HomeMy WebLinkAboutFRONT RANGE STORAGE - PDP230011 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT
CTL|Thompson, Inc.
Denver, Fort Collins, Colorado Springs, Glenwood Springs, Pueblo, Summit County – Colorado
Cheyenne, Wyoming and Bozeman, Montana
Mountain Vista Property
Fort Collins, Colorado
Prepared for:
Eric Kelley
c/o JR Engineering LLC
2900 S College Avenue, Ste 3D,
Fort Collins, Colorado 80525
Attention:
Eric Kelley
Project No. FC10813.000-115
May 17, 2023
PRELIMINARY GEOTECHNICAL INVESTIGATION
Table of Contents
Scope .............................................................................................................................................. 1
Summary Of Conclusions ............................................................................................................... 1
Site Description ............................................................................................................................... 2
Proposed Development .................................................................................................................. 2
Previous Investigation ..................................................................................................................... 3
Site Geology.................................................................................................................................... 4
Geologic Hazards ........................................................................................................................... 4
Expansive Soils ........................................................................................................................... 5
Collapse-Prone Soils ................................................................................................................... 5
Groundwater ................................................................................................................................ 6
Surface Drainage ........................................................................................................................ 6
Frost Heave ................................................................................................................................. 6
Seismicity .................................................................................................................................... 7
Field And Laboratory Investigations ............................................................................................... 7
Subsurface Conditions .................................................................................................................... 8
Development Recommendations ................................................................................................... 8
Site Grading ................................................................................................................................ 8
Permanent Cut and Fill Slopes ................................................................................................... 9
Utility Construction ...................................................................................................................... 9
Retaining Walls ......................................................................................................................... 10
Preliminary Pavement Recommendations ................................................................................... 11
Subgrade Preparation ............................................................................................................... 11
Preliminary Pavement Thickness Design ................................................................................. 11
Preliminary Recommendations for Structures .............................................................................. 13
Foundations ............................................................................................................................... 13
Slabs-on-Grade Construction ................................................................................................... 13
Below-Grade Construction ........................................................................................................ 13
Surface Drainage ...................................................................................................................... 13
General Design Considerations ................................................................................................ 14
Corrosion Protection ..................................................................................................................... 14
Water Soluble Sulfates .............................................................................................................. 15
Recommended Future Investigations ........................................................................................... 16
Limitations ..................................................................................................................................... 16
FIGURE 1 – LOCATIONS OF EXPLORATORY BORINGS
FIGURES 2 THROUGH 3 – SUMMARY LOGS OF EXPLORATORY BORINGS
APPENDIX A – LABORATORY TEST RESULTS
APPENDIX B – GUIDELINE SITE GRADING SPECIFICATIONS
ERIC KELLEY C/O JR ENGINEERING LLC 1
MOUNTAIN VISTA PROPERTY
CTL|T PROJECT NO. FC10813-115
Scope
This report presents the results of our Geologic and Preliminary Geotechnical Investigation.
The purpose of our investigation was to identify ge ologic hazards that may exist at the site and to
evaluate the subsurface conditions to assist in planning and budgeting for the proposed
development. The report includes descriptions of site geology, our analysis of the impact of
geologic conditions on site development, a description of subsoil, bedroc k and groundwater
conditions found in our exploratory bori ngs, and discussions of site development as influenced by
geotechnical considerations. The scope was described in our Service Agreement (CTL |T Proposal
No. FC-23-0158) dated April 11, 2023.
This report was prepared based upon our understanding of the develop ment plans. The
recommendations are considered preliminary and can be used as guidelines for further planning of
development and design of gradin g. We should review final development and grading plans to
determine if additional investigation is merited, or if we need to revise our recommendations.
Additional investigations will be required to design building foundations and pavements. A
summary of our findings and recommendations is presented below. More detailed discussions of
the data, analysis, and recommendations are presented in the report.
Summary Of Conclusions
1. The site contains geologic hazards that should be mitigated during planning a nd
development. No geologic or geotechnical conditions were identified which would preclude
development of this site. Expansive soils and groundwater are the primary geologic
concerns pertaining to the development of the site .
2. The subsurface conditions encoun tered in our borings were variable across the site. In
general, the soils encountered in our borings consisted of 7 to 24 feet of sandy clay and
clayey sand over sandy gravel to depths explored. Groundwater was encountered at
depths ranging from 7 to 16 feet below the existing ground surface. Groundwater levels will
not likely affect planned development at this site.
3. We measured consolidation and low swell in several samples of clayey sand and sandy
clay. Soils exhibited non-expansive to 1.2 percent swells throughout the site. We anticipate
footing or pad-type foundations will be appropriate for most structures.
4. Asphaltic pavement sections on the order of 4 to 6 inches for streets, parking areas, and
access drives are anticipated for preliminary planning purposes. Unpaved road sections on
the order of 8 inches of roadbase are appropriate for the planned use.
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Site Description
The site is located east of Frontage Road north of Vine Drive in Fort Collins, Colorado. The
site is generally in a plains area and is primarily farm field. At the time of our exploration the site
was primarily undeveloped. The overall site is relatively level. The Larimer and Weld Canal flows
along the south side of the site and Boxelder Creek flows to the east of the site. An existing house
is located on the west side o f the site, which we understand will be demolished as a part of the
project.
Proposed Development
We understand the parcel is planned for the development of an RV/Boat storage lot with
covered parking for a portion of the site. Preliminary plans indicate the site improvements will
include ancillary features such as administrative structures, detention ponds, access roads , and
parking covers. We assume the structures will be 1-story, wood or steel frame structures. No below
grade construction is anticipated.
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Previous Investigation
CTL|Thompson has performed Geotechnical Investigations and Soils and Foundation
Investigations for the NEWT3 pipeline improvement project. This work was performed under
CTL|Thompson Project No. FC10581.000-125 Rev 2, dated January 10, 2023. The client for the
NEWT3 project has allowed the reuse of the data for this project. The data generated as a part of
that project was reviewed in preparation of this report, including four additional borings shown on
Figure 3.
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Site Geology
The geology of the site was investigated through review of mapping by Roger B Colton
(Geologic Map of the Boulder – Fort Collins – Greeley Area, Colorado, 1978). The majority of the
project site is mapped as Broadway Alluviums, with a smaller portion in the southern area of the site
mapped as Post-Piney Creek Alluvium or similar. Specific descriptions of each geologic unit are
provided below. In general, a layer of overburden soils (in this case sandy clays) is underlain by a
matrix of gravels and sands. The gravel layer is understood to be glacial outwash. The materials
encountered in our borings were in general agreeance with the re ferenced mapping.
Geologic Hazards
Our investigation identified several geologic hazards that must be considered during the
planning and development phases of this project. None of the geologic hazards identified will
preclude development of the property. Development plans are preliminary.
Planning should consider the geologic hazards discussed below. The hazards require
mitigation which could include av oidance, non-conflicting use or engineered design and
construction during site development. The following sections discuss each of these geologic
hazards and associated development concerns. Mitigation concepts are discussed below and in
the Development Recommendations section of the report.
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Expansive Soils
Colorado is a challenging loca tion to practice geotechnical engin eering. The climate is
relatively dry, and the near-surface soils are typically dry and relati vely 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 w etting 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 bed rock 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 condi tions.
As a result of this moisture fluctuation, some soil movement due to heave or settlement is
inevitable. There is a risk that improvements will experience damage. It is critical that precautions
are taken to increase the chances that the foundations and slabs-on-grade will perform
satisfactorily. Engineered planning, design and construction of grading, pavements, foundations,
slabs-on-grade, and drainage can mitigate, but not eliminate the effects of expansive and
compressible soils.
The soils at this site include sandy clay with expansive potential. Samples tested exhibited
behavior of low swell after wetting under a 1,000-psf load. We believe the risk from collapse-prone
soils is probably greater than the risk from expansive soils at the site.
Collapse-Prone Soils
Soils encountered in the borings at this site include silty sandy clays and silty clayey sands.
Some of these soils had a porous, friable structure and moderately low density. These soils have
the potential for consolidation or collapse upon wetting. Some increase in subsurface moisture
must be assumed due to the effects of site development. However, we anticipate the risk of large
or deep deposits of collapsible soil is low due to the historical agricultural modification and irrigation
efforts. Regardless, engineered design of foundations, slabs-on-grade, pavements, and surface
drainage can mitigate the effects of collapse -prone soils.
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Groundwater
Groundwater was encountered during drilling or when the holes were checked several days
after drilling. Groundwater generally ranged between 7 and 16 feet below ground surface at the
time of our exploration. We do not expect current groundwater levels will affect site development
but may impact detention ponds depending on design depth. Groundwater may rise due to site
development and will likely occur during extended periods of flow in nearby water features. A
groundwater monitoring plan will be performed over the course of the next several months to
determine if ponds will be impacted by water levels.
Surface Drainage
The Civil Engineer should evaluate and quantify the potential flow in each drainage during
peak precipitation events, and design surface drainage and storm collec tion systems to
accommodate the water. Active drainageways should be avoided for development. Structures
should not be located within a lateral distance from the cr est equivalent to twice the depth of the
drainageway where slopes are steeper than about 2:1. Storm drainage should be collected in
detention basins and released at historic rates or less. Development in the steeper areas should be
carefully situated and engineered so as not to contribute to or become damaged by erosion.
Frost Heave
Our borings indicate shallow groundwater is present and some of the overburden soils at the
site consist of materials that may be susceptible to frost heave. Based on our experience and local
construction practice in the area, the minimum depth of cover for frost protection is 30 inches. We
recommend foundations have a minimum cover of 30 inches. If the foundations are constructed
with the appropriate frost protection, we do not belie ve frost heave will affect the proposed
structures. Slabs-on-grade may experience some mov ement due to frost heave. If the structures
are insulated or heated, the potential for slab movement due to frost heave is minimal. If the
structures are not insulated or heated, slabs-on-grade should be constructed with frost protection.
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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 earthqu akes within the
past 100 years, shown to be related to deep drilling, liquid injection, and oil/gas extraction. Naturally
earthquakes along faults due to tectonic shifts are rare in this area.
The soils 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 CRIT ERIA
Seismic Site Class , 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 765 and 1010 feet per second with an
average value of 925 feet per second. We judge a Seismic Site Classification of D. The field
penetration test results along with the empirical estimates imply that shear -wave velocity seismic
tests to directly measure could result in a better Seismic Site Classification. The subsurface
conditions indicate low susceptibility to liquefaction from a materials and groundwater perspective.
Field And Laboratory Investigations
Subsurface conditions were further investigated by drilling seven exploratory borings at the
approximate locations shown on Figure 1. The borings were drilled using a truck-mounted drill rig
with a 4-inch diameter continuous-flight auger. Our field representative observed drilling, logged the
soils found in the borings, and obtained samples. Summary logs of the soils found in the borings
and field penetration resistance values are presented in Figures 2 and 3.
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Samples of soils were obtained during drilling by driving a modified California-type sampler
(2.5-inch O.D.) into the subsoils using a 140-pound hammer falling 30 inches. Samples recovered
from the test holes were returned to our laboratory and visually classifi ed by the geotechnical
engineer. Laboratory testing included determination of moisture content, dry density, swell-
consolidation characteristics, particle-size analysis, and water- soluble sulfate content. Laboratory
test results are presented in Appendix A.
Subsurface Conditions
Subsurface conditions encountered in the borings included approximately 7 to 24 feet of
sandy clay and clayey sand over sandy gravel to the depths explored. Groundwater was
encountered at depths ranging from 7 to 16 feet below the existing ground surface. Groundwater
levels will not likely affect planned development at this site. A more detailed description of the
subsurface conditions is presented in our boring logs and laboratory testing.
Summary of Swell Behavior by Soil Type
*Swell measured after wetting under the approximate weight of the overlying soils (overburden pressures).
Development Recommendations
Site Grading
At the time of this investigation, site grading plans were not available for review in
conjunction with this subsurface exploration progr am. It is important that deep fills (if planned) be
constructed as far in advance of surface construction as possible. It is our experience that fill
compacted in accordance with the compaction recommendations in this report may settle about 1
percent of its height under its own weight. Most of this settlement usually occurs during and soon
Soil Type Compression Range of Measured Swell (%)*
0 to <2 2 to <4 4 to <6 >6
Number of Samples and Percent
Sandy Clay 1 5 0 0 0
17% 83% 0% 0% 0%
Clayey Sand 1 3 0 0 0
25% 75% 0% 0% 0%
Overall Sample Number 2 8 0 0 0
Overall Sample Percent 20% 80% 0% 0% 0%
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after construction. Some additional settlement is possible after development and la ndscape
irrigation increases soil moisture. We recommend delaying the construction of structures underlain
by deep fills as long as possible to allow for this set tlement to occur. Delaying construction of
structures up to one year where located on deep fill s is recommended.
The existing onsite soils are suitable for re-use as fill material provided debris or deleterious
organic materials are removed. Prior to fill placement, all trash and debris should be removed from
fill areas and properly disposed. Import fill should generally have similar or better engineering
properties as the onsite materials and should be approved by CTL|T. The ground surface in areas
to be filled should be stripped of vegetation, topsoil, and other deleterious materials, scarified to a
depth of at least 8 inches, moisture conditioned and compa cted as recommended below. The
depth of any topsoil is not anticipated to be more than 2 to 3 inches in most areas.
Site grading fill should be placed in thin, loose lifts, moisture conditioned and compacted. In
areas of deep fill, we recommend higher compaction criteria to help reduce settlement of the fill.
Compaction and moisture requirements are presented in Appendix B. The placement and
compaction of fill should be observed, and density tested during construction. Guideline site grading
specifications are presented in Appendix B.
Permanent Cut and Fill Slopes
We recommend permanent cut and fill slopes be designed with a maximum inclination of 3:1
(horizontal to vertical). Where fills will be placed on slopes exceeding 20 percent (5:1) the slope
should be benched. Structures should be setback from the top or bottom of cut and fill slopes. If
site constraints (property boundaries and streets) do not permit construction with recommended
slopes, we should be contacted to evaluate the subsurface soi ls and steeper slopes.
Utility Construction
We believe excavations for utility installation in the overb urden soils can be performed with
conventional heavy-duty trenchers or large backhoes. If groundwater is encountered during
construction, dewatering may be accomplished by sloping excavations to occasional sumps where
water can be removed by pumping.
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Utility trenches should be sloped or shored to meet local, State , and federal safety
regulations. Based on our investigation, we believe the soil at this site classifies as Type B soil
based on OSHA standards. Excavation slopes specified by OSHA are dependent upon soil types
and groundwater conditions encountered. Seepage and grou ndwater conditions in trenches may
downgrade the soil type. Contractors should identify the soils encountered in the excavation and
refer to OSHA standards to determine appropriate slopes. Excavations deeper t han 20 feet should
be designed by a professional engineer.
The width of the top of an excavation may be limited in so me areas. Bracing or “trench box”
construction may be necessary. Bracing systems include sheet piling, braced sheeting, and others.
Lateral loads on bracing depend on the depth of excavation, slope of excavation above the bracing,
surface loads, hydrostatic pressures, and allowable movement. For trench boxes and bracing
allowed to move enough to mobilize the strength of the soils, with associated cracking of the ground
surface, the “active” earth pressure conditions are appropriate for design. If movem ent is not
tolerable, the “at rest” earth pressures are appropriate. We suggest an equivalent fluid density of 30
pcf for the “active” earth pressure condition and 45 pcf for the “at rest” earth pressure condition,
assuming level backfill. These pressure s do not include allowances for surcharge loading or for
hydrostatic conditions. We are available to assist further with bracing design if desired.
Water and sewer lines are usually constructed beneath paved roads. Compaction of trench
backfill can have significant effect on the life and serviceability of pavements. We believe trench
backfill should be placed in thin, loose lifts, and m oisture conditioned to between optimum and 3
percent above optimum content for clay soils and within 2 percent of optim um moisture content for
sand. Trench backfill should be compacted to at least 95 percent of maximum dry density (ASTM D
698). The placement and compaction of fill and backfill shoul d be observed and tested by our firm
during construction.
Retaining Walls
Site retaining walls can be constructed on footing foundations, however, some movement is
possible for footings constructed on expansive soil. For mechanically stabilized earth (MSE) wall
design, we recommend using a friction angle of 20 degrees and no cohesion for the retained soil.
We recommend an imported granular soil be used as backfill within the reinforced zone behind the
walls.
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Some walls may be subjected to lateral loading. Lateral loads are dependent on the heigh t
and type of wall, backfill configuration , and backfill type. For purposes of design, we have assumed
backfill will consist of onsite clay. For walls that are free to rotate, we recommend walls be designed
to resist an “active” earth pressure using an eq uivalent fluid density of 50 pcf without hydrostatic
pressure. If imported granular soil meeting the requirements of CDOT Class 6 Road Base i s used
as backfill, the equivalent fluid density can be reduced to 35 pcf. These values are for dry
conditions. We recommend appropriate hydrostatic pressure be included in the design. Drains
should be installed to help control hydrostatic pressures. The d rain should lead to a positive gravity
outlet, or the wall could be provided with weep holes. A “passive” resistance calculated using 250
pcf equivalent fluid density can be used for walls subject to lateral loads. The recommended
“passive” pressure assumes fill placed in front of walls will be densely compacted and will not be
removed. The friction coefficient for concrete sliding on the site soil can be taken to be 0.3.
The top 2 feet of exterior backfill behind walls should be clayey soils to reduce water
infiltration. Backfill behind retaining walls should be placed in thin, loose lifts; moisture conditio ned
and compacted. Settlement on the order of 1 to 2 percent of the backfill depth may occur;
improvements constructed over backfill should b e designed to perform considering anticipated
settlements.
Preliminary Pavement Recommendations
Subgrade Preparation
Based on the borings, the near surface soil s on this site will consist of loose to medium
dense clayey and/or silty sands and stiff sandy, silty clays. These soils will generally be of low
plasticity and will provide relatively poor to moderate subgrade support below the pavements.
Preliminary Pavement Thickness Design
Roadway surfacing preferences were not determined at the time of this report. We
understand that access drives, parking, and storage areas could be asphalt or unsurfaced granular
materials. Preliminary guidelines for pavement s ystems on this site are provided. Final pavement
sections should be determined based on a design level geotechnical investigation and anticipated
frequency of load applications on the pavement during the desired design life. Flexible hot mix
asphalt (HMA) over aggregate base course (ABC) pavements can be used at this site for
automobile and light truck traffic use. As an option, unsurfaced granular materials (roadbase ,
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recycled asphalt, or recycled concrete) could be selected. We anticipate asphalt pavement sections
for access roads and parking will be on the order of 4 to 5 inches thick. Minimum pavement section
thicknesses are provided in the table below.
Minimum Pavement Thickness
Roadway
Designation
Hot Mix Asphalt (HMA)
+
Aggregate Base Course
(ABC)
Unsurfaced
Granular Materials
Portland Cement
Concrete (PCC)
Access Roads,
Parking Lots, and
Storage Areas
4.0” HMA +
6.0” ABC 8.0” Not Anticipated
Heavy Vehicle Areas 6” HMA +
8.0” ABC Not Recommended 6”
Portland cement concrete (PCC) pavement is recommended in areas subject to any heavy
truck traffic such as garbage pickup and/or dumpster trucks and any heavy delivery trucks. A
minimum 6-inch-thick section is anticipated in main drives and any areas subject to some heavy
traffic. Any areas subject to frequent heavy trucks should be designed based on frequency and
wheel loads. PCC pavements in this area are typically reinforced due to the underlying active clays.
Properly designed control joints and other joints systems are required to control cracking and allow
pavement movement.
Granular Surfacing
We believe a section of 8 to 10 inches of aggregate base course or recycled concrete and/or
asphalt should provide adequate support for planned traffic. Heavy vehicle traffic should be avoided
on this surface. Some distress including aggregate loss and segregations of the road should be
expected, and occasional maintenance should be performed to keep the road in a serviceable
condition.
The aggregate base course or recycled concrete and/or asphalt should conform to CDOT
standards and be Class 5 or 6 or better. The aggregate road base should be placed in thin, loose
lifts not to exceed 6 inches and be moisture-conditioned within 2 percent of optimum moisture
content and compacted to at least 95 percent of modified Proctor maximum dry density (ASTM D
1557). Placement of aggregate base course should be observed and tested by a representative of
our firm. If traffic volume or loading changes or construction traffic is planned for this road, we
should be contacted to review our thickness recommendations.
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Preliminary Recommendations for Structures
The property is currently planned for commercial construction. Our field and laboratory data
indicate the soil conditions vary across the site. The following discussions are preliminary and are
not intended for design or construction. After grading is completed, a detailed Soils and Foundation
investigation should be performed.
Foundations
Our geologic and preliminary geotechnical investigation for this site indicates structures may
be founded on a shallow foundation. A design level geotechnical investigation may identify
potential hazards for specified areas not indicated by our borings which may suggest the need for a
deeper foundation system.
Slabs-on-Grade Construction
The use of slab-on-grade floors should be limited to areas where soils within the depth likely
to influence floor performance are consolidating to low swelling granular soils or clay. We believe
most of the site will be rated with low risk of poor slab performance. Structurally supported floor
systems should be planned where slab movements cannot be tolerated. Slab performance risk
should be more thoroughly defined during the design level soils and foundation investigation.
Below-Grade Construction
Below grade construction is not understood to be a part of the planned development. If
plans change to include below grade spaces, our office should be contacted to evaluate the
changes to this report and provide recommendations for design and const ruction.
Surface Drainage
The performance of foundations will be influenced by surface drainage. The ground surface
around the proposed structures should be shaped to provide runoff of surface water away from the
structures and off of pavements. We generally recommend slopes of at least 12 inches in the first
10 feet where practical in the landscaping areas surrounding structures. There are practical
limitations on achieving these slopes. Irrigation should be minimized to control wetting. Roof
downspouts should discharge beyond the limits of backfill. Water should not be allowed to pond on
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or adjacent to pavements. Proper control of surface runoff is also important to limit the erosion of
surface soils. Sheet flow should not be directed over unprotected slopes. Water should not be
allowed to pond at the crest of slopes. Permanent slopes should be re-vegetated to reduce erosion.
Water can follow poorly compacted fill behind curb and gutter and in utility trenches. This
water can soften fill and undermine the performance of the roadways, flatwork , and foundations.
We recommend compactive e ffort be used in placement of all fill.
General Design Considerations
Exterior sidewalks and pavements supported above the on-site clays are subject to post
construction movement. Flat grades should be avoided t o prevent possible ponding, particularly
next to structures due to soil movement. Positive grades a way from structures should be used for
sidewalks and flatwork around the perimeter of the structure in order to reduce the possibility of
lifting of this flatwork, resulting in ponding next to the structures. Where movement of the flatwork is
objectionable, procedures recommended for on-grade floor slabs should be considered.
Joints next to structures should be thoroughly sealed to prevent the infiltrat ion of surface
water. Where concrete pave ment is used, joints should also be sealed to reduce the infiltration of
water. Since some post construction movement of pavement and flatwork may occur, joints around
the structures should be periodically observed and resealed where necessary.
Roof drains should be discharged well away from the structures, preferably by closed pipe
systems. Where roof drains are allowed to discharge on concrete flatwork or pavement areas next
to the structures, care should be tak en to ensure the area is as water-tight as practical to eliminate
the infiltration of this water next to the structures.
Corrosion Protection
As a part of our testing program, a series of corrosion tests were performed to provide
guidance in material sele ction for the subsurface structures on this project. We recommend this
test data be provided to a corrosion engineer for evaluation.
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Water Soluble Sulfates
Concrete in contact with soil can be subject to sulfate attack. We measured water -soluble
sulfate concentrations of 0.04 to 1.60 percent in six samples. As indicated in our tests and ACI 318-
19, the sulfate exposure class is Severe or S2. Deviations from the exposure class may occur as a
result of additional sampling and testing.
SULFATE EXPOSURE CLASSES PER ACI 318 -19
Exposure Classes
Water-Soluble Sulfate (SO4)
in Soil A
(%)
Not Applicable S0 < 0.10
Moderate S1 0.10 to 0.20
Severe S2 0.20 to 2.00
Very Severe S3 > 2.00
A) Percent sulfate by mass in soil determined by ASTM C1580
For this level of sulfate concentration, ACI 318-19 Code Requirements indicates there are
special cement type requirements for sulfate resistance as indicated in the table below . Additional
sulfate testing is recommended during the design -level phase.
CONCRETE DESIGN REQUIREMENTS FOR SULFATE EXPOSURE PER ACI 318 -19
Exposure
Class
Maximum
Water/
Cement
Ratio
Minimum
Compressive
Strength
(psi)
Cementitious Material Types A
Calcium
Chloride
Admixtures
ASTM
C150/
C150M
ASTM
C595/
C595M
ASTM
C1157/
C1157M
S0 N/A 2500 No Type
Restrictions
No Type
Restrictions
No
Type
Restrictions
No
Restrictions
S1 0.50 4000 IIB
Type with
(MS)
Designation
MS No
Restrictions
S2 0.45 4500 V B
Type with
(HS)
Designation
HS Not
Permitted
S3 Option 1 0.45 4500
V +
Pozzolan or
Slag Cement
C
Type with
(HS)
Designation
plus
Pozzolan or
Slag
Cement C
HS +
Pozzolan or
Slag
Cement C
Not
Permitted
S3 Option 2 0.4 5000 V D
Type with
(HS)
Designation
HS Not
Permitted
A) Alternate combinations of cementitious materials shall be permitted when tested for sulfate resistance meeting
the criteria in section 26.4.2.2(c).
ERIC KELLEY C/O JR ENGINEERING LLC 16
MOUNTAIN VISTA PROPERTY
CTL|T PROJECT NO. FC10813-115
B) Other available types of cement such as Type III or Type I are permitted in Exposure Classes S1 or S2 if the
C3A contents are less than 8 or 5 percent, respectively.
C) The amount of the specific source of pozzolan or slag to be used shall not be less than the amou nt 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 and meeting the criteria in section 26.4.2.2(c) of ACI 318.
D) If Type V cement is used as the sole cementitious material, the optional sulfate resistance requirement of 0.040
percent maximum expansion in ASTM C150 shall be specified.
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.
Recommended Future Investigations
Based on the results of this investigation and the proposed development, we recommend
the following investigations be performed:
1. Review of final site grading plans by our firm;
2. Construction testing and obs ervation for site development;
3. Subgrade investigation and pavement design after site grading is complete;
4. Design-level soils and foundation investigations after grading;
5. Construction testing and observation for construction and paving.
Limitations
Our exploratory borings were located to obtain preliminary subsoil data indicative of
conditions on this site. Although our borings were spaced to obtain a reasonably accurate picture of
subsurface conditions, variations in the subsoils not indicated in our borings are always possible.
We believe this investigation was conducted in a manner consistent with that level of skill and care
ordinarily used by members of the profession currently practicing under s imilar conditions in the
locality of this project. No warranty, express or implied, is made.
ERIC KELLEY C/O JR ENGINEERING LLC 17
MOUNTAIN VISTA PROPERTY
CTL|T PROJECT NO. FC10813-115
This report was prepared from data developed during our field exploration, laboratory
testing, engineering analysis, and experience with similar conditions. The recommendations
contained in this report were based upon our understanding of the planned construction. If plans
change or differ from the assumptions presented herein, we should be contacted to review our
recommendations.
If we can be of further service in discussing the contents of this report or in the analysis of
the building and pavement from the geotechnical point of view, please call.
Very truly yours,
CTL|THOMPSON, INC.
Alexander G. Leadbetter R.B. "Chip" Leadbetter, III, P.E.
Staff Engineer Senior Engineer
TH-12
TH-2
TH-1
TH-4
TH-13
TH-5
TH-3
TH-14
TH-6
TH-15
TH-7I-25E Vine DR.I-25Can
a
l N CR 5E CR 50
Site
NE FRONTAGE RDLEGEND:
INDICATES APPROXIMATE
LOCATION OF EXPLORATORY
BORING
INDICATES APPROXIMATE
LOCATION OF EXPLORATORY
BORINGS PERFORMED FOR NEWT
3 PIPELINE PROJECT (FC10581)
TH-1
TH-12
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CTL I T PROJECT NO. FC10813-115
FIGURE 1
Locations of
Exploratory Borings
VICINITY MAP
(FORT COLLINS, COLORADO)
NOT TO SCALE
550'275'
APPROXIMATE
SCALE: 1" = 550'
0'
0
5
10
15
20
25
30
35
40
0
5
10
15
20
25
30
35
40
6/12
14/12
9/12
11/12
50/10
WC=11.2
DD=109
SW=0.0
SS=0.370
WC=4.7
DD=116
-200=23
WC=8.7
DD=114
SW=-0.1
TH-1
10/12
15/12
WC=19.9
DD=104
SW=0.9
SS=1.300
TH-2
7/12
9/12
9/12
17/12
37/12
WC=10.1
DD=114
-200=45
WC=10.8
DD=116
SW=0.0
TH-3
9/12
26/12
WC=23.2
DD=106
SW=0.4
TH-4
21/12
10/12
29/12
8/12
WC=5.6
DD=114
SW=0.0
SS=0.800
TH-5
7/12
4/12
50/5
WC=25.6
DD=96
-200=83
WC=17.2
DD=111
SW=-0.1
TH-6
7/12
2/12
4/12
WC=17.6
DD=107
SW=0.3
SS=0.040
TH-7
DEPTH - FEETDEPTH - FEETSummary Logs of
Exploratory Borings
FIGURE 2
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CTL | T PROJECT NO. FC10813-115
0
5
10
15
20
25
30
35
40
0
5
10
15
20
25
30
35
40
8/12
42/12
40/12
26/12
WC=0.0DD=102SW=1.3SS=1.600
WC=5.1-200=7
WC=0.0DD=102SW=1.3SS=1.600
WC=5.1-200=7
TH-12
11/12
14/12
12/12
9/12
WC=10.3-200=16WC=10.3-200=16
TH-13
14/12
6/12
15/12
31/12
WC=0.0DD=113SW=0.0SS=0.490
WC=0.0DD=113SW=0.0SS=0.490
TH-14
11/12
5/12
7/12
7/12
WC=30.8DD=91WC=30.8DD=91
TH-15
DRIVE SAMPLE. THE SYMBOL 8/12 INDICATES 8 BLOWS OF A 140-POUND HAMMER
FALLING 30 INCHES WERE REQUIRED TO DRIVE A 2.5-INCH O.D. SAMPLER 12 INCHES.
SAND, CLAYEY, SILTY, SLIGHTLY MOIST TO MOIST, LOOSE TO MEDIUM DENSE, BROWN,
TAN, RUST (SC)
1.
4.
LEGEND:
CLAY, SANDY, MOIST, STIFF, BROWN (CL)DEPTH - FEETTHESE LOGS ARE SUBJECT TO THE EXPLANATIONS, LIMITATIONS AND CONCLUSIONS IN
THIS REPORT.
NOTES:
WATER LEVEL MEASURED MAY 1, 2023
GRAVEL, SANDY, SLIGHTLY MOIST TO WET,MEDIUM DENSE TO VERY DENSE, REDDISH
BROWN (GP)
INDICATES DEPTH WHERE HOLE CAVED PRIOR TO SECONDARY
GROUNDWATER MEASUREMENTS.
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 (%).
3.DEPTH - FEETWATER LEVEL MEASURED AT TIME OF DRILLING.
Summary Logs of
Exploratory Borings
BORINGS 1-7 WERE DRILLED ON APRIL 21ST, 2023 USING 4-INCH DIAMETER
CONTINUOUS-FLIGHT AUGERS AND A TRUCK-MOUNTED DRILL RIG.
FIGURE 3
WC
DD
SW
-200
LL
PI
UC
SS
-
-
-
-
-
-
-
-
ERIC KELLEY C/O JR ENGINEERING LLC
MOUNTAIN VISTA PROPERTY
CTL | T PROJECT NO. FC10813-115
BORINGS 12-15 WERE PERFORMED ON NOVEMBER 8TH, 2022 AS A PART OF THE NEWT 3
PIPELINE PROJECT (FC10581)
2.
APPENDIX A
LABORATORY TEST RESULTS
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=109 PCF
From TH - 1 AT 4 FEET MOISTURE CONTENT=11.2 %
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=114 PCF
From TH - 1 AT 14 FEET MOISTURE CONTENT=8.7 %
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CTL | T PROJECT NO. FC10813-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-1COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
NO MOVEMENT DUE TO WETTING
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
ADDITIONAL COMPRESSION UNDER
CONSTANT PRESSURE DUE TO
WETTING
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=104 PCF
From TH - 2 AT 4 FEET MOISTURE CONTENT=19.9 %
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=116 PCF
From TH - 3 AT 9 FEET MOISTURE CONTENT=10.8 %
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APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-2COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
NO MOVEMENT DUE TO WETTING
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=106 PCF
From TH - 4 AT 4 FEET MOISTURE CONTENT=23.2 %
Sample of SAND, CLAYEY (SC) DRY UNIT WEIGHT=114 PCF
From TH - 5 AT 4 FEET MOISTURE CONTENT=5.6 %
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APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-3COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
NO MOVEMENT DUE TO WETTING
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=111 PCF
From TH - 6 AT 9 FEET MOISTURE CONTENT=17.2 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=107 PCF
From TH - 7 AT 4 FEET MOISTURE CONTENT=17.6 %
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APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-4COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
ADDITIONAL COMPRESSION UNDER
CONSTANT PRESSURE DUE TO
WETTING
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=102 PCF
From TH - 12 AT 4 FEET MOISTURE CONTENT=21.8 %
Sample of CLAY, SANDY (CL) DRY UNIT WEIGHT=113 PCF
From TH - 14 AT 9 FEET MOISTURE CONTENT=12.7 %
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MOUTAIN VISTA PROPERTY
CTL | T PROJECT NO. FC10813-115
APPLIED PRESSURE -KSFCOMPRESSION % EXPANSIONSwell Consolidation
FIGURE A-5COMPRESSION % EXPANSION-4
-3
-2
-1
0
1
2
3
EXPANSION UNDER CONSTANT
PRESSURE DUE TO WETTING
0.1 10 1001.0
0.1 1.0 10 100APPLIED PRESSURE -KSF
-4
-3
-2
-1
0
1
2
3
NO MOVEMENT DUE TO WETTING
Sample of SAND, SLIGHTLY CLAYEY (SP-SC)GRAVEL 32 %SAND 61 %
From TH - 12 AT 9 FEET SILT & CLAY 7 %LIQUID LIMIT %
PLASTICITY INDEX %
Sample of SAND, CLAYEY, GRAVELLY (SC)GRAVEL 25 %SAND 59 %
From TH - 13 AT 9 FEET SILT & CLAY 16 %LIQUID LIMIT %
PLASTICITY INDEX %
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FIGURE A-6
Gradation
Test Results
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
127
5"
152
6"
200
8"
.001
45 MIN.
0
10
20
30
40
50
60
70
80
90
100
CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS
FINE MEDIUM COARSE
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR.7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PERCENT PASSING0
10
20
30
50
60
70
80
90
100 PERCENT RETAINED40
0.002
15 MIN.
.005
60 MIN.
.009
19 MIN.
.019
4 MIN.
.037
1 MIN.
.074
*200
.149
*100
.297
*50
0.42
*40
.590
*30
1.19
*16
2.0
*10
2.38
*8
4.76
*4
9.52
3/8"
19.1
3/4"
36.1
1½"
76.2
3"
127
5"
152
6"
200
8"
.001
45 MIN.
0
10
20
30
40
50
60
70
80
90
100
CLAY (PLASTIC) TO SILT (NON-PLASTIC)SANDS
FINE MEDIUM COARSE
GRAVEL
FINE COARSE COBBLES
DIAMETER OF PARTICLE IN MILLIMETERS
25 HR.7 HR.
HYDROMETER ANALYSIS SIEVE ANALYSIS
TIME READINGS U.S. STANDARD SERIES CLEAR SQUARE OPENINGS
PERCENT PASSINGPERCENT RETAINED0
10
20
30
40
50
60
70
80
90
100
PASSING WATER-
MOISTURE DRY APPLIED NO. 200 SOLUBLE
DEPTH CONTENT DENSITY SWELL*PRESSURE SIEVE SULFATES
BORING (FEET)(%)(PCF)(%)(PSF)(%)(%)DESCRIPTION
TH-1 4 11.2 109 0.0 500 0.37 SAND, CLAYEY (SC)
TH-1 9 4.7 116 23 SAND, CLAYEY (SC)
TH-1 14 8.7 114 -0.1 1,800 SAND, CLAYEY (SC)
TH-2 4 19.9 104 0.9 500 1.30 CLAY, SANDY (CL)
TH-3 4 10.1 114 45 SAND, CLAYEY (SC)
TH-3 9 10.8 116 0.0 1,100 SAND, CLAYEY (SC)
TH-4 4 23.2 106 0.4 500 CLAY, SANDY (CL)
TH-5 4 5.6 114 0.0 500 0.80 SAND, CLAYEY (SC)
TH-6 4 25.6 96 83 CLAY, SANDY (CL)
TH-6 9 17.2 111 -0.1 1,100 CLAY, SANDY (CL)
TH-7 4 17.6 107 0.3 500 0.04 CLAY, SANDY (CL)
TH-12 4 21.8 102 1.2 2,400 1.60 CLAY, SANDY (CL)
TH-12 9 5.1 7 SAND, SLIGHTLY CLAYEY (SP-SC)
TH-13 9 10.3 16 SAND, CLAYEY, GRAVELLY (SC)
TH-14 9 12.7 113 0.2 2,400 0.49 CLAY, SANDY (CL)
SWELL TEST RESULTS*
TABLE A-I
SUMMARY OF LABORATORY TESTING
Page 1 of 1
* NEGATIVE VALUE INDICATES COMPRESSION.
ERIC KELLEY C/O JR ENGINEERING LLC
MOUTAIN VISTA PROPERTY
CTL|T PROJECT NO. FC10813-115
APPENDIX B
GUIDELINE SITE GRADING SPECIFICATIONS
ERIC KELLEY C/O JR ENGINEERING LLC
MOUNTAIN VISTA PROPERTY
CTLT PROJECT NO. FC10813-115
Appendix B-1
GUIDELINE SITE GRADING SPECIFICATIONS
1. DESCRIPTION
This item shall consist of the excavation, transportation, placement and compaction of
materials from locations indicated on the plans, or staked by the Engineer, as
necessary to achieve preliminary street and ove rlot elevations. These specifications
shall also apply to compaction of excess cut materials that may be placed outside of
the development boundaries.
2. GENERAL
The Soils Engineer shall be the Owner's representative. The Soils Engineer shall
approve fill materials, method of placement, moisture contents and percent
compaction, and shall give written approval of the completed fill.
3. CLEARING JOB SITE
The Contractor shall remove all vegetation and debris before excavation or fill
placement is begun. The Contractor shall dispose of the cleared material to provide
the Owner with a clean, neat appearing job site. Cleared material shall not be placed
in areas to receive fill or where the material will support structures of any kind.
4. SCARIFYING AREA TO BE FILLED
All topsoil and vegetable matter shall be removed from the ground surface upon
which fill is to be plac ed. The surface shall then be plowed or scarified until the
surface is free from ruts, hummocks, or other uneven features, which would prev ent
uniform compaction.
5. COMPACTING AREA TO BE FILLED
After the foundation for the fill has been cleared and scar ified, it shall be disked or
bladed until it is free from large clods, brought to the proper moisture content (0 to 3
percent above optimum moisture content for clays and within 2 percent of optimum
moisture content for sands) and compacted to not less tha n 95 percent of maximum
dry density as determined in accordance with ASTM D698.
6. FILL MATERIALS
Fill soils shall be free from organics , debris, or other deleterious substances, and shall
not contain rocks or lumps having a diameter greater than six (6) inches. Fill
materials shall be obtained from cut areas shown on the plans or staked in the field
by the Engineer.
On-site materials classifying as CL, CH, SC, SM, SW, SP, GP, GC, and GM are
acceptable. Concrete, asphalt, organic matter and other delete rious materials or
debris shall not be used as fill.
ERIC KELLEY C/O JR ENGINEERING LLC
MOUNTAIN VISTA PROPERTY
CTLT PROJECT NO. FC10813-115
Appendix B-2
7. MOISTURE CONTENT AND DENSITY
Fill material shall be moisture conditioned and comp acted to the criteria in the table,
below. Maximum density and optimum moisture content shall be determined from the
appropriate Proctor compaction tests. Sufficient laboratory compaction tests shall be
made to determine the optimum moisture content for the various soils encountered in
borrow areas.
FILL COMPACTION AND MOISTURE REQUIREMENTS
Soil
Type
Depth from
Overlot Grade
(feet)
Moisture Requirement
(% from optimum) Density Requirement
Clay 0 to 20 feet +1 to +4 95% of ASTM D 698
Sand -2 to +2 95% of ASTM D 698
Clay Greater than 20
feet
-2 to +1 98% of ASTM D 698
Sand -2 to +1 95% of ASTM D 1557
The Contractor may be required to add moisture to the excavation materials in the
borrow area if, in the opinion of the Soils Engineer, it is not pos sible to obtain uniform
moisture content by adding water on the fill surface. The Contractor may be required
to rake or disc the fill soils to provide uniform moisture content through the soils.
The application of water to embankment materials shall be m ade with any type of
watering equipment approved by the Soils Engineer, which will give the desired
results. Water jets from the spreader shall not be directed at the embankment with
such force that fill materials are washed out.
Should too much water be added to any part of the fill, such that the material is too
wet to permit the desired compaction from being obtained, rolling and all work on that
section of the fill shall be delayed until the material has been allowed to dry to the
required moisture content. The Contractor will be permitted to rework wet material in
an approved manner to hasten its drying.
8. COMPACTION OF FILL AREAS
Selected fill material shall be placed and mixed in evenly spread layers. After each fill
layer has been placed, it shall be uniformly compacted to not less than the specified
percentage of maximum density. Fill shall be compacted to the criteria above. At the
option of the Soils Engineer, soils classifying as SW, GP, GC, or GM may be
compacted to 95 percent of maximum density as determined in accordance with
ASTM D 1557 or 70 percent relative density for cohesionless sand soils. Fill
materials shall be placed such that the thickness of loose materials does not exceed
12 inches and the compacted lift thickness does not exceed 6 inches.
ERIC KELLEY C/O JR ENGINEERING LLC
MOUNTAIN VISTA PROPERTY
CTLT PROJECT NO. FC10813-115
Appendix B-3
Compaction as specified above, shall be obtained by the use of sheepsfoot rollers,
multiple-wheel pneumatic-tired rollers, or other equipment approved by the Engineer
for soils classifying as CL, CH, or SC. Granular fill shall be compacted using vibratory
equipment or other equipment approved by the Soils Engineer. Compaction shall be
accomplished while the fill material is at the specified moisture content. Compaction
of each layer shall be continuous over the entire area. Compaction equipment shall
make sufficient trips to ensure that the required density is obtained.
9. COMPACTION OF SLOPES
Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable
equipment. Compaction operations shall be continued until slop es are stable, but not
too dense for planting, and there is not an appreciable amount of loose soils on the
slopes. Compaction of slopes may be done progressively in increments of three to
five feet (3' to 5') in height or after the fill is brought to its to tal height. Permanent fill
slopes shall not exceed 3:1 (horizontal to vertical).
10. PLACEMENT OF FILL ON NATURAL SLOPES
Where natural slopes are steeper than 20 percent in grade and the placement of fill is
required, benches shall be cut at the rate of one bench for each 5 feet in height
(minimum of two benches). Benches shall be at least 10 feet in width. Larger bench
widths may be required by the Engineer. Fill shall be placed on completed benches
as outlined within this specification.
11. DENSITY TESTS
Field density tests shall be made by the Soils Engineer at locations and depths of his
choosing. Where sheepsfoot rollers are used, the soil may be disturbed to a depth of
several inches. Density tests shall be taken in compacted material below the
disturbed surface. When density tests indicate that the density or moisture content of
any layer of fill or portion thereof is not within specification, the particular layer or
portion shall be reworked until the required density or moisture content h as been
achieved.
12. SEASONAL LIMITS
No fill material shall be placed, spread, or rolled while it is frozen, thawing, or during
unfavorable weather conditions. When work is interrupted by heavy precipitation, fill
operations shall not be resumed until the Soils Engineer indicates that the moisture
content and density of previously placed materials are as specified.
13. NOTICE REGARDING START OF GRADING
The Contractor shall submit notification to the Soils Engineer and Owner advising
them of the start of grading operations at least three (3) days in advance of the
starting date. Notification shall also be submitted at least 3 days in advance of any
resumption dates when grading operations have been stopped for any reason other
than adverse weather cond itions.
ERIC KELLEY C/O JR ENGINEERING LLC
MOUNTAIN VISTA PROPERTY
CTLT PROJECT NO. FC10813-115
Appendix B-4
14. REPORTING OF FIELD DENSITY TESTS
Density tests made by the Soils Engineer, as specified under "Density Tests" above,
shall be submitted progressively to the Owner. Dry density, moisture content, and
percentage compaction shall be reported for each test taken.
15. DECLARATION REGARDING COMPLETED FILL
The Soils Engineer shall provide a written declaration stating that the site was filled
with acceptable materials and was placed in general accordance with the
specifications.