HomeMy WebLinkAboutMULBERRY CONNECTION - PDP190015 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTGeotechnical Evaluation
Proposed Poudre Valley Development
Redman Drive and NW Frontage Road
Fort Collins, Colorado
Comunale Properties
1855 South Pearl Street, Suite 20 | Denver, Colorado 80210
July 2, 2019 | Project No. 501710001
DRAFT
Kelley Lange, EI
Senior Staff Engineer
Brian F. Gisi, PE
Principal Engineer
Geotechnical Evaluation
Proposed Poudre Valley Development
Redman Drive and NW Frontage Road
Fort Collins, Colorado
Mr. Josh Heiney
Comunale Properties
1855 South Pearl Street, Suite 20 | Denver, Colorado 80210
July 2, 2019 | Project No. 501710001
KL/BFG/lm
Distribution: (1) Addressee (via e-mail)
6001 South Willow Drive, Suite 195 | Greenwood Village, Colorado 80111 | p. 303.629.6000 | www.ninyoandmoore.com
07/2/2019
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 i
CONTENTS
1 INTRODUCTION 1
2 SCOPE OF SERVICES 1
3 SITE DESCRIPTION AND BACKGROUND REVIEW 2
4 PROPOSED CONSTRUCTION 2
5 FIELD EXPLORATION AND LABORATORY TESTING 2
6 GEOLOGY AND SUBSURFACE CONDITIONS 3
6.1 Geologic Setting 3
6.2 Subsurface Conditions 3
6.2.1 Loam 3
6.2.2 Alluvium 4
6.3 Groundwater 4
7 GEOLOGIC HAZARDS 4
7.1 Faulting and Seismicity 4
7.2 Expansive Soils 6
7.3 Compressible/Collapsible Soils 7
7.4 Liquefaction Potential 7
8 CONCLUSIONS 8
9 RECOMMENDATIONS 9
9.1 Earthwork 9
9.1.1 Excavations 9
9.1.2 Site Grading 10
9.1.3 Re-Use of Site Soils 11
9.1.4 Fill Placement and Compaction 11
9.1.5 Imported Soil 12
9.1.6 Controlled Low Strength Material 12
9.1.7 Utility Installation 13
9.1.8 Temporary Cut Slopes 14
9.2 Spread Footing Foundations 14
9.3 Slab-On-Grade Floors 15
9.4 Earth Pressures and Below-Grade Walls 17
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 ii
9.5 Pavements 17
9.5.1 Pavement Design 18
9.5.2 Dolly Pads 20
9.5.3 Pavement Subgrade Preparation 20
9.5.4 Pavement Materials 21
9.5.5 Pavement Maintenance 21
9.6 Concrete Flatwork 22
9.7 Corrosion Considerations 23
9.7.1 Concrete 23
9.7.2 Buried Metal Pipes 24
9.8 Scaling 24
9.9 Frost Heave 25
9.10 Construction in Cold or Wet Weather 25
9.11 Site Drainage 26
9.12 Construction Observation and Testing 26
9.13 Plan Review 27
9.14 Pre-Construction Meeting 27
10 LIMITATIONS 27
11 REFERENCES 29
TABLES
1 – 2015 International Building Code Seismic Design Criteria 5
2 – Slab Performance Risk Categories 6
3 – Lateral Earth Pressures 17
4 – Recommended Pavement Thickness 19
FIGURES
1 – Site Location
2 – Boring Locations
APPENDICES
A – Boring Logs
B – Laboratory Testing
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 1
1 INTRODUCTION
In accordance with your authorization and our proposal dated May 29, 2019, we have
performed a geotechnical evaluation for the proposed Poudre Valley Development located on
the northwest corner of the intersection of Redman Drive and the NW Frontage Road in Fort
Collins, Colorado. The approximate location of the site is depicted on Figure 1.
The purpose of our study was to evaluate the subsurface conditions and to provide design and
construction recommendations regarding geotechnical aspects of the proposed project. This
report presents the findings of our subsurface exploration program, results of our laboratory
testing, conclusions regarding the subsurface conditions at the site, and geotechnical
recommendations for design and construction of this project.
2 SCOPE OF SERVICES
The scope of our services for the project generally included:
• Review of referenced background information, including aerial imagery, published geologic
and maps, in-house geotechnical data, and available topographical information pertaining to
the project site and vicinity.
• Performance of a geologic reconnaissance and mark-out of the boring locations at the
project site.
• Notification of Utility Notification Center of Colorado of the boring locations prior to drilling.
• Drilling, logging, and sampling of 17 small-diameter exploratory borings within the project
site to depths ranging between approximately 15.5 and 20.5 feet below ground surface
(bgs). The boring logs are presented in Appendix A. Boring locations are presented on
Figure 2.
• Performance of laboratory tests on selected samples obtained from the borings to evaluate
engineering properties including in-situ moisture content and dry density, Atterberg limits,
percent materials finer than the No. 200 sieve and gradation, consolidation/swell potential,
and soil corrosivity characteristics (including pH, resistivity, water soluble sulfates, and
chlorides). The results of the laboratory testing are presented on the boring logs and in
Appendix B.
• Compilation and analysis of the data obtained.
• Preparation of this report presenting our findings, conclusions, and geotechnical
recommendations regarding design and construction of the project.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 2
3 SITE DESCRIPTION AND BACKGROUND REVIEW
The site is an approximately 20-acre parcel of land in Fort Collins, Colorado. The project site is
bounded by agricultural land followed by East Vine Drive to the north, by the NW Frontage Road
to the east, by Redman Drive to the south, and by a creek followed by agricultural land to the
west. The site is approximately 2.5 miles southeast of Lindenmeier Lake and Long Pond
Reservoir.
The project site was used as farmland at the time of our subsurface exploration. Aerial
photograph review indicates that the subject site has existed similar to its current condition since
1999 or earlier. The approximate location of the site is presented on Figure 1.
4 PROPOSED CONSTRUCTION
The development of the site includes the design and construction of two industrial buildings with
plan areas ranging from approximately 74,400 to 94,000 square feet (sf). Ancillary construction
of pavement areas surrounding the development and an approximately 40,500 sf detention
pond are also anticipated.
Based on the site conditions and the anticipated construction, cut/fill thicknesses of generally
less than 5 feet are anticipated for the development. Deeper cut/fill should be anticipated for
deeper utilities. Detailed information regarding the finished floor elevations and anticipated
loading information was not available for review at the time of this report.
5 FIELD EXPLORATION AND LABORATORY TESTING
On June 3, 2019, Ninyo & Moore conducted a subsurface exploration at the site to evaluate the
existing subsurface conditions and to collect soil samples for laboratory testing. The evaluation
consisted of the drilling, logging, and sampling of 17 small-diameter borings using a truck-
mounted drill rig equipped with 4-inch diameter solid-stem augers. The borings were drilled to
depths ranging between approximately 15.5 and 20.5 feet bgs. The approximate locations of the
borings are presented on Figure 2. Relatively undisturbed and disturbed soil samples were
collected at selected intervals. The sampling methods used during the subsurface evaluation
are presented in Appendix A.
Soil samples collected during the subsurface exploration were transported to the Ninyo & Moore
laboratory for geotechnical laboratory analyses. Selected samples were analyzed to evaluate
engineering properties including in-situ moisture content and dry density, Atterberg limits,
percent materials finer than the No. 200 sieve and gradation, swell/consolidation potential, and
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 3
soil corrosivity characteristics (including resistivity, pH, water soluble sulfates and chlorides).
The results of the in-situ moisture content and dry density tests are presented on the boring logs
in Appendix A. Descriptions of the laboratory test methods and the remainder of the test results
are presented in Appendix B.
6 GEOLOGY AND SUBSURFACE CONDITIONS
The geology and subsurface conditions at the site are described in the following sections.
6.1 Geologic Setting
The site is located approximately 9 miles east of the Rocky Mountain Front Range, within the
Colorado Piedmont section of the Great Plains Physiographic Province. The Laramide Orogeny
uplifted the Rocky Mountains during the late Cretaceous and early Tertiary Periods. Subsequent
erosion deposited sediments east of the Rocky Mountains, including the Pierre Shale in the
area. As a result of regional uplift approximately 5 to 10 million years ago streams, such as the
South Platte River, downcut and excavated into the Great Plains forming the Colorado Piedmont
section (Trimble, 1980).
The surficial geology of the site is mapped by Colton (1978) as Pleistocene-age Broadway
Alluvium generally consisting of sand and gravel. The Pierre Shale bedrock is mapped as
underlying the site at depth.
6.2 Subsurface Conditions
Our understanding of the subsurface conditions at the project site is based on our field
exploration, laboratory testing, review of published geologic maps, historic aerial imagery, and
our experience with the general geology of the area. The following sections provide a
generalized description of the subsurface materials encountered. More detailed descriptions are
presented on the boring logs in Appendix A.
6.2.1 Loam
Loam was encountered at the surface in each boring and extended to depths between
approximately 2 and 9 feet bgs. The loam generally consisted of various shades of brown,
white, and red, moist, firm to very stiff, fat clay with varying amounts of sand and gravel and
lean clay with varying amounts of sand and gravel. As the site is used for agricultural
purposes, a surficial plow zone with loosened soil should be anticipated.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 4
Based on the results of the laboratory testing, selected samples of the loam generally
exhibited moderate to high plasticity, had in-place moisture contents ranging from
approximately 10.4 to 21.9 percent, and dry densities ranging from approximately 102.0 to
119.9 pounds per cubic foot (pcf).
6.2.2 Alluvium
Alluvium was encountered in each boring beneath the loam and extended to the borings’
termination depths of up to approximately 20.5 feet bgs. The alluvium was generally
composed of various shades of brown, red, yellow, and gray, moist to wet, very loose to
very dense, fine to coarse sand with varying amounts of clay, silt, and gravel, and firm to
stiff, sandy, silty clay and sandy lean and fat clay.
Based on the laboratory test results, the selected samples of the alluvium had in-place
moisture contents ranging from approximately 1.1 to 27.0 percent and dry densities ranging
from approximately 93.9 to 128.1 pcf.
6.3 Groundwater
Groundwater was encountered in our borings at depths ranging between approximately 8.5 and
12 feet bgs during drilling. Groundwater levels can fluctuate due to seasonal variations,
precipitation, irrigation, groundwater withdrawal or injection, and other factors. Depending on the
time of year construction occurs, groundwater, particularly perched groundwater within the
upper loam soils, could be encountered. However, based on the knowledge of the area and the
results of our subsurface exploration, groundwater is not considered to be a constraint to the
construction of this project, but may be encountered during deep utility excavation and
installation.
7 GEOLOGIC HAZARDS
The following sections describe potential geologic hazards at the site including faulting and
seismicity, expansive soils, compressible/collapsible soils, and liquefaction potential.
7.1 Faulting and Seismicity
Historically, several minor earthquakes have been recorded around the Front Range area.
Based on our field observations and our review of readily available published geological maps
and literature there are no known active faults underlying or adjacent to the subject site. The
faults closest to the project site include the Walnut Creek and Rock Creek Faults and the
Golden Fault.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 5
The Rock Creek and Walnut Creek Faults lay approximately 45 miles southwest of the site
(Widmann, Kirkham, and Rogers, 1998). Both faults are mapped as 3 kilometer long reverse
faults with slip rates of less than 0.2 millimeters per year. Both Faults are located in the High
Plains region, just east of the Front Range. They are downthrown to the southeast and may
become listric at depth where it is floored within the Laramie Formation (Risk Engineering,
1994). The surface of the Quaternary-age alluvium above the bedrock does not appear to be
displaced so there is not strong evidence of Quaternary faulting.
The Golden Fault lies approximately 50 miles southwest of the site. The fault is considered to be
late Quaternary in age and has not shown displacement in Holocene time, as Pleistocene
deposits overlie the fault (approximately 75 to 125 thousand years before the present [Kirkham,
1977]). Therefore, the probability of damage at the site from seismically induced ground surface
rupture from this fault is considered to be low.
Design of any proposed improvements should be performed in accordance with the
requirements of the governing jurisdictions and applicable building codes. Table 1 presents the
preliminary seismic design parameters for the site in accordance with the 2015 International
Building Code guidelines and adjusted maximum considered earthquake spectral response
acceleration parameters evaluated using the web-based OSHPD ground motion calculator
(OSHPD, 2019).
Table 1 – 2015 International Building Code Seismic Design Criteria
Seismic Design Factors Value
Site Class D
Site Coefficient, Fa 1.6
Site Coefficient, Fv 2.4
Mapped Spectral Acceleration at 0.2-second Period, Ss 0.178 g
Mapped Spectral Acceleration at 1.0-second Period, S1 0.057 g
Spectral Acceleration at 0.2-second Period Adjusted for Site Class, SMS 0.284 g
Spectral Acceleration at 1.0-second Period Adjusted for Site Class, SM1 0.137 g
Design Spectral Response Acceleration at 0.2-second Period, SDS 0.190 g
Design Spectral Response Acceleration at 1.0-second Period, SD1 0.092 g
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 6
7.2 Expansive Soils
One of the more significant geologic hazards in Colorado is the presence of swelling clays in
bedrock or surficial deposits. Moisture changes to bedrock or surficial deposits containing
swelling clays can result in volumetric expansion and collapse of those units. Changes in soil
moisture content can result from rainfall, irrigation, pipeline leakage, surface drainage, perched
groundwater, drought, or other factors. Volumetric change of expansive soil may cause
excessive cracking and heaving of structures with shallow foundations, concrete slabs-on-
grade, or pavements supported on these materials. Construction on soils known to be
potentially expansive could have a significant impact to the project.
A review of a Colorado Geological Survey map delineating areas based on their relative
potential for swelling in the Front Range area by Hart (1973-1974) indicates soil and bedrock
materials in the project vicinity typically exhibit low swell potential.
Based on the results of our laboratory testing, the loam deposits exhibited swell percentages of
up to approximately 5 percent when inundated against surcharge pressures of 200 pounds per
square foot (psf). The alluvial deposits exhibited swell percentages of up to approximately 1.5
percent at surcharge pressures of 500 psf.
Based on the results of our subsurface exploration, laboratory testing, and the information
obtained from our background review, the on-site soils expected to be encountered during
project development would have a slab performance risk category of “LOW”, based on the
criteria presented in Table 2. Recommendations intended to reduce the risk for post-
construction movement due to swelling soils are included in this report.
Table 2 – Slab Performance Risk Categories
Slab Performance Risk
Category
Representative Percent
Swell
(500 psf Surcharge)
Representative Percent
Swell
(1,000 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: Based on Colorado Association of Geotechnical Engineers, Guidelines for Slab Performance Risk Evaluation
and Residential Basement Floor System Recommendations (Denver Metropolitan Area, 1996).
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 7
We recommend supporting the proposed buildings on shallow foundations and slab-on-grade
floors bearing on a zone of moisture conditioned and compacted fill material (i.e., fill prism). The
recommendations provided in this report assume supporting the proposed improvements on a
fill prism is acceptable to the Owner and can be accommodated by the structural design. It
should be recognized that the proposed buildings may experience distortions of approximately
1-inch (vertical) over 50 feet (horizontal) due to the swell potential of the on-site soils that will be
used to construct the fill prism. Failure to follow the site drainage recommendations provided in
Section 9.10 may also result in additional building movement that is difficult to quantify.
7.3 Compressible/Collapsible Soils
Compressible soils are generally comprised of soils that undergo consolidation when exposed
to new loadings, such as fill or foundation loads. Soil collapse (or hydro-collapse) is a
phenomenon where soils undergo a significant decrease in volume upon an increase in
moisture content, with or without an increase in external loads. Buildings, structures, and other
improvements may be subject to excessive settlement-related distress when compressible soils
or collapsible soils are present.
Based on our subsurface evaluation, the results of our laboratory testing, and provided the
recommendations provided herein are followed, it is our opinion post-construction settlements
due to the imposed foundation loads will be within generally accepted construction practices.
7.4 Liquefaction Potential
Liquefaction is a phenomenon in which loose, saturated soils lose shear strength under short-
term (dynamic) loading conditions. Ground shaking of sufficient duration results in the loss of
grain-to-grain contact in potentially liquefiable soils due to a rapid increase in pore water
pressure, causing the soil to behave as a fluid for a short period of time.
To be potentially liquefiable, a soil is typically cohesionless with a grain-size distribution
generally consisting of sand and silt. It is generally loose to medium dense and has a relatively
high moisture content, which is typical near or below groundwater level. The potential for
liquefaction decreases with increasing clay and gravel content, but increases as the ground
acceleration and duration of shaking increase. Potentially liquefiable soils need to be subjected
to sufficient magnitude and duration of ground shaking for liquefaction to occur. Based on our
subsurface exploration, laboratory testing, and the relatively low ground motion anticipated at
the site, liquefaction is not considered a hazard at this site.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 8
8 CONCLUSIONS
Based on the results of the subsurface evaluation, laboratory testing, and data analyses, it is
our opinion that the proposed project is feasible from a geotechnical standpoint, provided the
recommendations presented herein are implemented and appropriate construction practices are
followed. Geotechnical design and construction considerations for the proposed project include
the following:
• Loam was encountered at the surface in each boring and extended to depths between
approximately 2 and 9 feet bgs. The loam generally consisted of various shades of brown,
white, and red, moist, firm to very stiff, fat clay with varying amounts of sand and gravel and
lean clay with varying amounts of sand and gravel. Laboratory testing indicates the loam
deposits exhibit high swell potential.
• Alluvium was encountered in each boring beneath the loam and extended to the borings’
termination depths of up to approximately 20.5 feet bgs. The alluvium was generally
composed of various shades of brown, red, yellow, and gray, moist to wet, very loose to very
dense, fine to coarse sand with varying amounts of clay, silt, and gravel, and firm to stiff,
sandy, silty clay and sandy lean and fat clay. Laboratory testing indicates the alluvial
deposits exhibit low swell potential.
• Based on our aerial imagery review, the site has been used for agricultural purposes since
1999 or earlier. A plow zone should be anticipated at the subgrade level. The loosened soil
within the plow zone should be removed and recompacted as engineered fill.
• As an alternative to deep foundation systems, overlot grading improvements should be
designed carefully so that the swelling soils are removed and replaced to create a zone of
low-swelling material below the proposed structures and surface improvements. Chemical
treatment of pavement subgrade could also be considered to reduce the swell potentials.
• The on-site soils should generally be excavatable with medium- to heavy-duty earthmoving
or excavating equipment in good operating condition.
• Groundwater was encountered at depths ranging between approximately 8.5 and 12 feet
bgs during drilling. Groundwater levels will fluctuate due to seasonal variations from
precipitation, irrigation, groundwater withdrawal or injection, and other factors. In general,
groundwater is not anticipated to be a constraint to the proposed construction but may be
encountered during excavation and installation of deep utilities.
• Based on our laboratory data and our experience with similar materials at adjacent sites, the
sulfate content of the tested soils presents a moderate risk of sulfate attack to concrete. We
recommend the use of Type II cement for construction of concrete structures at this site.
• Based on our laboratory data and our experience with similar materials at adjacent sites, the
subgrade soils at the site are moderately corrosive to ferrous metals. Therefore, special
consideration should be given to the use of heavy gauge, corrosion-protected, underground
steel pipe or culverts, if any are planned. As an alternative, plastic pipe or reinforced
concrete pipe could be considered. A corrosion specialist should be consulted for further
recommendations.
• No known or reported active faults are reported underlying, or adjacent to, the site. Based
on the low ground motion hazard, the likelihood or potential for liquefaction is considered to
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 9
be negligible and therefore not a design consideration.
9 RECOMMENDATIONS
Based on our understanding of the project, the following sections present our geotechnical
recommendations for design and construction of the proposed buildings and other site
improvements.
9.1 Earthwork
The following sections provide our earthwork recommendations for this project. We anticipate
the site grading may consist of material cuts and fills on the order of 5 feet. Deeper cuts and fills
may be needed to install buried utilities.
9.1.1 Excavations
Our evaluation of the excavation characteristics of the on-site materials is based on the
results of the subsurface exploration, our site observations, and our experience with similar
materials. The on-site surface and near surface soils (loam and alluvium) may generally be
excavated with moderate- to heavy-duty earthmoving or excavation equipment in good
operating condition.
Equipment and procedures that do not cause significant disturbance to the excavation
bottoms should be used. Excavators and backhoes with buckets having large claws to
loosen the soil should be avoided when excavating the bottom approximately 6 to 12 inches
of excavations as such equipment may disturb the excavation bases.
The site has been used as agriculture fields. It should be anticipated that loose and
disturbed soil will be encountered at the subgrade level which will need to be compacted
and moisture-conditioned prior to fill placement.
The contractor should provide safely sloped excavations or an adequately constructed and
braced shoring system, in compliance with Occupational Safety and Health Administration
(OSHA) (OSHA, 2005) guidelines, for employees working in an excavation that may expose
employees to the danger of moving ground. If material is stored or equipment is operated
near an excavation, stronger shoring should be used to resist the extra pressure due to
superimposed loads.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 10
9.1.2 Site Grading
Prior to grading, the ground surface in proposed structure and improvement areas should
be cleared of any surface obstructions, debris, topsoil, organics (including vegetation), and
other deleterious material.
Materials generated from clearing operations should be removed from the project site for
disposal (e.g. at a legal landfill site). Obstructions that extend below finish grade, if present,
should be removed and resulting voids filled with compacted, engineered fill or Controlled
Low Strength Material (CLSM).
The proposed buildings may be supported on shallow foundation systems consisting of
spread-footings bearing on a relatively uniform thickness of moisture-conditioned and
compacted engineered fill extending to 12 or more inches below the bottom of the footings.
The buildings may be provided with slab-on-grade floors bearing 3 or more feet of moisture
conditioned and compacted engineered fill. The limits of this fill layer should extend 5 or
more feet out beyond the footings to reduce the swell potential within the structures, as well
as the surrounding building appurtenances, such as exterior flatwork adjacent to the
building.
There are risks associated with supporting pavements over expansive soils without soil
modification. However, the costs associated with remediating pavement subgrades for
expansive soils are generally considered cost-prohibitive. Therefore, the following
recommendation for pavement subgrade preparation is provided assuming the owner is
willing to accept some risk of poor pavement performance as a result of post-construction
vertical movements associated with the high swell potential of the overburden soils.
Asphalt and concrete pavements and flatwork may be placed on 24 or more inches of
moisture conditioned and compacted engineered fill. As an alternative, the upper 12 or
more inches of subgrade below the pavements sections could be chemically treated using
fly ash or lime to reduce plasticity, reduce swell-potential, and increase strength of the
treated subgrade soils.
The geotechnical consultant should be retained to observe the remedial excavations, and
the elevations of the excavation bottoms should be surveyed by the project civil engineer.
The exposed subgrade materials should be firm and unyielding prior to fill placement. The
extent of and depths of removal should be evaluated by our representative during the
excavation work based on observation of the soils exposed. Additional recommendations
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 11
specific to the site conditions encountered may be provided at the time of construction. The
project budget should include additional cost associated with the removal and replacement
of additional fill material. Subgrade materials that are disturbed during grading should be
moisture conditioned and re-compacted according to the recommendations provided in
this report.
9.1.3 Re-Use of Site Soils
The onsite soils encountered during our subsurface exploration consisted of loam and
alluvium. Laboratory testing indicates the onsite soils have high swell potential at low
confinement pressures (near surface soils) at their in-situ moisture contents. Soils
generated from on-site excavation activities in the loam and alluvium deposits that are free
of deleterious materials and organic matter, do not contain particles larger than 3 inches in
diameter, can generally be used as engineered fill as evaluated by the geotechnical
consultant provided they are compacted and moisture conditioned as recommended in this
report.
Fragments of rock, cobbles, and inert construction debris (e.g., concrete or asphalt) larger
than 3 inches in diameter may be incorporated into the project fills in non-structural areas
and below the anticipated utility installation depths. A Geotechnical Engineer should be
consulted regarding appropriate recommendations for usage of such materials on a case-
by-case basis when such materials have been observed during earthwork. Care should be
taken to avoid nesting of oversized materials during placement. Recommendations
provided in Section 203 of the current CDOT Standard Specifications for Road and Bridge
Construction should be followed during the placement of oversized material.
9.1.4 Fill Placement and Compaction
Fine-grained soils (on-site soils that classify as CL or CH) used as engineered fill should be
moisture-conditioned to moisture contents between optimum moisture content and 3
percent over optimum moisture content. Granular soils (on-site soils that classify as SC,
SW, SP-SC, or import soils) used as engineered fill should be moisture-conditioned to
moisture contents within 2 percent of optimum moisture content. Engineered fill should be
placed in uniform horizontal lifts. Engineered fill should be compacted to a relative
compaction of 95 percent, or more, as evaluated by the American Society for Testing and
Materials (ASTM) D698.
The engineered fill should be compacted by appropriate mechanical methods. Lift thickness
for fill will be dependent upon the type of compaction equipment utilized. Backfill should be
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 12
placed in lifts not exceeding 8 inches in loose thickness in areas compacted by other-than
hand operated machines. Backfill should be placed in lifts not exceeding 6 inches in loose
thickness in areas compacted by hand operated machines.
Fill materials should not be placed, worked, rolled while they are frozen, thawing, or during
poor/inclement weather conditions.
Compaction areas should be kept separate, and no lift should be covered by another until
relative compaction and moisture content within the recommended ranges are obtained.
Use of controlled low-strength material (CLSM) should be considered in lieu of compacted
fill for areas with low tolerances for surface settlements, for excavations that extend below
the groundwater table and in areas with difficult access for compaction equipment. CLSM
should be placed in lifts of 5 feet or less with a 24-hour or more curing period between each
lift.
9.1.5 Imported Soil
Imported soil to be used as engineered fill should be free of organic material and other
deleterious materials should consist of relatively impervious material with a very low to low
expansion potential (less than 1 percent against a surcharge pressure of 500 psf when
remolded at optimum moisture content). Imported fill should have less than 50 percent
passing the No. 200 Sieve and should have a plasticity index that is between 10 and 20.
Import soil in contact with ferrous metals should have low corrosion potential. Import
material in contact with concrete should have a soluble sulfate content less than
0.1 percent.
We further recommend that proposed import soils be evaluated by the project’s
geotechnical consultant at the borrow source for its suitability prior to importation to the
project site. Import soil should be moisture-conditioned and placed and compacted in
accordance with the recommendations set forth in Section 9.1.4.
9.1.6 Controlled Low Strength Material
Use of CLSM should be considered in lieu of compacted fill for areas with low tolerances for
surface settlements, for excavations that extend below the groundwater table and in areas
with difficult access for compaction equipment. CLSM consists of a fluid, workable mixture
of aggregate, Portland cement, and water. CLSM should be placed in lifts of 5 feet or less
with a 24-hour or more curing period between each lift.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 13
The use of CLSM has several advantages:
• A narrower excavation can be used where shoring is present, thereby minimizing the
quantity of soil to be excavated and possibly reducing disturbance to the near-by traffic;
• Compaction requirements do not apply;
• There is less risk of damage to improvements, since little compaction is needed to
place CLSM;
• CLSM can be batched to flow into irregularities in excavation bottoms and walls; and
• The number of workers needed inside the trench excavation is reduced.
The CLSM mix design should be submitted for review prior to placement. The 28-day
strength of the material should be no less than 50 pounds per square inch (psi) and no
more than 150 psi. CLSM should be observed and tested by the geotechnical consultant.
9.1.7 Utility Installation
The contractor should take particular care to achieve and maintain adequate compaction of
the backfill soils around manholes, valve risers and other vertical pipeline elements where
settlements are commonly observed. Use of CLSM or a similar material should be
considered in lieu of compacted soil backfill in areas with low tolerances for surface
settlement. This would also reduce the permeability of the utility trenches.
Pipe bedding materials, placement and compaction should meet the specifications of the
pipe manufacturer and applicable municipal standards. Materials proposed for use as pipe
bedding should be tested for suitability prior to use.
Special care should be exercised to avoid damaging the pipe or other structures during the
compaction of the backfill. In addition, the underside (or haunches) of the buried pipe
should be supported on bedding material that is compacted as described above. This may
need to be performed with placement by hand or small-scale compaction equipment.
Surface drainage should be designed to divert the surface water away from utility trench
alignments. Where topography, site constraints or other factors limit or preclude adequate
surface drainage, the granular bedding materials should be surrounded by a non-woven
geotextile fabric (e.g., TenCate Mirafi® 140N or the equivalent) to reduce the migration of
fines into the bedding which can result in severe, isolated settlements.
Development of site grading plans should consider the subsurface transfer of water in utility
trenches and the pipe bedding. Sandy pipe bedding materials can function as efficient
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 14
conduits for re-distribution of natural and applied waters in the subsurface. Cut-off walls in
utility trenches or other water-stopping measures should be implemented to reduce the
rates and volumes of water transmitted along utility alignments and toward buildings,
pavements and other structures where excessive wetting of the underlying soils will be
damaging. Incorporation of water cut-offs and/or outlet mechanisms for saturated bedding
materials into development plans could be beneficial to the project. These measures also
will reduce the risk of loss of fine-grained backfill soils into the bedding material with
resultant surface settlement.
9.1.8 Temporary Cut Slopes
Temporary excavations will be needed for this project to construct utilities. Based on the
subsurface information obtained from our exploratory excavations and our experience with
similar projects, we anticipate that the soil conditions and stability of the excavation
sidewalls may vary with depth. Soils with higher fines content may stand vertically for a
short time (less than 12 hours) with little sloughing. However, as the soil dries after
excavation or as the excavations are exposed to rainfall, sloughing may occur. Soils with
low cohesion (e.g., predominately sandy or gravelly material), may slough or cave during
excavation, especially if wet or saturated.
The contractor should provide safely sloped excavations or an adequately constructed and
braced shoring system, in compliance with OSHA regulations as mentioned in
Section 9.1.1.
In our opinion, the site soils should generally be considered a Type C soil when applying
the OSHA regulations. For these soil conditions, OSHA recommends a temporary slope
inclination of 1.5H:1V or flatter for excavations 20 feet or less in depth. Appropriate slope
inclinations should be evaluated in the field by an OSHA-qualified “Competent Person”
based on the conditions encountered.
9.2 Spread Footing Foundations
Perimeter footings should extend to 36 inches or more below the lowest exterior finished grade
(for frost protection), and bear on 12 or more inches of moisture-conditioned and compacted
engineered fill as described in Section 9.1.2 of this report. Continuous wall footings should have
a width of 18 inches or more and column footings should have a width of 24 inches or more.
Footings should be reinforced in accordance with the recommendations of the Structural
Engineer.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 15
Footings may be designed using an allowable bearing pressure of 2,500 pounds psf for static
conditions. The bearing capacity may be increased by one-third when considering loads of short
duration such as wind or seismic forces. The foundations should preferably be proportioned
such that the resultant force from design loads, including lateral loads, falls within the kern (i.e.,
middle one-third of the footing base).
Uplift resistance can be developed from the weight of the footings, the effective weight of any
overlying soil, and the weight of the supported structure itself. The effective unit weight of the
soil can be assumed to be 120 pcf. Soil uplift resistance may be calculated as the weight of the
soil prism defined by a diagonal line extending from the perimeter of the foundation to the
ground surface at an angle θ equal to 20 degrees from the vertical. Under large moment and/or
shear loading, the effective size of the uplift soil prism may be reduced. An appropriate safety
factor should be applied.
The bottom surface of foundation excavations should be compacted with hand-held dynamic
compaction equipment (i.e., jumping jack, flat-plate vibrator) prior to placement of forms and
reinforcing steel. The base of foundation excavations should be free of water and loose soil prior
to placing concrete. Concrete should be placed soon after subgrade compaction to reduce
bearing soil disturbance. Should the soils at bearing level become excessively dry, disturbed, or
saturated, the affected soil should be moisture conditioned and compacted. It is recommended
that Ninyo & Moore be retained to observe, test, and evaluate the soil foundation bearing
materials.
Based on the results of our subsurface exploration and laboratory testing, and provided our
grading recommendations provided in Section 9.1 are followed, we estimate total and
differential settlement of approximately 1-inch and 1/2-inch, respectively. Distortions of
approximately 1-inch (vertical) over 50 feet (horizontal) are possible due the swell potential of
the on-site soils.
9.3 Slab-On-Grade Floors
The buildings may be provided with slab-on-grade floors bearing 3 or more feet of moisture
conditioned and compacted engineered fill as described in Section 9.1.2 of this report.
For slab design, a design modulus of subgrade reaction (K) of 150 pounds per square inch per
inch of deflection (pci) may be used for the subgrade soils in evaluating such deflections. This
value is based on a unit square foot area and can be adjusted for large slabs. Adjusted values
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 16
of the modulus of subgrade reaction, Kv, can be obtained from the following equation for slabs
of various widths:
Kv = K[(B+1)/2B]2 (pci)
B in the above equation represents the width of the slab in feet between line loads/point loads.
The design of the floor slabs (including jointing and reinforcement) is the responsibility of the
Structural Engineer. Joints should be constructed at intervals designed by the Structural
Engineer to help reduce random cracking of the slab. Floor slabs should be adequately
reinforced. Recommendations based on structural considerations for slab thickness, jointing,
and steel reinforcement should be developed by the Structural Engineer in accordance with
American Concrete Institute recommendations. Proper placement of reinforcement in the slab is
vital for satisfactory performance.
The slab should be constructed so that it “floats” independent of the foundations. Floor slabs
should be separated from bearing walls and columns with expansion joints, which allow
unrestrained vertical movement. Joints should be observed periodically, particularly during the
first several years after construction. Slab movement can cause previously free-slipping joints to
bind. Measures should be taken so that slab isolation is maintained in order to reduce the
likelihood of damage to walls and other interior improvements. If post-construction vertical slab
movement of approximately 1 inch cannot be tolerated or desired, then we recommend utilizing
a structural floor system spanning over a void or a crawl space.
Interior partitions resting on floor slabs should be provided with slip joints so that if the slabs
move, the movement cannot be transmitted to the upper structure, including wallboards and
door frames. A slip joint that allows 2 or more inches of vertical movement is recommended for
placement at the bottoms of the interior partitions. If slip joints are placed at the tops of walls, in
the event that the floor slabs move, it is expected that the wall will show signs of distress,
especially where the floors meet the exterior wall. Interior plumbing lines that penetrate interior
partition walls, where the slip joints are placed at the top of the walls, should be provided with
flexible connections that can handle 2 or more inches of vertical movement.
The need for a moisture retarding and/or vapor retarding system should be considered by the
Structural Engineer or Architect, based on the moisture sensitivity of the anticipated flooring.
The placement of a vapor retarder is recommended in areas where moisture-sensitive floor
coverings are anticipated.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 17
9.4 Earth Pressures and Below-Grade Walls
Earth pressures are used to compute the lateral forces acting on below-grade walls. These
pressures can be classified as at-rest, active, and passive. The direction and magnitude of the
soil/wall movement just before failure affects the resulting pressure condition. At-rest conditions
exist when there is no movement, such as for a restrained wall. Active stresses are exerted
when the wall moves out and the soil moves toward the wall away from the soil mass, thereby
mobilizing the shear strength of the soil. Passive stresses exist when the wall moves toward the
soil mass.
The recommended equivalent fluid pressures in Table 3 assume moisture-conditioned and
compacted engineered fill with an angle of internal friction (φ) of 26 degrees and a unit weight of
120 pcf. The values listed below are for static conditions.
Table 3 – Lateral Earth Pressures
Soil Condition Active Pressure
(pcf)
At-rest Pressure
(pcf)
Passive Pressure
(pcf)
Engineered Fill 47 67 307
The use of heavy compaction equipment adjacent to below-grade walls could result in lateral
earth pressures well in excess of those predicted in Table 3. We recommend that the upper 24
inches of soil that is not protected by pavement or a concrete slab, be neglected when
calculating passive resistance. This zone, where applicable, should be backfilled with cohesive
soils to minimize infiltration of surface water into the backfill. For frictional resistance to lateral
loads, we recommend that an ultimate coefficient of friction of 0.35 be used between soil and
concrete.
To limit long-term hydrostatic pressure behind the wall, we recommend measures, such as
placement of sealants, be taken such that surface water is not allowed to penetrate between the
loading dock walls and exterior slabs.
9.5 Pavements
We understand project pavements will be privately maintained. Pavement section alternatives
are included herein for the paved surfaces, which include standard duty automobile parking
areas and driveways, and heavy duty drive lanes and fire lanes.
The pavement sections recommended below were developed in general accordance with the
guidelines and procedures of the American Association of State Highway and Transportation
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 18
Officials (AASHTO), (AASHTO, 1993), CDOT, and Larimer County. Table 4 summarizes the
minimum pavement sections for asphaltic concrete (AC) pavements and Portland cement
concrete pavements (PCCP). Pavement sections may be modified once more detailed
information regarding traffic volumes and vehicle usage is available for review.
9.5.1 Pavement Design
Specific traffic loadings for the project were not available at the time of this report
preparation. Based on our experience with similar commercial facilities, an equivalent 18-
kip single axle load value of 36,500 was assumed for standard-duty automobile parking
areas and 365,000 was assumed for heavy-duty drive lanes and loading areas for 20-year
design lives, respectively. If design traffic loadings differ significantly from this assumed
value, we should be notified to re-evaluate the pavement recommendations below.
The current subgrade soils encountered in our borings typically consisted of lean clay to fat
clay with varying amounts of sand and gravel that classify as A-6 and A-7 soils in
accordance with the AASHTO classification system. It is anticipated that fill imported to the
site will classify as A-6 or better. We utilized a design R-Value of 5 for the pavement
subgrade soils for the project.
The design of flexible pavements was based on the following input parameters:
Initial Serviceability: 4.5
Terminal Serviceability: 2.0
Reliability 80%
Overall Standard Deviation: 0.44
Resilient Modulus (untreated): 3,025 psi (R-Value of 5)
Stage Construction: 1.0
The design of rigid pavements was based on the following input parameters:
Initial Serviceability: 4.5
Terminal Serviceability: 2.0
Reliability 80%
28-Day Mean PCC Modulus Rupture: 650 psi
28-Day Mean Modulus of Elasticity: 3.6 x 106 psi
Mean Effective k value: 100 psi/in
Overall Standard Deviation: 0.34
Load Transfer Coefficient: 4.2
Overall Drainage Coefficient: 1.0
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 19
Based on the above-mentioned guidelines, procedures, and input parameters, Table 4
provides our recommended pavement section thicknesses for pavements supported on 2 or
more feet of moisture conditioned and compacted engineered fill (overexcavated and
recompacted in-situ deposits).
Table 4 – Recommended Pavement Thickness
Traffic Type Full Depth AC
(inches)
Composite AC /
ABC (inches)
PCCP
(inches)
Standard-Duty Areas 6.0 4.0 / 6.0 5.0
Heavy-Duty Areas 8.0 6.0 / 8.0 6.0
Notes: AC = Asphalt Concrete, ABC = Aggregate Base Course, PCCP = Portland Cement Concrete Pavement
We recommend PCCP be utilized in entrance and exit sections, dumpster pads, loading
areas, or other areas where extensive wheel maneuvering are expected. The dumpster pad
should be large enough to support the wheels of the truck, which will bear the load of the
dumpster.
Although the use of ABC is not integral for structural support in PCCP pavements, the
placement of 4 or more inches of ABC below PCCP pavements will develop a more stable
subgrade for concrete truck traffic associated with the pavement construction and help
reduce potential slab curl, shrinkage cracking, and subgrade “pumping” through joints.
Adequate joint spacing and reinforcement is recommended to prevent loss of load transfer
across saw-cut crack control joints. Joints should be sealed to reduce water infiltration. The
design guidelines provided in the referenced ACI 330R-01 guide should be followed for joint
spacing and reinforcing.
Where practical, we recommend “early-entry” cutting of crack-control joints in PCCP.
Cutting of PCCP in its ‘green” state typically reduces the potential for micro-cracking of the
pavements prior to the crack control joints being formed, compared to cutting the joints after
the concrete has fully set. Micro-cracking of pavements may lead to crack formation in
locations other than the sawed joints, and/or reduction of fatigue life of the pavement.
Ninyo & Moore has observed dishing in some AC parking lots. Dishing is observed in
frequently-used parking stalls (such as near the front of buildings), and occurs under the
wheel footprint in these stalls. The use of higher-grade AC, or surfacing these areas with
PCCP, could be considered. The dishing is exacerbated by factors such as irrigated islands
or planter areas, and sheet surface drainage to the front of structures.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 20
If AC pavements are utilized in the trailer parking areas, dishing of the AC pavements
should be anticipated where trailer dollies are in contact with the AC surface due to the
concentrated loads which occur at the trailer dollies. As a result, we recommend a PCCP
dolly pad be constructed within the heavy-duty AC areas. The dolly pad should have a width
of 5 feet or more. Reinforcing and joint spacing should be designed by the project structural
engineer.
9.5.2 Dolly Pads
If trailer parking is desired in the heavy-duty AC areas, dishing of the AC areas should be
anticipated where trailer dollies are in contact with the AC surface due to the concentrated
loads which occur at the trailer dollies. As a result, we recommend a PCCP dolly pad be
constructed within the heavy-duty AC areas if trailing parking is desired in these areas. The
dolly pad should be constructed on both the shipping and receiving pavements and should
have a width of 5 feet or more. Reinforcing and joint spacing should be designed by the
project structural engineer.
9.5.3 Pavement Subgrade Preparation
Due to the measured swell potential of the subgrade fill materials, we recommend
pavements are placed on a zone of moisture-conditioned and compacted fill extending 24
or more inches below the bottom of the pavement section or flatwork as discussed above in
Section 9.1.2. As an alternative, the pavements can be placed on a zone of 12 or more
inches of CTS using fly ash, lime, or Portland cement to reduce plasticity, reduce swell-
potential, and increase strength of the treated subgrade soils.
The contractor should be prepared either to dry the subgrade materials or moisten them, as
needed, prior to compaction. Some site soils may pump or deflect during compaction if
moisture levels are not carefully monitored. The contractor should be prepared to process
and compact such soils to establish a stable platform for paving, including use of chemical
stabilization or geotextiles, where needed.
The prepared subgrade should be protected from the elements prior to pavement
placement. Subgrades that are exposed to the elements may need additional moisture
conditioning and compaction, prior to pavement placements.
Immediately prior to paving, the subgrade should be proofrolled with a heavily loaded,
pneumatic tired vehicle and checked for moisture. Areas that show excessive deflection
during proof rolling should be excavated and replaced and/or stabilized. Areas allowed to
pond prior to paving may need to be re-worked prior to proofrolling.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 21
It should be noted that the subgrade recommendations included in this report are provided
based on the owner accepting some risk of poor pavement performance due to the on-site
swelling soils. The measures recommended above are intended to minimize this risk.
Additional recommendations could be provided to further reduce this risk.
9.5.4 Pavement Materials
The AC pavement shall consist of a bituminous plant mix composed of a mixture of high
quality aggregate and bituminous material, which meets the requirements of a job-mix
formula established by a qualified engineer. The asphalt material used should be based on
a SuperPave Gyratory Design Revolution of 75. Lower lifts should be constructed using an
asphalt mix Grading S and asphalt cement binder grade PG 58-28. The top lift should be
constructed using an asphalt mix Grading SX and asphalt cement binder grade PG 64-22.
Pavement layer thickness should be between 2 and 3 inches for the lower lifts and 2 to 2.5
inches for the top lift. The geotechnical engineer should be retained to review the proposed
pavement mix designs, grading, and lift thicknesses prior to construction.
PCCP should consist of a plant mix composed of a mixture of aggregate, Portland cement
and appropriate admixtures meeting the requirements of Larimer County. Concrete should
have a modulus of rupture of third point loading of 650 psi or more. The concrete should be
air-entrained with approximately 6 percent air and should have a cement content of six or
more sacks per cubic yard. Allowable slump should be approximately 4 inches.
Thickened edges should be used along outside edges of PCCP. The edge thickness
should be 2 inches or more than the recommended PCCP thickness and taper to the
recommended PCCP thickness 36 inches inward from the edge. Integral curbs may be
used in lieu of thickened edges.
PCCP should have longitudinal and transverse joints that meet the applicable requirements
of Larimer County.
9.5.5 Pavement Maintenance
The collection and diversion of surface drainage away from paved areas is vital to
satisfactory performance of the pavements. The subsurface and surface drainage systems
should be carefully designed to facilitate removal of the water from paved areas and
subgrade soils. Allowing surface waters to pond on pavements will cause premature
pavement deterioration. Where topography, site constraints or other factors limit or preclude
adequate surface drainage, pavements should be provided with edge drains to reduce loss
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 22
of subgrade support. The long-term performance of the pavement also can be improved
greatly by backfilling and compaction behind curbs, gutters, and sidewalks so that ponding
is not permitted and water infiltration is reduced.
Landscape irrigation in planters adjacent to pavements and in “island” planters within paved
areas should be carefully monitored or differential heave and/or rutting of the nearby
pavements will result. Drip irrigation systems are recommended for such planters to reduce
over-spray and water infiltration beyond the planters. We recommend edge drains where
the profile/slopes are less than 1 percent.
The standard care of practice in pavement design describes the recommended flexible
pavement section as a “20-year” design pavement; however, many pavements will not
remain in satisfactory condition without routine, preventive maintenance and rehabilitation
procedures performed during the life of the pavement. Preventive pavement treatments are
surface rehabilitation and operations applied to improve or extend the functional life of a
pavement. These treatments preserve, rather than improve, the structural capacity of the
pavement structure. In the event the existing pavement is not structurally sound, the
preventive maintenance will have no long-lasting effect. Therefore, a routine maintenance
program to seal joints and cracks, and repair distressed areas is recommended.
9.6 Concrete Flatwork
Ground-supported flatwork, such as walkways, will be subject to soil-related movements
resulting from heave/settlement, frost, etc. Thus, where these types of elements abut rigid
building foundations or isolated/suspended structures, differential movements should be
anticipated. We recommend that flexible joints be provided where such elements abut the main
structure to allow for differential movement at these locations.
We recommend that exterior concrete flatwork and the target structures be supported on
improved subgrade as described in Section 9.1.2 of this report. Positive drainage should be
established and maintained adjacent to flatwork. Water should not be allowed to pond on
flatwork.
In no case should exterior flatwork extend under any portion of the building where there is less
than 2 inches of clearance between the flatwork and any element of the building. Exterior
flatwork in contact with brick, rock facades, or any other element of the building can cause
damage to the structure if the flatwork experiences movements.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 23
The ground-supported flatwork should be provided with crack-control and expansion joints in
accordance with Larimer County Specifications.
9.7 Corrosion Considerations
The corrosion potential of on-site soils to concrete and buried metal was evaluated in the
laboratory using selected samples obtained from the exploratory borings. Laboratory testing
was performed to assess the effects of sulfate on concrete and the effects of soil resistivity on
buried metal. Results of these tests are presented in Appendix B. Recommendations regarding
concrete to be utilized in construction of proposed improvements and for buried metal pipes are
provided in the following sections.
9.7.1 Concrete
The test for water-soluble sulfate content of the soils was performed using CDOT Test
Method CP-L 2104. The laboratory test results are presented in Appendix B. The
percentage of water-soluble sulfates in water measured was 0.025 percent, corresponding
to 250 parts per million, respectively. Based on Table 601-2 of the CDOT 2011 Standard
Specifications for Road and Bridge Construction, the on-site soils represent a Class 1
severity of sulfate exposure to concrete on a scale that ranges between Class 0 and Class
3. Therefore, we recommend that the concrete used for this project should have a
maximum water to cementitious material ratio of 0.45 and the cementitious materials should
meet one of the below outlined requirements.
• ASTM C 150 Type II or V; Class C fly ash shall not be substituted for cement.
• ASTM C 595 Type IP(MS) or IP(HS); Class C fly ash shall not be substituted for
cement.
• ASTM C 1157 Type MS or HS; Class C fly ash shall not be substituted for cement.
• When ASTM C 150 Type III cement is allowed, as in Class E concrete, it shall have no
more than 8 percent C3A. Class C fly ash shall not be substituted for cement.
The Structural Engineer should ultimately select the concrete design strength based on the
project specific loading conditions. However, higher strength concrete may be selected for
increased durability, resistance to slab curling and shrinkage cracking. We recommend the
use of concrete with a design 28-day compressive strength of 4,000 psi or more, for
concrete slabs at this site. Concrete exposed to the elements should be air-entrained.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 24
9.7.2 Buried Metal Pipes
The corrosion potential of the on-site materials was analyzed to evaluate its potential
effects on buried metals. Corrosion potential was evaluated using the results of laboratory
testing of samples obtained during the subsurface evaluation that were considered
representative of soils at the subject site.
The results of the laboratory testing indicate the on-site materials have low resistivity and
could potentially be moderately corrosive to ferrous metals. Therefore, special
consideration should be given to the use of heavy gauge, corrosion protected, underground
steel pipe or culverts, if any are planned. As an alternative, plastic pipe or reinforced
concrete pipe could be considered. A corrosion specialist should be consulted for further
recommendations.
9.8 Scaling
Climatic conditions in the project area including relatively low humidity, large temperature
changes and repeated freeze-thaw cycles, may cause surficial scaling and spalling of exterior
concrete. Occurrence of surficial scaling and spalling can be aggravated by poor workmanship
during construction, such as “over-finishing” concrete surfaces and the use of de-icing salts on
exterior concrete flatwork, particularly during the first winter after construction. The use of de-
icing salts on nearby roadways, which can be transferred by vehicle traffic onto newly placed
concrete, can be sufficient to induce scaling.
The measures below can be beneficial for reducing the concrete scaling. However, because of
the other factors involved, including workmanship, surface damage to concrete can develop
even though the measures provided below were followed. The mix design criteria should be
coordinated with other project requirements including the criteria for soluble sulfate resistance
presented in Section 9.7.1.
• Curing concrete in accordance with applicable codes and guidelines.
• Maintaining a water/cement ratio of 0.45 by weight for exterior concrete mixes.
• Including Type F fly ash in exterior concrete mixes as 20 percent of the cementitious
material.
• Specifying a 28-day, compressive strength of 4,500 or more psi for exterior concrete that
may be exposed to de-icing salts.
• Avoiding the use of de-icing salts through the first winter after construction.
• If colored concrete is being proposed for use at this site, Ninyo & Moore should be consulted
for additional recommendations.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 25
9.9 Frost Heave
Site soils are susceptible to frost heave if allowed to become saturated and exposed to freezing
temperatures and repeated freeze/thaw cycling. The formation of ice in the underlying soils can
result in two or more inches of heave of pavements, flatwork and other hardscaping in sustained
cold weather. A portion of this movement may be recovered when the soils thaw, but due to loss
of soil density some degree of displacement will remain. Frost heave of hardscaping could also
result in areas where the subgrade soils were placed on engineered fill.
In areas where hardscape movements are a design concern (i.e. exterior flatwork located
adjacent to the building within the doorway swing zone), replacement of the subgrade soils with
2 or more feet of clean, coarse sand or gravel, or supporting the element on foundations similar
to the building, or spanning over a void should be considered. Recommendations in this regard
can be provided upon request.
9.10 Construction in Cold or Wet Weather
During construction, the site should be graded such that surface water can drain readily away
from the building areas. Given the soil conditions, it is important to avoid ponding of water in or
near excavations. Water that accumulates in excavations should be promptly pumped out or
otherwise removed and these areas should be allowed to dry out before resuming construction.
Berms, ditches, and similar means should be used to decrease stormwater entering the work
area and to efficiently convey it off site.
Earthwork activities undertaken during the cold weather season may be difficult and should be
done by an experienced contractor. Fill should not be placed on top of frozen soils. The frozen
soils should be removed prior to the placement of fill or other construction material. Frozen soil
should not be used as engineered fill or backfill. The frozen soil may be reused (provided it
meets the selection criteria) once it has thawed completely. In addition, compaction of the soils
may be more difficult due to the viscosity change in water at lower temperatures.
If construction proceeds during cold weather, foundations, slabs, or other concrete elements
should not be placed on frozen subgrade soil. Frozen soil should either be removed from
beneath concrete elements, or thawed and recompacted. To limit the potential for soil freezing,
the time passing between excavation and construction should be minimized. Blankets, straw,
soil cover, or heating may be used to discourage the soil from freezing.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 26
9.11 Site Drainage
Infiltration of water into subsurface soils can lead to soil movement and associated distress, and
chemically and physically related deterioration of concrete and masonry structures. To reduce
the potential for infiltration of moisture into subsurface soils at the site, we recommend the
following:
• Positive drainage should be established and maintained away from the proposed buildings.
Positive drainage may be established by providing a surface gradient for paved areas of 2 to
5 percent or more for a distance of 10 feet or more away from structures. Where concrete
flatwork is placed adjacent to structures and other considerations are required by law, such
as ADA requirements, slopes of 1 percent or more are considered acceptable. For unpaved
areas, positive drainage may be established by a slope of 5 to 10 percent for 10 feet or
more away from structures, where possible.
• Adequate surface drainage should be provided to channel surface water away from on-site
structures and off paved surfaces to a suitable outlet such as a storm drain. Adequate
surface drainage may be enhanced by utilization of graded swales, area drains, and other
drainage devices. Surface run-off should not be allowed to pond near structures.
• Building roof drains should have downspouts tightlined to an appropriate outlet, such as a
storm drain or the street, away from structures, pavements, and flatwork. If tightlining of the
downspouts is not practicable, they should discharge 5 feet or more away from structures
and onto surfaces that slope away from the structure. Downspouts should not be allowed to
discharge onto the ground surface adjacent to building foundations or on exterior walkways.
• The possibility of moisture infiltration beneath a structure, in the event of plumbing leaks,
should be considered in the design and construction of underground water and sewer
conduits. Permitting increases in moisture to the building supporting soils may result in a
decrease in bearing capacity and an increase in settlement, heave, and/or differential
movement. Incorporating a perimeter drainage system around the building foundations that
will aid in reduction of the moisture infiltration of subsurface soils may be considered. Due to
the proposed construction and anticipated utilities within the structures, not placing the
perimeter drainage would be considered a low risk to the owner.
• Irrigated landscaping, consisting of sprinklers to water plants with high demands for water,
should not be placed within 10 feet of the building(s). Drip irrigation is considered acceptable
within this zone.
• Utility trenches should be backfilled with compacted, low permeability fill (i.e. permeability of
5-10 cm/s or less) within 5 feet of the building. Planters, if any, should be maintained 10 feet
or more from the building and constructed with closed bottoms or with drainage systems to
drain excess irrigation away from the building.
9.12 Construction Observation and Testing
A qualified geotechnical consultant should perform appropriate observation and testing services
during grading and construction operations. These services should include observation of any
soft, loose, or otherwise unsuitable soils, evaluation of subgrade conditions where soil removals
are performed, evaluation of the suitability of proposed borrow materials for use as fill,
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 27
evaluation of the stability of open temporary excavations, evaluation of the results of any
subgrade stabilization or dewatering activities, and performance of observation and testing
services during placement and compaction of engineered fill and backfill soils.
The geotechnical consultant should also perform observation and testing services during
placement of concrete, mortar, grout, asphalt concrete, and steel reinforcement. If another
geotechnical consultant is selected to perform observation and testing services for the project,
we request that the selected consultant provide a letter to the owner, with a copy to Ninyo &
Moore, indicating that they fully understand our recommendations and that they are in full
agreement with the recommendations contained in this report. Qualified subcontractors utilizing
appropriate techniques and construction materials should perform construction of the proposed
improvements.
9.13 Plan Review
The recommendations presented in this report are based on preliminary design information for
the proposed project and on the findings of our geotechnical evaluation. When finished, project
plans and specifications should be reviewed by the geotechnical consultant prior to submitting
the plans and specifications for bid. Additional field exploration and laboratory testing may be
needed upon review of the project design plans.
9.14 Pre-Construction Meeting
We recommend a pre-construction meeting be held. The owner or the owner’s representative,
the architect, the contractor, and the geotechnical consultant should be in attendance to discuss
the plans and the project.
10 LIMITATIONS
The field evaluation, laboratory testing, and geotechnical analyses presented in this
geotechnical report have been conducted in general accordance with current practice and the
standard of care exercised by geotechnical consultants performing similar tasks in the project
area. No warranty, expressed or implied, is made regarding the conclusions, recommendations,
and opinions presented in this report. There is no evaluation detailed enough to reveal every
subsurface condition. Variations may exist and conditions not observed or described in this
report may be encountered during construction. Uncertainties relative to subsurface conditions
can be reduced through additional subsurface exploration. Additional subsurface evaluation will
be performed upon request. Please also note that our evaluation was limited to assessment of
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 28
the geotechnical aspects of the project, and did not include evaluation of structural issues,
environmental concerns, or the presence of hazardous materials.
This document is intended to be used only in its entirety. No portion of the document, by itself, is
designed to completely represent any aspect of the project described herein. Ninyo & Moore
should be contacted if the reader requires additional information or has questions regarding the
content, interpretations presented, or completeness of this document.
This report is intended for design purposes only. It does not provide sufficient data to prepare an
accurate bid by contractors. It is suggested that the bidders and their geotechnical consultant
perform an independent evaluation of the subsurface conditions in the project areas. The
independent evaluations may include, but not be limited to, review of other geotechnical reports
prepared for the adjacent areas, site reconnaissance, and additional exploration and
laboratory testing.
Our conclusions, recommendations, and opinions are based on an analysis of the observed site
conditions. If geotechnical conditions different from those described in this report are
encountered, our office should be notified and additional recommendations, if warranted, will be
provided upon request. It should be understood that the conditions of a site could change with
time as a result of natural processes or the activities of man at the subject site or nearby sites.
In addition, changes to the applicable laws, regulations, codes, and standards of practice may
occur due to government action or the broadening of knowledge. The findings of this report may,
therefore, be invalidated over time, in part or in whole, by changes over which Ninyo & Moore
has no control.
This report is intended exclusively for use by the client. Any use or reuse of the findings,
conclusions, and/or recommendations of this report by parties other than the client is
undertaken at said parties’ sole risk.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019 29
11 REFERENCES
American Association of State Highway and Transportation Officials (AASHTO), 1993, AASHTO
Guide for Design of Pavement Structures.
American Association of State Highway and Transportation Officials (AASHTO), 2011, Standard
Specifications for Transportation Materials and Methods of Sampling and Testing, 31st
Edition, and Provisional Standards.
American Concrete Institute (ACI), 2010, Guide to Design of Slabs-On-Ground (ACI 360R-10).
American Concrete Institute (ACI), 2011, Building Code Requirements for Structural Concrete
(ACI 318-11) and Commentary.
American Concrete Institute (ACI), 2015, Guidelines for Concrete Floor and Slab Construction
(ACI 302.1R-15).
American Society for Testing and Materials (ASTM), 2015 Annual Book of ASTM Standards.
Colorado Association of Geotechnical Engineers (CAGE), 2007, Geotechnical Study Guidelines
for Light Commercial and Residential Buildings in Colorado, dated September.
Colorado Association of Geotechnical Engineers (CAGE), 1996, Guideline for Slab Performance
Risk Evaluation and Residential Basement Floor System Recommendations (Denver
Metropolitan Area), dated December.
Colorado Department of Transportation (CDOT), 2017, Standard Specifications for Road and
Bridge Construction.
Colton, Roger B., 1978, Geologic Map of the Boulder-Fort Collins-Greeley Area, Colorado,
United States Geological Survey.
Hart, Stephen S., 1973-1974, Potentially Swelling Soil and Rock in the Front Range Urban
Corridor, Colorado: Colorado Geological Survey, Sheet 1 of 4.
International Code Council, 2015, International Building Code.
Kirkham, R.M., and Rogers, W.P., 1981, Earthquake potential in Colorado: Colorado Geological
Survey Bulletin 43, 171 p., 3 pls.
Ninyo & Moore, In-house proprietary information.
Occupational Safety and Health Administration (OSHA), 2005, OSHA Standards for the
Construction Industry, 29 CFR Part 1926: dated June.
OSHPD, 2019, Seismic Design Maps, http://seismicmaps.org/.
Rogers, W. P. and Widmann B. L., Fault Number 2324, Golden Fault; in Quaternary Fault and
Fold Database of the United States: U.S. Geological Survey website,
http://earthquakes.usgs.gov/regional/qfaults.
Trimble, Donald E., 1980, The Geologic Story of the Great Plains, Geological Survey Bulletin
1493.
United States Geological Survey and Colorado Geological Survey (USGS & CGS), 2019,
Quaternary fault and fold database for the United States, accessed April 18, 2019, from
USGS web site: http://earthquakes.usgs.gov/regional/qfaults/.
Google Earth, October 1999, October 2017.
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019
Appendix A
Photographic Documentation
FIGURES
DRAFT
FIGURE 1
bsm file no: 1710vmap0619
501710001 | 6/19
REDMAN DRIVE AND NORTHWEST FRONTAGE ROAD
FORT COLLINS, COLORADO
POUDRE VALLEY DEVELOPMENT
SITE LOCATION
NOTE: DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE.
Source: US Geological Survey 7.5-minute topographic map, Fort Collins and Timnath, Colorado, 2016.
0 2000
FEET
NN
APPROXIMATE
SITE LOCATION
DRAFT
Source: NAVTEQ, 10/14/17.
bsm file no: 1710blm0619
FIGURE 2
501710001 | 6/19
REDMAN DRIVE AND NORTH WEST FRONTAGE ROAD
FORT COLLINS, COLORADO
POUDRE VALLEY DEVELOPMENT
BORING LOCATIONS
NOTE: DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE.
0 120
FEET
NN
Geotechnical & Environmental Sciences Consultants
B-16
B-9 B-10
B-1
B-2
B-4 B-2
B-17
B-14 B-15
B-7 B-8
B-3
B-6
B-13
B-12
B-11
5
REDMAN DRIVE
NORTH WEST FRONTAGE ROAD
U.S. INTERSTATE 25
LEGEND
B-17 Boring Location
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019
APPENDIX A
Boring Logs
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019
APPENDIX A
BORING LOGS
Field Procedure for the Collection of Disturbed Samples
Disturbed soil samples were obtained in the field using the following methods.
Bulk Samples
Bulk samples of representative earth materials were obtained from the exploratory borings.
The samples were bagged and transported to the laboratory for testing.
Field Procedure for the Collection of Ring-lined Samples
Ring-lined soil samples were obtained in the field using the following methods.
The Modified California Split-Barrel Drive Sampler
The sampler, with an external diameter of 3.0 inches, was lined with thin brass rings with
inside diameters of approximately 2.4 inches. The sample barrel was driven into the ground
with the weight of a hammer in general accordance with ASTM D 3550. The driving weight
was permitted to fall freely. The approximate length of the fall, the weight of the hammer or
bar, and the number of blows per foot of driving are presented on the boring logs as an
index to the relative resistance of the materials sampled. The samples were removed from
the sample barrel in the brass rings, sealed, and transported to the laboratory for testing.
The California Drive Sampler
The sampler, with an external diameter of 2.4 inches, was lined with four 4-inch long, thin
brass rings with inside diameters of approximately 1.9 inches. The sample barrel was
driven into the ground with the weight of a hammer in general accordance with ASTM
D 3550. The driving weight was permitted to fall freely. The approximate length of the fall,
the weight of the hammer, and the number of blows per foot of driving are presented on the
boring logs as an index to the relative resistance of the materials sampled. The samples
were removed from the sample barrel in the brass liners, sealed, and transported to the
laboratory for testing.
DRAFT
SOIL CLASSIFICATION CHART PER ASTM D 2488
PRIMARY DIVISIONS
SECONDARY DIVISIONS
GROUP SYMBOL GROUP NAME
COARSE-
GRAINED
SOILS
more than
50% retained
on No. 200
sieve
GRAVEL
more than
50% of
coarse
fraction
retained on
No. 4 sieve
CLEAN GRAVEL
less than 5% fines
GW well-graded GRAVEL
GP poorly graded GRAVEL
GRAVEL with
DUAL
CLASSIFICATIONS
5% to 12% fines
GW-GM well-graded GRAVEL with silt
GP-GM poorly graded GRAVEL with silt
GW-GC well-graded GRAVEL with clay
GP-GC poorly graded GRAVEL with clay
GRAVEL with
FINES
more than
12% fines
GM silty GRAVEL
GC clayey GRAVEL
GC-GM silty, clayey GRAVEL
SAND
50% or more
of coarse
fraction
passes
No. 4 sieve
CLEAN SAND
less than 5% fines
SW well-graded SAND
SP poorly graded SAND
SAND with
DUAL
CLASSIFICATIONS
5% to 12% fines
SW-SM well-graded SAND with silt
SP-SM poorly graded SAND with silt
SW-SC well-graded SAND with clay
SP-SC poorly graded SAND with clay
SAND with FINES
more than
12% fines
SM silty SAND
SC clayey SAND
BORING LOG EXPLANATION SHEET
0
5
XX/XX
10
15
Bulk sample.
Modified split-barrel drive sampler.
2-inch inner diameter split-barrel drive sampler.
No recovery with modified split-barrel drive sampler, or 2-inch inner diameter split-barrel
drive sampler.
Sample retained by others.
Standard Penetration Test (SPT).
No recovery with a SPT.
Shelby tube sample. Distance pushed in inches/length of sample recovered in inches.
No recovery with Shelby tube sampler.
Continuous Push Sample.
Seepage.
Groundwater encountered during drilling.
Groundwater measured after drilling.
SM MAJOR MATERIAL TYPE (SOIL):
Solid line denotes unit change.
CL Dashed line denotes material change.
Attitudes: Strike/Dip
b: Bedding
c: Contact
j: Joint
f: Fracture
F: Fault
cs: Clay Seam
s: Shear
bss: Basal Slide Surface
sf: Shear Fracture
sz: Shear Zone
sbs: Shear Bedding Surface
The total depth line is a solid line that is drawn at the bottom of the boring.
20
BORING LOG
Explanation of Boring Log Symbols
PROJECT NO. DATE FIGURE
DEPTH (feet)
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
CLASSIFICATION
U.S.C.S.
6<0%2/
%XON
'ULYHQ
6$03/(6
DRAFT
0
10
20
30
40
17
5
43
7
34
20.9
15.0
6.7
106.6
106.2
122.2
CH
CL-ML
SW
SM
SP
LOAM:
Brown, moist, very stiff, fat CLAY; trace sand and gravel.
ALLUVIUM:
Red, moist, firm, sandy silty CLAY.
Red with yellow and gray, wet, dense, fine to coarse SAND with gravel; trace clay.
@10': Groundwater encountered during drilling.
Light brown with red, wet, loose, silty SAND; trace iron oxide staining.
Light brown with red, wet, very dense, fine to medium SAND; trace clay.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 10 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 1
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO. B-1
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
18
5
15
90/10"
21.4
17.3
103.9
104.3
CH
CL
SW
LOAM:
Brown with white, moist, very stiff, sandy fat CLAY with few calcium mineralizations.
ALLUVIUM:
Red, moist, firm, sandy lean CLAY; trace gravel.
Light brown with red, moist, medium dense, fine to coarse SAND; trace clay.
@12': Groundwater encountered during drilling.
Wet; very dense.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 12 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 2
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO. B-2
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
12
5
25
7
16.8
17.1
3.8
111.8
106.8
CH
CL
SW
LOAM:
Brown, moist, sandy fat CLAY.
ALLUVIUM:
Pale red to red, moist, stiff, lean CLAY with sand.
Firm.
Pale red to light brown, moist to wet, moderately dense, fine to coarse SAND with gravel;
trace clay.
@11': Groundwater encountered during drilling.
Loose with few clayey interlayers.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 11 feet during drilling.
Backfilled with on-site soils on 06/08/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 3
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO. B-3
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
10
3
36
17
14.4
16.0
6.1
113.2
109.5
123.7
CL
SC
SW
LOAM:
Light brown to brown, moist, stiff, sandy lean CLAY; trace gravel.
ALLUVIUM:
Reddish brown, moist, very loose, clayey SAND.
Reddish brown, moist to wet, medium dense, fine to coarse SAND with gravel; trace clay.
@10': Groundwater encountered during drilling.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 10 feet during drilling.
Backfilled with on-site soils on 06/08/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 4
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO. B-4
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
19
6
24
20
20.8
15.3
106.7
107.8
CH
CL
SW
LOAM:
Reddish brown to brown mottled, moist, very stiff, fat CLAY; trace sand.
Red, moist, firm, sandy lean CLAY.
ALLUVIUM:
Light brown to red, moist, medium dense, fine to coarse SAND; trace clay.
@11': Groundwater encountered during drilling.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 11 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 5
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO. B-5
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
13
7
24
9
19.1
27.0
2.4
106.1
93.9
CH
CH
SW
LOAM:
Reddish brown, moist, stiff, fat CLAY; trace sand and gravel.
ALLUVIUM:
Pale red to red, moist, stiff, fat CLAY; trace sand.
Reddish brown with white and gray, moist, medium dense, fine to coarse SAND with
gravel; trace clay.
@11': Groundwater encountered during drilling.
Total Depth = 15.5 feet.
Groundwater was encountered at a depth of approximately 11 feet during drilling.
Backfilled with on-site soils on 06/08/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 6
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO. B-6
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
14
6
37
37
20
16.0
15.8
5.7
110.7
107.6
128.1
CL
CL
SW
LOAM:
Red to brown, moist, very stiff, lean CLAY; trace sand.
Red to reddish brown, moist, firm, sandy lean CLAY.
ALLUVIUM:
Pale red to red, moist to wet, medium dense, fine to coarse SAND with gravel; trace clay.
@10': Groundwater encountered during drilling.
Pale brown to yellowish brown.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 10 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 7
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO. B-7
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
19
20
27
32
51
26.9
7.7
98.6
126.0
CL
CH
SW
LOAM:
Brown to reddish brown, moist, very stiff, fat CLAY; trace sand, gravel, and few calcium
mineralizations.
ALLUVIUM:
Red to reddish brown, moist, very stiff, fat CLAY; trace sand and gravel.
Red to reddish brown, moist, medium dense, fine to coarse SAND with gravel; trace clay.
@12': Groundwater encountered during drilling.
Wet; dense.
Very dense; grading to clayey sand.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 12 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 8
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO. B-8
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
17
16
50/5"
20
21.9
1.8
102.0
123.1
CH
SW-SC
LOAM:
Brown with white, moist, very stiff, sandy fat CLAY with few calcium mineralizations.
ALLUVIUM:
Reddish brown to yellowish brown, moist, medium dense, fine to coarse SAND with clay
and gravel.
@9': Groundwater encountered during drilling.
Very dense.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 9 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 9
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO. B-9
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
14
6
22
15
30
21.2
8.2
103.7
120.5
CH
SC-SM
SW
LOAM:
Brown and reddish brown mottled, moist, very stiff, sandy fat CLAY.
ALLUVIUM:
Red to reddish brown, moist, loose, silty, clayey SAND with gravel.
@9': Groundwater encountered during drilling.
Light brown to reddish brown, wet, medium dense, fine to coarse SAND; trace clay.
Dense.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 9 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 10
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO. B-10
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
6
12
50/3"
23
11.4
2.0
107.8
CL
SP
LOAM:
Pale red to red, moist, firm, lean CLAY; trace sand.
ALLUVIUM:
Reddish yellow to pale red, moist, loose, fine to medium SAND.
@9': Groundwater encountered during drilling.
Very dense.
@10': Scattered cobbles.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 9 feet during drilling.
Backfilled with on-site soils on 06/08/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 11
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO. B-11
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
15
13
8
9
1.1
CH
SW
LOAM:
Brown, moist, very stiff, sandy fat CLAY with gravel.
ALLUVIUM:
Red to reddish brown, moist, loose, fine to coarse SAND with gravel; trace clay.
@8.5': Groundwater encountered during drilling.
Wet; medium dense; with few clayey fine sand interlayers.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 8.5 feet during drilling.
Backfilled with on-site soils on 06/08/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 12
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO. B-12
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
4
6
50
30
15.5
4.1
106.5
106.0
CH
CL
SC
SW
LOAM:
Brown, moist, sandy fat CLAY.
ALLUVIUM:
Red, moist, firm, sandy lean CLAY; trace gravel.
Red with gray and brown, moist, loose, clayey SAND with gravel.
Red with gray and brown, moist, very dense, fine to coarse SAND; trace clay.
@9': Groundwater encountered during drilling.
Dense.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 9 feet during drilling.
Backfilled with on-site soils on 06/07/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 13
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/07/2019 BORING NO. B-13
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
13
17
64
37
14
10.4
8.0
119.9
142.4
CH
SW-SC
LOAM:
Brown to dark brown, moist, stiff, sandy fat CLAY.
ALLUVIUM:
Reddish yellow to yellow, dry, medium dense, fine to coarse SAND with clay and gravel.
@9': Groundwater encountered during drilling.
Wet; dense.
Medium dense.
Light brown.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 9 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 14
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO. B-14
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
18
10
50
27
19
17.2
6.8
109.5
102.6
CH
SM
SP-SC
LOAM:
Brown to dark brown, moist, very stiff, fat CLAY with sand; trace gravel and calcium
mineralizations.
ALLUVIUM:
Pale red to reddish yellow, dry, loose, silty SAND; trace gravel.
Pale red to reddish yellow, wet, very dense, fine to medium SAND with clay and gravel.
@10': Groundwater encountered during drilling.
Dense.
Medium dense.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 10 feet during drilling.
Backfilled with on-site soils on 06/03/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 15
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/03/2019 BORING NO. B-15
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
13
5
50/2"
11
14
12.4 110.9
CL
SC
LOAM:
Brown with white and red, moist, stiff, sandy lean CLAY; trace gravel.
ALLUVIUM:
Pale red to pale reddish brown, moist to wet, loose, clayey SAND; trace gravel and
scattered cobbles.
@8.5': Groundwater encountered during drilling.
Very dense.
Medium dense; few clayey interlayers.
Total Depth = 20.5 feet.
Groundwater was encountered at a depth of approximately 8.5 feet during drilling.
Backfilled with on-site soils on 06/08/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 16
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO. B-16
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
0
10
20
30
40
18
14
29
19
16.7
5.8
8.1
109.9
124.6
132.7
CL
SC
SW
LOAM:
Brown with white and red, moist, very stiff, lean CLAY with sand; trace gravel.
ALLUVIUM:
Reddish brown to brown, moist, loose, clayey SAND with gravel.
@8': Groundwater encountered during drilling.
Wet; medium dense.
Reddish brown, wet, medium dense, fine to coarse SAND; trace clay and gravel.
Total Depth = 19 feet.
Groundwater was encountered at a depth of approximately 9 feet during drilling.
Backfilled with on-site soils on 06/07/2019.
Notes:
Groundwater may rise to a level higher than that measured in borehole due to seasonal
variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 17
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 | 7/19
DEPTH (feet)
Bulk SAMPLES
Driven
BLOWS/FOOT
MOISTURE (%)
DRY DENSITY (PCF)
SYMBOL
CLASSIFICATION
U.S.C.S.
DESCRIPTION/INTERPRETATION
DATE DRILLED 06/08/2019 BORING NO. B-17
GROUND ELEVATION -- SHEET 1 OF
METHOD OF DRILLING CME-45, 4" Solid-Stem Auger (Unlimited Access Drilling)
DRIVE WEIGHT 140 Lbs. (Automatic-Trip Hammer) DROP 30"
SAMPLED BY DLH LOGGED BY DLH REVIEWED BY BFG
1
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019
APPENDIX B
Laboratory Testing
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019
APPENDIX B
LABORATORY TESTING
Classification
Soils were visually and texturally classified in accordance with the Unified Soil Classifications
System (USCS) in general accordance with ASTM D 2488. Soil classifications are indicated on
the logs of the exploratory excavations in Appendix A.
In-Place Moisture and Density Tests
The moisture content and dry density of ring-lined samples obtained from the exploratory
borings were evaluated in general accordance with ASTM D 2837. These test results are
presented on the logs of the exploratory borings in Appendix A.
Atterberg Limits
Tests were performed on selected representative fine-grained soil samples to evaluate the liquid
limit, plastic limit, and plasticity index in general accordance with ASTM D 4318. These test
results were utilized to evaluate the soil classification in accordance with the Unified Soil
Classification System. The test results and classifications are shown on Figures B-1
through B-4.
No. 200 Sieve Analysis
An evaluation of the percentage of particles finer than the No. 200 sieve in selected soil
samples was performed in general accordance with ASTM D 1140. The results of the tests are
presented on Figures B-5 through B-7.
Consolidation/Swell Tests
Consolidation/swell tests were performed on selected ring-lined soil samples in general
accordance with ASTM D 4546. The samples were inundated during testing to represent
adverse field conditions. The percent of consolidation or swell for each load cycle was recorded
as a ratio of the amount of vertical compression to the original height of the sample. The results
of the tests are summarized on Figures B-8 through B-25.
Soil Corrosivity Tests
A soil pH test was performed on a representative sample in general accordance with ASTM Test
Method D 4972. A soil minimum resistivity test was performed on a representative sample in
general accordance with AASHTO T288. The sulfate content of a selected sample was
evaluated in general accordance with CDOT Test Method CP-L 2103. The chloride content of a
selected sample was evaluated in general accordance with CDOT Test Method CP-L 2104. The
test results are presented on Figure B-26.
DRAFT
∆
X
+
NP - INDICATES NON-PLASTIC
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4318
7/19
18 35
15 36
17 42
CH
CH
CH
CH
CH
B-5 CH
4.0-5.0 17
CL
59
29
CL
16
7
13
16 31
CL-ML
CL
2.0-3.0
13
17
CL
2.0-3.0 57 40
SC
CH
CL-ML
CH
EQUIVALENT
USCS
CL
No. 40 Sieve)
SYMBOL LOCATION DEPTH (ft) LIQUID
LIMIT
USCS
(Fraction Finer Than
PLASTICITY
INDEX
CLASSIFICATION
B-1
PLASTIC
LIMIT
17
B-6 4.0-5.0
4.0-5.0
14.0-15.5
24
30
B-6
B-1
B-1
B-2
∆
X
+
NP - INDICATES NON-PLASTIC
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4318
7/19
FORT COLLINS, COLORADO
501710001
POUDRE VALLEY DEVELOPMENT
B-15 4.0-5.0
2.0-3.0
4.0-5.0
51
56
B-15
B-8
B-8
B-10
B-10
2.0-3.0
2.0-3.0
22
54
NP
EQUIVALENT
USCS
CH
No. 40 Sieve)
SYMBOL LOCATION DEPTH (ft) LIQUID
LIMIT
USCS
(Fraction Finer Than
PLASTICITY
INDEX
CLASSIFICATION
B-7
PLASTIC
LIMIT
17
16
SC-SM
2.0-3.0 46 30
CH
CL
CH
CL
B-12
2.0-3.0 23
CL-ML
62
62
CH
45
28
39
17 5
CH
CH
4.0-5.0
NP - INDICATES NON-PLASTIC
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4318
7/19
2.0-3.0 18
CL
31
-
CL
17
2.0-3.0 46 29
SC
CL
CL
CL
EQUIVALENT
USCS
No. 40 Sieve)
SYMBOL LOCATION DEPTH (ft) LIQUID
LIMIT
USCS
(Fraction Finer Than
PLASTICITY
INDEX
CLASSIFICATION
B-16
PLASTIC
LIMIT
4.0-5.0 13
49
-
B-17
B-17
FORT COLLINS, COLORADO
501710001
POUDRE VALLEY DEVELOPMENT
CH or OH
CL or OL
MH or OH
CL - ML ML or OL
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110 120
PLASTICITY INDEX, PI
LIQUID LIMIT, LL
FIGURE B-3
ATTERBERG LIMITS TEST RESULTS
DRAFT
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 1140
501710001 7/19
B-6 4.0-5.0 Pale Red to Red Fat CLAY; Trace Sand 100 96 CH
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
SAMPLE
LOCATION
SAMPLE
DEPTH
(ft)
PERCENT
PASSING
NO. 200
PERCENT
PASSING
NO. 4
DESCRIPTION
99 88
EQUIVALENT
USCS
4.0-5.0
2.0-3.0
B-3
B-1
B-1
Red Sandy Lean CLAY; Trace Gravel
Pale Red to Red Lean CLAY with Sand
Brown Fat CLAY; Trace Sand and Gravel
Red Sandy Silty CLAY CL-ML
2.0-3.0
B-4
B-5 2.0-3.0
Red Sandy Lean CLAY
Reddish Brown Fat CLAY; Trace Sand and Gravel
B-5
B-6
Light Brown to Brown Sandy Lean CLAY; Trace Gravel
Reddish Brown to Brown Mottled Fat CLAY; Trace
Sand
100 57
CH
4.0-5.0
2.0-3.0
2.0-3.0
4.0-5.0
B-2
99
92
100
100 91
62
CH
CL
88
69 CL
CH
99
100
CL
CL
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 1140
7/19
99
100
CH
CH
90
98
Brown to Reddish Brown Fat CLAY; Trace Sand and
Gravel
Red to Reddish Brown Fat CLAY; Trace Sand and
Gravel
CH
CL
77
25 SC-SM
CH
79
96
82 55
67
100 70
CL
2.0-3.0
4.0-5.0
2.0-3.0
4.0-5.0
B-8
2.0-3.0 99
B-10
B-12 2.0-3.0 Brown Sandy Fat CLAY with Gravel
B-13 Red Sandy Lean CLAY; Trace Gravel
B-15
Red to Reddish Brown Silty, Clayey SAND with Gravel
Brown to Dark Brown Fat CLAY with Sand; Trace
Gravel
SAMPLE
LOCATION
SAMPLE
DEPTH
(ft)
PERCENT
PASSING
NO. 200
PERCENT
PASSING
NO. 4
DESCRIPTION
100 93
EQUIVALENT
USCS
2.0-3.0
4.0-5.0
B-8
B-7
B-7
Red to Brown Lean CLAY; Trace Sand
Red to Reddish Brown Sandy Lean CLAY CL
501710001
B-15 4.0-5.0 96 23 SM
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 1140
501710001 7/19
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
DESCRIPTION
95 60
EQUIVALENT
USCS
B-16
B-17
Brown with White and Red Sandy Lean CLAY; Trace
Gravel
Brown with White and Red Lean CLAY with Sand;
Trace Gravel
Reddish Brown to Brown Clayey SAND with Gravel
95 77
CL
4.0-5.0
2.0-3.0
SAMPLE
LOCATION
SAMPLE
DEPTH
(ft)
PERCENT
PASSING
NO. 200
PERCENT
PASSING
NO. 4
2.0-3.0
B-17 75
CL
18 SC
NO. 200 SIEVE ANALYSIS TEST RESULTS
FIGURE B-6
DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2" 1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
-- --
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)
D30
Fine
Sample
Location
100
D10
16 200
D60 C
u
Equivalent
USCS
2.25 11.3 1.0 4.4 SW
Passing
No. 200
(percent)
Cc
B-1 9.0-10.0 -- 0.20 0.67
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
100 10 1 0.1 0.01 0.001 0.0001
PERCENT FINER BY WEIGHT
GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-7
DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2" 1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
-- --
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)
D30
Fine
Sample
Location
100
D10
16 200
D60 C
u
Equivalent
USCS
4.50 19.6 1.2 5.4 SW-SC
Passing
No. 200
(percent)
Cc
B-9 4.0-5.0 -- 0.23 1.10
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
100 10 1 0.1 0.01 0.001 0.0001
PERCENT FINER BY WEIGHT
GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-8
DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2" 1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
Cu
Equivalent
USCS
4.75 31.7 0.4 4.6 SP
Passing
No. 200
(percent)
Cc
B-11 4.0-5.0 -- 0.15 0.54
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)
D30
Fine
Sample
Location
100
D10
16 200
D60
-- --
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
100 10 1 0.1 0.01 0.001 0.0001
PERCENT FINER BY WEIGHT
GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-9
DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2" 1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
-- --
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)
D30
Fine
Sample
Location
100
D10
16 200
D60 C
u
Equivalent
USCS
3.90 9.8 1.0 3.2 SW
Passing
No. 200
(percent)
Cc
B-12 4.0-5.0 -- 0.40 1.25
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
100 10 1 0.1 0.01 0.001 0.0001
PERCENT FINER BY WEIGHT
GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-10
DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2" 1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
-- --
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)
D30
Fine
Sample
Location
100
D10
16 200
D60 C
u
Equivalent
USCS
-- -- -- 16 SC
Passing
No. 200
(percent)
Cc
B-13 4.0-5.0 -- -- --
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
100 10 1 0.1 0.01 0.001 0.0001
PERCENT FINER BY WEIGHT
GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-11
DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2" 1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
-- --
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)
D30
Fine
Sample
Location
100
D10
16 200
D60 C
u
Equivalent
USCS
5.40 18.0 1.4 5.1 SW-SC
Passing
No. 200
(percent)
Cc
B-14 4.0-5.0 -- 0.30 1.50
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
100 10 1 0.1 0.01 0.001 0.0001
PERCENT FINER BY WEIGHT
GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-12
DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2" 1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
-- --
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)
D30
Fine
Sample
Location
100
D10
16 200
D60 C
u
Equivalent
USCS
2.50 83.3 3.1 12 SP-SC
Passing
No. 200
(percent)
Cc
B-15 9.0-10.5 -- 0.03 0.48
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
100 10 1 0.1 0.01 0.001 0.0001
PERCENT FINER BY WEIGHT
GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-13
DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2" 1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
-- --
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)
D30
Fine
Sample
Location
100
D10
16 200
D60 C
u
Equivalent
USCS
-- -- -- 32 SC
Passing
No. 200
(percent)
Cc
B-16 14.0-15.5 -- -- --
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
100 10 1 0.1 0.01 0.001 0.0001
PERCENT FINER BY WEIGHT
GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-14
DRAFT
Coarse Fine Coarse Medium SILT CLAY
3" 2" 1-1/2" 1" 3/4" 3/8" 4 10 30 50
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 6913
-- --
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
GRAVEL SAND FINES
Symbol Plasticity
Index
Plastic
Limit
Liquid
Limit
Depth
(ft)
D30
Fine
Sample
Location
100
D10
16 200
D60 C
u
Equivalent
USCS
-- -- -- 13 SC
Passing
No. 200
(percent)
Cc
B-17 9.0-10.0 -- -- --
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
100 10 1 0.1 0.01 0.001 0.0001
PERCENT FINER BY WEIGHT
GRAIN SIZE IN MILLIMETERS
U.S. STANDARD SIEVE NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIGURE B-15
DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-1
2.0-3.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
19.8%
21.8%
3.4
5700
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)
STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-16
DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-1
4.0-5.0
CL-ML
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
15.8%
20.9%
-
-
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)
STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-17
DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-4
2.0-3.0
CL
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
14.7%
18.7%
3.6
3370
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)
STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-18
DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-6
2.0-3.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
18.9%
21.5%
2.9
2600
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)
STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-19
DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-6
4.0-5.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
24.2%
27.8%
0.6
680
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)
STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-20
DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-7
2.0-3.0
CL
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
15.6%
21.0%
3.3
4000
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)
STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-21
DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-8
2.0-3.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
16.8%
22.9%
5.0
2700
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)
STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-22
DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-8
4.0-5.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
22.2%
23.7%
1.5
1850
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)
STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-23
DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-10
2.0-3.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
18.9%
22.3%
3.8
3800
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)
STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-24
DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-12
2.0-3.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
16.9%
21.1%
1.4
2350
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)
STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-25
DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-15
2.0-3.0
CH
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
18.2%
20.7%
4.2
6400
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)
STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-26
DRAFT
Seating Cycle
Loading Prior to Inundation
Loading After Inundation
Rebound Cycle
B-16
2.0-3.0
CL
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4546
12.9%
20.4%
2.4
3000
Sample Location:
Depth (ft):
Soil Type:
Moisture Content Before Test (%):
Moisture Content After Test (%):
Swell Percentage (%):
Swell Pressure (psf):
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001 7/19
-5.0
-3.0
-1.0
1.0
3.0
5.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)
STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
FIGURE B-27
DRAFT
1
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4972
2
PERFORMED IN GENERAL ACCORDANCE WITH AASHTO T288
3
PERFORMED IN GENERAL ACCORDANCE WITH CDOT TEST METHOD CP-L 2103
4
PERFORMED IN GENERAL ACCORDANCE WITH CDOT TEST METHOD CP-L 2104
7/19
pH
SAMPLE 1
DEPTH (ft)
SAMPLE
LOCATION
RESISTIVITY
2
(ohm-cm)
SULFATE CONTENT
3
(ppm) (%)
B-16 and B-17 0.0-5.0 8.1 1,667 250 0.025 40
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
501710001
CHLORIDE
CONTENT
4
(ppm)
CORROSIVITY TEST RESULTS
FIGURE B-28
DRAFT
Ninyo & Moore | Proposed Poudre Valley Development, Fort Collins, Colorado | 501710001 R | July 2, 2019
6001 South Willow Drive, Suite 195 | Greenwood Village, Colorado 80111 | p. 303.629.6000
ARIZONA | CALIFORNIA | COLORADO | NEVADA | TEXAS | UTAH
www.ninyoandmoore.com
DRAFT
POUDRE VALLEY DEVELOPMENT
FORT COLLINS, COLORADO
Pale Red to Reddish Yellow Silty SAND; Trace Gravel
NO. 200 SIEVE ANALYSIS TEST RESULTS
FIGURE B-5
DRAFT
65
80
NO. 200 SIEVE ANALYSIS TEST RESULTS
FIGURE B-4
DRAFT
17
SM
CH
CH
NP
CH
CH
NP NP
17 37
18 44
CH or OH
CL or OL MH or OH
CL - ML ML or OL
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110 120
PLASTICITY INDEX, PI
LIQUID LIMIT, LL
FIGURE B-2
ATTERBERG LIMITS TEST RESULTS
DRAFT
B-4
2.0-3.0
2.0-3.0
47
51
53
FORT COLLINS, COLORADO
501710001
POUDRE VALLEY DEVELOPMENT
CH or OH
CL or OL
MH or OH
CL - ML ML or OL
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110 120
PLASTICITY INDEX, PI
LIQUID LIMIT, LL
FIGURE B-1
ATTERBERG LIMITS TEST RESULTS
DRAFT
SC-SM silty, clayey SAND
FINE-
GRAINED
SOILS
50% or
more passes
No. 200 sieve
SILT and
CLAY
liquid limit
less than 50%
INORGANIC
CL lean CLAY
ML SILT
CL-ML silty CLAY
ORGANIC
OL (PI > 4) organic CLAY
OL (PI < 4) organic SILT
SILT and
CLAY
liquid limit
50% or more
INORGANIC
CH fat CLAY
MH elastic SILT
ORGANIC
OH (plots on or
above “A”-line) organic CLAY
OH (plots below
“A”-line) organic SILT
Highly Organic Soils PT Peat
USCS METHOD OF SOIL CLASSIFICATION
Explanation of USCS Method of Soil Classification
PROJECT NO. DATE FIGURE
APPARENT DENSITY - COARSE-GRAINED SOIL
APPARENT
DENSITY
SPOOLING CABLE OR CATHEAD AUTOMATIC TRIP HAMMER
SPT
(blows/foot)
MODIFIED
SPLIT BARREL
(blows/foot)
SPT
(blows/foot)
MODIFIED
SPLIT BARREL
(blows/foot)
Very Loose < 4 < 8
< 3 < 5
Loose 5 - 10 9 - 21 4 - 7 6 - 14
Medium
Dense 11 - 30 22 - 63 8 - 20 15 - 42
Dense 31 - 50 64 - 105 21 - 33 43 - 70
Very Dense > 50 > 105 > 33 > 70
CONSISTENCY - FINE-GRAINED SOIL
CONSIS-
TENCY
SPOOLING CABLE OR CATHEAD AUTOMATIC TRIP HAMMER
SPT
(blows/foot)
MODIFIED
SPLIT BARREL
(blows/foot)
SPT
(blows/foot)
MODIFIED
SPLIT BARREL
(blows/foot)
Very Soft < 2 < 3 < 1 < 2
Soft 2 - 4 3 - 5 1 - 3 2 - 3
Firm 5 - 8 6 - 10 4 - 5 4 - 6
Stiff 9 - 15 11 - 20 6 - 10 7 - 13
Very Stiff 16 - 30 21 - 39 11 - 20 14 - 26
Hard > 30 > 39 > 20 > 26
LIQUID LIMIT (LL), %
PLASTICITY INDEX (PI), %
0 10
10
7
4
20
30
40
50
60
70
0
20 30 40 50 60 70 80 90 100
MH or OH
CL - ML ML or OL
PLASTICITY CHART
GRAIN SIZE
DESCRIPTION SIEVE
SIZE
GRAIN
SIZE
APPROXIMATE
SIZE
Boulders > 12” > 12” Larger than
basketball-sized
Cobbles 3 - 12” 3 - 12” Fist-sized to
basketball-sized
Gravel
Coarse 3/4 - 3” 3/4 - 3” Thumb-sized to
fist-sized
Fine #4 - 3/4” 0.19 - 0.75” Pea-sized to
thumb-sized
Sand
Coarse #10 - #4 0.079 - 0.19” Rock-salt-sized to
pea-sized
Medium #40 - #10 0.017 - 0.079” Sugar-sized to
rock-salt-sized
Fine #200 - #40 0.0029 -
0.017”
Flour-sized to
sugar-sized
Fines Passing #200 < 0.0029” Flour-sized and
smaller
CH or OH
CL or OL
DRAFT