HomeMy WebLinkAboutCORE SPACES AT TRILBY & COLLEGE - PDP220009 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTPRELIMINARY SUBSURFACE EXPLORATION REPORT
APPROXIMATELY 39-ACRE RESIDENTIAL DEVELOPMENT
6301 SOUTH COLLEGE AVENUE
FORT COLLINS, COLORADO
EEC PROJECT NO. 1212019
Prepared for:
UDC Miller, LLC
6900 E. Belleview Avenue, Suite 300
Greenwood Village, Colorado 80111
Attn: Mr. John Vitella (jvitella@udcos.com)
Prepared by:
Earth Engineering Consultants, LLC
4396 Greenfield Drive
Windsor, Colorado 80550
4396 GREENFIELD DRIVE
W INDSOR, COLORADO 80550
(970) 545-3908 FAX (970) 663-0282
April 7, 2021
UDC Miller, LLC
6900 E. Belleview Avenue, Suite 300
Greenwood Village, Colorado 80111
Attn: Mr. John Vitella (jvitella@udcos.com)
Re: Preliminary Subsurface Exploration Report
Approximately 39-Acre Residential Development
6301 South College Avenue
Fort Collins, Colorado
EEC Project No. 1212019
Mr. Vitella:
Enclosed, herewith, are the results of the supplemental preliminary subsurface exploration
completed by Earth Engineering Consultants, LLC personnel for the referenced project. In 2000,
EEC performed a similar preliminary subsurface exploration report for the site. For further
information and findings thereof, please refer to Earth Engineering Consultants, Inc.’s
Preliminary Subsurface Exploration Report – Tiley Property, Project No. 1002194, and dated
October 24, 2000. This supplemental preliminary subsurface exploration was completed to
provide additional information on current subsurface conditions and update the previous report.
A total of five (5) supplemental/preliminary soil borings (labeled herein as B-18 through B-22)
were drilled on March 5 and 8, 2021, at the approximate locations as indicated on the enclosed
Boring Location Diagrams included with this report. These supplemental borings were extended
to depths of approximately 25 feet below existing site grades. Individual boring logs from the
initial preliminary geo-report and the five (5) supplemental borings, 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
December 28, 2020.
In summary, the subsurface soils encountered in the supplemental preliminary test borings
generally consisted of lean clay with varying amounts of sand soils. The lean clay subsoils were
generally dry to moist in-situ, medium stiff to very stiff, exhibited low to moderate plasticity and
low to very high swell potential at current moisture and density conditions. Varying zones of
interbedded sandstone/siltstone/claystone bedrock were encountered below the lean clay subsoils
at depths of approximately 2 to 12 feet below the ground surface. The bedrock formation was
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generally highly weathered to hard/poorly cemented to cemented with depth and exhibited low to
high swell potential at current moisture and density conditions. The subsurface conditions
encountered within the five (5) supplemental borings are relatively consistent with those as
described in the 2000 Geo-Report. At the time of drilling, groundwater was observed in boring
B-18 at a depth of approximately 18 feet below the ground surface. Groundwater was not
encountered in the remaining borings which extended to maximum depths of approximately 25
feet below the ground surface. It should be noted that groundwater was encountered during the
2000 subsurface exploration at depths ranging from approximately 2 to 7 feet below site grades
at that time. Perched and/or trapped water may be encountered in more permeable zones in the
subgrade soils at varying 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 amount of perched water may occur over time depending on
variations in hydrologic conditions, irrigation activities on surrounding properties, site
improvements over time, and other conditions not apparent at the time of this report.
Based on the materials observed within the supplemental preliminary boring locations and the
anticipated foundation loads, we believe the proposed lightly to moderately loaded residential
structures with possible lower level/basement construction, could be supported by either drilled
piers/caissons extending into the bedrock formation or on conventional spread footings bearing
on a zone of engineered/controlled fill material placed and compacted as described within this
report. Interior slab-on-grades and exterior flatwork should be supported on a zone of
engineered/controlled fill material placed and compacted as described within this report.
Pavements should be supported on a zone of moisture conditioned engineered fill or imported
structural fill material or fly ash treated subgrades placed and compacted as described within this
report.
Further subsurface explorations will be required on a lot by lot basis after final design layouts
and structural loads have been determined as well as grading operations have been completed.
Each respective builders’ geotechnical engineering consultants may provide a variation in those
separation limits from foundation to bedrock, so it is important to understand what the separation
criteria is prior to any over-excavation and replacement concepts.
PRELIMINARY SUBSURFACE EXPLORATION REPORT
APPROXIMATELY 39-ACRE RESIDENTIAL DEVELOPMENT
6301 SOUTH COLLEGE AVENUE
FORT COLLINS, COLORADO
EEC PROJECT NO. 1212019
April 7, 2021
INTRODUCTION
The supplemental preliminary subsurface exploration for the proposed approximately 39-acre
residential development property located at 6301 South College Avenue in Fort Collins, Colorado
has been completed. In 2000, Earth Engineering Consultants, Inc. performed a similar preliminary
subsurface exploration for the site, which consisted of seventeen (17) soil borings extending to
depths of approximately 8 to 15 feet below present site grades, advanced in the proposed
development area to obtain information on existing subsurface conditions at that time. Six (6) of the
original borings (B-1 through B-6) were sampled for evaluation of subgrade composition and
consistency, while the remaining ten (10) borings (B-7 through B-17) were logged for composition,
however, were predominately completed for installation of site piezometers. For further information
and findings thereof, please refer to Earth Engineering Consultants, Inc.’s Preliminary Subsurface
Exploration Report – Tiley Property, Project No. 1002194, and dated October 24, 2000. This
supplemental preliminary subsurface exploration was completed to provide additional information
on current subsurface conditions and update the previous report.
This supplemental preliminary subsurface exploration was completed to provide additional
information on current subsurface conditions and update the previous report. A total of five (5)
supplemental soil borings, labeled herein as B-18 through B-22, were drilled on March 5 and 8, 2021
at the approximate locations as indicated on the enclosed Boring Location Diagrams included with
this report. The supplemental preliminary soil borings were advanced to depths of approximately 25
feet below existing site grades across the proposed development property to obtain information on
existing subsurface conditions. Individual boring logs, (both the original 1002194 boring logs and
the recently completed supplemental boring logs), and site diagrams indicating the approximate
boring locations are included with this report.
The residential development parcel is located at 6301 South College Avenue in Fort Collins,
Colorado. The property, as we understand, will be developed for a mix of single-family and multi-
family residential use, including utility and interior roadway infrastructure. Foundation loads for the
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proposed residential development 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 150 kips. Floor loads
are expected to be light. Proposed residential structures are expected to include possible below
grade construction such as crawl spaces, garden-level and/or full-depth basements. 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 roadways designed in general
accordance with Larimer County Urban Area Street Standards (LCUASS).
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.
EXPLORATION AND TESTING PROCEDURES
The supplemental 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.
The locations of each boring 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 supplemental borings were performed using 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
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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,
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 proposed residential development parcel is located at 6301 South College Avenue in Fort
Collins, Colorado. The project site is generally undeveloped with little to no surficial topsoil and
vegetation. An irrigation ditch on the western side of the property runs from the south to north edge
of the property. Surface water drainage across the site is generally to the east. Estimated relief
across the site from west to east is approximately 20 to 50 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 the field and laboratory evaluation, subsurface
conditions can be generalized as follows.
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Sparse vegetation and topsoil were encountered at the surface of some borings. The vegetation
layers were generally underlain by varying zones of apparent native lean clay with varying amounts
of sand soils. The lean clay subsoils were generally dry to moist in-situ, medium stiff to very stiff,
exhibited low to moderate plasticity and low to very high swell potential at current moisture and
density conditions. Varying zones of interbedded sandstone/siltstone/claystone bedrock were
encountered below the lean clay subsoils at depths of approximately 2 to 12 feet below the ground
surface. The bedrock formation was generally highly weathered to hard/poorly cemented to
cemented with depth and exhibited low to high swell potential at current moisture and density
conditions. The subsurface profile conditions encountered within the five (5) supplemental borings
are relatively consistent with those as described in the 2000 Geo-Report.
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. At the time of drilling, groundwater was observed in boring B-18 at a depth of
approximately 18 feet below the ground surface. Groundwater was not encountered in the remaining
borings which extended to maximum depths of approximately 25 feet below the ground surface. The
remaining borings were backfilled upon completion, and therefore subsequent groundwater
measurements were not made. Groundwater measurements provided with this report are indicative
of groundwater levels at the locations and at the time the borings/groundwater measurements were
completed.
It should be noted that groundwater was encountered during the 2000 subsurface exploration at
depths ranging from approximately 2 to 7 feet below site grades at that time. Perched and/or trapped
water may be encountered in more permeable zones in the subgrade soils at varying 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 amount of
perched water may occur over time depending on variations in hydrologic conditions, irrigation
activities on surrounding properties, site improvements over time, and other conditions not apparent
at the time of this report.
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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 six (6) swell/consolidation tests on relatively
undisturbed soil samples obtained at various intervals/depths on the site. The swell index values for
the in-situ soil samples analyzed revealed low to moderate swell characteristics as indicated on the
attached swell test summaries. The (+) test results indicate the soil materials swell potential
characteristics while the (-) test results indicate the soils materials collapse/consolidation potential
characteristics when inundated with water. The following table summarizes the swell-consolidation
laboratory test results for samples obtained during our field explorations for the subject site.
Table I – Laboratory Swell-Consolidation Test Results
No of
Samples
Tested
Pre-Load /
Inundation
Pressure,
PSF
Description of Material
In-Situ Characteristics Range of Swell – Index
Test Results Range of Moisture
Contents, %
Range of Dry Densities,
PCF
Low
End, %
High
End, %
Low End,
PCF
High End,
PCF
Low End
(+/-) %
High
End, (+/-)
%
1 150 Lean Clay with Sand (CL) 7.2 119.9 (+) 13.9
5 500 Lean Clay with Sand (CL) or
Sandstone/Siltstone/Claystone 5.7 19.1 107.0 128.0 (-) 0.4 (+) 9.7
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
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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 and the underlying bedrock
formation analyzed ranged from low to very high risk. It should be noted that groundwater levels
encountered during the 2000 subsurface exploration in comparison to those measured during the
2021 supplemental exploration were shallower. It should also be noted that the current moisture
profile with depth in comparison to the borings completed in 2000, are drier, mainly due the
groundwater table being noticeably lower, which may be the cause for the swell potential
characteristics presented herein.
General Considerations
General guidelines are provided below for the site subgrade preparation. However, it should be
noted that for possible residential development, compaction and moisture requirements vary between
home builders and, consequently, between geotechnical engineering companies. If the residential
development lots will be marketed to a target group of builders, fill placement criteria should be
obtained from those builders and/or their geotechnical engineering consultants prior to beginning
earthwork activities on the site. Representatives from those entities should verify that the fill is
being placed consistent with the home builders’ guidelines.
The near surface soils were relatively dry and very stiff at the time of drilling and generally exhibited
low to very high swell potential characteristics. The presence of bedrock was identified in the soil
borings extended within the proposed development area as previously discussed. The presence of
bedrock throughout the site should be thoroughly evaluated prior to construction activities
commencing. It is likely that individual builders’ geotechnical engineering representatives will
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require a minimum separation that should be maintained between the bottom of any potential footing
foundations and/or floor slabs and bedrock. If the overburden soils or underlying bedrock were to
become wetted subsequent to construction of overlying improvements, heaving, consolidation,
and/or differential heaving caused by soils/underlying bedrock could result in significant total and
differential movement of site improvements. Therefore, in areas where shallow bedrock was
encountered, consideration could be given to the use of a straight shaft drilled pier foundation system
and a structural floor slab system. In addition, with the acceptance of greater risk for movement,
preliminary considerations and/or recommendations for an over-excavation and replacement concept
to reduce the potential movement of foundations, floor slabs, and pavements, are included herein.
Specific methods of reducing the potential for movement are to be determined by the individual/lot-
specific builder.
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. 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.
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 to very high swell potential in some areas of the dry and very stiff site
overburden lean clay soils and zones of shallow claystone bedrock, mitigation procedures to prevent
heaving caused by swelling soils might be considered in those areas. That mitigation would
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commonly include removal of dry and stiff materials to a depth specified by the lot-specific
geotechnical representative, and either replacing the soils as moisture-controlled fill or replacing the
over excavated zone with imported structural fill materials. Mitigation should be completed on an
individual residence/roadway basis; however, care should be taken during overlot grading to avoid
placing fill above the dry, dense soils with moderate swell potential which would require future
removal and reworking.
After stripping and completing all cuts, any overexcavation, 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 approved imported structural fill or with the understanding of greater potential for movement,
the site lean clay soils could be used as fill in these areas. If granular imported structural fill is used,
it should be similar to CDOT Class 5, 6 or 7 base course material with sufficient fines to prevent
ponding of water in the fill. 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 lot to develop
recommendations specific to the proposed structure and owner/builder and for specific pavement
sections. A greater or lesser degree of compaction could be specified for specific individual
structures along with alternative moisture requirements. The preliminary recommendations provided
in this report are, by necessity, general in nature and would be superseded by site specific
explorations/recommendations.
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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.
Foundation Systems – General Considerations
The cohesive subsoils and underlying bedrock will require attention in the design and construction to
reduce the amount of movement/differential movement in various areas due to the in-situ swelling
characteristics, compressible conditions near the groundwater table, and relatively shallow depth to
bedrock. The following foundation systems were evaluated for use on the site; however final
subsurface explorations should be performed after building footprint and elevations have been better
defined and actual design loads determined:
x Straight shaft drilled piers bearing into the underlying bedrock formation. Consideration could
also be given to the use of a structural floor slab in conjunction with a drilled pier/caisson
foundation system or providing a zone of engineered/replaced fill material below floor slabs.
x Spread Footing foundations with possible overexcavation to reduce potential for movement. If
spread footings are chosen, overexcavation and replacement of the lean clay soils should be
considered below the bottom of the footings. Additional recommendations regarding
separation to bedrock may vary depending upon potential builder’s independent hired
geotechnical engineering consultants. If greater potential for movement cannot be tolerated,
drilled pier foundations should be used.
Other alternative foundation systems could be considered, and we would be pleased to provide
additional alternatives upon request.
Preliminary Drilled Piers/Caissons Foundation Recommendations
Based on the subsurface conditions and relatively shallow depth to bedrock across a majority of the
site, as well as the anticipated foundation loads, we believe site structures could be supported on a
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grade beam and straight shaft drilled pier/caisson foundation system extending into the underlying
bedrock formation.
For axial compression loads, we estimate a design maximum end-bearing pressure in the range of
15,000 pounds per square foot (psf) to 25,000 psf, along with an estimated skin-friction in the range of
1,500 psf to 2,500 psf for the portion of the pier extended into the underlying firm and/or harder
bedrock formation. Specific explorations should be made for each building and/or individual
residential lot to determine actual design end-bearing and skin friction values. Additional
recommendations for the design of straight shaft piers can be made at the time the lot-specific
subsurface explorations.
Drilling caissons to design depth should be possible with conventional heavy-duty single flight power
augers equipped with rock teeth on the majority of the site. However, areas of well-cemented
sandstone bedrock lenses may be encountered throughout the site at various depths where specialized
drilling equipment and/or rock excavating equipment may be required. Excavation penetrating the
well-cemented sandstone bedrock may require the use of specialized heavy-duty equipment, together
with rock augers and/or core barrels. Consideration should be given to obtaining a unit price for
difficult caisson excavation in the contract documents for the project. Due to the shallow depth of
groundwater in some borings, we expect temporary casings will be required to maintain open
boreholes.
Preliminary Spread Footing Foundation Recommendations
An alternative foundation system to consider, should the drilled pier option not be selected, with the
understanding of greater potential for movement, could be a spread footing foundation system with
possible ground modifications to reduce the potential for post-construction movement. We expect
varying depths of over excavation and replacement below the footings to reduce the potential for
movement. Overexcavation depths should be expected to vary across the site, based on
builder/owner requirements and lot-specific conditions and could be expected to be in the range of
anywhere from 2 to 10 feet below footings. Certain residential home builders may also have a
specified separation from bottom of footings to the underlying bedrock formation.
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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 overexcavation and replacement or other ground
modification procedure. Deeper overexcavation depths may be necessary depending upon the
observed subsoils at the time of the foundation excavation observation. In general, the
overexcavation area would extend 8 inches laterally beyond the building perimeter for every 12
inches of overexcavation depth. Backfill materials should be placed and compacted as described in
the section Site Preparation.
We expect footing foundations could be supported on moisture conditioned and compacted
controlled engineered fill material consisting of the native lean clay or imported structural fill
material. If the lean clay material is re-worked to be used as controlled fill material, the moisture
content should be adjusted to slightly wet of optimum to reduce swell potential. Higher risk of
movement should be expected with the use of the site lean clay as engineered fill material. If that
risk cannot be accepted, we recommend that imported structural fill materials be used.
For design of footing foundations bearing on ground modified native subsoils, properly placed and
compacted engineered fill materials or imported structural fill material as outlined above, maximum
net allowable total load soil bearing pressures on the order of 1,500 psf to 3,000 psf could be
considered depending upon the specific subgrade material used. Footing foundations should
maintain separation above bedrock as required by the lot specific geotechnical engineering
consultants 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. Additional footing design recommendations can be provided at the time of lot-
specific subsurface explorations.
Care should be taken to avoid placement of structures on dissimilar fill materials to avoid differential
settlement. If the lean clay soils are used as reconditioned engineered fill materials, steps should be
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taken to maintain moisture content at slightly above optimum. If these materials are allowed to dry
and become wetted, swelling should be expected. 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 Basement Design and Construction
Groundwater was encountered within one of the preliminary supplemental borings (B-18) at an
approximate depth of 18 feet below existing site grades. As previously mentioned, groundwater
encountered in the 2000 subsurface exploration were measured at depths of approximately 2 to 7 feet
below 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.
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-
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.
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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 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,
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 Floor Slab/Exterior Flatwork Subgrades
If structural floor slabs in conjunction with the drilled pier/caisson foundations are not planned, and
with the understanding of greater potential movement, an alternative approach to consider would be to
over excavate and place and compact fill material below floor slabs. The over excavation depths
should be expected to vary between buildings and should be determined through lot specific
subsurface explorations.
Preparation of the initial zone at the bottom of the excavation as well as fill procedures or preparation
of the natural undisturbed subgrades (if structural floor slabs are planned), should be completed as
described in the section Site Preparation. 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.
Earth Engineering Consultants, LLC
EEC Project No. 1212019
April 7, 2021
Page 14
Lateral Earth Pressures
Any site retaining walls or similarly related structural elements that would be subjected to
unbalanced lateral earth pressures would also be subjected to lateral soil forces. Passive lateral earth
pressures may help resist the driving forces for retaining wall or other similar site structures.
Active lateral earth pressures could be used for design of structures where some movement of the
structure is anticipated, such as retaining walls. The total deflection of structures for design with
active earth pressure is estimated to be on the order of one half of one percent of the height of the
down slope side of the structure. We recommend at-rest pressures be used for design of structures
where rotation of the walls is restrained, including the grade beam walls for the loading docks. Free
standing wing walls could be designed for active pressures assuming rotation of the walls is allowed.
Passive pressures and friction between the footing and bearing soils could be used for design of
resistance to movement of retaining walls.
Coefficient values for backfill with anticipated types of soils for calculation of active, at rest and
passive earth pressures are provided in Table III below. Equivalent fluid pressure is equal to the
coefficient times the appropriate soil unit weight. Those coefficient values are based on horizontal
backfill with backfill soils consisting of essentially granular materials or low volume change
cohesive soils. For the at-rest and active earth pressures, slopes down and away from the structure
would result in reduced driving forces with slopes up and away from the structures resulting in
greater forces on the walls. The passive resistance would be reduced with slopes away from the
wall. The top 30 inches of soil on the passive resistance side of walls could be used as a surcharge
load; however, should not be used as a part of the passive resistance value. Frictional resistance is
equal to the tangent of the friction angle times the normal force. Surcharge loads or point loads
placed in the backfill can also create additional loads on below grade walls. Those situations should
be designed on an individual basis.
Earth Engineering Consultants, LLC
EEC Project No. 1212019
April 7, 2021
Page 15
Table III Parameters for Lateral Earth Pressures
Soil Type Lean Clay with Sand Granular Structural Fill
Wet Unit Weight 115 135
Saturated Unit Weight 135 145
Friction Angle, f (assumed) 25° 35°
Active Pressure Coefficient 0.40 0.27
At-rest Pressure Coefficient 0.58 0.42
Passive Pressure Coefficient 2.46 3.69
The outlined values do not include factors of safety nor allowances for hydrostatic loads and are
based on assumed friction angles, which should be verified after potential material sources have been
identified. The outlined values assume wall backfill consists of non-expansive material extending a
minimum distance of 4 feet laterally away from all walls.
Care should be taken to develop appropriate drainage systems behind below grade walls to reduce
potential for hydrostatic loads developing on the walls and infiltration of water into below grade
areas. Those systems would likely include perimeter drain systems extending to sump areas or free
outfall where reverse flow cannot occur into the system. Where necessary, appropriate hydrostatic
load values should be used for design.
Preliminary Pavement Subgrades
Based on the current subsurface conditions, we believe pavements could be placed directly on
properly prepared native subsoils and/or structural fill material. Pavement subgrades should be
prepared as described in the section site preparation.
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. 1212019
April 7, 2021
Page 16
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. An assumed
R-Value of 10 was used for the preliminary pavement design. Suggested preliminary pavement
sections for the local residential and minor collector roadways are provided below in Table III.
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 IV – PRELIMINARY MINIMUM PAVEMENT THICKNESS 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
80%
3562
2.5
25
80%
3562
2.2
Design Structure Number 2.67 3.11
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
4ފ
9ފ
(2.75)
5ފ
9ފ
(3.19)
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
4ފ
6 ފ
12Ǝ
(2.92)
4ފ
7ފ
12ފ
(3.04)
PCC (Non-reinforced) – placed on an approved subgrade 6Ǝ 6½Ǝ
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 Standards (LCUASS).
Aggregate base should be consistent with CDOT requirements for Class 5 or Class 6 aggregate base.
Earth Engineering Consultants, LLC
EEC Project No. 1212019
April 7, 2021
Page 17
As previously mentioned, a final subgrade investigation and pavement design should be performed
in general accordance with LCUASS 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. 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 V: Water Soluble Sulfate Test Results
Sample Location Description Soluble Sulfate Content %
B-18, S-2, at 9’ Siltstone/Sandstone 0.06
B-22, S-1, at 4’ Sandy Lean Clay (CL) 0.08
Based on the results as presented above, ACI 318, Section 4.2 indicates the site sandy lean clay soils
and underlying bedrock have a low risk of sulfate attack on Portland cement concrete, therefore, ACI
Class S0 requirements should be followed for concrete placed in the overburden soils and underlying
bedrock. Foundation concrete should be designed in accordance with the provisions of the ACI
Design Manual, Section 318, Chapter 4.
Earth Engineering Consultants, LLC
EEC Project No. 1212019
April 7, 2021
Page 18
Other Considerations and Recommendations
Although evidence of fills or underground facilities such as septic tanks, cesspools, and basements
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 lean clay soils and bedrock can be expected to stand on relatively steep
temporary slopes during construction. 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.
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 UDC Miller, LLC 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. 1212019
April 7, 2021
Page 19
reviewed, and the conclusions of this report modified or verified in writing by the geotechnical
engineer.
Well Location Shallow Well Deep Well
(feet) (feet)
B-1 3.1 2.5
B-2 Dry Dry
B-3 Dry 6.7
B-4 Dry 7.7
B-5 Dry Dry
B-6 1.9 1.9
B-7 3.9 3.9
B-8 Dry Dry
B-9 1.2 1.3
B-10 Dry Dry
B-11 Dry 5.6
B-12 Dry 5.4
B-13 0.4 0.3
B-14 2.6 2.5
B-15 Dry 8.0
B-16 Dry 8.0
B-17 "(0.4)" "(0.7)"
NOTE: BORING B-1 TO B-16 VALUES INDICATE DEPTH TO GROUNDWATER SURFACE FROM GROUND SURFACE
BORING B-17 VALUE INDICATES HEIGHT TO GROUNDWATER SURFACE ABOVE GROUND SURFACE
Project: Tiley Property
Fort Collins, Colorado
Project No: 1002194
Date 10/25/00
GROUNDWATER MONITORING DATA
TILEY PROPERTY - FORT COLLINS, COLORADO
EEC PROJECT NUMBER: 1002194
MEASUREMENT DATE: 10/24/00
EarthEngineeringConsultants,LLC
DRILLING AND EXPLORATION
DRILLING&SAMPLINGSYMBOLS:
SS:SplitSpoonͲ13/8"I.D.,2"O.D.,unlessotherwisenotedPS:PistonSample
ST:ThinͲWalledTubeͲ2"O.D.,unlessotherwisenotedWS:WashSample
R:RingBarrelSamplerͲ2.42"I.D.,3"O.D.unlessotherwisenoted
PA:PowerAugerFT:FishTailBit
HA:HandAugerRB:RockBit
DB:DiamondBit=4",N,BBS:BulkSample
AS:AugerSamplePM:PressureMeter
HS:HollowStemAugerWB:WashBore
Standard"N"Penetration:Blowsperfootofa140poundhammerfalling30inchesona2ͲinchO.D.splitspoon,exceptwherenoted.
WATERLEVELMEASUREMENTSYMBOLS:
WL:WaterLevelWS:WhileSampling
WCI:WetCaveinWD:WhileDrilling
DCI:DryCaveinBCR:BeforeCasingRemoval
AB:AfterBoringACR:AfterCastingRemoval
Waterlevelsindicatedontheboringlogsarethelevelsmeasuredintheboringsatthetimeindicated.Inpervioussoils,theindicated
levelsmayreflectthelocationofgroundwater.Inlowpermeabilitysoils,theaccuratedeterminationofgroundwaterlevelsisnot
possiblewithonlyshorttermobservations.
DESCRIPTIVESOILCLASSIFICATION
SoilClassificationisbasedontheUnifiedSoilClassification
systemandtheASTMDesignationsDͲ2488.CoarseGrained
Soilshavemovethan50%oftheirdryweightretainedona
#200sieve;theyaredescribedas:boulders,cobbles,gravelor
sand.FineGrainedSoilshavelessthan50%oftheirdryweight
retainedona#200sieve;theyaredescribedas:clays,ifthey
areplastic,andsiltsiftheyareslightlyplasticornonͲplastic.
Majorconstituentsmaybeaddedasmodifiersandminor
constituentsmaybeaddedaccordingtotherelative
proportionsbasedongrainsize.Inadditiontogradation,
coarsegrainedsoilsaredefinedonthebasisoftheirrelativeinͲ
placedensityandfinegrainedsoilsonthebasisoftheir
consistency.Example:Leanclaywithsand,tracegravel,stiff
(CL);siltysand,tracegravel,mediumdense(SM).
CONSISTENCYOFFINEͲGRAINEDSOILS
UnconfinedCompressive
Strength,Qu,psf Consistency
<500 VerySoft
500Ͳ1,000 Soft
1,001Ͳ2,000 Medium
2,001Ͳ4,000 Stiff
4,001Ͳ8,000 VeryStiff
8,001Ͳ16,000 VeryHard
RELATIVEDENSITYOFCOARSEͲGRAINEDSOILS:
NͲBlows/ft RelativeDensity
0Ͳ3VeryLoose
4Ͳ9Loose
10Ͳ29MediumDense
30Ͳ49Dense
50Ͳ80VeryDense
80+ExtremelyDense
PHYSICALPROPERTIESOFBEDROCK
DEGREEOFWEATHERING:
SlightSlightdecompositionofparentmaterialon
joints.Maybecolorchange.
ModerateSomedecompositionandcolorchange
throughout.
HighRockhighlydecomposed,maybeextremely
broken.
HARDNESSANDDEGREEOFCEMENTATION:
LimestoneandDolomite:
HardDifficulttoscratchwithknife.
ModeratelyCanbescratchedeasilywithknife.
HardCannotbescratchedwithfingernail.
SoftCanbescratchedwithfingernail.
Shale,SiltstoneandClaystone:
HardCanbescratchedeasilywithknife,cannotbe
scratchedwithfingernail.
ModeratelyCanbescratchedwithfingernail.
Hard
SoftCanbeeasilydentedbutnotmoldedwith
fingers.
SandstoneandConglomerate:
WellCapableofscratchingaknifeblade.
Cemented
CementedCanbescratchedwithknife.
PoorlyCanbebrokenaparteasilywithfingers.
Cemented
Group
Symbol
Group Name
Cu≥4 and 1<Cc≤3E GW Well-graded gravel F
Cu<4 and/or 1>Cc>3E 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≤3E SW Well-graded sand I
Cu<6 and/or 1>Cc>3E 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
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 102030405060708090100110PLASTICITY 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
B-18
B-19
B-20 B-21
B-22
Figure 1: Proposed Boring Location Diagram
United Development Companies - NWC of College and Trilby
Fort Collins, Colorado
December 2020
B-1 Through B-17
Approximate Locations
of 17 Borings 2000
EARTH ENGINEERING CONSULTANTS, LLC
Legend
B-18 Through B-22
Approximate Locations
for 5 Supplemental
Preliminary Borings
B-18
B-19
B-20
B-21
B-22
Approximate
Locations for 5
Supplemental
Preliminary Borings
EARTH ENGINEERING CONSULTANTS, LLC
Legend
Figure 2: Proposed Boring Location Diagram
United Development Companies - NWC of College and Trilby
Fort Collins, Colorado
December 2020
6301 SOUTH COLLEGE AVENUE
FORT COLLINS, COLORADO
EEC PROJECT NO. 1212019
MARCH 2021
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-1
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING 3'
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR 2.5'
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
tan to dark brown 2
soft to stiff _ _
3
_ _
4
_ _
CS 57<<500 ps f 25.0 103.4 31 18 55.9 <500 psf None
_ _
6
_ _
7
_ _
firmed and olive brown @ 8.0' 8
_ _
9
_ _
SS 10 57 9000+17.8
_ _
11
_ _
CLAYSTONE 12
rust/brown _ _
soft 13
with interbedded sandstone _ _
14
_ _
SS 15 14/1 9000+17.6
_ _
BOTTOM OF BORING 15.5' 16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-2
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING None
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR None
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
brown 2
stiff _ _
3
_ _
4
_ _
SS 510 77000 16.7
_ _
6
_ _
7
_ _
8
_ _
9
_ _
CS 10 21 9000+12.7
_ _
11
_ _
CLAYSTONE 12
rust/brown _ _
soft 13
with interbedded sandstone _ _
14
_ _
SS 15 50/5 9000+8.7
_ _
BOTTOM OF BORING 15.5' 16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-3
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING 6'
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR 6.7'
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
LEAN CLAY WITH SAND (CL) _ _
brown 2
stiff _ _
3
_ _
4
_ _
CS 59 33500 20.4 104.9 38 23 75.4 <500 psf None
_ _
6
_ _
7
CLAYSTONE _ _
grey/rust/brown 8
soft _ _
with interbedded sandstone 9
_ _
SS 10 38/7 9000+13.4
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 17/1 9000+12.4
_ _
BOTTOM OF BORING 15.5' 16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-4
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING None
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR 7.7'
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
brown 2
stiff _ _
3
_ _
4
_ _
SS 58 44500 20.8
_ _
6
_ _
7
_ _
8
_ _
9
CLAYSTONE _ _
olive/rust CS 10 35/4 9000+13.4 123.7 38 24 70.2 3800 psf 2.4%
soft _ _
with interbedded sandstone 11
_ _
12
_ _
13
_ _
14
_ _
SS 15 50/7 9000+11.7
_ _
BOTTOM OF BORING 15.5' 16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-5
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING None
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR None
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
tan 2
stiff _ _
3
_ _
4
_ _
CS 510 99000+12.7 106.4 40 26 68.9 3200 2.0%
_ _
6
_ _
7
_ _
8
_ _
9
_ _
SS 10 15 3500 18.1
_ _
11
CLAYSTONE _ _
rust/brown 12
soft _ _
with interbedded sandstone 13
_ _
14
_ _
SS 15 50/9 9000+14.2
_ _
BOTTOM OF BORING 15.5' 16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-6
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING 2.5'
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR 1.9'
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
tan to dark brown 2
soft to stiff _ _
3
_ _
4
_ _
SS 56 11500 23.9
_ _
6
_ _
CLAYSTONE 7
rust/brown _ _
soft 8
with interbedded sandstone _ _
9
_ _
CS 10 6 2000 22.5
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 12 2000 23.2
_ _
BOTTOM OF BORING 15.5' 16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-7
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING 4.5'
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR 3.9'
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
tan to dark brown 2
_ _
3
_ _
4
_ _
5
_ _
6
_ _
7
_ _
8
BOTTOM OF BORING 8.0' _ _
9
_ _
10
_ _
11
_ _
12
_ _
13
_ _
14
_ _
15
_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-8
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING None
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR None
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
brown 2
_ _
3
_ _
4
_ _
5
_ _
6
_ _
7
_ _
8
BOTTOM OF BORING 8.0' _ _
9
_ _
10
_ _
11
_ _
12
_ _
13
_ _
14
_ _
15
_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-9
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING 3'
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR 1.3'
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
tan to brown 2
_ _
3
_ _
4
_ _
5
_ _
6
_ _
7
_ _
8
BOTTOM OF BORING 8.0' _ _
9
_ _
10
_ _
11
_ _
12
_ _
13
_ _
14
_ _
15
_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-10
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING None
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR None
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
brown 2
_ _
3
_ _
4
_ _
5
_ _
6
_ _
7
_ _
8
BOTTOM OF BORING 8.0' _ _
9
_ _
10
_ _
11
_ _
12
_ _
13
_ _
14
_ _
15
_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-11
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING 7'
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR 5.6'
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
brown 2
_ _
3
_ _
4
_ _
5
_ _
6
_ _
7
_ _
8
BOTTOM OF BORING 8.0' _ _
9
_ _
10
_ _
11
_ _
12
_ _
13
_ _
14
_ _
15
_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-12
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING 7.0'
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING None
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR 5.4'
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
tan to brown 2
_ _
3
_ _
4
_ _
5
_ _
6
_ _
7
_ _
8
BOTTOM OF BORING 8.0' _ _
9
_ _
10
_ _
11
_ _
12
_ _
13
_ _
14
_ _
15
_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-13
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING 2'
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR 0.3'
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
brown 2
_ _
3
_ _
4
_ _
5
_ _
6
_ _
7
_ _
8
BOTTOM OF BORING 8.0' _ _
9
_ _
10
_ _
11
_ _
12
_ _
13
_ _
14
_ _
15
_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-14
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING 3.0'
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING None
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR 2.5'
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
brown 2
_ _
3
_ _
4
_ _
5
_ _
6
_ _
7
_ _
8
BOTTOM OF BORING 8.0' _ _
9
_ _
10
_ _
11
_ _
12
_ _
13
_ _
14
_ _
15
_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-15
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING 8.0'
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR 8.0'
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
brown 2
_ _
3
_ _
4
_ _
5
_ _
6
_ _
7
_ _
8
BOTTOM OF BORING 8.0' _ _
9
_ _
10
_ _
11
_ _
12
_ _
13
_ _
14
_ _
15
_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-16
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING None
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING None
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR 8.0'
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
tan to brown 2
_ _
3
_ _
4
_ _
5
_ _
6
_ _
7
_ _
8
BOTTOM OF BORING 8.0' _ _
9
_ _
10
_ _
11
_ _
12
_ _
13
_ _
14
_ _
15
_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
TILEY PROPERTY
FORT COLLINS, COLORADO
PROJECT NO: 1002194 DATE: OCTOBER 2000
LOG OF BORING B-17
RIG TYPE: CME 45 SHEET 1 OF 1 WATER DEPTH
FOREMAN: JB START DATE 9/29/2000 WHILE DRILLING 2'
AUGER TYPE: 4" CFA FINISH DATE 9/29/2000 AFTER DRILLING -
SPT HAMMER: Manual SURFACE ELEV N/A 24 HOUR 0.7' - AGL
DN QU MCDD A-LIMITS -200 SWELL
SOIL DESCRIPTION TYPE (FEET) (BLOWS/FT) (PSF) (%) (PCF) LL PI (%) PRESSURE % @ 500 PSF
TOPSOIL AND VEGETATION _ _
1
SANDY LEAN CLAY (CL) _ _
tan to dark brown 2
_ _
3
_ _
4
_ _
5
_ _
6
_ _
7
_ _
8
BOTTOM OF BORING 8.0' _ _
9
_ _
10
_ _
11
_ _
12
_ _
13
_ _
14
_ _
15
_ _
16
_ _
17
_ _
18
_ _
19
_ _
20
_ _
21
_ _
22
_ _
23
_ _
24
_ _
25
Earth Engineering Consultants, Inc.
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
NO VEGETATION OR TOPSOIL _ _
1
SANDY LEAN CLAY (CL) _ _
brown 2
_ _
3
_ _
SILTSTONE / SANDSTONE 4
brown / gray _ _
poorly cemented to cemented CS 5 50/4" 4500 5.7 112.8 24 4 25.9 800 psf 0.3%
_ _
*bedrock classified as SILTY SAND (SM) 6
_ _
7
_ _
8
_ _
9
_ _
SS 10 50/4.5" 9000+ 11.3
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CS 15 50/3" 9000+ 12.6 107.8
_ _
16
with cemented lenses _ _
17
_ _
18
_ _
19
_ _
SS 20 50/3" 9000+ 12.7
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 50/2" 9000+ 13.1 90.2
BOTTOM OF BORING DEPTH 25' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
FINISH DATE 3/8/2021
SHEET 1 OF 1 WATER DEPTH
START DATE 3/8/2021 WHILE DRILLING 18'
6301 SOUTH COLLEGE AVENUE
FORT COLLINS, COLORADO
PROJECT NO: 1212019 LOG OF BORING B-18 MARCH 2021
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
NO VEGETATION OR TOPSOIL _ _
1
SANDY LEAN CLAY (CL) _ _
brown, very stiff 2
_ _
CS 3 50 9000+ 7.9 120.7
SANDSTONE / SILTSTONE / CLAYSTONE _ _
brown / gray 4
highly weathered to moderately hard/poorly cemented _ _
with calcareous deposits SS 5 50 9000+ 9.0
_ _
6
_ _
7
_ _
8
_ _
9
_ _
*bedrock classified as SANDY LEAN CLAY (CL) CS 10 50/5" 9000+ 9.8 128.2 40 24 60.2 ~10,000 PSF 9.7%
_ _
11
_ _
12
_ _
13
_ _
14
_ _
SS 15 50/7" 9000+ 11.3
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 50/5" 9000+ 12.3 123.0
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 50/9.5" 9000+ 13.4
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
FINISH DATE 3/8/2021
SHEET 1 OF 1 WATER DEPTH
START DATE 3/5/2021 WHILE DRILLING None
6301 SOUTH COLLEGE AVENUE
FORT COLLINS, COLORADO
PROJECT NO: 1212019 LOG OF BORING B-19 MARCH 2021
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 TO NO VEGETATION _ _
1
LEAN CLAY with SAND (CL) _ _
brown 2
stiff to very stiff _ _% @ 150 psf
with calcareous deposits CS 3 26 5500 7.2 114.2 37 22 70.7 7000 psf 13.9%
_ _
4
_ _
SS 5 13 7000 7.6
_ _
6
_ _
7
_ _
8
_ _
9
_ _
* classified as SANDY LEAN CLAY (CL) CS 10 28 9000+ 6.2 109.3 32 18 65.4 7000 psf 6.5%
_ _
11
_ _
12
_ _
SANDSTONE / SILTSTONE / CLAYSTONE 13
brown / gray / rust _ _
highly weathered to hard 14
with gypsum crystals _ _
SS 15 50 9000+ 10.4
_ _
16
_ _
17
_ _
18
_ _
19
_ _
CS 20 50/5" 9000+ 9.3 126.9
_ _
21
_ _
22
_ _
23
_ _
24
_ _
SS 25 50/3" 9000+ 9.3
BOTTOM OF BORING DEPTH 25.5' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
FINISH DATE 3/8/2021
SHEET 1 OF 1 WATER DEPTH
START DATE 3/8/2021 WHILE DRILLING None
6301 SOUTH COLLEGE AVENUE
FORT COLLINS, COLORADO
PROJECT NO: 1212019 LOG OF BORING B-20 MARCH 2021
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
NO VEGETATION OR TOPSOIL _ _
1
SANDY LEAN CLAY (CL) _ _
brown 2
_ _
3
_ _
4
_ _
SANDSTONE / SILTSTONE / CLAYSTONE CS 5 50/7.5" 9000+ 9.2 124.2 39 24 80.4 ~ 7000 PSF 9.2%
brown / gray / rust _ _
moderately hard to hard 6
_ _
7
*bedrock classified as LEAN CLAY with SAND (CL) _ _
8
_ _
9
_ _
SS 10 50/8" 8000 11.0
_ _
11
_ _
12
_ _
13
_ _
14
_ _
CS 15 50/5.5" 9000+ 11.4 125.2
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 50/5" 9000+ 11.4
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 50/5" 9000+ 11.5 122.3
BOTTOM OF BORING DEPTH 25' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
FINISH DATE 3/8/2021
SHEET 1 OF 1 WATER DEPTH
START DATE 3/8/2021 WHILE DRILLING None
6301 SOUTH COLLEGE AVENUE
FORT COLLINS, COLORADO
PROJECT NO: 1212019 LOG OF BORING B-21 MARCH 2021
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 AND TOPSOIL _ _
1
SANDY LEAN CLAY (CL) _ _
dark brown 2
stiff to medium stiff _ _
3
_ _
4
_ _
CS 5 11 6000 19.1 102.8 <500 psf None
_ _
6
_ _
7
_ _
8
_ _
9
with calcareous deposits _ _
SS 10 10 5000 20.8
_ _
11
_ _
SANDSTONE / SILTSTONE / CLAYSTONE 12
brown / gray / rust _ _
weathered to moderately hard 13
_ _
14
_ _
CS 15 50/6" 9000+ 13.7 119.8
_ _
16
_ _
17
_ _
18
_ _
19
_ _
SS 20 50/5" 9000+ 8.7
_ _
21
_ _
22
_ _
23
_ _
24
_ _
CS 25 50/7" 9000+ 15.0 118.7
BOTTOM OF BORING DEPTH 25' _ _
Earth Engineering Consultants, LLC
A-LIMITS SWELL
FINISH DATE 3/5/2021
SHEET 1 OF 1 WATER DEPTH
START DATE 3/5/2021 WHILE DRILLING None
6301 SOUTH COLLEGE AVENUE
FORT COLLINS, COLORADO
PROJECT NO: 1212019 LOG OF BORING B-22 MARCH 2021
Project:
Location:
Project #:
Date:
6301 South College Avenue
Fort Collins, Colorado
1212019
March 2021
Beginning Moisture: 5.7% Dry Density: 104.8 pcf Ending Moisture: 23.7%
Swell Pressure: 800 psf % Swell @ 500: 0.3%
Sample Location: Boring 18, Sample 1, Depth 4'
Liquid Limit: 24 Plasticity Index: 4 % Passing #200: 25.9%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: brown / gray Siltstone / Sandstone
-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 10Percent MovementLoad (TSF)SwellConsolidatioWater Added
Project:
Location:
Project #:
Date:
6301 South College Avenue
Fort Collins, Colorado
1212019
March 2021
Beginning Moisture: 9.8% Dry Density: 128 pcf Ending Moisture: 14.4%
Swell Pressure: ~10,000 psf % Swell @ 500: 9.7%
Sample Location: Boring 19, Sample 3, Depth 9'
Liquid Limit: 40 Plasticity Index: 24 % Passing #200: 60.2%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: brown / gray Sandstone / Siltstone / Claystone - (SANDY LEAN CLAY)
-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 10Percent MovementLoad (TSF)SwellConsolidatioWater Added
Project:
Location:
Project #:
Date:
6301 South College Avenue
Fort Collins, Colorado
1212019
March 2021
Beginning Moisture: 7.2% Dry Density: 119.9 pcf Ending Moisture: 17.6%
Swell Pressure: 7000 psf % Swell @ 150: 13.9%
Sample Location: Boring 20, Sample 1, Depth 2'
Liquid Limit: 37 Plasticity Index: 22 % Passing #200: 70.7%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: brown Lean Clay with Sand (CL)
-6.0
-4.0
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
0.01 0.1 1 10Percent MovementLoad (TSF)SwellConsolidatioWater Added
Project:
Location:
Project #:
Date:
6301 South College Avenue
Fort Collins, Colorado
1212019
March 2021
Beginning Moisture: 6.2% Dry Density: 124.9 pcf Ending Moisture: 17.3%
Swell Pressure: 7000 psf % Swell @ 500: 6.5%
Sample Location: Boring 20, Sample 3, Depth 9'
Liquid Limit: 32 Plasticity Index: 18 % Passing #200: 65.4%
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 10Percent MovementLoad (TSF)SwellConsolidatioWater Added
Project:
Location:
Project #:
Date:
6301 South College Avenue
Fort Collins, Colorado
1212019
March 2021
Beginning Moisture: 9.2% Dry Density: 127.2 pcf Ending Moisture: 15.8%
Swell Pressure: ~7,000 psf % Swell @ 500: 9.2%
Sample Location: Boring 21, Sample 1, Depth 4'
Liquid Limit: 39 Plasticity Index: 24 % Passing #200: 80.4%
SWELL / CONSOLIDATION TEST RESULTS
Material Description: brown / gray / Rust Claystone - (LEAN CLAY with SAND)
-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 10Percent MovementLoad (TSF)SwellConsolidatioWater Added
Project:
Location:
Project #:
Date:
6301 South College Avenue
Fort Collins, Colorado
1212019
March 2021
Beginning Moisture: 19.1% Dry Density: 107 pcf Ending Moisture: 18.7%
Swell Pressure: <500 psf % Swell @ 500: None
Sample Location: Boring 22, Sample 1, Depth 4'
Liquid Limit: - - Plasticity Index: - - % Passing #200: - -
SWELL / CONSOLIDATION TEST RESULTS
Material Description: Dark 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 10Percent MovementLoad (TSF)SwellConsolidatioWater Added