=1.5SS=0.050
WC=11.3DD=119LL=39 PI=25-200=82
WC=8.2DD=96SW=1.5SS=0.050
WC=11.3DD=119LL=39 PI=25-200=82
P-3
40/12
30/12
17/12
WC=9.9DD=119LL=44 PI=26-200=73
WC=7.4DD=101SW=3.2SS=0.030
WC=9.9DD=119LL=44 PI=26-200=73
WC=7.4DD=101SW=3.2SS=0.030
P-4
27/12
22/12
20/12
WC=11.7DD=113SW=9.6SS=<0.01
WC=10.7DD=119LL=44 PI=24-200=86
WC=11.7DD=113SW=9.6SS=<0.01
WC=10.7DD=119LL=44 PI=24-200=86
P-5
26/12
15/12
24/12
WC=10.6DD=118LL=45 PI=26-200=77
WC=9.4DD=101SW=4.9SS=<0.01
WC=10.6DD=118LL=45 PI=26-200=77
WC=9.4DD=101SW=4.9SS=<0.01
P-6
DRIVE SAMPLE. THE SYMBOL 25/12 INDICATES 25 BLOWS OF A 140-POUND HAMMER
FALLING 30 INCHES WERE REQUIRED TO DRIVE A 2.5-INCH O.D. SAMPLER 12 INCHES.
CLAY, SLIGHTLY SILTY TO SILTY, SLIGHTLY SANDY TO SANDY, SLIGHTLY MOIST TO MOIST,
MEDIUM STIFF TO VERY STIFF, BROWN, TAN, DARK GREY, RUST (CL)
1.
3.
LEGEND:
CLAYSTONE, SILTSTONE, MOIST, HARD, BROWN, GREY, RUST, DARK GREY
DEPTH - FEETTHESE LOGS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS AND CONCLUSIONS IN
THIS REPORT.
NOTES:
WATER LEVEL MEASURED ON MAY 2ND, 2023.
SAND, SLIGHTLY CLAYEY TO CLAYEY, SLIGHTLY GRAVELLY, MOIST, MEDIUM DENSE,
BROWN (SC)
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 (%).
2.DEPTH - FEETWATER LEVEL MEASURED AT TIME OF DRILLING.
THE BORINGS WERE DRILLED ON MARCH 29TH THROUGH APRIL 6TH, 2023 USING 4-INCH
DIAMETER CONTINUOUS-FLIGHT AUGERS AND A TRUCK-MOUNTED DRILL RIG.
WC
DD
SW
-200
LL
PI
UC
SS
-
-
-
-
-
-
-
-
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Summary Logs of
Exploratory Borings
FIGURE 2
0
5
10
15
20
25
30
35
40
0
5
10
15
20
25
30
35
40
18/12
17/12
13/12
WC=12.7
DD=116
SW=2.1
TH-1
14/12
26/12
22/12
22/12
WC=8.8
DD=103
SW=2.6
TH-2
21/12
25/12
21/12
17/12
16/12
WC=13.2
DD=115
SW=2.2
WC=13.7
DD=121
LL=42 PI=28
-200=73
TH-3
22/12
21/12
15/12
WC=10.9
DD=122
SW=0.7
TH-4
20/12
15/12
19/12
20/12
WC=8.3
DD=120
SW=2.2
TH-5
15/12
19/12
18/12
20/12
WC=6.5
DD=112
SW=-0.2
TH-6
20/12
22/12
28/12
19/12
WC=5.2
DD=114
SW=-0.8
TH-7
18/12
13/12
28/12
28/12
WC=11.3
DD=117
SW=1.8
WC=10.5
DD=127
LL=37 PI=24
-200=61
TH-8
14/12
22/12
31/12
WC=7.4
pF=4.96
-200=82
TH-9
8/12
28/12
34/12
37/12
WC=8.4
DD=101
SW=0.8
WC=8.9
DD=106
SW=-3.1
TH-10
DEPTH - FEETDEPTH - FEETSummary Logs of
Exploratory Borings
FIGURE 3
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
0
5
10
15
20
25
30
35
40
0
5
10
15
20
25
30
35
40
16/12
16/12
23/12
WC=8.0
DD=114
SW=1.7
WC=13.5
DD=115
LL=38 PI=25
-200=82
TH-11
7/12
18/12
25/12
21/12
WC=7.4
DD=105
SW=1.0
TH-12
20/12
21/12
34/12
21/12
27/12
WC=7.5
DD=118
SW=1.5
WC=11.6
DD=116
pF=4.38
-200=72
TH-13
25/12
32/12
22/12
16/12
WC=4.9
DD=119
SW=0.1
TH-14
12/12
50/11
32/12
WC=13.3
DD=121
SW=1.4
TH-15
36/12
21/12
20/12
20/12
WC=13.3
DD=116
SW=4.0
TH-16
32/12
26/12
22/12
16/12
11/12
WC=12.7
DD=120
SW=3.1
WC=14.4
DD=112
LL=37 PI=23
-200=82
TH-17
18/12
16/12
17/12
18/12
WC=10.0
DD=123
SW=4.4
pF=4.38
SS=<0.01
WC=13.3
DD=118
SW=1.0
pF=4.11
WC=18.4
DD=111
SW=0.0
pF=3.59
WC=19.1
DD=112
SW=0.1
pF=3.61
TH-18
29/12
28/12
17/12
WC=11.7
DD=122
SW=4.0
TH-19
22/12
23/12
20/12
11/12
WC=10.7
DD=124
SW=5.1
TH-20
DEPTH - FEETDEPTH - FEETSummary Logs of
Exploratory Borings
FIGURE 4
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
0
5
10
15
20
25
30
35
40
0
5
10
15
20
25
30
35
40
13/12
25/12
23/12
22/12
50/4
WC=12.5
DD=123
SW=4.7
TH-21
14/12
25/12
19/12
9/12
WC=9.7
DD=99
SW=1.9
TH-22
21/12
36/12
38/12
26/12
TH-23
34/12
27/12
32/12
WC=7.8
DD=125
SW=3.4
TH-24
25/12
50/12
32/12
WC=7.4
DD=110
SW=1.9
TH-25
20/12
30/12
24/12
22/12
50/6
WC=6.3
DD=110
SW=-0.4
pF=4.64
SS=0.010
WC=8.3
DD=123
SW=1.6
pF=4.21
WC=14.9
DD=117
SW=3.0
pF=4.05
WC=17.8
DD=112
SW=0.1
pF=3.20
WC=14.6
DD=119
SW=1.0
pF=4.50
TH-26
DEPTH - FEETDEPTH - FEETSummary Logs of
Exploratory Borings
FIGURE 5
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
APPENDIX A
RESULTS OF LABORATORY TESTING
TABLE A-I: SUMMARY OF LABORATORY TEST RESULTS
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=108 PCF
From P - 1 AT 2 FEET MOISTURE CONTENT=5.9 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=114 PCF
From P - 2 AT 4 FEET MOISTURE CONTENT=5.8 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-1COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNTAONSER CION UNDSNAPXE
GINETTTO WRE DUESSUERP
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
TNSTAONER CION UNDANSPXE
GINTETWTORE DUESSUERP
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=96 PCF
From P - 3 AT 2 FEET MOISTURE CONTENT=8.2 %
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
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=101 PCF
From P - 4 AT 4 FEET MOISTURE CONTENT=7.4 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-3
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=113 PCF
From P - 5 AT 2 FEET MOISTURE CONTENT=11.7 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-4
-3
-2
-1
0
1
2
3
4
5
6
7
8
9
10
11
12
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=101 PCF
From P - 6 AT 4 FEET MOISTURE CONTENT=9.4 %
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
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=116 PCF
From TH - 1 AT 9 FEET MOISTURE CONTENT=12.7 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=103 PCF
From TH - 2 AT 4 FEET MOISTURE CONTENT=8.8 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-6COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNTAONSER CION UNDSNAPXE
GINETTTO WRE DUESSUERP
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
TNSTAONER CION UNDANSPXE
GINTETWTORE DUESSUERP
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=115 PCF
From TH - 3 AT 9 FEET MOISTURE CONTENT=13.2 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=122 PCF
From TH - 4 AT 9 FEET MOISTURE CONTENT=10.9 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-7COMPRESSION % EXPANSION-3
-2
-1
0
1
2
3
4
TNTAONSER CION UNDSNAPXE
GINETTTO WRE DUESSUERP
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
TNSTAONER CION UNDANSPXE
GINTETWTORE DUESSUERP
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=120 PCF
From TH - 5 AT 9 FEET MOISTURE CONTENT=8.3 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=112 PCF
From TH - 6 AT 9 FEET MOISTURE CONTENT=6.5 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-8COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNTAONSER CION UNDSNAPXE
GINETTTO WRE DUESSUERP
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
RENDUONSSIMPRENAL CODD OITIA
OTUEE DSSURANT PRESTC NO
GINTWE T
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=114 PCF
From TH - 7 AT 9 FEET MOISTURE CONTENT=5.2 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=117 PCF
From TH - 8 AT 9 FEET MOISTURE CONTENT=11.3 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-9COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
REDNUNSSIPRE OMNAL CODID IOTA
TOUEE DSURN SNT PREATSOC
GNETTIW
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
TNSTAONER CION UNDANSXPE
GINTETWTORE DUESSURP E
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=101 PCF
From TH - 10 AT 4 FEET MOISTURE CONTENT=8.4 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-10
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=106 PCF
From TH - 10 AT 9 FEET MOISTURE CONTENT=8.9 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-11
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
RDEUNSIONOMPRESCLATIDD NOIA
GNTITEWTODUERESSUREPNTASTONC
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=114 PCF
From TH - 11 AT 4 FEET MOISTURE CONTENT=8.0 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=105 PCF
From TH - 12 AT 4 FEET MOISTURE CONTENT=7.4 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-12COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNTAONSER CION UNDSNAPXE
GINETTTO WRE DUESSUERP
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
TNSTAONER CION UNDANSPXE
GINTETWTORE DUESSUERP
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=118 PCF
From TH - 13 AT 4 FEET MOISTURE CONTENT=7.5 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=119 PCF
From TH - 14 AT 4 FEET MOISTURE CONTENT=4.9 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-13COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNTAONSER CION UNDSNAPXE
GINETTTO WRE DUESSUERP
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
TNSTAONER CION UNDANSPXE
GINTETWTORE DUESSUERP
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=121 PCF
From TH - 15 AT 9 FEET MOISTURE CONTENT=13.3 %
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
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=116 PCF
From TH - 16 AT 9 FEET MOISTURE CONTENT=13.3 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-15
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=120 PCF
From TH - 17 AT 9 FEET MOISTURE CONTENT=12.7 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-16
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=123 PCF
From TH - 18 AT 4 FEET MOISTURE CONTENT=10.0 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-17
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=118 PCF
From TH - 18 AT 9 FEET MOISTURE CONTENT=13.3 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=111 PCF
From TH - 18 AT 14 FEET MOISTURE CONTENT=18.4 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-18COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNTAONSER CION UNDSNAPXE
GINETTTO WRE DUESSUERP
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
GNTIEWETOTUEDEMENTMOVON
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=112 PCF
From TH - 18 AT 19 FEET MOISTURE CONTENT=19.1 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-19
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=122 PCF
From TH - 19 AT 9 FEET MOISTURE CONTENT=11.7 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-20
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=124 PCF
From TH - 20 AT 9 FEET MOISTURE CONTENT=10.7 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-21
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=123 PCF
From TH - 21 AT 9 FEET MOISTURE CONTENT=12.5 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-22
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=99 PCF
From TH - 22 AT 4 FEET MOISTURE CONTENT=9.7 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-23
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=125 PCF
From TH - 24 AT 9 FEET MOISTURE CONTENT=7.8 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
Test Results FIGURE A-24
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
ANTNSTONDER CUNONXPE SIA
GETTINUE TO WDERUSSREP
0.1 1.0 10 100
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=110 PCF
From TH - 25 AT 4 FEET MOISTURE CONTENT=7.4 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=110 PCF
From TH - 26 AT 4 FEET MOISTURE CONTENT=6.3 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-25COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNTAONSER CION UNDSNAPXE
GINETTTO WRE DUESSUERP
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
RENDUONSSIMPRENAL CODD OITIA
OTUEE DSSURANT PRESTC NO
GINTWE T
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=123 PCF
From TH - 26 AT 9 FEET MOISTURE CONTENT=8.3 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=117 PCF
From TH - 26 AT 14 FEET MOISTURE CONTENT=14.9 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-26COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNTAONSER CION UNDSNAPXE
GINETTTO WRE DUESSUERP
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
TNSTAONER CION UNDANSPXE
GINTETWTORE DUESSUERP
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=112 PCF
From TH - 26 AT 19 FEET MOISTURE CONTENT=17.8 %
Sample of INTERBEDDED CLAYSTONE AND SANDSTONE DRY UNIT WEIGHT=119 PCF
From TH - 26 AT 24 FEET MOISTURE CONTENT=14.6 %
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-27COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
TNTAONSER CION UNDAPE NX S
GINETTTO WRE DUESSUEPR
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
TNSTAONER CION UNDANSPXE
GINTETWTORE DUESSUP ER
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL | T PROJECT NO. FC10774.000-120
PASSING WATER-
MOISTURE DRY LIQUID PLASTICITY APPLIED NO. 200 SOLUBLE
DEPTH CONTENT DENSITY LIMIT INDEX SWELL*PRESSURE SUCTION SIEVE SULFATES
BORING (FEET)(%)(PCF)(%)(PSF)(PF)(%)(%)DESCRIPTION
P-1 2 5.9 108 0.3 150 0.03 SAND, CLAYEY (SC)
P-1 4 6.5 32 16 41 SAND, CLAYEY (SC)
P-2 2 8.0 37 20 68 CLAY, SANDY (CL)
P-2 4 5.8 114 0.4 150 0.03 CLAY, SANDY (CL)
P-3 2 8.2 96 1.5 150 0.05 CLAY, SANDY (CL)
P-3 4 11.3 119 39 25 82 CLAY, SANDY (CL)
P-4 2 9.9 119 44 26 73 CLAY, SANDY (CL)
P-4 4 7.4 101 3.2 150 0.03 CLAY, SANDY (CL)
P-5 2 11.7 113 9.6 150 <0.01 CLAY, SANDY (CL)
P-5 4 10.7 119 44 24 86 CLAY, SANDY (CL)
P-6 2 10.6 118 45 26 77 CLAY, SANDY (CL)
P-6 4 9.4 101 4.9 150 <0.01 CLAY, SANDY (CL)
S-1 0-4 14.7 37 22 70 CLAY, SANDY (CL)
S-2 0-4 43 22 CLAY, SANDY (CL)
TH-1 9 12.7 116 2.1 1,100 CLAY, SANDY (CL)
TH-2 4 8.8 103 2.6 500 CLAY, SANDY (CL)
TH-3 9 13.2 115 2.2 1,100 CLAY, SANDY (CL)
TH-3 14 13.7 121 42 28 73 CLAY, SANDY (CL)
TH-4 9 10.9 122 0.7 1,100 CLAY, SANDY (CL)
TH-5 9 8.3 120 2.2 1,100 CLAY, SANDY (CL)
TH-6 9 6.5 112 -0.2 1,100 CLAY, SANDY (CL)
TH-7 9 5.2 114 -0.8 1,100 CLAY, SANDY (CL)
TH-8 9 11.3 117 1.8 1,100 CLAY, SANDY (CL)
TH-8 14 10.5 127 37 24 61 CLAY, SANDY (CL)
TH-9 4 7.4 4.96 82 CLAY, SANDY (CL)
TH-10 4 8.4 101 0.8 500 CLAY, SANDY (CL)
TH-10 9 8.9 106 -3.1 1,100 CLAY, SANDY (CL)
TH-11 4 8.0 114 1.7 500 CLAY, SANDY (CL)
TH-11 14 13.5 115 38 25 82 CLAY, SANDY (CL)
TH-12 4 7.4 105 1.0 500 CLAY, SANDY (CL)
TH-13 4 7.5 118 1.5 500 CLAY, SANDY (CL)
TH-13 14 11.6 116 4.38 72 CLAY, SANDY (CL)
TH-14 4 4.9 119 0.1 500 CLAY, SANDY (CL)
TH-15 9 13.3 121 1.4 1,100 CLAY, SANDY (CL)
SWELL TEST RESULTS*
TABLE A-I
SUMMARY OF LABORATORY TESTING
ATTERBERG LIMITS
Page 1 of 2
* NEGATIVE VALUE INDICATES COMPRESSION.
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL|T PROJECT NO. FC10774.000-120
PASSING WATER-
MOISTURE DRY LIQUID PLASTICITY APPLIED NO. 200 SOLUBLE
DEPTH CONTENT DENSITY LIMIT INDEX SWELL*PRESSURE SUCTION SIEVE SULFATES
BORING (FEET)(%)(PCF)(%)(PSF)(PF)(%)(%)DESCRIPTION
SWELL TEST RESULTS*
TABLE A-I
SUMMARY OF LABORATORY TESTING
ATTERBERG LIMITS
TH-16 9 13.3 116 4.0 1,100 CLAY, SANDY (CL)
TH-17 9 12.7 120 3.1 1,100 CLAY, SANDY (CL)
TH-17 14 14.4 112 37 23 82 CLAY, SANDY (CL)
TH-18 4 10.0 123 4.4 500 4.38 <0.01 CLAY, SANDY (CL)
TH-18 9 13.3 118 1.0 1,100 4.11 CLAY, SANDY (CL)
TH-18 14 18.4 111 0.0 1,800 3.59 CLAY, SANDY (CL)
TH-18 19 19.1 112 0.1 2,400 3.61 CLAY, SANDY (CL)
TH-19 9 11.7 122 4.0 1,100 CLAY, SANDY (CL)
TH-20 9 10.7 124 5.1 1,100 CLAY, SANDY (CL)
TH-21 9 12.5 123 4.7 1,100 CLAY, SANDY (CL)
TH-22 4 9.7 99 1.9 500 CLAY, SANDY (CL)
TH-24 9 7.8 125 3.4 1,100 CLAY, SANDY (CL)
TH-25 4 7.4 110 1.9 500 CLAY, SANDY (CL)
TH-26 4 6.3 110 -0.4 500 4.64 0.01 CLAY, SANDY (CL)
TH-26 9 8.3 123 1.6 1,100 4.21 CLAY, SANDY (CL)
TH-26 14 14.9 117 3.0 1,800 4.05 CLAY, SANDY (CL)
TH-26 19 17.8 112 0.1 2,400 3.20 CLAY, SANDY (CL)
TH-26 24 14.6 119 1.0 3,000 4.50 INTERBEDDED CLAYSTONE AND SANDSTONE
Page 2 of 2
* NEGATIVE VALUE INDICATES COMPRESSION.
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTL|T PROJECT NO. FC10774.000-120
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTLT PROJECT NO. FC10774.000-120
B-1
APPENDIX B
SLAB PERFORMANCE RISK EVALUATION,
INSTALLATION AND MAINTENANCE
As part of our evaluation of the subsoils and bedrock, samples were tested in the
laboratory using a swell test. In the test procedure, a relatively undisturbed sample obtained
during drilling is first loaded and then flooded with water and allowed to swell. The pressure
applied prior to wetting can approximate the weight of soil above the sample depth or be some
standard load. The measured percent swell is not the sole criteria in assessing potential
movement of slabs-on-grade and the risk of poor slab performance. The results of a swell test on
an individual lot are tempered with data from surrounding lots, depth of tests, depth of excavation,
soil profile, and other tests. This judgment has been described by the Colorado Association of
Geotechnical Engineers (CAGE, 1996) as it relates to slab-on-grade floors. It can also be used to
help judge performance risk for other slabs-on-grade such as garage floors, driveways, and
sidewalks. CTL Thompson also performs potential heave calculations to aid in our judgment. The
risk evaluation is considered when we evaluate appropriate foundation systems for a given site.
In general, more conservative foundation designs are used for higher risk sites to control the
likelihood of excessive foundation movement.
As a result of the Slab Performance Risk Evaluation, sites are categorized as low,
moderate, high, or very high risk. This is a judgment of the swelling characteristics of the soils
and bedrock likely to influence slab performance.
REPRESENTATIVE MEASURED SWELL AND CORRESPONDING SLAB
PERFORMANCE RISK CATEGORIES
Slab Performance
Risk Category
Representative Percent Swell*
(500 psf Surcharge)
Representative Percent Swell*
(1000 psf Surcharge)
Low 0 to <3 0 to <2
Moderate 3 to <5 2 to <4
High 5 to <8 4 to <6
Very High > 8 > 6
*Note: The representative percent swell values presented are not necessarily measured values; rather, they are
a judgment of the swelling characteristics of the soil and bedrock likely to influence slab performance.
The rating of slab performance risk on a site as low or high is not absolute. Rather, this
rating represents a judgment. Movement of slabs may occur with time in low, moderate, high, and
very high risk areas as the expansive soils respond to increases in moisture content. Overall, the
severity and frequency of slab damage usually is greater in high and very high rated areas. Heave
of slabs-on-grade of 3 to 5 inches is not uncommon in areas rated as high or very high risk. On
low and moderate risk sites, slab heave of 1 to 2 inches is considered normal and we believe in
the majority of instances, movements of this magnitude constitute reasonable slab performance;
more heave can occur. Slabs can be affected on all sites. On lots rated as high or very high risk,
there is more likelihood of need to repair, maintain, or replace garage floors and exterior flatwork.
MILESTONE DEVELOPMENT GROUP, LLC
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B-2
CTL | Thompson, Inc. recommends use of structurally supported floors, known as
“structural floors,” for lots rated as high and very high risk. We also recommend use of structural
floors on walkout and garden level lots rated as moderate, high, or very high risk. If
owners/managers cannot tolerate movement of a slab-on-grade floor, they should select a lot
where a structurally supported floor will be constructed or request that a structurally supported
floor be installed.
The owner/manager should be advised the floor slab in the may move and crack due to
heave or settlement and that there may be maintenance costs associated. Finished areas have
the risk of slab heave, cracking, and consequential damages. Heave or settlement may require
maintenance of finish details to control damage. Our experience suggests that soil moisture
increases below structures due to covering the ground with the structure and exterior flatwork,
coupled with the introduction of landscape irrigation. In most cases, slab movements (if any)
resulting from this change occur within three to five years.
Where conventional slabs-on-grade are used, we recommend the following precautions.
These measures will not keep slabs-on-grade from heaving; they tend to mitigate damages due
to slab heave.
1. Where possible, slab-on-grade floor construction should be limited to areas such
as exterior walks and patios where slab movement and cracking are acceptable to
the builder and manager.
2. The 2021 International Building Code (IBC) states that a 4-inch base course layer
consisting of clean graded sand, gravel, crushed stone, or crushed blast furnace
slag shall be placed beneath below grade floors (unless the underlying soils are
free-draining), along with a vapor retarder. Installation of the base course and
vapor retarder is not common in this area. Historically, there has been some
concern that installation of clean base course could allow wetting of expansive
soils to spread from an isolated source.
IRC states that the vapor retarder can be omitted where approved by the building
official. The merits of installation of a vapor retarder below floor slabs depend on
the sensitivity of floor coverings and building use to moisture. A properly installed
vapor retarder is more beneficial below concrete slab-on-grade floors where floor
coverings, painted floor surfaces, or products stored on the floor will be sensitive
to moisture. The vapor retarder is most effective when concrete is placed directly
on top of it, rather than placing a sand or gravel leveling course between the vapor
retarder and the floor slab. Placement of concrete on the vapor retarder may
increase the risk of shrinkage cracking and curling. Use of concrete with reduced
shrinkage characteristics including minimized water content, maximized coarse
aggregate content, and reasonably low slump will reduce the risk of shrinkage
cracking and curling. Considerations and recommendations for the installation of
vapor retarders below concrete slabs are outlined in Section 3.2.3 of the 2015
American Concrete Institute (ACI) Committee 302, “Guide for Concrete Floor and
Slab Construction (ACI 302.R-96)”.
3. Conventional slabs should be separated from exterior walls and interior bearing
members with a slip joint that allows free vertical movement of the slabs. These
joints must be maintained by the property manager to avoid transfer of movement.
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B-3
4. Underslab plumbing should be thoroughly pressure tested during construction for
leaks and be provided with flexible couplings. Gas and waterlines leading to slab-
supported appliances should be constructed with flexibility. The property manager
must maintain these connections.
5. Use of slab bearing partitions should be minimized. Where such partitions are
necessary, a slip joint (or float) allowing at least 2 inches of free vertical slab
movement should be used. Doorways should also be designed to allow vertical
movement of slabs. To limit damage in the event of movement, sheetrock should
not extend to the floor. The property manager should monitor partition voids and
other connections and re-establish the voids before they close to less than 1/2-
inch.
6. Plumbing and utilities that pass through slabs should be isolated from the slabs.
Heating and air conditioning systems constructed on slabs should be provided with
flexible connections capable of at least 2 inches of vertical movement so slab
movement is not transmitted to the ductwork. These connections must be
maintained by the property manager.
7. Roofs that overhang a patio or porch should be constructed on the same
foundation as the structure. Isolated piers or pads may be installed beneath a roof
overhang provided the slab is independent of the foundation elements. Patio or
porch roof columns may be positioned on the slab, directly above the foundation
system, provided the slab is structural and supported by the foundation system.
Structural porch or patio slabs should be constructed to reduce the likelihood that
settlement or heave will affect the slab by placing loose backfill under the
structurally supported slab or constructing the slab over void-forming materials.
8. Patio and porch slabs without roofs and other exterior flatwork should be isolated
from the foundation. Movements of slabs should not be transmitted to the
foundation. Decks are more flexible and more easily adjusted in the event of
movement.
9. Frequent control joints should be provided in conventional slabs-on-grade to
reduce problems associated with shrinkage cracking and curling. Panels that are
approximately square generally perform better than rectangular areas. We suggest
an additional joint about 3 feet away from and parallel to foundation walls.
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C-1
APPENDIX C
SURFACE DRAINAGE,
IRRIGATION AND MAINTENANCE
Performance of foundations and concrete flatwork is influenced by the moisture conditions
existing within the foundation soils. Surface drainage should be designed to provide rapid runoff
of surface water away from proposed structures. Proper surface drainage and irrigation practices
can help control the amount of surface water that penetrates to foundation levels and contributes
to settlement or heave of soils and bedrock that support foundations and slabs-on-grade. Positive
drainage away from the foundation and avoidance of irrigation near the foundation also help to
avoid excessive wetting of backfill soils, which can lead to increased backfill settlement and
possibly to higher lateral earth pressures, due to increased weight and reduced strength of the
backfill. CTL | Thompson, Inc. recommends the following precautions. The property manager
should maintain surface drainage and, if an irrigation system is installed, it should substantially
conform to these recommendations.
1. Wetting or drying of the open foundation excavations should be avoided.
2. Excessive wetting of foundation soils before, during and after construction can
cause heave or softening of foundation soils and result in foundation and slab
movements. Proper surface drainage around the structure and between lots is
critical to control wetting.
3. The ground surface surrounding the exterior of each structure should be sloped to
drain away from the building in all directions. We recommend a minimum
constructed slope of at least 12 inches in the first 10 feet (10 percent) in
landscaped areas around each structure, where practical. The recommended
slope is for the soil surface slope, not surface of landscaping rock.
4. We do not view the recommendation to provide a 10 percent slope away from the
foundation as an absolute. It is desirable to create this slope where practical
because we know that backfill will likely settle to some degree. By starting with
sufficient slope, positive drainage can be maintained for most settlement
conditions. There are many situations around a structure where a 10 percent slope
cannot be achieved practically, such as around patios, at inside foundation
corners, and between a house and nearby sidewalk. In these areas, we believe it
is desirable to establish as much slope as practical and to avoid irrigation. We
believe it is acceptable to use a slope on the order of 5 percent perpendicular to
the foundation in these limited areas.
5. For lots graded to direct drainage from the rear yard to the front, it is difficult to
achieve 10 percent slope at the high point behind the house. We believe it is
acceptable to use a slope of about 6 inches in the first 10 feet (5 percent) at this
location.
6. Between houses that are separated by a distance of less than 20 feet, the
constructed slope should generally be at least 10 percent to the swale used to
convey water out of this area. For lots that are graded to drain to the front and
back, we believe it is acceptable to install a slope of 5 to 8 percent at the high point
(aka “break point”) between houses.
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C-2
7. Construction of retaining walls and decks adjacent to the structure should not alter
the recommended slopes and surface drainage around the structure. The ground
surface under decks should be compacted and slope away from the structure. 10-
mil plastic sheeting and landscaping rock may be placed under decks to soil
erosion and/or formation of depressions under the deck. The plastic sheeting
should direct water away from the structure. Retaining walls should not flatten the
surface drainage around the structure or impede surface runoff.
8. Swales used to convey water across yards and between houses should be sloped
so that water moves quickly and does not pond for extended periods of time. We
suggest minimum slopes of about 2 to 2.5 percent in grassed areas and about 2
percent where landscaping rock or other materials are present. If slopes less than
about 2 percent are necessary, concrete-lined channels or plastic pipe should be
used. Fence posts, trees, and retaining walls should not impede runoff in the
swales.
9. Backfill around the foundation walls should be moistened and compacted.
10. Roof downspouts and drains should discharge well beyond the limits of all backfill.
Splash blocks and/or extensions should be provided at all downspouts so water
discharges onto the ground beyond the backfill. We generally recommend against
burial of downspout discharge. Where it is necessary to bury downspout discharge,
solid, rigid pipe should be used and it should slope to an open gravity outlet.
Downspout extensions, splash blocks and buried outlets must be maintained by
the property manager.
11. The importance of proper irrigation and drainage practices and maintenance
cannot be over-emphasized. Irrigation should be limited to the minimum amount
sufficient to maintain vegetation; application of more water will increase likelihood
of slab and foundation movements. Landscaping should be carefully designed and
maintained to minimize irrigation. Plants placed close to foundations, particularly
within 5 feet of the foundation, should be limited to those with low moisture
requirements and utilize only sub-surface irrigation such as standard low volume
drip emitters or in-line drip irrigation. Irrigated grass, irrigation mainlines, above-
surface spray heads, rotors, and other above-surface irrigation spray devices
should not be located or discharge above the ground surface within 5 feet of the
foundation
12. Plastic sheeting should not be placed beneath landscaped areas adjacent to
foundation walls or grade beams. Geotextile fabric will inhibit weed growth yet still
allow natural evaporation to occur.
APPENDIX D
SAMPLE SITE GRADING SPECIFICATIONS
MILESTONE DEVELOPMENT GROUP, LLC
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CTLT PROJECT NO. FC10774.000-120 D-1
SAMPLE 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 building site elevations.
2. GENERAL
The Geotechnical Engineer shall be the Owner's representative. The Geotechnical
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 trees, brush and rubbish 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 to a depth of 8 inches until
the surface is free from ruts, hummocks, or other uneven features, which would prevent
uniform compaction by the equipment to be used.
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 and compacted to
not less than 95 percent of maximum dry density as determined in accordance with ASTM
D 698 or AASHTO T 99.
6. FILL MATERIALS
On-site materials classifying as CL, SC, SM, SW, SP, GP, GC, and GM are acceptable.
Fill soils shall be free from organic matter, debris, or other deleterious substances, and
shall not contain rocks or lumps having a diameter greater than three (3) inches. Fill
materials shall be obtained from the existing fill and other approved sources.
7. MOISTURE CONTENT
Fill materials shall be moisture treated. Clay soils placed below the building envelope
should be moisture-treated to between optimum and 3 percent above optimum moisture
content as determined from Standard Proctor compaction tests. Clay soil placed exterior
to the building should be moisture treated between optimum and 3 percent above optimum
moisture content. Sand soils can be moistened to within 2 percent of optimum moisture
content. Sufficient laboratory compaction tests shall be performed to determine the
optimum moisture content for the various soils encountered in borrow areas.
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The Contractor may be required to add moisture to the excavation materials in the borrow
area if, in the opinion of the Geotechnical 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 disk 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 Geotechnical 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 dry density. 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. Fill placed under foundations, exterior flatwork and pavements should
be compacted to a minimum of 95 percent of maximum standard Proctor dry density
(ASTM D698).
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.
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 dry 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 no appreciable amount of loose soil 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. DENSITY TESTS
Field density tests shall be made by the Geotechnical 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 dry density or moisture content of any layer
of fill or portion thereof is below that required, the particular layer or portion shall be
reworked until the required dry density or moisture content has been achieved.
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11. 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 Geotechnical Engineer indicates that the
moisture content and dry density of previously placed materials are as specified.
12. NOTICE REGARDING START OF GRADING
The contractor shall submit notification to the Geotechnical 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.
13. REPORTING OF FIELD DENSITY TESTS
Density tests performed by the Geotechnical Engineer, as specified under "Density Tests"
above, shall be submitted progressively to the Owner. Dry density, moisture content and
percent compaction shall be reported for each test taken.
APPENDIX E
PAVEMENT CONSTRUCTION RECOMMENDATIONS
MILESTONE DEVELOPMENT GROUP, LLC
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CTLT PROJECT NO. FC10774.000-120
E-1
SUBGRADE PREPARATION
Moisture Treated Subgrade (MTS)
1. The subgrade should be stripped of organic matter, scarified, moisture
treated and compacted to the specifications stated below in Item 2. The
compacted subgrade should extend at least 3 feet beyond the edge of the
pavement where no edge support, such as curb and gutter, are to be
constructed.
2. Sandy and gravelly soils (A-1-a, A-1-b, A-3, A-2-4, A-2-5, A-2-6, A-2-7)
should be moisture conditioned near optimum moisture content and
compacted to at least 95 percent of standard Proctor maximum dry density
(ASTM D 698, AASHTO T 99). Clayey soils (A-6, A-7-5, A-7-6) should be
moisture conditioned between optimum and 3 percent above optimum
moisture content and compacted to at least 95 percent of standard Proctor
maximum dry density (ASTM D 698, AASHTO T 99).
3. Utility trenches and all subsequently placed fill should be properly
compacted and tested prior to paving. As a minimum, fill should be
compacted to 95 percent of standard Proctor maximum dry density.
4. Final grading of the subgrade should be carefully controlled so the design
cross-slope is maintained and low spots in the subgrade that could trap
water are eliminated.
5. Once final subgrade elevation has been compacted and tested to
compliance and shaped to the required cross-section, the area should be
proof-rolled using a minimum axle load of 18 kips per axle. The proof-roll
should be performed while moisture contents of the subgrade are still within
the recommended limits. Drying of the subgrade prior to proof-roll or paving
should be avoided.
6. Areas that are observed by the Engineer that have soft spots in the
subgrade, or where deflection is not uniform of soft or wet subgrade shall
be ripped, scarified, dried, or wetted as necessary and recompacted to the
requirements for the density and moisture. As an alternative, those areas
may be over-excavated and replaced with properly compacted structural
backfill. Where extensively soft, yielding subgrade is encountered; we
recommend a representative of our office observe the excavation.
Chemically Stabilized Subgrade (CSS)
1. Utility trenches and all subsequently placed fill should be properly
compacted and tested prior to subgrade preparation. As a minimum, fill
should be compacted to 95 percent of standard Proctor maximum dry
density.
2. The subgrade should be stripped of organic matter and should be shaped
to final line and grade.
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3. The contractor or owner’s representative should have a mix design
performed in general accordance with ASTM D 558 using the actual site
soils and the approved stabilizing agent (lime, fly ash or a combination of
lime and fly ash). Scheduling should allow at least five weeks for the mix
design to be completed prior to construction.
4. High calcium quicklime should conform to the requirements of ASTM C 977
and ASTM C 110. Dolomitic quicklime, magnesia quicklime with
magnesium oxide contents in excess of 4 percent, or carbonated quicklime
should not be used.
5. Fly ash should consist of Class C in accordance with ASTM C 593 and C
618.
6. All stabilizing agents should come from the same source as used in the mix
design. If the source is changed, a new mix design should be performed.
7. Stabilizing agents should be spread with a mechanical spreader from back
of curb to back of curb for detached sidewalks or back of walk to back of
walk for attached sidewalks, where applicable.
8. The subgrade should be mixed to the specified depth and at the specified
concentration until a uniform blend of soil, stabilizing agent and water is
obtained and the moisture content is at least 2 percent (for fly ash) and 3
percent (for lime) above the optimum moisture content of the design
mixture (ASTM D 558).
9. If lime is used, a mellowing period of up to seven days may be required
following initial mixing. Once the pH of the mixture is 12.3 or higher and
the plasticity index is less than 10, the soils shall again be mixed and
moisture conditioned to at least 3 percent over optimum moisture content
and compacted to at least 95 percent of the mixture’s maximum dry density
(ASTM D 558). Up to seven additional days may be required for curing prior
to paving. The treated surface shall be kept moist or sealed with emulsified
asphalt. Traffic should not be allowed on the surface during the mellowing
and curing periods.
10. If fly ash is used, the mixture should be moisture conditioned to at least 2
percent over optimum moisture content and compacted to at least 95
percent of the mixture’s maximum dry density (ASTM D 558) within 2 hours
from the time of initial fly ash mixing.
11. If a lime/fly ash combination is used, the lime should be mixed first and
allowed to mellow as indicated for lime treatment in item 9. Following the
mellowing period, the fly ash should be added, moisture conditioned and
compacted as indicated above within 2 hours of initial fly ash mixing.
12. Samples of loose, blended stabilizing agent/soil mixture should be sampled
by a representative of CTL Thompson, Inc. for compressive strength testing
(ASTM D 1663) to determine compliance (optional) when full credit for the
FASS layer is used in the pavement thickness design.
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTLT PROJECT NO. FC10774.000-120
E-3
13. Batch tickets should be supplied to the owner or owner’s representative
with the application area for that batch to determine compliance with the
recommended proportions of fly ash to soil.
14. The subgrade should be re-shaped to final line and grade.
15. The subgrade should be sealed with a pneumatic-tire roller that is
sufficiently light in weight so as to not cause hairline cracking of the
subgrade.
16. Mixing of the fly ash, lime, or lime/fly ash treated subgrade should not occur
if the temperature of the soil mixture is below 40oF.
17. We recommend a minimum of 2 days curing prior to paving. The surface
of the stabilized area should be kept moist during the cure period by
periodic, light sprinkling if needed. Strength gains will be slower during
cooler weather. Traffic should not be permitted on the treated subgrade
during the curing period. The subgrade should be protected from freezing
or drying at all times until paving.
18. The treated areas will gain greater strength if they are allowed to cure for 1
to 3 days prior to paving. Construction traffic on the treated subgrade prior
to pavement section construction should be limited and the subgrade
should be protected from freezing or drying at all times until paving.
19. Placement, mixing and compaction of stabilized subgrade should be
observed and tested by a representative of our firm.
PAVEMENT MATERIALS AND CONSTRUCTION
Aggregate Base Course (ABC)
1. A Class 5 or 6 Colorado Department of Transportation (CDOT) specified
ABC should be used. A reclaimed concrete pavement (RCP) alternative
which meets the Class 5 or 6 designation and design R-value/strength
coefficient is also acceptable. Blending of recycled products with ABC may
be considered.
2. Bases should have a minimum Hveem stabilometer value of 72, or greater.
ABC, RAP, RCP, or blended materials must be moisture stable. The
change in R-value from 300-psi to 100-psi exudation pressure should be
12 points or less.
3. ABC or RCP bases should be placed in thin lifts not to exceed 6 inches and
moisture treated to near optimum moisture content. Bases should be
moisture treated to near optimum moisture content, and compacted to at
least 95 percent of standard Proctor maximum dry density (ASTM D 698,
AASHTO T 99).
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTLT PROJECT NO. FC10774.000-120
E-4
4. Placement and compaction of ABC or RCP should be observed and tested
by a representative of our firm. Placement should not commence until the
underlying subgrade is properly prepared and tested.
Hot Mix Asphalt (HMA)
1. HMA should be composed of a mixture of aggregate, filler, hydrated lime,
and asphalt cement. Some mixes may require polymer modified asphalt
cement, or make use of up to 20 percent reclaimed asphalt pavement
(RAP). A job mix design is recommended and periodic checks on the job
site should be made to verify compliance with specifications.
2. HMA should be relatively impermeable to moisture and should be designed
with crushed aggregates that have a minimum of 80 percent of the
aggregate retained on the No. 4 sieve with two mechanically fractured
faces.
3. Gradations that approach the maximum density line (within 5 percent
between the No. 4 and 50 sieves) should be avoided. A gradation with a
nominal maximum size of 1 or 2 inches developed on the fine side of the
maximum density line should be used.
4. Total void content, voids in the mineral aggregate (VMA) and voids filled
should be considered in the selection of the optimum asphalt cement
content. The optimum asphalt content should be selected at a total air void
content of approximately 4 percent. The mixture should have a minimum
VMA of 14 percent and between 65 percent and 80 percent of voids filled.
5. Asphalt cement should meet the requirements of the Superpave
Performance Graded (PG) Binders. The minimum performing asphalt
cement should conform to the requirements of the governing agency.
6. Hydrated lime should be added at the rate of 1 percent by dry weight of the
aggregate and should be included in the amount passing the No. 200 sieve.
Hydrated lime for aggregate pretreatment should conform to the
requirements of ASTM C 207, Type N.
7. Paving should be performed on properly prepared, unfrozen surfaces
that are free of water, snow, and ice. Paving should only be performed
when both air and surface temperatures equal, or exceed, the temperatures
specified in Table 401-3 of the 2006 Colorado Department of
Transportation Standard Specifications for Road and Bridge Construction.
8. HMA should not be placed at a temperature lower than 245oF for mixes
containing PG 64-22 asphalt, and 290oF for mixes containing polymer-
modified asphalt. The breakdown compaction should be completed before
the HMA temperature drops 20oF.
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTLT PROJECT NO. FC10774.000-120
E-5
9. Wearing surface course shall be Grading S or SX for residential roadway
classifications and Grading S for collector, arterial, industrial, and
commercial roadway classifications.
10. The minimum/maximum lift thicknesses for Grade SX shall be 1½
inches/2½ inches. The minimum/maximum lift thicknesses for Grade S
shall be 2 inches/3½ inches. The minimum/maximum lift thicknesses for
Grade SG shall be 3 inches/5 inches.
11. Joints should be staggered. No joints should be placed within wheel paths.
12. HMA should be compacted to between 92 and 96 percent of Maximum
Theoretical Density. The surface shall be sealed with a finish roller prior to
the mix cooling to 185oF.
13. Placement and compaction of HMA should be observed and tested by a
representative of our firm. Placement should not commence until approval
of the proof rolling as discussed in the Subgrade Preparation section of this
report. Sub base, base course or initial pavement course shall be placed
within 48 hours of approval of the proof rolling. If the Contractor fails to
place the sub base, base course or initial pavement course within 48 hours
or the condition of the subgrade changes due to weather or other
conditions, proof rolling and correction shall be performed again.
Portland Cement Concrete (PCC)
1. Portland cement concrete should consist of Class P of the 2021 CDOT -
Standard Specifications for Road and Bridge Construction specifications
for normal placement. PCC should have a minimum compressive strength
of 4,500 psi at 28 days and a minimum modulus of rupture (flexural
strength) of 650 psi. Job mix designs are recommended and periodic
checks on the job site should be made to verify compliance with
specifications.
2. Portland cement should be Type II “low alkali” and should conform to ASTM
C 150.
3. Portland cement concrete should not be placed when the subgrade or air
temperature is below 40°F.
4. Concrete should not be placed during warm weather if the mixed concrete
has a temperature of 90°F, or higher.
5. Mixed concrete temperature placed during cold weather should have a
temperature between 50°F and 90°F.
6. Free water should not be finished into the concrete surface. Atomizing
nozzle pressure sprayers for applying finishing compounds are
recommended whenever the concrete surface becomes difficult to finish.
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTLT PROJECT NO. FC10774.000-120
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7. Curing of the Portland cement concrete should be accomplished by the use
of a curing compound. The curing compound should be applied in
accordance with manufacturer recommendations.
8. Curing procedures should be implemented, as necessary, to protect the
pavement against moisture loss, rapid temperature change, freezing, and
mechanical injury.
9. Construction joints, including longitudinal joints and transverse joints,
should be formed during construction, or sawed after the concrete has
begun to set, but prior to uncontrolled cracking.
10. All joints should be properly sealed using a rod back-up and approved
epoxy sealant.
11. Traffic should not be allowed on the pavement until it has properly cured
and achieved at least 80 percent of the design strength, with saw joints
already cut.
12. Placement of Portland cement concrete should be observed and tested by
a representative of our firm. Placement should not commence until the
subgrade is properly prepared and tested.
APPENDIX F
PAVEMENT MAINTENANCE PROGRAM
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTLT PROJECT NO. FC10774.000-120
F-1
MAINTENANCE RECOMMENDATIONS FOR FLEXIBLE PAVEMENTS
A primary cause for deterioration of pavements is oxidative aging resulting in brittle
pavements. Tire loads from traffic are necessary to "work" or knead the asphalt concrete to keep
it flexible and rejuvenated. Preventive maintenance treatments will typically preserve the original
or existing pavement by providing a protective seal or rejuvenating the asphalt binder to extend
pavement life.
1. Annual Preventive Maintenance
a. Visual pavement evaluations should be performed each spring or fall.
b. Reports documenting the progress of distress should be kept current to provide
information on effective times to apply preventive maintenance treatments.
c. Crack sealing should be performed annually as new cracks appear.
2. 3 to 5 Year Preventive Maintenance
a. The owner should budget for a preventive treatment at approximate intervals
of 3 to 5 years to reduce oxidative embrittlement problems.
b. Typical preventive maintenance treatments include chip seals, fog seals, slurry
seals and crack sealing.
3. 5 to 10 Year Corrective Maintenance
a. Corrective maintenance may be necessary, as dictated by the pavement
condition, to correct rutting, cracking, and structurally failed areas.
b. Corrective maintenance may include full depth patching, milling and overlays.
c. In order for the pavement to provide a 20-year service life, at least one major
corrective overlay should be expected.
MILESTONE DEVELOPMENT GROUP, LLC
THE SAVOY
CTLT PROJECT NO. FC10774.000-120
F-2
MAINTENANCE RECOMMENDATIONS FOR RIGID PAVEMENTS
High traffic volumes create pavement rutting and smooth polished surfaces. Preventive
maintenance treatments will typically preserve the original or existing pavement by providing a
protective seal and improving skid resistance through a new wearing course.
1. Annual Preventive Maintenance
a. Visual pavement evaluations should be performed each spring or fall.
b. Reports documenting the progress of distress should be kept current to provide
information of effective times to apply preventive maintenance.
c. Crack sealing should be performed annually as new cracks appear.
2. 4 to 8 Year Preventive Maintenance
a. The owner should budget for a preventive treatment at approximate intervals
of 4 to 8 years to reduce joint deterioration.
b. Typical preventive maintenance for rigid pavements includes patching, crack
sealing and joint cleaning and sealing.
c. Where joint sealants are missing or distressed, resealing is mandatory.
3. 15 to 20 Year Corrective Maintenance
a. Corrective maintenance for rigid pavements includes patching and slab
replacement to correct subgrade failures, edge damage, and material failure.
b. Asphalt concrete overlays may be required at 15 to 20 year intervals to improve
the structural capacity of the pavement.