HomeMy WebLinkAboutMONTAVA PUD - ODP - ODP180002 - MONTAVA SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTPRELIMINARY SUBSURFACE EXPLORATION REPORT
800 ACRE MIXED USE DEVELOPMENT
SOUTH OF LCR 52 AND WEST OF ANHEUSER BUSCH
FORT COLLINS, COLORADO
EEC PROJECT NO. 1172058
Prepared for:
Chase Merritt
1637 Pearl Street
Suite 204
Boulder, Colorado 80302
Attn: Mr. Max Moss (max@chasemerritt.com)
Prepared by:
Earth Engineering Consultants, LLC
4396 Greenfield Drive
Windsor, Colorado 80550
4396 GREENFIELD DRIVE
WINDSOR, COLORADO 80550
(970) 545-3908 FAX (970) 663-0282
October 2, 2017
Chase Merritt
1637 Pearl Street
Suite 204
Boulder, Colorado 80302
Attn: Mr. Max Moss (max@chasemerritt.com)
Re: Preliminary Subsurface Exploration Report
800 Acre Mixed Use Development
South of LCR 52 and West of Anheuser Busch
Windsor, Colorado
EEC Project No. 1172058
Mr. Moss:
Enclosed, herewith, are the results of the preliminary subsurface exploration completed by Earth
Engineering Consultants, LLC personnel for the referenced project. A total of thirty (30)
preliminary soil borings were drilled from August 14 through 30, 2017, at the approximate
locations as indicated on the enclosed Figure 1: Boring Location Diagram included with this
report. The borings were extended to depths of approximately 25 to 40 feet below existing site
grades. Individual boring logs, including groundwater observations, depth to bedrock, and
results of laboratory testing are included as a part of the attached report. This exploration was
completed in general accordance with our proposal dated June 26, 2017.
In summary, the subsurface soils encountered in the preliminary test borings generally consisted
of cohesive lean clay with varying amounts of sand subsoils. The cohesive soils were generally
soft to very stiff and exhibited low to high swell potential at current moisture and density
conditions. The lean clay subsoils were underlain by sand/gravel with varying amounts of silt
soils at depths of approximately 7 to 39 feet. The sand/gravel subsoils extended to the depths
explored, approximately 25 to 40 feet, or to the underlying bedrock. The
sandstone/siltstone/claystone bedrock was encountered in seven (7) of the thirty (30) preliminary
test borings at depths ranging from approximately 24 to 27 feet below existing site grades and
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extended to the depths explored. The bedrock formation was highly weathered and became more
competent/harder with increased depth. Groundwater was observed in the majority of the
preliminary test borings at depths ranging from approximately 2 to 36½ feet below existing site
grades.
Based on the materials observed within the preliminary boring locations and the anticipated
foundation loads, we believe the proposed lightly to moderately loaded structures, either
commercial/retail building and/or residential structures with possible basements, could be
supported by conventional spread footings bearing on either suitable native subsoils or on a zone
of engineered/controlled fill material placed and compacted as described within this report. Due
to the variable depth to groundwater across the site, moderate to high swells at various locations,
and occasional areas with lower bearing capacities, ground modifications may be necessary in
these areas, as described within this report.
Groundwater was encountered across the site within the majority of the preliminary borings at
approximate depths of 2 to 36½ feet below existing site grades. If lower level construction or
full-depth basements are being considered for the site, we would suggest that the lower level
subgrade(s) be placed a minimum of 3 feet above the maximum anticipated rise in groundwater
levels, or a combination exterior and interior perimeter drainage system(s) be installed.
Foundations for slab-on-grade buildings should also be placed at least 3 feet above maximum
groundwater levels or have proper drainage in areas with extremely shallow groundwater.
Additional drainage system recommendations are provided within the text portion of this report.
In general, it appears the in-situ site materials could be used for support of interior slab-on-
grades, exterior flatwork, and site pavements; however, ground modification procedures such as
over-excavation and replacement of existing fill materials as approved engineered fill and
placement of an approved imported fill material may be required to reduce post-construction
movement in some areas. Post-construction movement can be reduced but cannot be eliminated.
Additionally, the cohesive subsoil materials may be subject to strength loss and instability when
wetted. Close monitoring and evaluation during the construction phase should be performed to
reduce post-construction movement.
PRELIMINARY SUBSURFACE EXPLORATION REPORT
800 ACRE MIXED USE DEVELOPMENT
SOUTH OF LCR 52 AND WEST OF ANHEUSER BUSCH
FORT COLLINS, COLORADO
EEC PROJECT NO. 1172058
October 2, 2017
INTRODUCTION
The preliminary subsurface exploration for the proposed 800-acre mixed use development located
southeast of Larimer County Road (LCR) 52 and LCR 50E in Fort Collins, Colorado has been
completed. A total of thirty (30) soil borings were drilled from August 14 through 30, 2017 at the
approximate locations as indicated on the enclosed Boring Location Diagrams included with this
report. The thirty (30) preliminary soil borings were advanced to depths of approximately 25 to 40
feet below existing site grades across the proposed development property to obtain information on
existing subsurface conditions. Individual boring logs and site diagrams indicating the approximate
boring locations are included with this report.
The 800-acre development property is located southeast of Larimer County Road (LCR) 52 and LCR
50E and generally extends east to the existing Budweiser property and Interstate 25 and south to
LCR 50 and Canal Access Road in Fort Collins, Colorado. The property will be developed for
residential, commercial, and industrial use, including utility and interior roadway infrastructure.
Foundation loads for the proposed residential, commercial, and industrial structures are anticipated
to be light to moderate with continuous wall loads less than 4 kips per lineal foot and individual
column loads less than 250 kips. Floor loads are expected to be light. Those structures are expected
to include slab-on-grade, below grade construction such as crawl spaces, garden-level and/or full-
depth basements where applicable. We anticipate maximum cuts and fills on the order of 5 feet (+/-)
will be completed to develop the site grades. Overall site development will include construction of
interior roadway designed in general accordance with the Larimer County Urban Area Street
Standards (LCUASS) Pavement Design Criteria.
The purpose of this report is to describe the subsurface conditions encountered in the preliminary
borings, analyze and evaluate the test data and provide preliminary geotechnical recommendations
concerning site development including foundations, floor slabs, pavement sections and the
possibility for an area underdrain system to support basement construction.
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EXPLORATION AND TESTING PROCEDURES
The boring locations were established in the field by a representative of Earth Engineering
Consultants, LLC (EEC) by pacing and estimating angles from identifiable site features. Those
locations should be considered accurate only to the degree implied by the methods used to make the
field measurements. Photographs of the site taken at the time of drilling are provided with this
report.
The borings were performed using either a truck-mounted CME-55 drill rig equipped with a
hydraulic head employed in drilling and sampling operations. The boreholes were advanced using
4-inch nominal diameter continuous flight augers. Samples of the subsurface materials encountered
were obtained using split-barrel and California barrel sampling procedures in general accordance
with ASTM Specifications D1586 and D3550, respectively.
In the split-barrel and California barrel sampling procedures, standard sampling spoons are driven
into the ground by means of a 140-pound hammer falling a distance of 30 inches. The number of
blows required to advance the samplers is recorded and is used to estimate the in-situ relative density
of cohesionless soils and, to a lesser degree of accuracy, the consistency of cohesive soils and
hardness of weathered bedrock. In the California barrel sampling procedure, relatively undisturbed
samples are obtained in brass liners. All samples obtained in the field were sealed and returned to the
laboratory for further examination, classification and testing.
Laboratory moisture content tests were performed on each of the recovered samples. In addition,
selected samples were tested for fines content and plasticity by washed sieve analysis and Atterberg
limits tests. Swell/consolidation tests were completed on selected samples to evaluate the subgrade
materials’ tendency to change volume with variation in moisture content and load. Several samples
were obtained from borings for Hveem Stabilometer/R-Value (ASTM Specification D2844) testing
analyses to determine the in-situ subgrade strength characteristics. The quantity of water soluble
sulfates was determined on select samples to evaluate the risk of sulfate attack on site concrete.
Results of the outlined tests are indicated on the attached boring logs and summary sheets.
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As a part of the testing program, all samples were examined in the laboratory and classified in
general accordance with the attached General Notes and the Unified Soil Classification System,
based on the sample's texture and plasticity. The estimated group symbol for the Unified Soil
Classification System is shown on the boring logs and a brief description of that classification
system is included with this report. Classification of the bedrock was based on visual and tactual
observation of disturbed samples and auger cuttings. Coring and/or petrographic analysis may reveal
other rock types.
SITE AND SUBSURFACE CONDITIONS
The 800-acre development is located southeast of LCR 52 and LCR 50E in Fort Collins, Colorado.
The project site is generally undeveloped farmland with a few existing structures scattered
throughout. Surface water drainage across the site is generally to the south and to the east.
Estimated relief across the site from northwest to southeast is approximately 25 to 30 feet (±).
An EEC field engineer was on-site during drilling to direct the drilling activities and evaluate the
subsurface materials encountered. Field descriptions of the materials encountered were based on
visual and tactual observation of disturbed samples and auger cuttings. The boring logs included
with this report may contain modifications to the field logs based on results of laboratory testing and
engineering evaluation. Based on results of field and laboratory evaluation, subsurface conditions
can be generalized as follows.
Sparse vegetation and topsoil were encountered at the surface of each boring. The topsoil and/or
agricultural/vegetation layers were underlain by brown lean clay with varying amounts of sand
subsoils. Some zones of clayey sand were encountered in a few of the borings. The lean clay
subsoils were generally soft to very stiff, exhibited low to moderate plasticity and low to high swell
potential at current moisture and density conditions. The lean clay subsoils were underlain by
sand/gravel with varying amounts of silt soils at depths of approximately 7 to 39 feet. The
sands/gravels extended to the depths explored, approximately 25 to 40 feet, or to the underlying
bedrock formation in a few borings.
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The overburden soils were underlain by bedrock consisting of interbedded layers of sandstone,
siltstone, and claystone. The sandstone/siltstone/claystone bedrock was encountered in seven (7) of
the thirty (30) preliminary test borings at depths ranging from approximately 24 to 29 feet below
existing site grades, was highly weathered and became more competent/harder with increased depth.
The bedrock formation exhibited moderate swell potential at current moisture and density
conditions. As presented herein, bedrock was encountered in borings B-4, B-6, B-19, B-20, B-24, B-
25 and B-30.
The stratification boundaries indicated on the boring logs represent the approximate locations of
changes in soil and rock types; in-situ, the transition of materials may be gradual and indistinct.
GROUNDWATER OBSERVATIONS
Observations were made while drilling and after the completion of drilling to detect the presence and
level of groundwater. Groundwater was observed in the majority of the preliminary test borings at
depths ranging from approximately 2 to 31 feet below existing site grades. Temporary field slotted
piezometers were installed in fifteen (15) of the test borings at the time of drilling and subsequent
groundwater measurements were taken on August 28 and September 8. At the time of the
subsequent measurements, groundwater was observed at depths ranging from approximately 4½ to
33 feet and 6½ to 36½ feet, respectively. As presented herein, groundwater was not encountered to
maximum depths of exploration in borings B-2 and B-8. The remaining fifteen (15) borings without
piezometers were backfilled upon completion, and therefore subsequent groundwater measurements
were not made. A diagram outlining approximate areas with relatively shallow groundwater
measurements has been provided along with a groundwater contour map, (please refer to Figure Nos.
2 and 3), included in the appendix of this report. Groundwater measurements provided with this
report are indicative of groundwater levels at the locations and at the time the borings/groundwater
measurements were completed. In general, the groundwater piezometric flow is in the south
direction.
Perched and/or trapped water may be encountered in more permeable zones in the subgrade soils at
times throughout the year. Perched water is commonly encountered in soils immediately overlying
less permeable bedrock materials. Fluctuations in ground water levels and in the location and
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amount of perched water may occur over time depending on variations in hydrologic conditions,
irrigation activities on surrounding properties and other conditions not apparent at the time of this
report.
SOIL/GEOLOGIC REVIEW
The site geology presented in this report is based upon review of listed literature and maps, and
previous experience with similar geologic conditions in this area. The locations of geologic features
are approximate and should be considered accurate only to the degree implied by the methods used
to identify those features.
The surficial soils at the project site are described as eolian deposits (Pleistocene and Holocene) and
valley fill deposits (Pleistocene and Holocene), the eolian deposits are described as fine grained
sand, silt and clay and the valley fill deposits are described as arkosic gravel and sand deposit. The
upper soil is overlying the Pierre Shale Formation (Upper Cretaceous), described as a claystone
shale containing beds of sandstone and siltstone, as illustrated on the Geologic Map of the Lower
Cache La Poudre River Basin, North-Central Colorado by Lloyd A. Hershey and Paul A. Schneider,
Jr., 1972.
No seismic faults are reported within approximately twenty-five miles of the site. The Colorado
Geological Survey (CGS) reports potentially active faults at least 25 miles west-southwest of the
project site. The Fort Collins/Wellington Anticline, a small fold set, is described in the literature
immediately west of the project location. The axis of the fold is described as trending north-
northwest with asymmetrical limbs. The bedrock strata nearest to the axis is described as dipping at
approximately 10 to 15 degrees east-northeast. The dip of the bedrock strata lessens with increased
distance from the axis.
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ANALYSIS AND RECOMMENDATIONS
Swell/Consolidation Test Results
Swell/consolidation testing is performed to evaluate the swell or collapse potential of soil or bedrock to
assist in determining/evaluating foundation, floor slab and/or pavement design criteria. In the
swell/consolidation test, relatively undisturbed samples obtained directly from the California barrel
sampler are placed in a laboratory apparatus and inundated with water under a pre-established load.
The swell-index is the resulting amount of swell or collapse under the initial loading condition
expressed as a percent of the sample’s initial thickness. After the inundation period, additional
incremental loads are applied to evaluate swell pressure and/or consolidation.
As a part of our laboratory testing, we conducted twenty-nine (29) swell/consolidation tests on
samples of the overburden cohesive subsoils and underlying claystone bedrock. The swell index
values for the samples analyzed revealed low to high swell characteristics of approximately (+) 0.0
to (+) 7.6% for the overburden lean clays and approximately (+) 3.7% for the bedrock when
inundated with water and pre-loaded at 150 psf and 500 psf. Results of the laboratory swell tests are
indicated on the attached boring logs and the enclosed summary sheets. A diagram outlining
approximate areas with swell indices higher than 3% has been included with this report as an
indication of locations where swell mitigation should be considered, (please refer to Figure No. 4) in
the appendix of this report
The Colorado Association of Geotechnical Engineers (CAGE) uses the following information to
provide uniformity in terminology between geotechnical engineers to provide a relative correlation risk
performance to measured swell. “The representative percent swell values are not necessarily measured
values; rather, they are a judgment of the swell of the soil and/or bedrock profile likely to influence
slab performance.” Geotechnical engineers use this information to also evaluate the swell potential
risks for foundation performance based on the risk categories.
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TABLE I: Recommended Representative Swell Potential Descriptions and Corresponding
Slab Performance Risk Categories
Slab Performance Risk Category Representative Percent Swell
(500 psf Surcharge)
Representative Percent Swell
(1000 psf Surcharge)
Low 0 to < 3 0 < 2
Moderate 3 to < 5 2 to < 4
High 5 to < 8 4 to < 6
Very High > 8 > 6
Based on the laboratory test results, the samples of overburden subsoils and the underlying bedrock
formation analyzed ranged from low to high risk.
General Considerations
If lower level construction or full-depth basements are being considered for the site, we would
suggest that the lower level subgrade(s) be placed a minimum of 3 feet above the maximum
anticipated rise in groundwater levels, or a combination exterior and interior perimeter drainage
system(s) be installed in areas with shallow groundwater, as shown on the attached diagram. Also,
consideration could be given to 1) either designing and installing an area underdrain system to lower
the groundwater levels provided a gravity discharge point can be established. If a gravity
outlet/system cannot be designed another consideration would be to design and install a mechanical
sump pump system to discharge the collected groundwater within the underdrain system, or 2)
elevate/raise the site grades to establish the minimum suggested 3-foot separation to the maximum
anticipated rise in groundwater.
Foundations for buildings that are constructed slab-on-grade (no basement) should also be placed a
minimum of 3 feet above the maximum anticipated rise in groundwater levels. During our
subsurface exploration groundwater was found at depths as shallow as 2 feet in some areas, as
shown on the attached diagram. Consideration should be given to the implementing a drainage or
grading plan, as listed above, in these areas.
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Site Preparation
All existing vegetation and/or topsoil should be removed from beneath site fills, roadways or
building subgrade areas. Care should be taken to ensure that the foundations associated with any of
the existing structures in the new building areas are completely removed. Stripping depths should be
expected to vary, depending, in part, on past agricultural activities. In addition, any soft/loose native
soils or any existing fill materials without documentation of controlled fill placement should be
removed from improvement and/or new fill areas.
After stripping and completing all cuts, any over excavation, and prior to placement of any fill, floor
slabs or pavements, we recommend the exposed soils be scarified to a minimum depth of 9 inches,
adjusted in moisture content and compacted to at least 95% of the material's maximum dry density
as determined in accordance with ASTM Specification D698, the standard Proctor procedure. The
moisture content of the scarified materials should be adjusted to be within a range of 2% of
standard Proctor optimum moisture at the time of compaction.
In general, fill materials required to develop the building areas or site pavement subgrades should
consist of approved, low-volume change materials which are free from organic matter and debris.
The near surface lean clay soils with low swell potential and/or the sand/gravel soils could be used
as fill in these areas. The claystone bedrock should not be used for fill in site improvement areas.
We recommend the fill soils be placed in loose lifts not to exceed 9 inches thick, adjusted in
moisture content and compacted to at least 95% of the material’s maximum dry density as
determined in accordance with the standard Proctor procedure. The moisture content of
predominately clay soils should be adjusted to be within the range of ± 2% of optimum moisture
content at the time of placement. Granular soil should be adjusted to a workable moisture content.
Specific explorations should be completed for each building/individual residential lot to develop
recommendations specific to the proposed structure and owner/builder and for specific pavement
sections.
Care should be taken after preparation of the subgrades to avoid disturbing the subgrade materials.
Positive drainage should be developed away from structures and across and away from pavement
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edges to avoid wetting of subgrade materials. Subgrade materials allowed to become wetted
subsequent to construction of the residences and/or pavements can result in unacceptable
performance of those improvements.
Areas of greater fills overlying areas with soft/compressible subsoils, especially within the deeper
utility alignments, may experience settlement due to the soft/compressible subsoils below and within
the zone of placed fill materials. Settlement on the order of 1-inch or more per each 10 feet of fill
depth would be estimated. The rate of settlement will be dependent on the type of fill material
placed and construction methods. Granular soils will consolidate essentially immediately upon
placement of overlying loads. Cohesive soils will consolidate at a slower rate. Preloading and/or
surcharging the fill areas could be considered to induce additional settlement in these areas prior to
construction of improvements in or on the fills. Unless positive steps are taken to pre-consolidate
the fill materials and/or underlying soft subgrades, special care will be needed for construction of
improvements supported on or within these areas.
Foundation Systems – General Considerations
The cohesive subsoils will require particular attention in the design and construction to reduce the
amount of movement due to moderate to high swell potential and in-situ soft/compressible
characteristics in some areas. Groundwater was also encountered at relatively shallow depths in a few
areas which will require special attention in the overall design and construction of the project. As
previously mentioned consideration could be given to the installation of an area underdrain system.
Conventional type spread footings bearing on native subsoils or engineered controlled fill material
were evaluated for use on the site; however final subsurface explorations should be performed after
building footprints and elevations have been better defined and actual design loads determined.
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Preliminary Spread Footing Foundation Recommendations
We anticipate use of conventional footing foundations could be considered for lightly to moderately
loaded structures at this site. We expect footing foundations would be supported either on the native
soils or on newly placed and compacted fills. A few soft zones were observed in the near surface
clay soils; therefore, care should be taken to see that foundations are not supported directly on soft
materials. Mitigation for swelling of the lean clay should be expected in the general areas shown on
the attached diagram and mitigation for soft subgrade soils should be expected in a few areas.
In areas where the cohesive subsoils exhibited elevated moisture contents near and/or encroaching
the groundwater levels and/or where relatively low SPT N-Blows/ft were recorded, indicating “soft
soils” we would expect these soft zones could require particular attention/ground modification
procedures to develop increased support capacity characteristics. We expect enhancing/stiffening of
the subgrade/bearing soils could be accomplished by incorporating into the soft/compressible
subsoils a layer granular rock (i.e., 1-½ inches minus crushed concrete aggregate) into the top 12 to
18 inches (+/-) of the subgrades as an initial means and method. Depending on the proximity to
groundwater and/or severity of the soft soils, overexcavation and backfill with an approved imported
structural fill material placed and compacted as outlined herein could also be considered.
We suggest an over excavation and backfill procedure be considered in areas with moderate to high
swell potential and/or soft/compressible subsoils to reduce the potential for post construction
movement. Over excavation depths should be expected to vary across the site, based on
builder/owner requirements and lot-specific conditions. After completing a site-specific/lot-specific
geotechnical exploration study, a thorough “open-hole/foundation excavation” observation should be
performed prior to foundation formwork placement to determine the extent of any over excavation
and replacement procedure. Deeper over excavation depths may be necessary depending upon the
observed subsoils at the time of the foundation excavation observation. In general, the over
excavation area would extend 8 inches laterally beyond the building perimeter for every 12 inches of
overexcavation depth. We anticipate backfill materials would consist of an approved imported
granular structural fill material such as a CDOT Class 7 aggregate base course (ABC) either native
and/or recycled concrete oriented and/or equivalent, which is placed in uniforms lifts, properly
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adjusted in moisture content and mechanically compacted to at least 95% of the material’s Standard
Proctor Density (ASTM D698) results.
For design of footing foundations bearing on approved native subsoils, (i.e., the native subsoils in
which expansive and/or soft/compressible conditions are not encountered), or on properly placed and
compacted fill materials as outlined above, maximum net allowable total load soil bearing pressures
on the order of 1,500 to 2,500 psf could be considered depending upon the specific backfill material
used. Footing foundations should maintain separation above maximum anticipated rise in
groundwater elevation of at least 3 feet as indicated earlier. The net bearing pressure refers to the
pressure at foundation bearing level in excess of the minimum surrounding overburden pressure.
Total load would include full dead and live loads.
Exterior foundations and foundations in unheated areas are typically located at least 30 inches below
adjacent exterior grade to provide frost protection. Formed continuous footings would have
minimum widths of 12 to 16 inches and isolated column foundations would have a minimum width
of 24 to 30 inches. Trenched foundations could probably be used in the near surface soils. If used,
trenched foundations would have a minimum width of 12 inches and formed continuous foundations
a minimum width of 8 inches.
Care should be taken to avoid placement of structures partly on native soils and partly on newly
placed fill materials to avoid differential settlement. In these areas, mitigation approaches could
include surcharging of the fill materials, overexcavation of the native soils or use of alternative
foundations, such as drilled piers, along with structural floors. Mitigation approaches may vary
between structures depending, in part, on the extent and depth of new fill placement. Specific
approaches could be established at the time of exploration for the individual structures. Care should
be taken on the site to fully document the horizontal and vertical extent of fill placement on the site,
including benching the fill into native slopes.
Preliminary Floor Slab/Exterior Flatwork Subgrades
We recommend all existing vegetation/topsoil be removed from beneath the floor slab and exterior
flatwork areas as outlined in the section titled Site Preparation. Due to the moderate to high swell
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potential in areas across the site, as shown on the attached diagram, an over excavation procedure
should be considered in those areas. The over excavation should be expected to extend to depths of
2 to 3 feet, and should be done in accordance with the recommendations for foundation over
excavations. After stripping and completing all cuts and any over excavation, and prior to placement
of any flatwork concrete or fill, the exposed subgrades should be scarified, adjusted in moisture
content and compacted. If the subgrades become dry and desiccated prior to floor slab construction,
it may be necessary to rework the subgrades prior to floor slab placement.
Fill soils required to develop the floor slab subgrades should consist of approved, low-volume
change materials which are free from organic matter and debris. Those fill materials should be
placed as previously described in the section Site Preparation and surcharged/preloaded and/or
monitored as necessary to limit total and differential movement after construction of overlying
improvements.
Preliminary Basement Design and Construction
Groundwater was encountered across the site within the preliminary soil borings at approximate
depths of 2 to 36½ feet below existing site grades. If lower level construction for either garden-level
or full-depth basements is being considered for the site, we would suggest that the lower level
subgrade(s) be placed a minimum of 3 feet above maximum anticipated rise in groundwater levels,
or a combination exterior and interior perimeter drainage system(s) be installed in areas with shallow
groundwater as indicated on the attached diagram.
Consideration could be given to 1) either designing and installing an area underdrain system to
lower the groundwater levels provided a gravity discharge point can be established. If a gravity
outlet/system cannot be designed another consideration would be to design and install a mechanical
sump pump system to discharge the collected groundwater within the underdrain system, or 2)
elevate/raise the site grades to establish the minimum required 3-foot separation to the maximum
anticipated rise in groundwater EEC is available to assist in the underdrain design if requested.
For each individual building with a garden level or full-depth basement located less than 3 feet
above maximum groundwater levels, the dewatering system should, at a minimum, include an under-
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slab gravel drainage layer sloped to an interior perimeter drainage system. Considerations for the
preliminary design of the combination exterior and interior perimeter drainage system are as follows:
The under-slab drainage system should consist of a properly sized perforated pipe, embedded in
free-draining gravel, placed in a trench at least 12 inches in width. The trench should be inset from
the interior edge of the nearest foundation a minimum of 12 inches. In addition, the trench should be
located such that an imaginary line extending downward at a 45-degree angle from the foundation
does not intersect the nearest edge of the trench. Gravel should extend a minimum of 3 inches
beneath the bottom of the pipe. The underslab drainage system should be sloped at a minimum 1/8
inch per foot to a suitable outlet, such as a sump and pump system.
The underslab drainage layer should consist of a minimum 6-inch thickness of free-draining gravel
meeting the specifications of ASTM C33, Size No. 57 or 67 or equivalent. Cross-connecting
drainage pipes should be provided beneath the slab at minimum 15-foot intervals, and should
discharge to the perimeter drainage system.
Sizing of drainage pipe will be dependent upon groundwater flow into the dewatering system.
Groundwater flow rates will fluctuate with permeability of the soils to be dewatered and the depth to
which groundwater may rise in the future. Pump tests to determine groundwater flow rates are
recommended in order to properly design the system. For preliminary design purposes, the drainage
pipe, sump and pump system should be sized for a projected flow of 0.5 x 10-3 cubic feet per second
(cfs) per lineal foot of drainage pipe. Additional recommendations can be provided upon request
and should be presented in final subsurface exploration reports for each residential/commercial lot.
The exterior drainage system should be constructed around the exterior perimeter of the lower
level/below grade foundation system, and sloped at a minimum 1/8 inch per foot to a suitable outlet,
such as a sump and pump system.
The exterior drainage system should consist of a properly sized perforated pipe, embedded in free-
draining gravel, placed in a trench at least 12 inches in width. Gravel should extend a minimum of 3
inches beneath the bottom of the pipe, and at least 2 feet above the bottom of the foundation wall.
The system should be underlain with a polyethylene moisture barrier, sealed to the foundation walls,
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and extended at least to the edge of the backfill zone. The gravel should be covered with drainage
fabric prior to placement of foundation backfill.
Preliminary Pavement Subgrades
The average swell index for the preliminary test borings is above the LCUASS pavement design
standard maximum value of 2%. Therefore, a swell mitigation plan consisting of a 2 to 3 foot over
excavation and replacement concept or fly ash treatment of the subgrades should be considered
within roadway alignments in areas with swell indices above 2%.
All existing vegetation and/or topsoil and any soft or loose materials should be removed from
pavement areas. After stripping, completing all cuts, and any over excavation, and prior to
placement of any fill or pavements, we recommend the exposed soils be scarified to a minimum
depth of 9 inches, adjusted in moisture content and compacted to at least 95% of the material's
maximum dry density as determined in accordance with ASTM Specification D698, the standard
Proctor procedure. The moisture content of the scarified soils should be adjusted to be within the
range of 2% of standard Proctor optimum moisture.
Fill materials required to develop the pavement subgrades should consist of approved, low-volume
change materials, free from organic matter and debris. The near surface lean clay and/or clayey sand
soils could be used for fill in these areas. We recommend those fill soils be placed in loose lifts not
to exceed 9 inches thick, adjusted in moisture content and compacted to at least 95% of the
material's standard Proctor maximum dry density. Settlement in the fill areas should be expected as
previously outlined with possible mitigation including surcharging or preloading.
After completion of the pavement subgrades, care should be taken to prevent disturbance of those
materials prior to placement of the overlying pavements. Soils which are disturbed by construction
activities should be reworked in-place or, if necessary, removed and replaced prior to placement of
overlying fill or pavements.
Depending on final site grading and/or weather conditions at the time of pavement construction,
stabilization of a portion of the site pavement subgrades may be required to develop suitable
Earth Engineering Consultants, LLC
EEC Project No. 1172058
October 2, 2017
Page 15
pavement subgrades. The site clayey soils could be subject to instability at higher moisture contents.
Stabilization could also be considered as part of the pavement design, although prior to finalizing
those sections, a stabilization mix design would be required.
Preliminary Site Pavements
Pavement sections are based on traffic volumes and subgrade strength characteristics. Based on the
results of our laboratory testing, an R-value of 14 would be appropriate for design of the pavements
supported on the subgrade soils. Suggested preliminary pavement sections for the local residential
and minor collector roadways are provided below in Table II. Thicker pavement sections may be
required for roadways classified as major collectors. A final pavement design thickness evaluation
will be determined when a pavement design exploration is completed (after subgrades are developed
to ± 6 inches of design and wet utilities installed in the roadways). The projected traffic may vary
from the traffic assumed from the roadway classification based on a site-specific traffic study.
TABLE II – PRELIMINARY PAVEMENT SECTIONS
Local Residential
Roadways
Minor Collectors
Roadways
EDLA – assume local residential roadways
Reliability
Resilient Modulus
PSI Loss – (Initial 4.5, Terminal 2.0 and 2.5 respectively)
10
75%
4060
2.5
25
85%
4060
2.2
Design Structure Number 2.49 3.01
Composite Section without Fly Ash – Alternative A
Hot Mix Asphalt (HMA) Grading S (75) PG 58-28
Aggregate Base Course ABC – CDOT Class 5 or 6
Design Structure Number
4ʺ
7ʺ
(2.53)
5ʺ
8ʺ
(3.08)
Composite Section with Fly Ash – Alternative B
Hot Mix Asphalt (HMA) Grading S (75) PG 58-28
Aggregate Base Course ABC – CDOT Class 5 or 6
Fly Ash Treated Subgrade
Design Structure Number
4ʺ
6 ʺ
12″
(3.02)
4ʺ
6ʺ
12ʺ
(3.02)
PCC (Non-reinforced) – placed on an approved subgrade 5-1/2″ 7″
Earth Engineering Consultants, LLC
EEC Project No. 1172058
October 2, 2017
Page 16
Asphalt surfacing should consist of grading S-75 or SX-75 hot bituminous pavement with PG 64-22
or PG 58-28 binder in accordance with Town of Windsor requirements. Aggregate base should be
consistent with CDOT requirements for Class 5 or Class 6 aggregate base. A suggested specification
for stabilization of the subgrades with class C fly ash is included with this report.
As previously mentioned a final subgrade investigation and pavement design should be performed in
general accordance with the LCUASS Pavement Design Criteria prior to placement of any pavement
sections, to determine the required pavement section after design configurations, roadway utilities
have been installed and roadway have been prepared to “rough” subgrade elevations have been
completed.
Detention Ponds
It is expected that various detention ponds may be designed/constructed throughout the site.
Detention ponds are generally designed to collect surface water and/or roof runoff for the project as
a temporary “holding basin” over time and eventually discharge the water into the storm sewer
drainage system. Depending upon the final design depth of the detention ponds, and due to the
potential for groundwater fluctuations to become elevated and enter the ponds, as well as the
permeability characteristics of the on-site cohesive materials, consideration could be given to lining
the pond bottom of the ponds with the on-site clay soils and/or approved imported cohesive soils, to
prevent groundwater intrusion from entering the pond. Sand and gravel generally exhibit high soil
percolation/permeability characteristics allowing for an increase in infiltration, not conducive for
containing water. In general, the bottom of any unlined detention pond should be at least 3-feet
above the maximum anticipate rise in groundwater. After site configurations and detention pond
elevations have been more defined we can provide additional geotechnical exploration activities,
laboratory testing and lining recommendations upon request.
Underground Utility Systems
All piping should be adequately bedded for proper load distribution. It is suggested that clean, graded
gravel compacted to 70 percent of Relative Density ASTM D4253 be used as bedding. Where utilities
are excavated below groundwater, temporary dewatering will be required during excavation, pipe
Earth Engineering Consultants, LLC
EEC Project No. 1172058
October 2, 2017
Page 17
placement and backfilling operations for proper construction. Utility trenches should be excavated on
safe and stable slopes in accordance with OSHA regulations as further discussed herein. Backfill
should consist of the on-site soils or approved imported materials. The pipe backfill should be
compacted to a minimum of 95 percent of Standard Proctor Density ASTM D698.
Water Soluble Sulfates – (SO4)
The water soluble sulfate (SO4) testing of the on-site subgrade material collected during our
subsurface exploration is provided in the following table below. Based on the reported sulfate
contents test results, this report includes a recommendation for the CLASS or TYPE of cement for
use for contact in association with the on-site subsoils.
TABLE III - Water Soluble Sulfate Test Results
Sample Location Description
Soluble Sulfate Content
(mg/kg)
Soluble Sulfate Content
(%)
B-1, S-1, at 2’
Clayey Sand/Sandy Lean
Clay (SC/CL)
5,600 0.56
B-5, S-1, at 2’ Lean Clay with Sand (CL) 880 0.09
B-5, S-3, at 9’ Lean Clay with Sand (CL) 880 0.09
B-11, S-1, at 4’ Sandy Lean Clay (CL) 14,600 1.46
B-18, S-1, at 4’ Lean Clay with Sand (CL) 14,800 1.48
B-21, S-1, at 4’ Lean Clay with Sand (CL) 12,200 1.22
B-25, S-2, at 4’ Sandy Lean Clay (CL) 13,200 1.32
B-29, S-1, at 4’ Lean Clay with Sand (CL) 7,930 0.79
Based on the results as presented in Table VI above, ACI 318, Section 4.2 indicates the site
overburden soils have a severe risk of sulfate attack on Portland cement concrete. Therefore Class 2
or Type V cement should be used for concrete on and below site grade within the on-site overburden
soils. Foundation concrete should be designed in accordance with the provisions of the ACI Design
Manual, Section 318, Chapter 4. These results are being compared to the following table.
Earth Engineering Consultants, LLC
EEC Project No. 1172058
October 2, 2017
Page 18
TABLE IV Requirements to Protect Against Damage to Concrete by Sulfate Attack from External Sources of Sulfate
Severity of Sulfate
exposure
Water-soluble sulfate (SO4)
in dry soil, percent
Water-cement ratio,
maximum
Cementitious material
Requirements
Class 0 0.00 to 0.10% 0.45 Class 0
Class 1 0.11 to 0.20% 0.45 Class 1
Class 2 0.21 to 2.00% 0.45 Class 2
Class 3 2.01 of greater 0.45 Class 3
Other Considerations and Recommendations
Groundwater was observed at depths of approximately 2 to 36½ feet below present site grades.
Excavations extending to the wetter soils could create difficulties for backfilling of the sewer
trenches with drying of the subgrade soils required to use those materials as backfill. In general, the
subgrade soils could be used as overlot fill and backfill soils although care will be necessary to
maintain sufficient moisture to reduce potential for post-construction movement.
Although evidence of fills or underground facilities such as septic tanks, cesspools, basements, and
utilities was not observed during the site reconnaissance, such features could be encountered during
construction. If unexpected fills or underground facilities are encountered, such features should be
removed and the excavation thoroughly cleaned prior to backfill placement and/or construction.
Excavations into the on-site soils will encounter a variety of conditions. Excavations into the clays
and bedrock can be expected to stand on relatively steep temporary slopes during construction;
however, caving soils may also be encountered especially in close proximity to the groundwater
table, as well as in the sand/gravel zones below the overlying clay soils. Groundwater seepage
should also be anticipated for utility excavations. Pumping from sumps may be utilized to control
water within the excavations. Well points may be required for significant groundwater flow, or
where excavations penetrate groundwater to a significant depth. The individual contractor(s) should
be made responsible for designing and constructing stable, temporary excavations as required to
maintain stability of both the excavation sides and bottom. All excavations should be sloped or
shored in the interest of safety following local and federal regulations, including current OSHA
excavation and trench safety standards.
Earth Engineering Consultants, LLC
EEC Project No. 1172058
October 2, 2017
Page 19
Positive drainage should be developed away from the structures and pavement areas with a
minimum slope of 1 inch per foot for the first 10 feet away from the improvements in landscape
areas. Care should be taken in planning of landscaping (if required) adjacent to the buildings to
avoid features which would pond water adjacent to the foundations or stemwalls. Placement of
plants which require irrigation systems or could result in fluctuations of the moisture content of the
subgrade material should be avoided adjacent to site improvements. Irrigation systems should not be
placed within 5 feet of the perimeter of the buildings and parking areas. Spray heads should be
designed not to spray water on or immediately adjacent to the structures or site pavements. Roof
drains should be designed to discharge at least 5 feet away from the structures and away from the
pavement areas.
GENERAL COMMENTS
The analysis and recommendations presented in this report are based upon the data obtained from
the soil borings performed at the indicated locations and from any other information discussed in this
report. This report does not reflect any variations which may occur between borings or across the
site. The nature and extent of such variations may not become evident until construction. If
variations appear evident, it will be necessary to re-evaluate the recommendations of this report.
Site specific explorations will be necessary for the proposed site buildings.
It is recommended that the geotechnical engineer be retained to review the plans and specifications
so that comments can be made regarding the interpretation and implementation of our geotechnical
recommendations in the design and specifications. It is further recommended that the geotechnical
engineer be retained for testing and observations during earthwork and foundation construction
phases to help determine that the design requirements are fulfilled.
This report has been prepared for the exclusive use of Chase Merritt for specific application to the
project discussed and has been prepared in accordance with generally accepted geotechnical
engineering practices. No warranty, express or implied, is made. In the event that any changes in
the nature, design or location of the project as outlined in this report are planned, the conclusions
and recommendations contained in this report shall not be considered valid unless the changes are
Earth Engineering Consultants, LLC
EEC Project No. 1172058
October 2, 2017
Page 20
reviewed and the conclusions of this report modified or verified in writing by the geotechnical
engineer.
Earth Engineering Consultants, LLC
DRILLING AND EXPLORATION
DRILLING & SAMPLING SYMBOLS:
SS: Split Spoon ‐ 13/8" I.D., 2" O.D., unless otherwise noted PS: Piston Sample
ST: Thin‐Walled Tube ‐ 2" O.D., unless otherwise noted WS: Wash Sample
R: Ring Barrel Sampler ‐ 2.42" I.D., 3" O.D. unless otherwise noted
PA: Power Auger FT: Fish Tail Bit
HA: Hand Auger RB: Rock Bit
DB: Diamond Bit = 4", N, B BS: Bulk Sample
AS: Auger Sample PM: Pressure Meter
HS: Hollow Stem Auger WB: Wash Bore
Standard "N" Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2‐inch O.D. split spoon, except where noted.
WATER LEVEL MEASUREMENT SYMBOLS:
WL : Water Level WS : While Sampling
WCI: Wet Cave in WD : While Drilling
DCI: Dry Cave in BCR: Before Casing Removal
AB : After Boring ACR: After Casting Removal
Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils, the indicated
levels may reflect the location of ground water. In low permeability soils, the accurate determination of ground water levels is not
possible with only short term observations.
DESCRIPTIVE SOIL CLASSIFICATION
Soil Classification is based on the Unified Soil Classification
system and the ASTM Designations D‐2488. Coarse Grained
Soils have move than 50% of their dry weight retained on a
#200 sieve; they are described as: boulders, cobbles, gravel or
sand. Fine Grained Soils have less than 50% of their dry weight
retained on a #200 sieve; they are described as : clays, if they
are plastic, and silts if they are slightly plastic or non‐plastic.
Major constituents may be added as modifiers and minor
constituents may be added according to the relative
proportions based on grain size. In addition to gradation,
coarse grained soils are defined on the basis of their relative in‐
place density and fine grained soils on the basis of their
consistency. Example: Lean clay with sand, trace gravel, stiff
(CL); silty sand, trace gravel, medium dense (SM).
CONSISTENCY OF FINE‐GRAINED SOILS
Unconfined Compressive
Strength, Qu, psf Consistency
< 500 Very Soft
500 ‐ 1,000 Soft
1,001 ‐ 2,000 Medium
2,001 ‐ 4,000 Stiff
4,001 ‐ 8,000 Very Stiff
8,001 ‐ 16,000 Very Hard
RELATIVE DENSITY OF COARSE‐GRAINED SOILS:
N‐Blows/ft Relative Density
0‐3 Very Loose
4‐9 Loose
10‐29 Medium Dense
30‐49 Dense
50‐80 Very Dense
80 + Extremely Dense
PHYSICAL PROPERTIES OF BEDROCK
DEGREE OF WEATHERING:
Slight Slight decomposition of parent material on
joints. May be color change.
Moderate Some decomposition and color change
throughout.
High Rock highly decomposed, may be extremely
broken.
Group
Symbol
Group Name
Cu≥4 and 1<Cc≤3
E
GW Well-graded gravel
F
Cu<4 and/or 1>Cc>3
E
GP Poorly-graded gravel
F
Fines classify as ML or MH GM Silty gravel
G,H
Fines Classify as CL or CH GC Clayey Gravel
F,G,H
Cu≥6 and 1<Cc≤3
E
SW Well-graded sand
I
Cu<6 and/or 1>Cc>3
E
SP Poorly-graded sand
I
Fines classify as ML or MH SM Silty sand
G,H,I
Fines classify as CL or CH SC Clayey sand
G,H,I
inorganic PI>7 and plots on or above "A" Line CL Lean clay
K,L,M
PI<4 or plots below "A" Line ML Silt
K,L,M
organic Liquid Limit - oven dried Organic clay
K,L,M,N
Liquid Limit - not dried Organic silt
K,L,M,O
inorganic PI plots on or above "A" Line CH Fat clay
K,L,M
PI plots below "A" Line MH Elastic Silt
K,L,M
organic Liquid Limit - oven dried Organic clay
K,L,M,P
Liquid Limit - not dried Organic silt
K,L,M,O
Highly organic soils PT Peat
(D30)2
D10 x D60
GW-GM well graded gravel with silt NPI≥4 and plots on or above "A" line.
GW-GC well-graded gravel with clay OPI≤4 or plots below "A" line.
GP-GM poorly-graded gravel with silt PPI plots on or above "A" line.
GP-GC poorly-graded gravel with clay QPI plots below "A" line.
SW-SM well-graded sand with silt
SW-SC well-graded sand with clay
SP-SM poorly graded sand with silt
SP-SC poorly graded sand with clay
Earth Engineering Consultants, LLC
IIf soil contains >15% gravel, add "with gravel" to
group name
JIf Atterberg limits plots shaded area, soil is a CL-
ML, Silty clay
Unified Soil Classification System
800 ACRES MIXED USE PROPERTY
FORT COLLINS, COLORADO
EEC PROJECT NO. 1172058
AUGUST 2017
800 ACRES MIXED USE PROPERTY
FORT COLLINS, COLORADO
EEC PROJECT NO. 1172058
AUGUST 2017
B-2
B-3
B-4
B-8
B-12
B-20
B-16 B-18 B-19
B-15
B-13
B-5
B-6
B-7
B-30
B-28 B-27
B-29 B-23
B-24
B-11
B-17
1 2
4
3
B-21 B-22
B-26
B-25
B-1
B-14
B-9
B-10
Figure 1: Boring Location Diagram
800-Acre Mixed Use Development
Fort Collins, Colorado
EEC Project Number: 1172058 Date: July 2017
EARTH ENGINEERING CONSULTANTS, LLC
Approximate Boring
Locations
1
Legend
Site Photos
(Photos taken in approximate
location, in direction of arrow)
5005
5005
5000
4995
4985
4980
4975
4970
4990
4975
4970
4980
4975
4985
4990
4995
5000
5005
5005
4970
Figure 2: Groundwater Contour Diagram
800-Acre Mixed Use Development
Fort Collins, Colorado
EEC Project Number: 1172058 Date: September 2017
EARTH ENGINEERING CONSULTANTS, LLC
Legend
Approximate
Groundwater Contours
B-2
B-3
B-4
B-8
B-12
B-20
B-16 B-18 B-19
B-15
B-13
B-5
B-6
B-7
B-30
B-28 B-27
B-29 B-23
B-24
B-11
B-17
B-21 B-22
B-26
17.5'
18.5'
21.0'
22.7'
18.0'
14.0'
14.5'
10.0'
31.0'
12.0'
2.0'
4.5'
12.0'
12.5'
13.5' 9.5'
6.5' 13.5' 9.0' 8.0'
12.3'
27.8' 4.0'
14.0'
11.0'
19.0'
B-25
8.0'
B-1
B-14
B-9
B-10
Figure 3: Depth to Groundwater Diagram
800-Acre Mixed Use Development
Fort Collins, Colorado
EEC Project Number: 1172058 Date: September 2017
EARTH ENGINEERING CONSULTANTS, LLC
Approximate Boring
Locations
Legend
Depth to
Groundwater 0-6 ft
Depth to
Groundwater 6-10 ft
Depth to
B-2
B-3
B-4
B-8
B-12
B-20
B-16 B-18 B-19
B-15
B-13
B-5
B-6
B-7
B-30
B-28 B-27
B-29 B-23
B-24
B-11
B-17
S1 @ 2'
(+) 4.8%
S1 @ 2'
(+) 1.2%
S1 @ 4'
(+) 3.3%
S3 @ 9'
None
S3 @ 9'
None
S1 @ 4'
(+) 0.1%
S1 @ 4'
None
S1 @ 4'
(+) 3.3%
S1 @ 2'
(+) 4.1%
S1 @ 2'
(+) 7.6%
S1 @ 4'
None
S3 @ 9'
None
S1 @ 2'
(+) 4.4%
B-21 B-22
S1 @ 2'
(+) 2.4%
S1 @ 4'
(+) 1.1%
S1 @ 2'
(+) 0.3%
S1 @ 2'
(+) 4.3%
B-26
S1 @ 2'
(+) 3.6%
B-25
B-1
B-14
S1 @ 4'
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
_ _
CLAYEY SAND / SANDY LEAN CLAY (SC / CL) 2
brown _ _
medium dense to very loose / stiff to very stiff to soft 3
with calcareous deposits _ _
with organics 4
_ _
CS 5 18 6500 6.9 93.7 31 19 49.4 1200 psf 1.7%
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 19 9000+ 9.9
_ _
11
_ _
12
_ _
13
_ _
14
brown / gray / rust _ _
CS 15 11 4000 17.5 108.0
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 10 4000 18.4
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 2
Continued on Sheet 2 of 2 _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
Continued from Sheet 1 of 2 26
_ _
27
CLAYEY SAND / SANDY LEAN CLAY (SC / CL) _ _
brown 28
medium dense _ _
with calcareous deposits 29
with organics _ _
sand / gravel seams SS 30 23 -- 11.4
_ _
31
_ _
32
_ _
33
_ _
34
_ _
auger cuttings 35 15.1
_ _
36
_ _
37
_ _
38
_ _
39
SAND / GRAVEL (SP / GP) _ _
brown / gray / rust SS 40 9 -- 9.3
loose to medium dense _ _
BOTTOM OF BORING DEPTH 40.5' 41
_ _
42
_ _
43
_ _
44
_ _
45
_ _
46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
N/A
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
very stiff to hard CS 3 18 9000+ 9.1 103.4
with calcareous deposits _ _
4
_ _
SS 5 23 9000+ 9.9
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 18 9000+ 9.2 107.7
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 21 9000+ 10.0
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 23 9000+ 9.6 111.9
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 13 9000+ 11.0
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
VEGETATION & TOPSOIL _ _
1
_ _
LEAN CLAY with SAND (CL) 2
brown _ _ % @ 150 psf
very stiff to stiff CS 3 24 9000+ 7.9 104.3 33 19 71 1400 psf 4.8%
with calcareous deposits _ _
with organics 4
_ _
SS 5 18 9000+ 9.2
_ _
6
_ _
7
_ _
8
_ _
9
_ _
*SANDY LEAN CLAY (CL) Lens CS 10 13 9000+ 13.2 111.0 32 15 60.8 1400 psf 0.7%
_ _
11
_ _
12
_ _
13
_ _
14
brown / gray / rust _ _
SS 15 13 5500 16.6
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 11 3000 19.6 106.7
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 20 4000 17.1
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _ % @ 150 psf
medium stiff to stiff CS 3 10 9000+ 13.7 113.0 30 23 54.3 1800 psf 1.2%
_ _
4
with calcareous deposits _ _
SS 5 6 6500 15.3
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 15 7500 19.5 105.9 1400 psf 0.7%
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 8 5000 21.1
_ _
16
_ _
17
_ _
18
_ _
SAND / GRAVEL (SP / GP) 19
brown _ _
very loose to medium dense CS 20 2 -- 11.8 114.2
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 17 -- 0.2
Continued on Sheet 2 of 2 _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
Continued from Sheet 1 of 2 26
_ _
27
SAND / GRAVEL (SP / GP) _ _
brown 28
medium dense to dense _ _
29
_ _
CLAYSTONE / SILTSTONE / SANDSTONE CS 30 33 9000+ 19.5 107.4
brown / gray / rust _ _
moderately hard to hard 31
_ _
32
_ _
33
_ _
gray 34
_ _
SS 35 50/4" 6000 19.8
_ _
36
_ _
37
_ _
38
_ _
auger cuttings 39 28.0
_ _
40
BOTTOM OF BORING DEPTH 40.0' _ _
41
_ _
42
_ _
43
_ _
44
_ _
45
_ _
46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
N/A
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
VEGETATION & TOPSOIL _ _
1
_ _
LEAN CLAY with SAND (CL) 2
gray / brown / rust _ _
soft to medium stiff CS 3 6 1500 26.6 94.8
with organics _ _
4
gray / rust _ _
SS 5 2 -- 44.3
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 6 1000 26.0 97.8 33 19 81.3 <500 psf none
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 7 1000 29.2
_ _
16
_ _
17
_ _
SILTY SAND / GRAVEL (SM / GM) 18
brown / rust / gray _ _
loose to medium dense 19
_ _
CS 20 15
_ _
21
_ _
22
_ _
23
_ _
24
intermittent clay seams _ _
SS 25 8
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
1
_ _
SANDY LEAN CLAY (CL) 2
gray / rust _ _
soft to medium stiff 3
_ _
4
_ _
CS 5 4 1500 21.3 103.2 34 20 58.2 <500 psf none
_ _
6
_ _
7
_ _
8
_ _
9
brown / rust / gray _ _
SS 10 14 1000 27.1
_ _
SILTY SAND / GRAVEL (SM / GM) 11
brown / rust / gray _ _
loose 12
_ _
13
_ _
14
_ _
CS 15 5
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 8 -- 10.6
_ _
21
_ _
22
_ _
23
_ _
24
SANDSTONE / SILTSTONE / CLAYSTONE _ _
gray / brown / rust CS 25 37 3500 17.8
BOTTOM OF BORING DEPTH 25.0' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
VEGETATION & TOPSOIL _ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _ % @ 150 psf
very stiff CS 3 27 9000+ 5.8 107.2 1600 psf 4.4%
with calcareous deposits _ _
with organics 4
_ _
SS 5 17 -- 7.6
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 21 9000+ 13.2 118.3
_ _
11
_ _
12
_ _
13
_ _
14
brown / rust / gray _ _
SS 15 10 4500 17.5
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 24 4000 13.2 119.7
SAND / GRAVEL (SP / GP) _ _
brown / rust / gray 21
medium dense _ _
22
_ _
23
_ _
24
_ _
SS 25 21 -- 8.0
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
stiff to very stiff to medium stiff 3
_ _
4
_ _
CS 5 24 9000+ 6.7 103.9 34 19 65.2 1800 psf 3.3%
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 11 9000+ 12.4
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CS 15 14 9000+ 13.1 110.7
_ _
16
_ _
17
_ _
18
_ _
19
with calcareous deposits _ _
SS 20 14 7000 18.3
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 7 3000 25.2 96.5
BOTTOM OF BORING DEPTH 25.0' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
very stiff to stiff CS 3 7 9000+ 14.2 112.8
_ _
4
with calcareous deposits _ _
SS 5 6 7500 16.8
_ _
6
_ _
7
_ _
8
_ _
9
brown / rust _ _
CS 10 16 8500 20.2 104.3 1600 psf 0.8%
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 6 2000 26.4
_ _
16
_ _
17
_ _
18
_ _
SAND / GRAVEL (SP / GP) 19
brown _ _
medium dense CS 20 19 -- 12.5 112.1
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 31 -- 9.9
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _ % @ 150 psf
very stiff to stiff CS 3 8 8500 16.4 107.5 2000 psf 2.4%
with calcareous deposits _ _
4
_ _
SS 5 7 8000 15.9
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 11 9000+ 14.5 112.4 30 16 52.1 2000 psf 0.9%
_ _
11
_ _
12
_ _
13
_ _
14
brown / tan / rust _ _
SS 15 9 3500 22.9
_ _
16
_ _
17
_ _
18
_ _
19
rust / brown / gray _ _
CS 20 10 -- 25.1 95.5
_ _
21
_ _
SAND / GRAVEL (SP/ GP) 22
brown _ _
medium dense 23
_ _
24
_ _
SS 25 13 -- 9.6
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
very stiff to stiff 3
_ _
4
_ _
CS 5 11 7000 16.4 111.5 32 20 63.1
_ _
6
_ _
7
_ _
8
_ _
9
tan / gray / rust _ _
SS 10 8 4000 14.9
_ _
11
_ _
12
_ _
13
_ _
14
brown / rust / gray _ _
CS 15 9 2000 17.6 115.3
_ _
16
_ _
SAND / GRAVEL (SP / GP) 17
brown / rust / gray _ _
medium dense 18
_ _
19
_ _
SS 20 18 -- 23.0
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 15 -- 27.6 108.9
BOTTOM OF BORING DEPTH 25.0' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
very stiff CS 3 8 6500 16.5 98.6
with calcareous deposits _ _
4
_ _
SS 5 9 6000 15.3
_ _
6
_ _
7
_ _
8
_ _
9
brown / tan _ _
CS 10 4 6000 20.7 100.2
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 9 6000 18.1
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SAND / GRAVEL (SP / GP) CS 20 20 -- 10.1 132.6
brown / tan _ _
medium dense 21
with cobbles and clay seams _ _
22
_ _
23
_ _
24
_ _
SS 25 10 -- 7.9
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
VEGETATION & TOPSOIL _ _
1
_ _
CLAYEY SAND (SC) 2
gray _ _
loose to very loose CS 3 8 4000 24.8 86.5
_ _
4
_ _
SS 5 2 1000 36.2
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SILTY SAND (SM) CS 10 6 -- 21.6 104.2 NL NP 30.3 <500 psf none
brown / rust / gray _ _
loose to medium dense 11
_ _
12
_ _
13
_ _
14
_ _
SS 15 12 1500 22.9
_ _
16
_ _
SAND / GRAVEL (SP / GP) 17
rust / brown _ _
medium dense 18
_ _
19
_ _
CS 20 22 1000 8.0 130.3
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 10 -- 9.2
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
very stiff to medium stiff 3
with calcareous deposits _ _
4
_ _
CS 5 10 6000 15.1 107.4 36 19 51.8 1600 psf 0.4%
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 8 4500 18.3
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CS 15 10 2500 18.6 110.0
_ _
16
_ _
17
_ _
18
_ _
19
brown / rust _ _
with intermittent silty sand lenses SS 20 14 1500 23.5
_ _
21
_ _
22
_ _
23
_ _
24
SAND / GRAVEL (SP / GP) _ _
brown / rust, loose, with intermittent clay seams CS 25 7 -- 10.4 117.6
BOTTOM OF BORING DEPTH 25.0' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
VEGETATION & TOPSOIL _ _
1
_ _
LEAN CLAY with SAND (CL) 2
brown _ _ % @ 150 psf
very stiff to medium stiff CS 3 30 9000+ 8.0 111.1 3500 psf 7.6%
with calcareous deposits _ _
4
_ _
SS 5 15 9000+ 7.6
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 25 9000+ 9.4 109.0 40 25 81.2 3500 psf 4.4%
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 35 9000+ 10.9
_ _
16
_ _
17
_ _
18
_ _
19
_ _
* SANDY LEAN CLAY (CL) Lens CS 20 17 9000+ 15.2 113.4 24 11 67.9 1600 psf 0.7%
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 18 3000 18.7
Continued on Sheet 2 of 2 _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
Continued from Sheet 1 of 2 26
_ _
27
LEAN CLAY with SAND (CL) _ _
brown 28
very stiff to medium stiff _ _
with calcareous deposits 29
_ _
CS 30 14 7000 17.0 112.8
_ _
31
_ _
32
_ _
33
_ _
34
_ _
SS 35 18 2000 19.2
_ _
36
SILTY SAND / GRAVEL (SM / GM) _ _
brown / gray / rust 37
medium dense _ _
38
_ _
39
_ _
CS 40 29 -- 4.0 128.1
BOTTOM OF BORING DEPTH 40.0' _ _
41
_ _
42
_ _
43
_ _
44
_ _
45
_ _
46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
N/A
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
_ _
CLAYEY SAND (SC) 2
brown _ _
medium dense to loose 3
with calcareous deposits _ _
4
_ _
CS 5 15 8000 15.5 112.3 25 11 43.8 800 psf 0.1%
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 4 -- 21.9
_ _
11
_ _
12
_ _
13
_ _
14
brown / rust _ _
CS 15 8 -- 21.0 112.7
_ _
16
_ _
17
_ _
18
_ _
19
_ _
brown / gray / rust SS 20 8 -- 19.2
_ _
21
_ _
22
_ _
SILTY SAND / GRAVEL (SM / GM) 23
brown / gray / rust _ _
medium dense 24
_ _
CS 25 17 -- 10.6 123.1
BOTTOM OF BORING DEPTH 25.0' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
very stiff to medium stiff CS 3 13 8000 18.3 102.4
with calcareous deposits _ _
4
_ _
SS 5 12 6000 19.1
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 8 3500 34.2 95.6
_ _
11
_ _
12
_ _
13
_ _
14
brown / rust / gray _ _
SS 15 8 2000 19.6
_ _
16
_ _
17
_ _
18
SILTY SAND / GRAVEL (SM / GM) _ _
brown / rust / gray 19
medium dense _ _
CS 20 17 -- 9.3 124.3
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 20 -- 6.1
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
very stiff to stiff to medium stiff 3
with calcareous deposits _ _
4
_ _
CS 5 12 9000+ 19.0 101.6 29 16 69.2 800 psf 0.3%
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 7 2500 22.7
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CS 15 8 3500 19.9 108.0
_ _
16
_ _
17
_ _
SILTY SAND / GRAVEL (SM / GM) 18
brown _ _
medium dense 19
_ _
SS 20 15 -- 11.4
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 22 -- 13.1 120.7
BOTTOM OF BORING DEPTH 25.0' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown / red _ _
very stiff 3
with calcareous deposits _ _
4
_ _
CS 5 10 6500 20.5 100.6 27 13 68 <500 psf none
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SAND / GRAVEL (SP / GP) SS 10 17 -- 5.4
brown / red _ _
medium dense 11
_ _
12
_ _
13
_ _
14
_ _
CS 15 28 -- 10.2 127.7 NL NP 2
_ _
16
_ _
17
_ _
18
_ _
19
intermittent clay seams _ _
SS 20 14 -- 7.9
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 23 -- 11.4 129.6
Continued on Sheet 2 of 2 _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
Continued from Sheet 1 of 2 26
_ _
27
SANDSTONE / SILTSTONE / CLAYSTONE _ _
brown / gray / rust 28
moderately hard to hard _ _
29
_ _
SS 30 30 9000+ 22.8
_ _
31
_ _
32
_ _
33
_ _
34
_ _
CS 35 50/11" 9000+ 22.6 107.0
_ _
36
_ _
37
_ _
38
_ _
39
_ _
SS 40 41 7000 24.4
_ _
BOTTOM OF BORING DEPTH 40.5' 41
_ _
42
_ _
43
_ _
44
_ _
45
_ _
46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
N/A
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
very stiff to stiff CS 3 10 5500 20.7 101.6
with calcareous deposits _ _
with gypsum crystals 4
_ _
SS 5 6 3000 21.8
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SILT (ML) CS 10 8 1000 19.6 109.7 23 6 64.7 <500 psf none
brown / rust _ _
soft 11
_ _
12
_ _
13
_ _
SAND / GRAVEL (SP / GP) 14
brown / rust _ _
loose to medium dense SS 15 8 -- 5.5 NL NP 3.4
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 17 -- 10.2 118.1
_ _
21
_ _
22
_ _
23
_ _
24
SANDSTONE / SILTSTONE / CLAYSTONE _ _
brown / gray / rust, moderately hard SS 25 38 3500 17.3
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
_ _
LEAN CLAY with SAND (CL) 2
brown _ _ % @ 150 psf
very stiff to medium stiff CS 3 12 9000+ 16.1 110.0 34 22 83.2 2000 psf 2.4%
with calcareous deposits _ _
4
brown / red / gray _ _
with silty seams SS 5 9 2000 23.5
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SAND / GRAVEL (SP / GP) CS 10 19 -- 8.2 124.6
brown / red / gray _ _
dense to medium dense 11
_ _
12
_ _
13
_ _
14
_ _
SS 15 43 -- 6.5
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 22 -- 8.6 134.4
_ _
21
_ _
22
_ _
23
_ _
24
_ _
auger cuttings 25 -- -- 10.1
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
VEGETATION & TOPSOIL _ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
very stiff 3
with calcareous deposits _ _
4
_ _ % @ 150 psf
CS 5 6 7000 16.4 97.0 1200 psf 1.1%
_ _
6
_ _
7
_ _
8
_ _
SAND / GRAVEL with SILT (SP - SM / GP - GM) 9
brown _ _
medium dense SS 10 23 -- 8.2
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CS 15 15 -- 9.0 122.8 NL NP 9.2
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 22 -- 9.9
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 16 -- 6.8 148.4
BOTTOM OF BORING DEPTH 25.0' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
stiff CS 3 7 4000 12.7 100.1
with calcareous deposits _ _
4
red / brown _ _
SS 5 6 2000 26.8
_ _
6
_ _
7
_ _
8
_ _
9
brown / gray / rust _ _
CS 10 8 3500 29.4 90.0
_ _
11
_ _
12
_ _
13
_ _
SAND / GRAVEL (SP / GP) 14
brown / gray / rust _ _
medium dense to dense SS 15 23 -- 8.0
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 32 -- 13.3 119.5
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 17 -- 6.2
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION _ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
medium stiff 3
with calcareous deposits _ _
4
_ _
CS 5 6 4000 25.5 89.6
_ _
6
_ _
7
_ _
8
_ _
9
gray / brown / rust _ _
SS 10 7 2500 31.4
_ _
11
_ _
12
_ _
13
_ _
CLAYEY SAND (SC) 14
gray / brown / rust _ _
loose to medium dense CS 15 10 -- 8.7
_ _
16
_ _
17
_ _
18
_ _
19
with gray silty lcay seams _ _
SS 20 9 -- 19.3 26 10 44.1
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 18 -- 9.0 107.9
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
Continued from Sheet 1 of 2 26
_ _
27
_ _
CLAYSTONE 28
gray / rust _ _
highly weathered to moderately hard to hard 29
_ _
CS 30 12 3000 29.5 91.5
_ _
31
_ _
32
_ _
33
_ _
34
_ _
SS 35 28 9000+ 20.8
_ _
36
_ _
37
_ _
38
_ _
39
_ _
CS 40 50/6" 9000+ 17.2 114.6 46 27 58.9 6500 psf 3.7%
BOTTOM OF BORING DEPTH 40.5' _ _
41
_ _
42
_ _
43
_ _
44
_ _
45
_ _
46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
N/A
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown / red _ _ % @ 150 psf
very stiff CS 3 19 9000+ 17.6 99.2 3500 psf 4.3%
with calcareous deposits _ _
with gypsum crystals 4
_ _
SS 5 11 9000+ 21.0
_ _
6
_ _
7
_ _
8
_ _
SAND / GRAVEL (SP / GP) 9
brown / red _ _
medium dense CS 10 26 -- 10.7 124.6
_ _
11
_ _
12
_ _
13
_ _
14
intermittent silty clay seams _ _
SS 15 19 -- 23.9
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 24 -- 12.7 110.6
_ _
21
_ _
22
_ _
23
_ _
24
SILTSTONE / SANDSTONE at 25' _ _
gray / rust SS 25 27 2000 11.0
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
ALFALFA _ _
1
_ _
LEAN CLAY with SAND (CL) 2
brown _ _ % @ 150 psf
very stiff CS 3 19 6000 9.6 101.5 37 10 81.3 1600 psf 3.6%
_ _
4
_ _
SS 5 19 9000+ 8.6
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 15 9000+ 16.7 109.1 39 22 78.6 2000 psf 1.5%
_ _
11
_ _
12
_ _
13
_ _
SILTY SAND / GRAVEL (SM / GM) 14
brown _ _
medium dense SS 15 19 -- 8.1
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 24 -- 8.6 129.7
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 13 -- 4.1
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
ALFALFA _ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _
very stiff 3
with calcareous deposits _ _
with organics 4
_ _
CS 5 21 5500 10.1 91.1
_ _
6
_ _
7
_ _
8
_ _
9
with gypsum crystals _ _
SS 10 11 8500 13.2
_ _
11
_ _
12
_ _
13
_ _
SAND / GRAVEL (SP / GP) 14
brown _ _
medium dense to dense CS 15 24 -- 13.1 107.6
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 27 -- 6.0
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 35 -- 9.4 132.5
BOTTOM OF BORING DEPTH 25.0' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
ALFALFA _ _
1
_ _
SANDY LEAN CLAY (CL) 2
brown _ _ % @ 150 psf
very stiff CS 3 20 9000+ 9.1 96.3 1200 psf 4.1%
_ _
4
with organics _ _
SS 5 12 4000 8.3
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 20 9000+ 11.7 98.8
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 17 9000+ 14.8
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 16 7000 19.6 103.8
_ _
21
_ _
22
_ _
23
_ _
24
with gravel _ _
SS 25 9 4000 18.6
Continued on Sheet 2 of 2 _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
Continued from Sheet 1 of 2 26
_ _
27
SANDY LEAN CLAY (CL) _ _
brown 28
very stiff _ _
29
_ _
CS 30 9 4000 21.3 106.6
_ _
31
_ _
32
_ _
33
_ _
34
_ _
SS 35 10 1000 21.1
_ _
36
_ _
37
_ _
38
_ _
39
SILTY SAND (SM) _ _
brown, very loose CS 40 1 -- 17.0
BOTTOM OF BORING DEPTH 40.0' _ _
41
_ _
42
_ _
43
_ _
44
_ _
45
_ _
46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
N/A
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
ALFALFA _ _
1
_ _
LEAN CLAY with SAND (CL) 2
brown _ _
very stiff 3
with calcareous deposits _ _
4
_ _
CS 5 19 9000+ 12.5 103.4 35 20 73.8 3500 psf 3.3%
_ _
6
_ _
7
_ _
8
_ _
9
_ _
brown / rust / gray SS 10 9 4000 21.4
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SILTY SAND / GRAVEL (SM / GM) SS 15 20 -- 17.7
brown _ _
medium dense 16
_ _
17
_ _
18
_ _
19
_ _
SS 20 27 -- 8.6
_ _
21
_ _
22
_ _
23
_ _
24
intermittent clay seams _ _
CS 25 11 -- 17.7
BOTTOM OF BORING DEPTH 25.0' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
ALFALFA _ _
1
_ _
SANDY LEAN CLAY (CL) 2
gray _ _
stiff to medium stiff CS 3 4 4000 26.7 90.9
with calcareous deposits _ _
4
gray / rust _ _
SS 5 2 1000 37.0
_ _
6
_ _
7
_ _
SAND / GRAVEL (SP / GP) 8
gray / rust _ _
medium dense to loose 9
_ _
CS 10 14 -- 12.0 112.1
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 9 -- 8.3 NL NP 5.2
_ _
16
_ _
17
_ _
18
_ _
19
intermittent clay seams _ _
CS 20 6 -- 10.9
_ _
21
_ _
22
_ _
CLAYSTONE / SILTSTONE / SANDSTONE 23
gray _ _
24
_ _
SS 25 50/7" 8500 17.2
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
Project:
Location:
Project #:
Date:
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
Beginning Moisture: 6.9% Dry Density: 99.9 pcf Ending Moisture: 23.3%
Swell Pressure: 1200 psf % Swell @ 500: 1.7%
Sample Location: Boring 1, Sample 1, Depth 4'
Liquid Limit: 31 Plasticity Index: 19 % Passing #200: 49.4%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Clayey Sand / Sandy Lean Clay (SC / CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
Beginning Moisture: 7.9% Dry Density: 102.8 pcf Ending Moisture: 20.8%
Swell Pressure: 1400 psf % Swell @ 150: 4.8%
Sample Location: Boring 3, Sample 1, Depth 2'
Liquid Limit: 33 Plasticity Index: 19 % Passing #200: 71.0%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Lean Clay with Sand (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
Sample Location: Boring 3, Sample 3, Depth 9'
Liquid Limit: 32 Plasticity Index: 15 % Passing #200: 60.8%
Beginning Moisture: 13.2% Dry Density: 117.9 pcf Ending Moisture: 16.9%
Swell Pressure: 1400 psf % Swell @ 500: 0.7%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
Beginning Moisture: 13.7% Dry Density: 119.5 pcf Ending Moisture: 15.0%
Swell Pressure: 1800 psf % Swell @ 150: 1.2%
Sample Location: Boring 4, Sample 1, Depth 2'
Liquid Limit: 30 Plasticity Index: 23 % Passing #200: 54.3%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
Beginning Moisture: 19.5% Dry Density: 107.4 pcf Ending Moisture: 19.1%
Swell Pressure: 1400 psf % Swell @ 500: 0.7%
Sample Location: Boring 4, Sample 3, Depth 9'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
Beginning Moisture: 26.0% Dry Density: 107 pcf Ending Moisture: 25.2%
Swell Pressure: <500 psf % Swell @ 500: None
Sample Location: Boring 5, Sample 3, Depth 9'
Liquid Limit: 33 Plasticity Index: 19 % Passing #200: 81.3%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Gray / Brown / Rust Lean Clay with Sand (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
Beginning Moisture: 21.3% Dry Density: 106.5 pcf Ending Moisture: 22.3%
Swell Pressure: <500 psf % Swell @ 500: None
Sample Location: Boring 6, Sample 1, Depth 4'
Liquid Limit: 34 Plasticity Index: 20 % Passing #200: 58.2%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Gray / Rust Sandy Lean Clay (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
Beginning Moisture: 5.8% Dry Density: 112.1 pcf Ending Moisture: 19.9%
Swell Pressure: 1600 psf % Swell @ 150: 4.4%
Sample Location: Boring 7, Sample 1, Depth 2'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
Beginning Moisture: 6.7% Dry Density: 107.9 pcf Ending Moisture: 23.5%
Swell Pressure: 1800 psf % Swell @ 500: 3.3%
Sample Location: Boring 8, Sample 1, Depth 4'
Liquid Limit: 34 Plasticity Index: 19 % Passing #200: 65.2%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
Beginning Moisture: 20.2% Dry Density: 107.2 pcf Ending Moisture: 18.0%
Swell Pressure: 1600 psf % Swell @ 500: 0.8%
Sample Location: Boring 9, Sample 3, Depth 9'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
Beginning Moisture: 16.4% Dry Density: 107.4 pcf Ending Moisture: 19.0%
Swell Pressure: 2000 psf % Swell @ 150: 2.4%
Sample Location: Boring 10, Sample 1, Depth 2'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
Beginning Moisture: 14.5% Dry Density: 116.3 pcf Ending Moisture: 16.4%
Swell Pressure: 2000 psf % Swell @ 500: 0.9%
Sample Location: Boring 10, Sample 3, Depth 9'
Liquid Limit: 30 Plasticity Index: 16 % Passing #200: 52.1%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown / Rust / Gray Silty Sand (SM)
Sample Location: Boring 13, Sample 3, Depth 9'
Liquid Limit: 25 Plasticity Index: NP % Passing #200: 30.3%
Beginning Moisture: 21.6% Dry Density: 109.8 pcf Ending Moisture: 20.2%
Swell Pressure: <500 psf % Swell @ 500: None
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
Sample Location: Boring 14, Sample 1, Depth 4'
Liquid Limit: 36 Plasticity Index: 19 % Passing #200: 51.8%
Beginning Moisture: 15.1% Dry Density: 116.5 pcf Ending Moisture: 18.5%
Swell Pressure: 1600 psf % Swell @ 500: 0.4%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
Sample Location: Boring 15, Sample 1, Depth 2'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
Beginning Moisture: 8.0% Dry Density: 118.8 pcf Ending Moisture: 18.9%
Swell Pressure: 3500 psf % Swell @ 150: 7.6%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Lean Clay with Sand (CL)
Sample Location: Boring 15, Sample 3, Depth 9'
Liquid Limit: 40 Plasticity Index: 25 % Passing #200: 81.2%
Beginning Moisture: 9.4% Dry Density: 109 pcf Ending Moisture: 21.3%
Swell Pressure: 3500 psf % Swell @ 500: 4.4%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Lean Clay with Sand (CL)
Sample Location: Boring 15, Sample 5, Depth 19'
Liquid Limit: 24 Plasticity Index: 11 % Passing #200: 67.9%
Beginning Moisture: 15.2% Dry Density: 116.6 pcf Ending Moisture: 17.4%
Swell Pressure: 1600 psf % Swell @ 500: 0.7%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Clayey Sand (SC)
Sample Location: Boring 16, Sample 1, Depth 4'
Liquid Limit: 25 Plasticity Index: 11 % Passing #200: 43.8%
Beginning Moisture: 15.5% Dry Density: 117.2 pcf Ending Moisture: 16.5%
Swell Pressure: 800 psf % Swell @ 500: 0.1%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown / Rust Clayey Sand (SC)
Sample Location: Boring 16, Sample 3, Depth 14'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
Beginning Moisture: 21.0% Dry Density: 109.8 pcf Ending Moisture: 19.2%
Swell Pressure: <500 psf % Swell @ 500: None
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Lean Clay with Sand (CL)
Sample Location: Boring 18, Sample 1, Depth 4'
Liquid Limit: 29 Plasticity Index: 16 % Passing #200: 69.2%
Beginning Moisture: 19.6% Dry Density: 102.2 pcf Ending Moisture: 20.3%
Swell Pressure: 800 psf % Swell @ 500: 0.3%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown / Red Lean Clay with Sand (CL)
Sample Location: Boring 19, Sample 1, Depth 4'
Liquid Limit: 27 Plasticity Index: 13 % Passing #200: 68.0%
Beginning Moisture: 20.4% Dry Density: 103.3 pcf Ending Moisture: 22.8%
Swell Pressure: <500 psf % Swell @ 500: None
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown / Rust Silt (ML)
Sample Location: Boring 20, Sample 3, Depth 9'
Liquid Limit: 23 Plasticity Index: 6 % Passing #200: 64.7%
Beginning Moisture: 19.6% Dry Density: 110.7 pcf Ending Moisture: 15.7%
Swell Pressure: <500 psf % Swell @ 500: None
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Lean Clay with Sand (CL)
Sample Location: Boring 21, Sample 1, Depth 2'
Liquid Limit: 34 Plasticity Index: 22 % Passing #200: 83.2%
Beginning Moisture: 16.1% Dry Density: 110 pcf Ending Moisture: 18.7%
Swell Pressure: 2000 psf % Swell @ 150: 2.4%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
Sample Location: Boring 22, Sample 1, Depth 4'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
Beginning Moisture: 16.4% Dry Density: 112.8 pcf Ending Moisture: 15.0%
Swell Pressure: 1200 psf % Swell @ 150: 1.1%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Gray / Rust Claystone
Sample Location: Boring 24, Sample 8, Depth 39'
Liquid Limit: 46 Plasticity Index: 27 % Passing #200: 58.9%
Beginning Moisture: 17.2% Dry Density: 115.2 pcf Ending Moisture: 18.9%
Swell Pressure: 6500 psf % Swell @ 500: 3.7%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown / Red Sandy Lean Clay (CL)
Sample Location: Boring 25, Sample 1, Depth 2'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
Beginning Moisture: 17.6% Dry Density: 110 pcf Ending Moisture: 22.4%
Swell Pressure: 3500 psf % Swell @ 150: 4.3%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Lean Clay with Sand (CL)
Sample Location: Boring 26, Sample 1, Depth 2'
Liquid Limit: 37 Plasticity Index: 10 % Passing #200: 81.3%
Beginning Moisture: 9.6% Dry Density: 104.5 pcf Ending Moisture: 29.4%
Swell Pressure: 1600 psf % Swell @ 150: 3.6%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Lean Clay with Sand (CL)
Sample Location: Boring 26, Sample 3, Depth 9'
Liquid Limit: 39 Plasticity Index: 22 % Passing #200: 78.6%
Beginning Moisture: 16.7% Dry Density: 106.9 pcf Ending Moisture: 19.3%
Swell Pressure: 2000 psf % Swell @ 500: 1.5%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
Sample Location: Boring 28, Sample 1, Depth 2'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
Beginning Moisture: 9.1% Dry Density: 100 pcf Ending Moisture: 25.0%
Swell Pressure: 1200 psf % Swell @ 150: 4.1%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Lean Clay with Sand (CL)
Sample Location: Boring 29, Sample 1, Depth 4'
Liquid Limit: 35 Plasticity Index: 20 % Passing #200: 73.8%
Beginning Moisture: 12.5% Dry Density: 111.6 pcf Ending Moisture: 18.6%
Swell Pressure: 3500 psf % Swell @ 500: 3.3%
800 Acre Mixed Use Development
Fort Collins, Colorado
1172058
Sep-17
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
PROJECT: 800 Acre Retail Development PROJECT NO. 1172058
LOCATION: DATE Sep-17
MATERIAL DESCRIPTION: Sandy Lean Clay (CL)
SAMPLE LOCATION:
LIQUID LIMIT: 34 PLASTICITY INDEX: 20 %PASSING #200: 63.2
R-VALUE LABORATORY TEST RESULTS
TEST SPECIMEN NO. 1 23
COMPACTION PRESSURE (PSI) 125 150 175
DENSITY (PCF) 108.8 112.9 111.1
MOISTURE CONTENT (%) 17.6 17.4 16.5
EXPANSION PRESSURE (PSI) 0.00 0.00 0.00
HORIZONTAL PRESSURE @ 160 PSI 128 125 124
SAMPLE HEIGHT (INCHES) 2.56 2.55 2.55
EXUDATION PRESSURE (PSI) 261.2 362.6 462.9
UNCORRECTED R-VALUE 12.6 14.6 15.4
CORRECTED R-VALUE 12.9 14.6 15.4
R-VALUE @ 300 PSI EXUDATION PRESSURE = 14 RESILIENT MODULUS, PSI = 4,060
Composite Sample Boring B-2 Upper 2'
RESISTANCE R-VALUE & EXPANSION PRESSURE OF
COMPACTED SOIL - ASTM D2844
Fort Collins, Colorado
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200 250 300 350 400 450 500 550 600
R-Value
Exudation Pressure, PSF
PROJECT: 800 Acre Retail Development PROJECT NO. 1172058
LOCATION: DATE Sep-17
MATERIAL DESCRIPTION: Sandy Lean Clay (CL)
SAMPLE LOCATION:
LIQUID LIMIT: PLASTICITY INDEX: %PASSING #200: 58.9
R-VALUE LABORATORY TEST RESULTS
TEST SPECIMEN NO. 1 23
COMPACTION PRESSURE (PSI) 250 225 200
DENSITY (PCF) 115.7 113.7 114.5
MOISTURE CONTENT (%) 15.5 16.2 17.1
EXPANSION PRESSURE (PSI) 0.00 0.00 0.00
HORIZONTAL PRESSURE @ 160 PSI 111 110 116
SAMPLE HEIGHT (INCHES) 2.54 2.55 2.56
EXUDATION PRESSURE (PSI) 530.5 389.9 263.6
UNCORRECTED R-VALUE 25.9 25.6 20.8
CORRECTED R-VALUE 25.9 25.6 21.3
R-VALUE @ 300 PSI EXUDATION PRESSURE = 25 RESILIENT MODULUS, PSI = 5,816
Composite Sample Boring B-4 Upper 2'
RESISTANCE R-VALUE & EXPANSION PRESSURE OF
COMPACTED SOIL - ASTM D2844
Fort Collins, Colorado
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200 250 300 350 400 450 500 550 600
R-Value
Exudation Pressure, PSF
PROJECT: 800 Acre Retail Development PROJECT NO. 1172058
LOCATION: DATE Sep-17
MATERIAL DESCRIPTION: Sandy Lean Clay (CL)
SAMPLE LOCATION:
LIQUID LIMIT: 33 PLASTICITY INDEX: 20 %PASSING #200: 56.0
R-VALUE LABORATORY TEST RESULTS
TEST SPECIMEN NO. 1 23
COMPACTION PRESSURE (PSI) 175 150 125
DENSITY (PCF) 111.6 112.8 111.7
MOISTURE CONTENT (%) 17.0 17.6 18.2
EXPANSION PRESSURE (PSI) 0.00 0.00 0.00
HORIZONTAL PRESSURE @ 160 PSI 123 125 130
SAMPLE HEIGHT (INCHES) 2.54 2.45 2.48
EXUDATION PRESSURE (PSI) 425.0 340.1 263.4
UNCORRECTED R-VALUE 17.8 15.8 13.0
CORRECTED R-VALUE 17.8 15.8 13.0
R-VALUE @ 300 PSI EXUDATION PRESSURE = 15 RESILIENT MODULUS, PSI = 4,195
Composite Sample Boring B-15 Upper 2'
RESISTANCE R-VALUE & EXPANSION PRESSURE OF
COMPACTED SOIL - ASTM D2844
Fort Collins, Colorado
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200 250 300 350 400 450 500 550 600
R-Value
Exudation Pressure, PSF
PROJECT: 800 Acre Retail Development PROJECT NO. 1172058
LOCATION: DATE Sep-17
MATERIAL DESCRIPTION: Lean Clay with Sand (CL)
SAMPLE LOCATION:
LIQUID LIMIT: --- PLASTICITY INDEX: --- %PASSING #200: 73.3
R-VALUE LABORATORY TEST RESULTS
TEST SPECIMEN NO. 1 23
COMPACTION PRESSURE (PSI) 250 225 200
DENSITY (PCF) 117.1 115.2 111.3
MOISTURE CONTENT (%) 14.2 15.4 15.9
EXPANSION PRESSURE (PSI) 0.00 0.00 0.00
HORIZONTAL PRESSURE @ 160 PSI 101 115 123
SAMPLE HEIGHT (INCHES) 2.50 2.55 2.50
EXUDATION PRESSURE (PSI) 660.7 426.1 262.7
UNCORRECTED R-VALUE 30.0 22.0 16.9
CORRECTED R-VALUE 30.0 22.0 16.9
R-VALUE @ 300 PSI EXUDATION PRESSURE = 18 RESILIENT MODULUS, PSI = 4,627
Composite Sample Boring B-23 Upper 2'
RESISTANCE R-VALUE & EXPANSION PRESSURE OF
COMPACTED SOIL - ASTM D2844
Fort Collins, Colorado
0
10
20
30
40
50
60
70
80
90
100
0 50 100 150 200 250 300 350 400 450 500 550 600
R-Value
Exudation Pressure, PSF
PRELIMINARY SUBSURFACE EXPLORATION REPORT
40-ACRE DEVELOPMENT
NORTH OF EAST LCR 50 AND EAST OF TURNBERRY ROAD
FORT COLLINS, COLORADO
EEC PROJECT NO. 1172058B
Prepared for:
HF2M Colorado
430 N College Ave. Suite 410
Fort Collins, Colorado 80524
Attn: Mr. Max Moss (max@hf2m.com)
Prepared by:
Earth Engineering Consultants, LLC
4396 Greenfield Drive
Windsor, Colorado 80550
4396 GREENFIELD DRIVE
WINDSOR, COLORADO 80550
(970) 545-3908 FAX (970) 663-0282
August 17, 2018
HF2M Colorado
430 N College Ave. Suite 410
Fort Collins, Colorado 80524
Attn: Mr. Max Moss (max@hf2m.com)
Re: Preliminary Subsurface Exploration Report
40-Acre Development
North of East LCR 50 and East of Turnberry Road
Fort Collins, Colorado
EEC Project No. 1172058B
Mr. Moss:
Enclosed, herewith, are the results of the preliminary subsurface exploration completed by Earth
Engineering Consultants, LLC personnel for the referenced project. A total of five (5)
preliminary soil borings were drilled on August 7, 2018, at the approximate locations as
indicated on the enclosed Boring Location Diagram included with this report. The borings were
extended to depths of approximately 30 to 40 feet below existing site grades. Individual boring
logs, including groundwater observations, depth to bedrock, and results of laboratory testing are
included as a part of the attached report. This exploration was completed in general accordance
with our proposal dated June 29, 2018.
In summary, the subsurface soils encountered in the preliminary test borings generally consisted
of cohesive lean clay with varying amounts of sand subsoils. Some zones of clayey sand were
encountered in a few of the borings. The lean clay subsoils were generally stiff to very stiff,
exhibited low to moderate plasticity and low to moderate swell potential at current moisture and
density conditions. The lean clay subsoils were underlain by sand/gravel soils in boring B-3 and
B-5 at depths of approximately 34 to 39 feet and extended to the depths explored of
approximately 30 to 40 feet in the remaining borings. The sands/gravels extended to the depths
explored, approximately 40 feet below the ground surface. Bedrock was not encountered to
maximum depths explored, approximately 40 feet. Groundwater was observed in the
preliminary test borings at depths ranging from approximately 24 to 29 feet below existing site
grades at the time of drilling and 24 hours after drilling.
PRELIMINARY SUBSURFACE EXPLORATION REPORT
40-ACRE DEVELOPMENT
NORTH OF EAST LCR 50 AND EAST OF TURNBERRY ROAD
FORT COLLINS, COLORADO
EEC PROJECT NO. 1172058B
August 17, 2018
INTRODUCTION
The preliminary subsurface exploration for the proposed 40-acre development parcel located
northeast of East Larimer County Road (LCR) 50 and Turnberry Road in Fort Collins, Colorado has
been completed. A total of five (5) preliminary soil borings were drilled on August 7, 2018, at the
approximate locations as indicated on the enclosed Boring Location Diagram included with this
report. The five (5) preliminary soil borings were advanced to depths of approximately 30 to 40 feet
below existing site grades across the proposed development property to obtain information on
existing subsurface conditions. Individual boring logs and site diagrams indicating the approximate
boring locations are included with this report.
The 40-acre development property is located northeast of East Larimer County Road (LCR) 50 and
Turnberry Road in Fort Collins, Colorado. As we understand, the property will be developed for a
potential Poudre School District Facility, including associated pavement and utility infrastructure.
Foundation loads for the proposed structures are anticipated to be light to moderate with continuous
wall loads less than 4 kips per lineal foot and individual column loads less than 250 kips. Floor
loads are expected to be light. We anticipate maximum cuts and fills on the order of 5 feet (+/-) will
be completed to develop the site grades. Overall site development will include construction of
associated pavements designed in general accordance with the Larimer County Urban Area Street
Standards (LCUASS) Pavement Design Criteria.
The purpose of this report is to describe the subsurface conditions encountered in the preliminary
borings, analyze and evaluate the test data and provide preliminary geotechnical recommendations
concerning site development including foundations, floor slabs, pavement sections and the
possibility for an area underdrain system to support basement construction.
Earth Engineering Consultants, LLC
EEC Project No. 1172058B
August 17, 2018
Page 2
EXPLORATION AND TESTING PROCEDURES
The boring locations were established in the field by a representative of Earth Engineering
Consultants, LLC (EEC) by pacing and estimating angles from identifiable site features in areas
accessible to our drilling equipment without disrupting to on-going farming activities. Those
locations should be considered accurate only to the degree implied by the methods used to make the
field measurements. Photographs of the site taken at the time of drilling are provided with this
report.
The borings were performed using either a truck-mounted CME-55 drill rig equipped with a
hydraulic head employed in drilling and sampling operations. The boreholes were advanced using
4-inch nominal diameter continuous flight augers. Samples of the subsurface materials encountered
were obtained using split-barrel and California barrel sampling procedures in general accordance
with ASTM Specifications D1586 and D3550, respectively.
In the split-barrel and California barrel sampling procedures, standard sampling spoons are driven
into the ground by means of a 140-pound hammer falling a distance of 30 inches. The number of
blows required to advance the samplers is recorded and is used to estimate the in-situ relative density
of cohesionless soils and, to a lesser degree of accuracy, the consistency of cohesive soils and
hardness of weathered bedrock. In the California barrel sampling procedure, relatively undisturbed
samples are obtained in brass liners. All samples obtained in the field were sealed and returned to the
laboratory for further examination, classification and testing.
Laboratory moisture content tests were performed on each of the recovered samples. In addition,
selected samples were tested for fines content and plasticity by washed sieve analysis and Atterberg
limits tests. Swell/consolidation tests were completed on selected samples to evaluate the subgrade
materials’ tendency to change volume with variation in moisture content and load. The quantity of
water soluble sulfates was determined on select samples to evaluate the risk of sulfate attack on site
concrete. Results of the outlined tests are indicated on the attached boring logs and summary sheets.
As a part of the testing program, all samples were examined in the laboratory and classified in
general accordance with the attached General Notes and the Unified Soil Classification System,
Earth Engineering Consultants, LLC
EEC Project No. 1172058B
August 17, 2018
Page 3
based on the sample's texture and plasticity. The estimated group symbol for the Unified Soil
Classification System is shown on the boring logs and a brief description of that classification
system is included with this report.
SITE AND SUBSURFACE CONDITIONS
The 40-acre development property is located northeast of East Larimer County Road (LCR) 50 and
Turnberry Road in Fort Collins, Colorado. The project site is generally undeveloped farmland with
an existing residential development to the west of the parcel. Surface water drainage across the site
is generally to the south and to the east. Estimated relief across the site from northwest to southeast
is approximately 15 to 20 feet (±).
An EEC field engineer was on-site during drilling to direct the drilling activities and evaluate the
subsurface materials encountered. Field descriptions of the materials encountered were based on
visual and tactual observation of disturbed samples and auger cuttings. The boring logs included
with this report may contain modifications to the field logs based on results of laboratory testing and
engineering evaluation. Based on results of field and laboratory evaluation, subsurface conditions
can be generalized as follows.
Sparse vegetation and topsoil were encountered at the surface of each boring. The topsoil and/or
agricultural/vegetation layers were underlain by lean clay with varying amounts of sand subsoils.
Some zones of clayey sand were encountered in a few of the borings. The lean clay subsoils were
generally stiff to very stiff, exhibited low to moderate plasticity and low to moderate swell potential
at current moisture and density conditions. The lean clay subsoils were underlain by sand/gravel
soils in boring B-3 and B-5 at depths of approximately 34 to 39 feet and extended to the depths
explored of approximately 30 to 40 feet in the remaining borings. The sands/gravels extended to the
depths explored, approximately 40 feet below the ground surface. Bedrock was not encountered to
maximum depths of exploration, approximately 40 feet.
The stratification boundaries indicated on the boring logs represent the approximate locations of
changes in soil and rock types; in-situ, the transition of materials may be gradual and indistinct.
Earth Engineering Consultants, LLC
EEC Project No. 1172058B
August 17, 2018
Page 4
GROUNDWATER OBSERVATIONS
Observations were made while drilling and approximately 24 hours after the completion of drilling
to detect the presence and level of groundwater. Groundwater was observed in the preliminary test
borings at depths ranging from approximately 24 to 29 feet below existing site grades. The borings
were backfilled after the 24-hour measurements, and therefore subsequent groundwater
measurements were not made. A diagram outlining approximate areas with relatively shallow
groundwater measurements has been provided along with a groundwater contour map, (please refer
to Figure Nos. 2 and 3), included in the appendix of this report. Groundwater measurements
provided with this report are indicative of groundwater levels at the locations and at the time the
borings/groundwater measurements were completed. In general, the groundwater piezometric flow
is in the south direction.
Fluctuations in ground water levels and in the location and amount of perched water may occur over
time depending on variations in hydrologic conditions, irrigation activities on surrounding properties
and other conditions not apparent at the time of this report.
ANALYSIS AND RECOMMENDATIONS
Swell/Consolidation Test Results
Swell/consolidation testing is performed to evaluate the swell or collapse potential of soil or bedrock to
assist in determining/evaluating foundation, floor slab and/or pavement design criteria. In the
swell/consolidation test, relatively undisturbed samples obtained directly from the California barrel
sampler are placed in a laboratory apparatus and inundated with water under a pre-established load.
The swell-index is the resulting amount of swell or collapse under the initial loading condition
expressed as a percent of the sample’s initial thickness. After the inundation period, additional
incremental loads are applied to evaluate swell pressure and/or consolidation.
As a part of our laboratory testing, we conducted five (5) swell/consolidation tests on samples of the
overburden cohesive subsoils at varying depths. The swell index values for the samples analyzed
revealed low to moderate swell characteristics of approximately (+) 0.7 to (+) 5.3% for the
Earth Engineering Consultants, LLC
EEC Project No. 1172058B
August 17, 2018
Page 5
overburden lean clays pre-loaded at 150 psf and 500 psf. Table 1 summarized the swell-
consolidation laboratory tests.
Table I – Swell Consolidation Test Results
Boring
No.
Depth,
ft.
Material Type
Swell Consolidation Test Results
In-Situ
Moisture
Content,
%
Dry
Density,
(pcf)
Inundation
Pressure,
(psf)
Swell Index, %
(+/-)
1 2 Lean Clay with Sand (CL) 8.2 113.3 150 (+) 5.3
1 9 Lean Clay with Sand (CL) 15.7 115.7 500 (+) 1.3
2 4 Sandy Lean Clay (CL) 13.3 116.3 500 (+) 0.7
4 4 Sandy Lean Clay (CL) 7.8 109.6 500 (+) 2.4
5 2 Clayey Sand (SC) 9.2 109.6 150 (+) 3.9
The Colorado Association of Geotechnical Engineers (CAGE) uses the following information to
provide uniformity in terminology between geotechnical engineers to provide a relative correlation risk
performance to measured swell. “The representative percent swell values are not necessarily measured
values; rather, they are a judgment of the swell of the soil and/or bedrock profile likely to influence
slab performance.” Geotechnical engineers use this information to also evaluate the swell potential
risks for foundation performance based on the risk categories.
TABLE II: Recommended Representative Swell Potential Descriptions and Corresponding
Slab Performance Risk Categories
Slab Performance Risk Category Representative Percent Swell
(500 psf Surcharge)
Representative Percent Swell
(1000 psf Surcharge)
Low 0 to < 3 0 < 2
Moderate 3 to < 5 2 to < 4
High 5 to < 8 4 to < 6
Very High > 8 > 6
Based on the laboratory test results, the samples of overburden subsoils analyzed ranged from low to
moderate risk.
Earth Engineering Consultants, LLC
EEC Project No. 1172058B
August 17, 2018
Page 6
Site Preparation
All existing vegetation and/or topsoil should be removed from beneath site fills, roadways or
building subgrade areas. Stripping depths should be expected to vary, depending, in part, on past
agricultural activities. In addition, any soft/loose native soils or any existing fill materials without
documentation of controlled fill placement should be removed from improvement and/or new fill
areas. Due to the moderate swell potential of the near surface lean clay soils we recommend a
minimum 2 feet of overexcavation and replacement below floor slabs, exterior flatwork, and
pavements.
After stripping and completing all cuts, any over excavation, and prior to placement of any fill, floor
slabs or pavements, we recommend the exposed soils be scarified to a minimum depth of 9 inches,
adjusted in moisture content and compacted to at least 95% of the material's maximum dry density
as determined in accordance with ASTM Specification D698, the standard Proctor procedure. The
moisture content of the scarified materials should be adjusted to be within a range of 2% of
standard Proctor optimum moisture at the time of compaction.
In general, fill materials required to develop the building areas or site pavement subgrades should
consist of approved, low-volume change materials which are free from organic matter and debris.
The near surface lean clay soils or imported granular structural fill could be used as fill in these
areas. The claystone bedrock should not be used for fill in site improvement areas. We recommend
the fill soils be placed in loose lifts not to exceed 9 inches thick, adjusted in moisture content and
compacted to at least 95% of the material’s maximum dry density as determined in accordance with
the standard Proctor procedure. The moisture content of predominately clay soils should be adjusted
to be within the range of ± 2% of optimum moisture content at the time of placement. Granular soil
should be adjusted to a workable moisture content.
Care should be taken after preparation of the subgrades to avoid disturbing the subgrade materials.
Positive drainage should be developed away from structures and across and away from pavement
edges to avoid wetting of subgrade materials. Subgrade materials allowed to become wetted
subsequent to construction of the residences and/or pavements can result in unacceptable
performance of those improvements.
Earth Engineering Consultants, LLC
EEC Project No. 1172058B
August 17, 2018
Page 7
Areas of greater fills, especially within the deeper utility alignments, may experience settlement.
Settlement on the order of 1-inch or more per each 10 feet of fill depth would be estimated. The rate
of settlement will be dependent on the type of fill material placed and construction methods.
Granular soils will consolidate essentially immediately upon placement of overlying loads.
Cohesive soils will consolidate at a slower rate. Preloading and/or surcharging the fill areas could be
considered to induce additional settlement in these areas prior to construction of improvements in or
on the fills. Unless positive steps are taken to pre-consolidate the fill materials, special care will be
needed for construction of improvements supported on or within these areas.
Foundation Systems – General Considerations
Conventional type spread footings bearing on native subsoils or engineered controlled fill material
were evaluated for use on the site; however final subsurface explorations should be performed after
building footprints and elevations have been better defined and actual design loads determined.
Depending on the expected building loads, alternative foundation systems could be considered and we
would be pleased to provide additional recommendations upon request.
Preliminary Spread Footing Foundation Recommendations
We anticipate use of conventional footing foundations could be considered for lightly to moderately
loaded structures at this site. We expect footing foundations would be supported either on the native
soils or on newly placed and compacted fills.
For design of footing foundations bearing on approved native subsoils or on properly placed and
compacted fill materials as outlined above, maximum net allowable total load soil bearing pressures
on the order of 1,500 to 2,500 psf could be considered depending upon the specific fill material
used. The net bearing pressure refers to the pressure at foundation bearing level in excess of the
minimum surrounding overburden pressure. Total load would include full dead and live loads.
Exterior foundations and foundations in unheated areas are typically located at least 30 inches below
adjacent exterior grade to provide frost protection. Formed continuous footings would have
minimum widths of 12 to 16 inches and isolated column foundations would have a minimum width
Earth Engineering Consultants, LLC
EEC Project No. 1172058B
August 17, 2018
Page 8
of 24 to 30 inches. Trenched foundations could probably be used in the near surface soils. If used,
trenched foundations would have a minimum width of 12 inches and formed continuous foundations
a minimum width of 8 inches.
Care should be taken to avoid placement of structures partly on native soils and partly on newly
placed fill materials to avoid differential settlement.
Preliminary Floor Slab/Exterior Flatwork Subgrades
We recommend all existing vegetation/topsoil be removed from beneath the floor slab and exterior
flatwork areas as outlined in the section titled Site Preparation. Due to the moderate swell potential
of the near surface lean clay soils, an over excavation procedure should be considered below floor
slabs. The over excavation should be expected to extend to a minimum depth of 2 feet and should
extend 8 inches laterally for every 12 inches of depth. After stripping and completing all cuts and
any over excavation, and prior to placement of any flatwork concrete or fill, the exposed subgrades
should be scarified, adjusted in moisture content and compacted. If the subgrades become dry and
desiccated prior to floor slab construction, it may be necessary to rework the subgrades prior to floor
slab placement.
Preliminary Pavement Subgrades
The average swell index for the preliminary test borings is above the LCUASS pavement design
standard maximum value of 2%. Therefore, a swell mitigation plan consisting of a 2-foot over
excavation and replacement concept or fly ash treatment of the subgrades should be considered.
All existing vegetation and/or topsoil and any soft or loose materials should be removed from
pavement areas. After stripping, completing all cuts, and any over excavation, and prior to
placement of any fill or pavements, we recommend the exposed soils be scarified to a minimum
depth of 9 inches, adjusted in moisture content and compacted to at least 95% of the material's
maximum dry density as determined in accordance with ASTM Specification D698, the standard
Proctor procedure. The moisture content of the scarified soils should be adjusted to be within the
range of 2% of standard Proctor optimum moisture.
Earth Engineering Consultants, LLC
EEC Project No. 1172058B
August 17, 2018
Page 9
Fill materials required to develop the pavement subgrades should consist of approved, low-volume
change materials, free from organic matter and debris. The near surface lean clay and/or clayey sand
soils could be used for fill in these areas. We recommend those fill soils be placed in loose lifts not
to exceed 9 inches thick, adjusted in moisture content and compacted to at least 95% of the
material's standard Proctor maximum dry density. Settlement in the fill areas should be expected as
previously outlined with possible mitigation including surcharging or preloading.
After completion of the pavement subgrades, care should be taken to prevent disturbance of those
materials prior to placement of the overlying pavements. Soils which are disturbed by construction
activities should be reworked in-place or, if necessary, removed and replaced prior to placement of
overlying fill or pavements.
Depending on final site grading and/or weather conditions at the time of pavement construction,
stabilization of a portion of the site pavement subgrades may be required to develop suitable
pavement subgrades. The site clayey soils could be subject to instability at higher moisture contents.
Stabilization could also be considered as part of the pavement design, although prior to finalizing
those sections, a stabilization mix design would be required.
Preliminary Site Pavements
Pavement sections are based on traffic volumes and subgrade strength characteristics. Based on the
observed subsoils, an R-value of 10 would be appropriate for design of the pavements supported on
the subgrade soils. Suggested preliminary pavement sections are provided below in Table II. Thicker
pavement sections may be required for roadways classified as major collectors. A final pavement
design thickness evaluation will be determined when a pavement design exploration is completed
(after subgrades are developed to ± 6 inches of design and wet utilities installed in the roadways).
The projected traffic may vary from the traffic assumed from the roadway classification based on a
site-specific traffic study.
Earth Engineering Consultants, LLC
EEC Project No. 1172058B
August 17, 2018
Page 10
TABLE III – PRELIMINARY PAVEMENT SECTIONS
Light Duty Areas Heavy Duty Areas
18-kip EDLA
18-kip ESAL
Reliability
Resilient Modulus (Based on R-Value=10)
PSI Loss
7
51,100
75%
3562
2.5
15
109,500
80%
3562
2.2
Design Structure Number 2.47 2.88
Composite Section – Option A (assume Stable Subgrade)
Hot Mix Asphalt
Aggregate Base Course
Structure Number
4"
7"
(2.53)
5"
7"
(2.97)
Composite Section with Fly Ash Treated Subgrade
Hot Mix Asphalt
Aggregate Base Course
Fly Ash Treated Subgrade (assume half-credit)
Structure Number
3-1/2"
6"
12"
(2.80)
4"
6"
12"
(3.02)
PCC (Non-reinforced) – placed on a stable subgrade 5½" 6"
Asphalt surfacing should consist of grading S-75 or SX-75 hot bituminous pavement with PG 64-22
or PG 58-28 binder in accordance with Larimer County Urban Area Street Standard (LCUASS)
requirements. Aggregate base should be consistent with CDOT requirements for Class 5 or Class 6
aggregate base. A suggested specification for stabilization of the subgrades with class C fly ash is
included with this report.
As previously mentioned a final subgrade investigation and pavement design should be performed in
general accordance with the LCUASS Pavement Design Criteria prior to placement of any pavement
sections, to determine the required pavement section after design configurations, roadway utilities
have been installed and roadway have been prepared to “rough” subgrade elevations have been
completed.
Underground Utility Systems
All piping should be adequately bedded for proper load distribution. It is suggested that clean, graded
gravel compacted to 70 percent of Relative Density ASTM D4253 be used as bedding. Where utilities
are excavated below groundwater, temporary dewatering will be required during excavation, pipe
Earth Engineering Consultants, LLC
EEC Project No. 1172058B
August 17, 2018
Page 11
placement and backfilling operations for proper construction. Utility trenches should be excavated on
safe and stable slopes in accordance with OSHA regulations as further discussed herein. Backfill
should consist of the on-site soils or approved imported materials. The pipe backfill should be
compacted to a minimum of 95 percent of Standard Proctor Density ASTM D698.
Water Soluble Sulfates – (SO4)
The water soluble sulfate (SO4) content of the on-site overburden subsoils, taken during our
subsurface exploration at random locations and intervals are provided below. Based on reported
sulfate content test results, the Class/severity of sulfate exposure for concrete in contact with the on-
site subsoils is provided in this report.
TABLE IV - Water Soluble Sulfate Test Results
Sample Location Description
Soluble Sulfate Content
(mg/kg)
Soluble Sulfate Content
(%)
B-1, S-1, at 2’ Lean Clay with Sand (CL) 340 0.03
B-5, S-2, at 4’
Clayey Sand / Sandy Lean
Clay (SC / CL)
90 0.01
Based on the results as presented above, ACI 318, Section 4.2 indicates the site soils and underlying
bedrock have a low risk of sulfate attack on Portland cement concrete, therefore, ACI Class 0
requirements should be followed. Foundation concrete should be designed in accordance with the
provisions of the ACI Design Manual, Section 318, Chapter 4. These results are being compared to
the following table.
Other Considerations and Recommendations
Excavations into the on-site soils will encounter a variety of conditions. Excavations into the clays
can be expected to stand on relatively steep temporary slopes during construction. Groundwater
seepage should also be anticipated for utility excavations. Pumping from sumps may be utilized to
control water within the excavations. Well points may be required for significant groundwater flow,
or where excavations penetrate groundwater to a significant depth. The individual contractor(s)
should be made responsible for designing and constructing stable, temporary excavations as required
Earth Engineering Consultants, LLC
EEC Project No. 1172058B
August 17, 2018
Page 12
to maintain stability of both the excavation sides and bottom. All excavations should be sloped or
shored in the interest of safety following local and federal regulations, including current OSHA
excavation and trench safety standards.
Positive drainage should be developed away from the structures and pavement areas with a
minimum slope of 1 inch per foot for the first 10 feet away from the improvements in landscape
areas. Care should be taken in planning of landscaping (if required) adjacent to the buildings to
avoid features which would pond water adjacent to the foundations or stemwalls. Placement of
plants which require irrigation systems or could result in fluctuations of the moisture content of the
subgrade material should be avoided adjacent to site improvements. Irrigation systems should not be
placed within 5 feet of the perimeter of the buildings and parking areas. Spray heads should be
designed not to spray water on or immediately adjacent to the structures or site pavements. Roof
drains should be designed to discharge at least 5 feet away from the structures and away from the
pavement areas.
GENERAL COMMENTS
The analysis and recommendations presented in this report are based upon the data obtained from
the soil borings performed at the indicated locations and from any other information discussed in this
report. This report does not reflect any variations which may occur between borings or across the
site. The nature and extent of such variations may not become evident until construction. If
variations appear evident, it will be necessary to re-evaluate the recommendations of this report.
Site specific explorations will be necessary for the proposed site buildings.
It is recommended that the geotechnical engineer be retained to review the plans and specifications
so that comments can be made regarding the interpretation and implementation of our geotechnical
recommendations in the design and specifications. It is further recommended that the geotechnical
engineer be retained for testing and observations during earthwork and foundation construction
phases to help determine that the design requirements are fulfilled.
This report has been prepared for the exclusive use of HF2M Colorado for specific application to the
project discussed and has been prepared in accordance with generally accepted geotechnical
Earth Engineering Consultants, LLC
EEC Project No. 1172058B
August 17, 2018
Page 13
engineering practices. No warranty, express or implied, is made. In the event that any changes in
the nature, design or location of the project as outlined in this report are planned, the conclusions
and recommendations contained in this report shall not be considered valid unless the changes are
reviewed and the conclusions of this report modified or verified in writing by the geotechnical
engineer.
Earth Engineering Consultants, LLC
DRILLING AND EXPLORATION
DRILLING & SAMPLING SYMBOLS:
SS: Split Spoon ‐ 13/8" I.D., 2" O.D., unless otherwise noted PS: Piston Sample
ST: Thin‐Walled Tube ‐ 2" O.D., unless otherwise noted WS: Wash Sample
R: Ring Barrel Sampler ‐ 2.42" I.D., 3" O.D. unless otherwise noted
PA: Power Auger FT: Fish Tail Bit
HA: Hand Auger RB: Rock Bit
DB: Diamond Bit = 4", N, B BS: Bulk Sample
AS: Auger Sample PM: Pressure Meter
HS: Hollow Stem Auger WB: Wash Bore
Standard "N" Penetration: Blows per foot of a 140 pound hammer falling 30 inches on a 2‐inch O.D. split spoon, except where noted.
WATER LEVEL MEASUREMENT SYMBOLS:
WL : Water Level WS : While Sampling
WCI: Wet Cave in WD : While Drilling
DCI: Dry Cave in BCR: Before Casing Removal
AB : After Boring ACR: After Casting Removal
Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils, the indicated
levels may reflect the location of ground water. In low permeability soils, the accurate determination of ground water levels is not
possible with only short term observations.
DESCRIPTIVE SOIL CLASSIFICATION
Soil Classification is based on the Unified Soil Classification
system and the ASTM Designations D‐2488. Coarse Grained
Soils have move than 50% of their dry weight retained on a
#200 sieve; they are described as: boulders, cobbles, gravel or
sand. Fine Grained Soils have less than 50% of their dry weight
retained on a #200 sieve; they are described as : clays, if they
are plastic, and silts if they are slightly plastic or non‐plastic.
Major constituents may be added as modifiers and minor
constituents may be added according to the relative
proportions based on grain size. In addition to gradation,
coarse grained soils are defined on the basis of their relative in‐
place density and fine grained soils on the basis of their
consistency. Example: Lean clay with sand, trace gravel, stiff
(CL); silty sand, trace gravel, medium dense (SM).
CONSISTENCY OF FINE‐GRAINED SOILS
Unconfined Compressive
Strength, Qu, psf Consistency
< 500 Very Soft
500 ‐ 1,000 Soft
1,001 ‐ 2,000 Medium
2,001 ‐ 4,000 Stiff
4,001 ‐ 8,000 Very Stiff
8,001 ‐ 16,000 Very Hard
RELATIVE DENSITY OF COARSE‐GRAINED SOILS:
N‐Blows/ft Relative Density
0‐3 Very Loose
4‐9 Loose
10‐29 Medium Dense
30‐49 Dense
50‐80 Very Dense
80 + Extremely Dense
PHYSICAL PROPERTIES OF BEDROCK
DEGREE OF WEATHERING:
Slight Slight decomposition of parent material on
joints. May be color change.
Moderate Some decomposition and color change
throughout.
High Rock highly decomposed, may be extremely
broken.
Group
Symbol
Group Name
Cu≥4 and 1<Cc≤3
E
GW Well-graded gravel
F
Cu<4 and/or 1>Cc>3
E
GP Poorly-graded gravel
F
Fines classify as ML or MH GM Silty gravel
G,H
Fines Classify as CL or CH GC Clayey Gravel
F,G,H
Cu≥6 and 1<Cc≤3
E
SW Well-graded sand
I
Cu<6 and/or 1>Cc>3
E
SP Poorly-graded sand
I
Fines classify as ML or MH SM Silty sand
G,H,I
Fines classify as CL or CH SC Clayey sand
G,H,I
inorganic PI>7 and plots on or above "A" Line CL Lean clay
K,L,M
PI<4 or plots below "A" Line ML Silt
K,L,M
organic Liquid Limit - oven dried Organic clay
K,L,M,N
Liquid Limit - not dried Organic silt
K,L,M,O
inorganic PI plots on or above "A" Line CH Fat clay
K,L,M
PI plots below "A" Line MH Elastic Silt
K,L,M
organic Liquid Limit - oven dried Organic clay
K,L,M,P
Liquid Limit - not dried Organic silt
K,L,M,O
Highly organic soils PT Peat
(D30)2
D10 x D60
GW-GM well graded gravel with silt NPI≥4 and plots on or above "A" line.
GW-GC well-graded gravel with clay OPI≤4 or plots below "A" line.
GP-GM poorly-graded gravel with silt PPI plots on or above "A" line.
GP-GC poorly-graded gravel with clay QPI plots below "A" line.
SW-SM well-graded sand with silt
SW-SC well-graded sand with clay
SP-SM poorly graded sand with silt
SP-SC poorly graded sand with clay
Earth Engineering Consultants, LLC
IIf soil contains >15% gravel, add "with gravel" to
group name
JIf Atterberg limits plots shaded area, soil is a CL-
ML, Silty clay
Unified Soil Classification System
1
2
1
2
Boring Location Diagram
40-Acre Parcel, West of 800-acre mixed used Development for PSD
Fort Collins, Colorado
EEC Project #: 1172058B Date: August 2018
Approximate Boring
Locations
1
EARTH ENGINEERING CONSULTANTS, LLC
Legend
Site Potos
Potos taen in approximate
location, in direction of arro
TURNBERRY ROAD AND ROAD 50 DEVELOPMENT
FORT COLLINS, COLORADO
EEC PROJECT NO. 1172058B
AUGUST 2018
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
DISKED FIELD _ _
1
LEAN CLAY with SAND (CL) _ _
brown 2
very stiff to stiff _ _ % @ 150 psf
with calcareous deposits CS 3 18 9000+ 8.2 107.5 30 20 2400 psf 5.3%
_ _
4
_ _
SS 5 15 9000 8.6
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 11 9000 15.7 110.8 32 19 76.5 2200 psf 1.3%
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 12 6000 18.3
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 14 7000 18.1 109.4
_ _
21
_ _
22
_ _
23
_ _
24
light brown _ _
SS 25 5 1000 21.2
Continued on Sheet 2 of 2 _ _
Earth Engineering Consultants, LLC
40-ACRE PARCEL W OF 800-ACRE MIXED USE DEVELOPMENT FOR PSD
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
Continued from Sheet 1 of 2 26
_ _
LEAN CLAY with SAND (CL) 27
light brown / red _ _
stiff 28
with gypsum crystals _ _
29
_ _
CS 30 14 2000 18.4 108.8
BOTTOM OF BORING DEPTH 30.0' _ _
31
_ _
32
_ _
33
_ _
34
_ _
35
_ _
36
_ _
37
_ _
38
_ _
39
_ _
40
_ _
41
_ _
42
_ _
43
_ _
44
_ _
45
_ _
46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants, LLC
40-ACRE PARCEL W OF 800-ACRE MIXED USE DEVELOPMENT FOR PSD
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
DISKED FIELD _ _
1
SANDY LEAN CLAY (CL) _ _
brown 2
stiff to very stiff _ _
with calcareous deposits 3
_ _
4
_ _
CS 5 12 9000+ 13.3 115.2 27 15 56.2 1300 psf 0.7%
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 8 8500 14.0
_ _
11
_ _
12
_ _
13
_ _
14
_ _
with gypsum crystals CS 15 18 8500 16.9 111.9
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 20 9000+ 16.6
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 12 7500 19.9 106.7
Continued on Sheet 2 of 2 _ _
Earth Engineering Consultants, LLC
40-ACRE PARCEL W OF 800-ACRE MIXED USE DEVELOPMENT FOR PSD
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
Continued from Sheet 1 of 2 26
_ _
SANDY LEAN CLAY (CL) 27
brown _ _
very stiff 28
_ _
29
_ _
SS 30 17 6000 16.2
_ _
BOTTOM OF BORING DEPTH 30.5' 31
_ _
32
_ _
33
_ _
34
_ _
35
_ _
36
_ _
37
_ _
38
_ _
39
_ _
40
_ _
41
_ _
42
_ _
43
_ _
44
_ _
45
_ _
46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants, LLC
40-ACRE PARCEL W OF 800-ACRE MIXED USE DEVELOPMENT FOR PSD
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
DISKED FIELD _ _
1
LEAN CLAY with SAND (CL) _ _
brown 2
very stiff _ _
with calcareous deposits 3
_ _
4
_ _
CS 5 17 9000+ 13.7 111.0 38 26 70.8
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 12 9000+ 16.8
_ _
11
_ _
12
_ _
13
_ _
14
with gypsum crystals _ _
CS 15 14 6500 20.8 105.4
_ _
16
_ _
17
_ _
18
_ _
19
_ _
brown / grey / rust SS 20 11 6000 23.7
_ _
21
_ _
22
_ _
23
_ _
24
brown / red _ _
CS 25 14 4000 18.7 110.7
Continued on Sheet 2 of 2 _ _
Earth Engineering Consultants, LLC
40-ACRE PARCEL W OF 800-ACRE MIXED USE DEVELOPMENT FOR PSD
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
Continued from Sheet 1 of 2 26
_ _
LEAN CLAY with SAND (CL) 27
brown / rust _ _
stiff 28
_ _
29
_ _
with trace gravel SS 30 20 2500 21.6
_ _
31
_ _
32
_ _
33
_ _
34
_ _
SAND & GRAVEL (SP/GP) CS 35 14 -- 10.9 118.0
brown / red _ _
medium dense 36
_ _
37
_ _
38
_ _
39
_ _
SS 40 17 -- 12.4
_ _
BOTTOM OF BORING DEPTH 40.5' 41
_ _
42
_ _
43
_ _
44
_ _
45
_ _
46
_ _
47
_ _
48
_ _
49
_ _
50
_ _
Earth Engineering Consultants, LLC
40-ACRE PARCEL W OF 800-ACRE MIXED USE DEVELOPMENT FOR PSD
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
_ _
1
SANDY LEAN CLAY (CL) _ _
brown 2
very stiff to stff _ _
3
_ _
4
_ _
CS 5 23 9000 7.8 107.1 1600 psf 2.4%
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 9 9000 11.1
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CS 15 13 9000 13.8 112.5
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 14 6000 16.7
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 11 3000 21.0 104.3
Continued on Sheet 2 of 2 _ _
Earth Engineering Consultants, LLC
40-ACRE PARCEL W OF 800-ACRE MIXED USE DEVELOPMENT FOR PSD
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
Continued from Sheet 1 of 2 26
_ _
SANDY LEAN CLAY (CL) 27
brown _ _
stiff to very stiff 28
_ _
29
_ _
SS 30 10 3000 22.6
_ _
31
_ _
32
_ _
33
_ _
34
light brown _ _
CS 35 13 1000 17.4 113.5
_ _
36
_ _
37
_ _
38
_ _
39
with gypsum crystals _ _
SS 40 16 4000 19.4
_ _
BOTTOM OF BORING DEPTH 40.5' 41
_ _
42
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43
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44
_ _
45
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46
_ _
47
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48
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49
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50
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Earth Engineering Consultants, LLC
40-ACRE PARCEL W OF 800-ACRE MIXED USE DEVELOPMENT FOR PSD
FORT COLLINS, COLORADO
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
SPARSE VEGETATION / WEEDS _ _
1
CLAYEY SAND / SANDY LEAN CLAY (SC / CL) _ _
brown 2
medium dense / very stiff to stiff _ _ % @ 150 psf
CS 3 17 9000+ 9.2 111.0 30 20 48.2 1200 psf 3.9%
_ _
4
with calcareous deposits _ _
SS 5 12 9000+ 11.5
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 8 9000+ 11.3 112.3
_ _
11
_ _
12
_ _
13
_ _
14
with gypsum crystals _ _
SS 15 11 4500 17.8
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 9 3500 20.1 106.9
_ _
21
_ _
22
_ _
23
_ _
24
brown / red / gray _ _
SS 25 15 6000 24.2
Continued on Sheet 2 of 2 _ _
Earth Engineering Consultants, LLC
40-ACRE PARCEL W OF 800-ACRE MIXED USE DEVELOPMENT FOR PSD
DATE:
RIG TYPE: CME55
FOREMAN: DG
AUGER TYPE: 4" CFA
SPT HAMMER: AUTOMATIC
SOIL DESCRIPTION D N QU MC DD -200
TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
Continued from Sheet 1 of 2 26
_ _
CLAYEY SAND / SANDY LEAN CLAY (SC / CL) 27
brown / red _ _
medium dense / stiff 28
with trace gravel _ _
29
_ _
CS 30 15 6000 19.2
_ _
31
_ _
32
_ _
33
_ _
34
with intermittent sand & gravel seams _ _
SS 35 11 -- 21.4
_ _
36
_ _
37
_ _
38
_ _
39
SAND & GRAVEL (SP/GP) _ _
brown, medium dense SS 40 11 -- 16.2
with trace clay zones _ _
BOTTOM OF BORING DEPTH 40.5' 41
_ _
42
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Earth Engineering Consultants, LLC
40-ACRE PARCEL W OF 800-ACRE MIXED USE DEVELOPMENT FOR PSD
FORT COLLINS, COLORADO
Project:
Location:
Project #:
Date:
40-Acre Parcel W of 800-Acre Mixed Use Development for PSD
Fort Collins, Colorado
1172058B
August 2018
Beginning Moisture: 8.2% Dry Density: 113.3 pcf Ending Moisture: 18.4%
Swell Pressure: 2400 psf % Swell @ 150: 5.3%
Sample Location: Boring 1, Sample 1, Depth 2'
Liquid Limit: 30 Plasticity Index: 20 % Passing #200: - -
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Lean Clay with Sand (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
40-Acre Parcel W of 800-Acre Mixed Use Development for PSD
Fort Collins, Colorado
1172058B
August 2018
Beginning Moisture: 15.7% Dry Density: 115.7 pcf Ending Moisture: 17.8%
Swell Pressure: 2200 psf % Swell @ 500: 1.3%
Sample Location: Boring 1, Sample 3, Depth 9'
Liquid Limit: 32 Plasticity Index: 19 % Passing #200: 76.5%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Lean Clay with Sand (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
40-Acre Parcel W of 800-Acre Mixed Use Development for PSD
Fort Collins, Colorado
1172058B
August 2018
Beginning Moisture: 13.3% Dry Density: 116.3 pcf Ending Moisture: 17.8%
Swell Pressure: 1300 psf % Swell @ 500: 0.7%
Sample Location: Boring 2, Sample 1, Depth 4'
Liquid Limit: 27 Plasticity Index: 15 % Passing #200: 56.2%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
40-Acre Parcel W of 800-Acre Mixed Use Development for PSD
Fort Collins, Colorado
1172058B
August 2018
Beginning Moisture: 7.8% Dry Density: 109.6 pcf Ending Moisture: 19.7%
Swell Pressure: 1600 psf % Swell @ 500: 2.4%
Sample Location: Boring 4, Sample 1, Depth 4'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Sandy Lean Clay (CL)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
Project:
Location:
Project #:
Date:
40-Acre Parcel W of 800-Acre Mixed Use Development for PSD
Fort Collins, Colorado
1172058B
August 2018
Beginning Moisture: 9.2% Dry Density: 109.6 pcf Ending Moisture: 19.0%
Swell Pressure: 1200 psf % Swell @ 150: 3.9%
Sample Location: Boring 5, Sample 1, Depth 2'
Liquid Limit: 30 Plasticity Index: 20 % Passing #200: 48.2%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Brown Clayey Sand (SC)
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
0.01 0.1 1 10
Percent Movement
Load (TSF)
Consolidatio Swell
Water Added
4396 GREENFIELD DRIVE
WINDSOR, COLORADO 80550
(970) 545-3908 FAX (970) 663-0282
www.earth-engineering.com
November 16, 2017
Chase Merritt
1637 Pearl Street
Suite 204
Boulder, Colorado 80302
Attn: Mr. Max Moss (max@chasemerritt.com)
Re: Geologic Hazards and Mineral Extraction Evaluation Report
800-Acre Mixed Use Development
South of LCR 52 and West of Anheuser Busch
Larimer County, Colorado
EEC Project No. 1172058
Mr. Moss:
Earth Engineering Consultants, LLC (EEC) personnel have completed the geologic hazards and
mineral extraction evaluation you requested for the referenced project. That evaluation was
completed by reviewing readily available data concerning soil and groundwater conditions for
the site, principally through review of United States Geological Survey (USGS)/Colorado
Geological Survey (CGS) and United States Department of Agriculture Soil Conservation
Service (SCS) published information. A listing of the references reviewed as a part of the
geologic hazard evaluation is included with this report. In addition, a site observation of the
property was conducted on November 7, 2017.
The approximate 800-acre development area is generally located within the east half of Section
33, and the west half of Section 33, Township 8 North, Range 68 West and the north half of
Section 4 Township 7 North, Range 68 West of the 6th Prime Meridian in Larimer County,
Colorado. It is our understanding that the approximate 800-acre development area is planned to
be developed for residential, commercial, and industrial use, including utility and interior
roadway infrastructure. The purpose of this evaluation is to identify potential geologic hazards
and potential mineral resources which may conflict with proposed development. The conclusions
and recommendations presented in this report are based upon the acquired field data, review of
the available literature and previous experience with similar geologic conditions in this area. A
Earth Engineering Consultants, LLC
EEC Project No. 1172058 – Geologic Report
November 16, 2017
Page 2
Preliminary Subsurface Exploration conducted by our firm (EEC Project No. 1172058, dated
October 2, 2017) was used to provide additional subsurface information.
The site can generally be described as follows. Slopes on the site appear to be gentle to the
south-southeast. The Number 8 Outlet Canal flows south and defines the property’s western
border along the center of Section 32 and the Larimer and Weld Canal flows east and defines the
southern border within the Northeast Quarter of Section 4. Larimer County Road 52 defines the
northern property boundary and the Burlington Northern Santa Fa Railroad line defines the east
boundary in Section 33. Overall site drainage appears to be from northwest to southeast and
within shallow valleys. Past agricultural use likely altered the shape of the shallow valleys,
however, the overall property drainage appears to reflect native conditions. No apparent areas of
slope instability were observed during our site visit. The property currently appears to be
agricultural land. Three (3) oil/gas wells are reported within the property boundary.
RESEARCH
Soil/Geologic Review
The site geology presented in this report is based upon the acquired field data, review of the
available literature and maps, and previous experience with similar geologic conditions in this
area. The locations of geologic features are approximate and should be considered accurate only
to the degree implied by the methods used to make those measurements.
The project site lies in the Colorado Piedmont Section of the Great Plains Physiographic
Province. The sediments which compose the Colorado Piedmont were formed when uplift of the
present day Rocky Mountains in Late Cretaceous-Eocene times (70-30 million years ago)
produced a large increase of stream sediments resulting in deposition of sediments on the flanks
next to the mountain belt and outlying areas. The Colorado Piedmont is an elongated trough in
the Great Plains, adjacent to the Front Range of the Southern Rockies. The Colorado Piedmont
was formed when uplift of the area in Miocene times (20-5 million years ago) produced an
increase of stream erosion resulting in scouring next to the foothills and outlying areas. The
Piedmont is bordered by the southern Rockies to the west, Great Plains escarpment to the
northeast, and Palmer Divide to the south.
Earth Engineering Consultants, LLC
EEC Project No. 1172058 – Geologic Report
November 16, 2017
Page 3
Structurally, the site lies within the Denver Basin, a thick accumulation of Paleozoic and
Mesozoic Era sediments involved with down-warping of the basin area and uplift of the adjacent
highlands. Small anticlinal folds occur adjacent to the Front Range. It is our understanding that
faulting has not taken place in the recent historic past in this area.
The U.S Geological Survey describes the bedrock underlying the site consisting of the Upper
Shale Member of the Pierre Shale (Upper Cretaceous) (Kpu). The Upper Shale Member of the
Pierre Shale generally consists of claystone interbedded with siltstones and minor sandstones.
The surficial soils at the project site are described as eolian deposits (Pleistocene and Holocene)
and valley fill deposits (Pleistocene and Holocene). The eolian deposits are described as fine-
grained sand, silt and clay and the valley fill deposits are described as arkosic gravel and sand
deposit. The United States Department of Agriculture Soil Conservation Survey (1) map describes
the surficial soils mainly as sand and clay loam. The surficial soils are generally classified as
exhibiting slight erosion potentials with low to high shrink/swell potential. In general, the near
surface soils at this site appear to consist of moderately plastic clay soils with varying amounts of
silt and sand to non-plastic to slightly plastic sand with varying amounts of silt and slay. The
upper soil is overlying the Pierre Shale Formation (Upper Cretaceous), described as a claystone
shale containing beds of sandstone and siltstone, as illustrated on the Geologic Map of the Lower
Cache La Poudre River Basin, North-Central Colorado by Lloyd A. Hershey and Paul A.
Schneider, Jr., 1972.
Areas of potentially expansive clays and shallow bedrock strata may exist on the parcel. A
thorough geotechnical engineering exploration should be conducted at each proposed building
site to identify if these conditions exist.
Landslide
Landslides as defined by CGS form on a preferential weakness zone causing a ‘dry’ mass of rock
to slide downhill under the pull of gravity. Slopes are very gentle on this parcel and no zones of
preferential weakness were observed during our site visit or on aerial photos available on Google
Earth. We therefore conclude that the risk from landslide to be negligible at this particular
location under current conditions.
Earth Engineering Consultants, LLC
EEC Project No. 1172058 – Geologic Report
November 16, 2017
Page 4
Oil and Gas Potential
A review of the Colorado Oil and Gas Conservation Commission (COGCC) database (a Division
of the Colorado Department of Natural Resources) and Oil and Gas Fields Map of Colorado:
Colorado Geological Survey Map Series 26 (2) indicate three (3) oil/gas wells (abandoned) exists
on the site. The site is situated approximately one mile southeast of the Fort Collins/Wellington
Oil/Gas Field.
Based on the available information, some of the sedimentary bedrock units located deep beneath
this parcel may produce oil and gas. However, due to the manner in which oil/gas is recovered,
development of the site should not greatly impact the extraction of this resource, as described,
beneath the project site should future extraction be proposed.
Coal Mines
The Colorado Geological Survey classifies the area of the project site to be within a low potential
area for coal formation and recovery. A review of the Colorado Department of Natural
Resources Division of Reclamation Mining and Safety (3) was performed to locate nearby active
and historical coal mining operations. No coal mines were listed in the vicinity of the project site.
Based on the available information and geology of the area, we believe that no deposits of coal
are located on the property which are of commercial grade or are an economical resource.
Radiation
A review of the available information from the Colorado Geologic Survey (a Division of the
Colorado Department of Natural Resources) indicates that no deposits of uranium have been
identified within the Pierre Shale Formation in Larimer County. Additionally, deposits of
uranium oxide are known to exist within the Fox Hills Sandstone, although known deposits are
several miles north and east of this site. Erosion in the geologic past has removed the Fox Hills
Sandstone from this parcel. At this time, we anticipate no radiation hazards based on our
understanding of these deposits and past land usage. However, we recommend that preliminary
radon mitigation measures be incorporated in the construction at the site and that buildings be
Earth Engineering Consultants, LLC
EEC Project No. 1172058 – Geologic Report
November 16, 2017
Page 5
tested for radon after a normal operating routine has been established as other rock formations at
depths beneath this parcel are capable of producing radon.
Sand, Gravel and Quarry Aggregate Resource
The Atlas of Sand, Gravel, and Quarry Aggregate Resources-Colorado Front Range Counties-
Colorado Geological Survey Special Publication 5-B (4) was used to gain a general overview of
the property. The CGS publication indicates that the parcel is within and/or near the Boxelder
Creek Valley Deposits, an identified aggregate resource area. The nearest mining operations are
sand and gravel pits located approximately one (1) mile south in the Terrace Deposits (T4) area
of the Cache La Poudre River. No sand and gravel pits are identified within the Boxelder Creek
Valley Deposits, within the immediate area. Significant sand and gravel deposits are expected
and were encountered within our soil borings at depths below this property. The Atlas of Sand,
Gravel, and Quarry Aggregate Resources Colorado Front Range Counties (1974) indicate that
the deposits within the Boxelder Creek Valley are questionable due to the thickness of
overburden and a high overburden to resource ratio. A mining consultant could provide guidance
on the potential resource value, if any.
CONCLUSION
Based on the conditions observed and researched, there are no apparent significant geologic
hazards on the property. Geotechnical subsurface explorations are recommended for each
building site to identify shrink/swell potential in the soils and/or bedrock strata. Pre-mitigation
radon control methods, such as sub-slab piping, as well as radon tests are recommended. Based
on these conditions and our observations, it is our opinion that the previously described future
development of this parcel is compatible with the geologic conditions at the site.
The data presented herein were collected to help determine the feasibility of this project.
Professional judgments on design alternatives and criteria are presented in this report. These are
based on evaluation of technical information gathered, partly on our understanding of the
characteristics of the development proposed, and partly on our experience with geologic
conditions in the area. We do not guarantee the performance of the project in any respect, only
that our geologic evaluation and opinions rendered were conducted in a manner consistent with
Figure 1: 800 Acre Mixed-Use Development
Larimer County, Colorado
EEC Project #: 1172058 Date: November 2017
EARTH ENGINEERING CONSULTANTS, LLC
Figure 1A: 800 Acre Mixed-Use Development
Larimer County, Colorado
EEC Project #: 1172058 Date: November 2017
EARTH ENGINEERING CONSULTANTS, LLC
Figure 2: 800-Acre Mixed Use Development
Fort Collins, Colorado
EEC Project Number: 1172058 Date: November 2017
EARTH ENGINEERING CONSULTANTS, LLC
Approximate
Project Site
Figure 3: 800-Acre Mixed Use Development
Fort Collins, Colorado
EEC Project Number: 1172058 Date: November 2017
EARTH ENGINEERING CONSULTANTS, LLC
Approximate
Project Site
MAP SHOWING POTENTIAL SOURCES OF GRAVEL & CRUSHED ROCK AGGREGATE
In the Boulder-Fort Collins-Greeley Area, Front Range Urban Corridor, Colorado
by Colton, R.B., Fitch, H.R., 1974, Map I-855-D USGS
PROJECT NO: 1172058B LOG OF BORING B-5 AUGUST 2018
SHEET 2 OF 2 WATER DEPTH
START DATE 8/7/2018 WHILE DRILLING 29'
8/7/2018 AFTER DRILLING N/A
SURFACE ELEV 8/8/2018 24.9'
FINISH DATE
A-LIMITS SWELL
N/A
FORT COLLINS, COLORADO
PROJECT NO: 1172058B LOG OF BORING B-5 AUGUST 2018
SHEET 1 OF 2 WATER DEPTH
START DATE 8/7/2018 WHILE DRILLING 29'
SURFACE ELEV N/A 8/8/2018 24.9'
FINISH DATE 8/7/2018 AFTER DRILLING N/A
A-LIMITS SWELL
PROJECT NO: 1172058B LOG OF BORING B-4 AUGUST 2018
SHEET 2 OF 2 WATER DEPTH
START DATE 8/7/2018 WHILE DRILLING 29'
8/7/2018 AFTER DRILLING N/A
SURFACE ELEV 8/8/2018 28.5'
FINISH DATE
A-LIMITS SWELL
N/A
FORT COLLINS, COLORADO
PROJECT NO: 1172058B LOG OF BORING B-4 AUGUST 2018
SHEET 1 OF 2 WATER DEPTH
START DATE 8/7/2018 WHILE DRILLING 29'
SURFACE ELEV N/A 8/8/2018 28.5'
FINISH DATE 8/7/2018 AFTER DRILLING N/A
A-LIMITS SWELL
PROJECT NO: 1172058B LOG OF BORING B-3 AUGUST 2018
SHEET 2 OF 2 WATER DEPTH
START DATE 8/7/2018 WHILE DRILLING 24'
8/7/2018 AFTER DRILLING N/A
SURFACE ELEV 8/8/2018 26.7'
FINISH DATE
A-LIMITS SWELL
N/A
FORT COLLINS, COLORADO
PROJECT NO: 1172058B LOG OF BORING B-3 AUGUST 2018
SHEET 1 OF 2 WATER DEPTH
START DATE 8/7/2018 WHILE DRILLING 24'
SURFACE ELEV N/A 8/8/2018 26.7'
FINISH DATE 8/7/2018 AFTER DRILLING N/A
A-LIMITS SWELL
PROJECT NO: 1172058B LOG OF BORING B-2 AUGUST 2018
SHEET 2 OF 2 WATER DEPTH
START DATE 8/7/2018 WHILE DRILLING None
8/7/2018 AFTER DRILLING N/A
SURFACE ELEV 24 HOUR N/A
FINISH DATE
A-LIMITS SWELL
N/A
FORT COLLINS, COLORADO
PROJECT NO: 1172058B LOG OF BORING B-2 AUGUST 2018
SHEET 1 OF 2 WATER DEPTH
START DATE 8/7/2018 WHILE DRILLING None
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/7/2018 AFTER DRILLING N/A
A-LIMITS SWELL
PROJECT NO: 1172058B LOG OF BORING B-1 AUGUST 2018
SHEET 2 OF 2 WATER DEPTH
START DATE 8/7/2018 WHILE DRILLING 28'
8/7/2018 AFTER DRILLING N/A
SURFACE ELEV 24 HOUR N/A
FINISH DATE
A-LIMITS SWELL
N/A
FORT COLLINS, COLORADO
PROJECT NO: 1172058B LOG OF BORING B-1 AUGUST 2018
SHEET 1 OF 2 WATER DEPTH
START DATE 8/7/2018 WHILE DRILLING 28'
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/7/2018 AFTER DRILLING N/A
A-LIMITS SWELL
Soil Classification
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests
Sands 50% or more
coarse fraction
passes No. 4 sieve
Fine-Grained Soils
50% or more passes
the No. 200 sieve
<0.75 OL
Gravels with Fines
more than 12%
fines
Clean Sands Less
than 5% fines
Sands with Fines
more than 12%
fines
Clean Gravels Less
than 5% fines
Gravels more than
50% of coarse
fraction retained on
No. 4 sieve
Coarse - Grained Soils
more than 50%
retained on No. 200
sieve
CGravels with 5 to 12% fines required dual symbols:
Kif soil contains 15 to 29% plus No. 200, add "with sand"
or "with gravel", whichever is predominant.
<0.75 OH
Primarily organic matter, dark in color, and organic odor
ABased on the material passing the 3-in. (75-mm)
sieve
ECu=D60/D10 Cc=
HIf fines are organic, add "with organic fines" to
group name
LIf soil contains ≥ 30% plus No. 200 predominantly sand,
add "sandy" to group name.
MIf soil contains ≥30% plus No. 200 predominantly gravel,
add "gravelly" to group name.
DSands with 5 to 12% fines require dual symbols:
BIf field sample contained cobbles or boulders, or
both, add "with cobbles or boulders, or both" to
group name. FIf soil contains ≥15% sand, add "with sand" to
GIf fines classify as CL-ML, use dual symbol GC-
CM, or SC-SM.
Silts and Clays
Liquid Limit less
than 50
Silts and Clays
Liquid Limit 50 or
more
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110
PLASTICITY INDEX (PI)
LIQUID LIMIT (LL)
ML OR OL
MH OR OH
For Classification of fine-grained soils and
fine-grained fraction of coarse-grained
soils.
Equation of "A"-line
Horizontal at PI=4 to LL=25.5
then PI-0.73 (LL-20)
Equation of "U"-line
Vertical at LL=16 to PI-7,
then PI=0.9 (LL-8)
CL-ML
HARDNESS AND DEGREE OF CEMENTATION:
Limestone and Dolomite:
Hard Difficult to scratch with knife.
Moderately Can be scratched easily with knife.
Hard Cannot be scratched with fingernail.
Soft Can be scratched with fingernail.
Shale, Siltstone and Claystone:
Hard Can be scratched easily with knife, cannot be
scratched with fingernail.
Moderately Can be scratched with fingernail.
Hard
Soft Can be easily dented but not molded with
fingers.
Sandstone and Conglomerate:
Well Capable of scratching a knife blade.
Cemented
Cemented Can be scratched with knife.
Poorly Can be broken apart easily with fingers.
Cemented
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/30/2017 CHECKED ON 9/8/2017 7.7'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/30/2017 WHILE DRILLING 6.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-30 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/30/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/30/2017 WHILE DRILLING 13.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-29 SEPTEMBER 2017
8/30/2017 CHECKED ON 9/8/2017 27.8
SURFACE ELEV 24 HOUR N/A
FINISH DATE
SHEET 2 OF 2 WATER DEPTH
START DATE 8/30/2017 WHILE DRILLING 30.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-28 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/30/2017 CHECKED ON 9/8/2017 27.8
SHEET 1 OF 1 WATER DEPTH
START DATE 8/30/2017 WHILE DRILLING 30.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-28 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/30/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/30/2017 WHILE DRILLING 14.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-27 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/30/2017 CHECKED ON 9/8/2017 15.2'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/30/2017 WHILE DRILLING 14.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-26 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/28/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/28/2017 WHILE DRILLING 8.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-25 SEPTEMBER 2017
8/28/2017 AFTER DRILLING N/A
SURFACE ELEV 24 HOUR N/A
FINISH DATE
SHEET 2 OF 2 WATER DEPTH
START DATE 8/28/2017 WHILE DRILLING 11.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-24 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/28/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/28/2017 WHILE DRILLING 11.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-24 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/28/2017 CHECKED ON 9/8/2017 12.3'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/28/2017 WHILE DRILLING 13.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-23 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/25/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/25/2017 WHILE DRILLING 8.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-22 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/25/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/25/2017 WHILE DRILLING 9.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-21 SEPTEMBER 2017
SURFACE ELEV N/A CHECKED ON 8/28/2017 10.7
FINISH DATE 8/25/2017 CHECKED ON 9/8/2017 12.0'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/25/2017 WHILE DRILLING 9.5
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-20 SEPTEMBER 2017
8/28/2017 AFTER DRILLING N/A
SURFACE ELEV 24 HOUR N/A
FINISH DATE
SHEET 2 OF 2 WATER DEPTH
START DATE 8/25/2017 WHILE DRILLING 9.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-19 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/28/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/25/2017 WHILE DRILLING 9.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-19 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/25/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/25/2017 WHILE DRILLING 13.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-18 SEPTEMBER 2017
SURFACE ELEV N/A CHECKED ON 8/28/2017 15.3'
FINISH DATE 8/18/2017 CHECKED ON 9/8/2017 16.9'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/18/2017 WHILE DRILLING 12.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-17 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/18/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/18/2017 WHILE DRILLING 12.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-16 SEPTEMBER 2017
8/18/2017 CHECKED ON 9/8/2017 36.5'
SURFACE ELEV CHECKED ON 8/28/2017 33.0'
FINISH DATE
SHEET 2 OF 2 WATER DEPTH
START DATE 8/18/2017 WHILE DRILLING 31.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-15 SEPTEMBER 2017
SURFACE ELEV N/A CHECKED ON 8/28/2017 33.0'
FINISH DATE 8/18/2017 CHECKED ON 9/8/2017 36.5'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/18/2017 WHILE DRILLING 31.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-15 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR 14.7'
FINISH DATE 8/14/2017 CHECKED ON 9/8/2017 18.2'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/14/2017 WHILE DRILLING 12.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-14 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/14/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/14/2017 WHILE DRILLING 10.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-13 SEPTEMBER 2017
SURFACE ELEV N/A CHECKED ON 8/28/2017 15.0'
FINISH DATE 8/14/2017 CHECKED ON 9/8/2017 16.5'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/14/2017 WHILE DRILLING 14.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-12 SEPTEMBER 2017
SURFACE ELEV N/A CHECKED ON 8/28/2017 14.0'
FINISH DATE 8/14/2017 CHECKED ON 9/8/2017 14.8'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/14/2017 WHILE DRILLING 15.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-11 SEPTEMBER 2017
SURFACE ELEV N/A CHECKED ON 8/28/2017 22.3'
FINISH DATE 8/14/2017 CHECKED ON 9/8/2017 22.7'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/14/2017 WHILE DRILLING 19.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-10 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/18/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/18/2017 WHILE DRILLING 18.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-9 SEPTEMBER 2017
SURFACE ELEV N/A CHECKED ON 8/28/2017 None
FINISH DATE 8/14/2017 CHECKED ON 9/8/2017 None
SHEET 1 OF 1 WATER DEPTH
START DATE 8/14/2017 WHILE DRILLING None
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-8 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/14/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/14/2017 WHILE DRILLING 18.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-7 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/18/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/18/2017 WHILE DRILLING 4.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-6 SEPTEMBER 2017
SURFACE ELEV N/A CHECKED ON 8/28/2017 4.6'
FINISH DATE 8/18/2017 CHECKED ON 9/8/2017 6.3'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/18/2017 WHILE DRILLING 2.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-5 SEPTEMBER 2017
8/18/2017 AFTER DRILLING N/A
SURFACE ELEV 24 HOUR N/A
FINISH DATE
SHEET 2 OF 2 WATER DEPTH
START DATE 8/18/2017 WHILE DRILLING 17.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-4 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/18/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/18/2017 WHILE DRILLING 17.5'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-4 SEPTEMBER 2017
SURFACE ELEV N/A CHECKED ON 8/28/2017 22.7'
FINISH DATE 8/14/2017 CHECKED ON 9/8/2017 23.4'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/14/2017 WHILE DRILLING 24.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-3 SEPTEMBER 2017
SURFACE ELEV N/A 24 HOUR N/A
FINISH DATE 8/14/2017 AFTER DRILLING N/A
SHEET 1 OF 1 WATER DEPTH
START DATE 8/14/2017 WHILE DRILLING None
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-2 SEPTEMBER 2017
8/14/2017 CHECKED ON 9/8/2017 22.7'
SURFACE ELEV CHECKED ON 8/28/2017 21.5'
FINISH DATE
SHEET 2 OF 2 WATER DEPTH
START DATE 8/14/2017 WHILE DRILLING 21.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-1 SEPTEMBER 2017
SURFACE ELEV N/A CHECKED ON 8/28/2017 21.5'
FINISH DATE 8/14/2017 CHECKED ON 9/8/2017 22.7'
SHEET 1 OF 1 WATER DEPTH
START DATE 8/14/2017 WHILE DRILLING 21.0'
800 ACRE MIXED USE DEVELOPMENT
FORT COLLINS, COLORADO
PROJECT NO: 1172058 LOG OF BORING B-1 SEPTEMBER 2017
(+) 1.7%
S1 @ 4'
(+) 0.4%
B-9
B-10
S3 @ 9'
(+) 0.8%
S1 @ 2'
(+) 2.4%
Figure 4: Swell Diagram
800-Acre Mixed Use Development
Fort Collins, Colorado
EEC Project Number: 1172058 Date: September 2017
EARTH ENGINEERING CONSULTANTS, LLC
Approximate Boring
Locations
Legend
Swell Indices 0-3%
Swell Indices 3%+
Note: Approximate swell-index values as measured in the laboratory. Variations
may occur across the site.
Groundwater 10+ ft Note: Approximate depths to groundwater. Variations may occur across the site.
Soil Classification
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests
Sands 50% or more
coarse fraction
passes No. 4 sieve
Fine-Grained Soils
50% or more passes
the No. 200 sieve
<0.75 OL
Gravels with Fines
more than 12%
fines
Clean Sands Less
than 5% fines
Sands with Fines
more than 12%
fines
Clean Gravels Less
than 5% fines
Gravels more than
50% of coarse
fraction retained on
No. 4 sieve
Coarse - Grained Soils
more than 50%
retained on No. 200
sieve
CGravels with 5 to 12% fines required dual symbols:
Kif soil contains 15 to 29% plus No. 200, add "with sand"
or "with gravel", whichever is predominant.
<0.75 OH
Primarily organic matter, dark in color, and organic odor
ABased on the material passing the 3-in. (75-mm)
sieve
ECu=D60/D10 Cc=
HIf fines are organic, add "with organic fines" to
group name
LIf soil contains ≥ 30% plus No. 200 predominantly sand,
add "sandy" to group name.
MIf soil contains ≥30% plus No. 200 predominantly gravel,
add "gravelly" to group name.
DSands with 5 to 12% fines require dual symbols:
BIf field sample contained cobbles or boulders, or
both, add "with cobbles or boulders, or both" to
group name. FIf soil contains ≥15% sand, add "with sand" to
GIf fines classify as CL-ML, use dual symbol GC-
CM, or SC-SM.
Silts and Clays
Liquid Limit less
than 50
Silts and Clays
Liquid Limit 50 or
more
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70 80 90 100 110
PLASTICITY INDEX (PI)
LIQUID LIMIT (LL)
ML OR OL
MH OR OH
For Classification of fine-grained soils and
fine-grained fraction of coarse-grained
soils.
Equation of "A"-line
Horizontal at PI=4 to LL=25.5
then PI-0.73 (LL-20)
Equation of "U"-line
Vertical at LL=16 to PI-7,
then PI=0.9 (LL-8)
CL-ML
HARDNESS AND DEGREE OF CEMENTATION:
Limestone and Dolomite:
Hard Difficult to scratch with knife.
Moderately Can be scratched easily with knife.
Hard Cannot be scratched with fingernail.
Soft Can be scratched with fingernail.
Shale, Siltstone and Claystone:
Hard Can be scratched easily with knife, cannot be
scratched with fingernail.
Moderately Can be scratched with fingernail.
Hard
Soft Can be easily dented but not molded with
fingers.
Sandstone and Conglomerate:
Well Capable of scratching a knife blade.
Cemented
Cemented Can be scratched with knife.
Poorly Can be broken apart easily with fingers.
Cemented