HomeMy WebLinkAboutTHE RETREAT AT FORT COLLINS (FORMERLY REDWOOD STREET MULTI-FAMILY) - PDP - PDP180002 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTREPORT COVER PAGE
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins
Fort Collins, Colorado
March 7, 2018
Terracon Project No. 20175058
Prepared for:
LCD Acquisitions, LLC
Athens, Georgia
Prepared by:
Terracon Consultants, Inc.
Fort Collins, Colorado
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REPORT TOPICS
REPORT TOPICS
REPORT SUMMARY ...................................................................................................... 1
INTRODUCTION ............................................................................................................. 1
SITE CONDITIONS ......................................................................................................... 1
PROJECT DESCRIPTION .............................................................................................. 2
GEOTECHNICAL CHARACTERIZATION ...................................................................... 3
GEOTECHNICAL OVERVIEW ....................................................................................... 4
EARTHWORK................................................................................................................. 5
SHALLOW FOUNDATIONS ......................................................................................... 11
FLOOR SYSTEMS........................................................................................................ 13
SEISMIC CONSIDERATIONS ...................................................................................... 14
PAVEMENTS ................................................................................................................ 15
CORROSIVITY.............................................................................................................. 18
GENERAL COMMENTS ............................................................................................... 18
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ATTACHMENTS
SITE LOCATION AND EXPLORATION PLANS
EXPLORATION RESULTS (EXPLORATION AND TESTING PROCEDURES, Boring
Logs and Laboratory Data)
SUPPORTING INFORMATION (General Notes and Unified Soil Classification System)
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
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REPORT SUMMARY
Topic
1 Overview Statement
2
Project
Overview
A preliminary geotechnical exploration has been performed for the proposed Retreat
at Fort Collins to be constructed southeast of the intersection of Redwood Street and
Conifer Street in Fort Collins, Colorado. Six (6) borings were performed to depths of
approximately 22 to 29 feet below existing site grades. Supplementary geotechnical
engineering exploration should be performed at the site upon completion of initial
design and studies in order to confirm or modify the recommendations contained in this
preliminary report and to allow the development of design-level recommendations more
specific to the proposed construction.
Subsurface
Conditions
Subsurface conditions encountered in our exploratory borings generally consisted of
about 4 to 6 feet of lean clay with varying amounts of sand or silty sand over about 15
to 20 feet of well graded sand with silt and gravel. Claystone bedrock was encountered
below the overburden soils in most of the borings at depths of approximately 16 to 20
feet below existing site grades. Boring logs are presented in the Exploration Results
section of this report.
Groundwater
Conditions
Groundwater was encountered in all of our test borings at depths of about 7 to 13½ feet
below existing site grades at the time of drilling or when checked several days after
drilling. Groundwater levels can fluctuate in response to site development and to
varying seasonal and weather conditions, irrigation on or adjacent to the site and
fluctuations in nearby water features.
Geotechnical
Concerns
■ Loose silty sand soils were encountered within the upper approximately 3 to 7
feet of the borings completed at this site. These materials can be susceptible
to disturbance and loss of strength under repeated construction traffic loads and
unstable conditions could develop. Stabilization of loose silty sand soils may be
required at some locations to provide adequate support for construction
equipment and proposed structures. Terracon should be contacted if these
conditions are encountered to observe the conditions exposed and to provide
guidance regarding stabilization (if needed).
■ Shallow groundwater was measured at depths ranging from about 7 to 13½ feet
below existing site grades. Terracon recommends maintaining a separation of at
least 3 feet between the bottom of proposed below-grade foundations and
measured groundwater levels. It is also possible and likely that groundwater
levels below this site may rise as water levels in the James Lake Canal rise. Final
site grading should be planned and designed to avoid cuts where shallow
groundwater is known to exist, and also in areas where such grading would create
shallow groundwater conditions. If deeper cuts are unavoidable, installation of a
subsurface drainage system may be needed.
Earthwork
On-site soils typically appear suitable for use as general engineered fill and backfill on
the site provided they are placed and compacted as described in this report. Import
materials (if needed) should be evaluated and approved by Terracon prior to delivery
to the site. Earthwork recommendations are presented in the Earthwork section of
this report.
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
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Topic
1 Overview Statement
2
Grading and
Drainage
The amount of movement of foundations, floor slabs, pavements, etc. will be related to
the wetting of underlying supporting soils. Therefore, it is imperative the
recommendations discussed in the Grading and Drainage section of this report be
followed to reduce potential movement. As discussed in the Grading and Drainage
section of this report, surface drainage should be designed, constructed and maintained
to provide rapid removal of surface water runoff away from the existing and proposed
buildings and pavements. Water should not be allowed to pond adjacent to foundations
or on pavements and conservative irrigation practices should be followed to avoid
wetting foundation/slab soils and pavement subgrade. Excessive wetting of
foundations/slab soils and subgrade can cause movement and distress to foundations,
floor slabs, concrete flatwork and pavements.
Foundations
We anticipate the proposed buildings can be supported on shallow foundations such
as spread footings, reinforced mats or post-tensioned slab foundation system bearing
on properly placed on-site soils or newly placed engineering fill. Some ground
improvement such as shallow over-excavation and compaction or rammed aggregate
piers may be needed for comparatively heavily-loaded foundations.
Floor Systems
Results of our preliminary geotechnical study indicate a slab-on-grade floor system can
likely be used for the proposed buildings provided the soils are properly prepared as
described in the Earthwork section of this report. Shallow over-excavation, likely on
the order of 1 to 3 feet, may be necessary below several of the buildings to reduce risk
for settlement and enhance performance. On-site soils are suitable as over-excavation
backfill below floor slabs.
Pavements
Preliminary recommendations for pavement thicknesses for this project include 4
inches of asphalt over 4 inches of aggregate base course in light-duty parking areas
and 4½ inches of asphalt over 6 inches of aggregate base course in heavy-duty drive
lanes and loading areas. Additional pavement section alternatives and discussion are
presented in the report.
Seismic
Considerations
As presented in the Seismic Considerations section of this report the 2015
International Building Code which refers to Section 20.4 of ASCE 7-10 indicates
seismic site classification for this site is C.
Construction
Observation
and Testing
Close monitoring of the construction operations and implementing drainage
recommendations discussed herein will be critical in achieving the intended
foundation, slab and pavement performance. We therefore recommend that Terracon
be retained to monitor this portion of the work.
General
Comments
This section contains important information about the limitations of this geotechnical
engineering report.
1. If the reader is reviewing this report as a pdf, the topics (bold orange font) above can be used to access the
appropriate section of the report by simply clicking on the topic itself.
2. This summary is for convenience only. It should be used in conjunction with the entire report for design
purposes.
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INTRODUCTION
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins
Southeast of Redwood Street and Conifer Street
Fort Collins, Colorado
Terracon Project No. 20175058
March 7, 2018
INTRODUCTION
This report presents the results of our preliminary subsurface exploration and geotechnical
engineering services performed for the proposed Retreat at Fort Collins to be located southeast
of the intersection of Redwood Street and Conifer Street in Fort Collins, Colorado. The purpose
of these services is to provide preliminary information and geotechnical engineering
recommendations relative to:
■ Subsurface soil and rock conditions ■ Foundation design and construction
■ Groundwater conditions ■ Floor system design and construction
■ Site preparation and earthwork ■ Seismic considerations
■ Excavation considerations ■ Pavement design and construction
The preliminary geotechnical engineering scope of services for this project included the
advancement of 6 test borings to depths ranging from approximately 22 to 29 feet below existing
site grades.
Maps showing the site and boring locations are shown in the Site Location and Exploration
Plans section of this report. The results of the laboratory testing performed on soil and bedrock
samples obtained from the site during the field exploration are included on the boring logs and as
separate graphs in the Exploration Results section of this report.
SITE CONDITIONS
The following description of site conditions is derived from our site visit in association with the
field exploration and our review of publicly available geologic and topographic maps.
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
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Item Description
Parcel Information
The site is located south of Conifer Street and east of Redwood Street in
Fort Collins, Colorado. The Approximate Latitude/Longitude of the center of
the site is 40.60208°N/105.06342°W.
Existing
Improvements
The site is currently vacant land. The Redwood Meadows single-family
housing subdivision is located west of the proposed project. Multi-family
housing is located to the north and vacant land lies to the east. The James
Lake Canal crosses the southeast edge of the property.
Current Ground
Cover The current ground cover is native grasses and weeds.
Existing Topography The site is relatively flat, published topographic maps indicate the site slopes
less than 2 percent from the northwest to southeast.
PROJECT DESCRIPTION
Our initial understanding of the project was provided in our proposal and was discussed in the
project planning stage. A period of collaboration has transpired since the project was initiated,
and our final understanding of the project conditions is as follows:
Item Description
Project Description
Site details are still being developed. Conceptually, the project will
include several multi-level, multi-bedroom housing consisting of 78 units
across 29 acres. A clubhouse and maintenance building, drive areas,
parking areas and new utilities are also proposed. In addition, storm
water management basins are included as part of the initial site
development.
Project Understanding
Terracon’s recommendations have been provided under the belief that this
site will be used as apartments. As such, Terracon would like to inform the
Client that if this apartment project is converted at any time to another
purpose such as condominiums, the Client understands the services
Terracon have provided are not applicable for a condominium project and
that a separate consultant will need to be retained for such services.
Terracon will have no liability for any such unintended use of our services
and Client agrees to defend, indeminify, and hold harmless Terracon for
any such unintended usage.
Grading/Slopes We anticipate minor cuts and fills on the order of 5 feet or less will be
required to achieve proposed grades.
Below-grade Structures We understand no below-grade are planned for this site.
Pavements
NAPA Traffic Class (assumed):
Automobile Parking Areas: Class I
Truck traffic and main drives: Class II
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
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GEOTECHNICAL CHARACTERIZATION
Subsurface Profile
Specific conditions encountered at each boring location are indicated on the individual boring logs.
Stratification boundaries on the boring logs represent the approximate location of changes in soil
types; in situ, the transition between materials may be gradual. Details for each of the borings can
be found in Exploration Results. A discussion of field sampling and laboratory testing procedures
and test results are presented in Exploration and Testing Procedures. Based on the results of
the borings, subsurface conditions on the project site can be generalized as follows:
Material Description Approximate Depth to
Bottom of Stratum Consistency/Density/Hardness
Topsoil, vegetative layer Approximately 6 inches below
existing site grades. --
Lean clay with varying amounts of
sand
About 4 to 6 feet below
existing site grades, only
encountered in Boring No. 4
and Boring No. 6.
Medium stiff to stiff
Silty sand with varying amounts of
gravel
About 2½ to 20 feet below
existing site grades. Loose to very dense
Well graded sand with silt and
gravel
About 16 to 23 feet below
existing site grads.
Medium dense to very dense
Claystone bedrock
To the maximum depth of
exploration of about 22 to 29
feet.
Hard to very hard
Groundwater Conditions
The boreholes were observed while drilling and after completion for the presence and level of
groundwater. In addition, delayed water levels were also obtained in the borings. The water levels
observed in the boreholes are noted on the attached boring logs, and are summarized below:
Boring Number Depth to groundwater
while drilling, ft.
Depth to groundwater
several days after
drilling, ft.
Elevation of
groundwater several
days after drilling, ft.
1
1 8 7.8 87.9
2 7 6.3 89.8
3 7 7 87.1
4 8 8.1 86.3
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
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Boring Number Depth to groundwater
while drilling, ft.
Depth to groundwater
several days after
drilling, ft.
Elevation of
groundwater several
days after drilling, ft.
1
5 11 13.5 83.1
6 12 9.5 87.2
1. Elevations refers to survived elevation of boring locations, referencing a temporary on-site benchmark
with an assumed elevation of 100 feet.
These observations represent groundwater conditions at the time of the field exploration, and may
not be indicative of other times or at other locations. Groundwater levels can be expected to
fluctuate with varying seasonal and weather conditions, and other factors.
Groundwater level fluctuations occur due to seasonal variations in the water levels present in the
James Lake Canal and other nearby water featrues, amount of rainfall, runoff and other factors
not evident at the time the borings were performed. Therefore, groundwater levels during
construction or at other times in the life of the structure(s) may be higher or lower than the levels
indicated on the boring logs. The possibility of groundwater level fluctuations should be
considered when developing the design and construction plans for the project.
Fluctuations in groundwater levels can best be determined by implementation of a groundwater
monitoring plan. Such a plan would include installation of groundwater piezometers, and periodic
measurement of groundwater levels over a sufficient period of time.
GEOTECHNICAL OVERVIEW
Based on subsurface conditions encountered in the borings, the site appears suitable for the
proposed construction from a geotechnical point of view provided certain precautions and design
and construction recommendations described in this report are followed. We have identified
several geotechnical conditions that could impact design, construction and performance of the
proposed structures, pavements, and other site improvements. These included shallow
groundwater, and potentially soft and loose, low strength soils. These conditions will require
particular attention in project planning, design and during construction and are discussed in
greater detail in the following sections.
Shallow Groundwater
As previously stated, groundwater was measured at depths ranging from about 7 to 13½ feet
below existing site grades. Groundwater will likely impact buried utility construction, possibly
requiring construction dewatering depending on excavation depths. Terracon recommends
Preliminary Geotechnical Engineering Report
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maintaining a separation of at least 3 feet between the bottom of proposed foundations and
measured groundwater levels. It is also possible and likely that groundwater levels below this
site may rise as water levels in the James Lake Canal rise. Final site grading should be planned
and designed to avoid cuts where shallow groundwater is known to exist, and also in areas where
such grading would create shallow groundwater conditions. If deeper cuts are unavoidable,
installation of a subsurface drainage system may be needed.
Low Strength Soils
Loose silty sand soils were encountered within the upper approximately 3 to 7 feet of some of the
borings completed at this site. These materials can be susceptible to disturbance and loss of
strength under repeated construction traffic loads and unstable conditions could develop.
Stabilization of loose silty sand soils may be required at some locations to provide adequate
support for construction equipment and proposed structures. Terracon should be contacted if
these conditions are encountered to observe the conditions exposed and to provide guidance
regarding stabilization (if needed).
Foundation Recommendations
We anticipate the proposed buildings can be supported by a shallow, spread footing foundation
systems, reinforced mats or post-tensioned slab foundations. Some ground improvement such as
shallow over-excavation and compaction or rammed aggregate piers may be needed for
comparatively heavily-loaded foundations. Preliminary design recommendations for foundations
are provided in the Shallow Foundations section of this report. The General Comments section
provides an understanding of the report limitations.
EARTHWORK
The following presents recommendations for site preparation, excavation, subgrade preparation,
fill materials, compaction requirements, utility trench backfill, grading and drainage and exterior
slab design and construction. Earthwork on the project should be observed and evaluated by
Terracon. Evaluation of earthwork should include observation and/or testing of over-excavation,
removal of existing fill, subgrade preparation, placement of engineered fills, subgrade stabilization
and other geotechnical conditions exposed during the construction of the project.
Site Preparation
Prior to placing any fill, strip and remove existing vegetation, topsoil, and any other deleterious
materials from the proposed construction areas. Stripped organic materials should be wasted from
the site or used to re-vegetate landscaped areas or exposed slopes after completion of grading
operations. Prior to the placement of fills, the site should be graded to create a relatively level
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
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surface to receive fill, and to provide for a relatively uniform thickness of fill beneath proposed
structures.
If fill is placed in areas of the site where existing slopes are steeper than 5:1 (horizontal:vertical),
the area should be benched to reduce the potential for slippage between existing slopes and fills.
Benches should be wide enough to accommodate compaction and earth moving equipment, and
to allow placement of horizontal lifts of fill.
Excavation
It is anticipated that excavations for the proposed construction can be accomplished with
conventional earthmoving equipment. Excavations into the on-site soils may encounter saturated
soil conditions with possible caving conditions.
The soils to be excavated can vary significantly across the site as their classifications are based
solely on the materials encountered in widely-spaced exploratory test borings. The contractor
should verify that similar conditions exist throughout the proposed area of excavation. If different
subsurface conditions are encountered at the time of construction, the actual conditions should be
evaluated to determine any excavation modifications necessary to maintain safe conditions.
Although evidence of fills or underground facilities such as grease pits, septic tanks, vaults,
basements, and utilities was not observed during the site reconnaissance, such features could be
encountered during construction. If unexpected underground facilities are encountered, such
features should be removed and the excavation thoroughly cleaned prior to backfill placement
and/or construction.
Any over-excavation that extends below the bottom of foundation elevation should extend laterally
beyond all edges of the foundations at least 8 inches per foot of over-excavation depth below the
foundation base elevation. The over-excavation should be backfilled to the foundation base
elevation in accordance with the recommendations presented in this report.
Depending upon depth of excavation and seasonal conditions, surface water infiltration and/or
groundwater may be encountered in excavations on the site. It is anticipated that pumping from
sumps may be utilized to control water within excavations. Well points may be required for
significant groundwater flow, or where excavations penetrate groundwater to a significant depth.
Groundwater seepage should be anticipated for excavations approaching the level of bedrock.
The subgrade soil conditions should be evaluated during the excavation process and the stability
of the soils determined at that time by the contractors’ Competent Person. Slope inclinations flatter
than the OSHA maximum values may have to be used. 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
Preliminary Geotechnical Engineering Report
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March 7, 2018 ■ Terracon Project No. 20175058
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shored in the interest of safety following local, and federal regulations, including current OSHA
excavation and trench safety standards.
As a safety measure, it is recommended that all vehicles and soil piles be kept a minimum lateral
distance from the crest of the slope equal to the slope height. The exposed slope face should be
protected against the elements
Subgrade Preparation
After topsoil has been removed from the construction area, the top 10 inches of the exposed
ground surface should be scarified, moisture conditioned, and recompacted to at least 95 percent
of the maximum dry unit weight as determined by ASTM D698 before any new fill or foundation
or pavement is placed.
If pockets of soft, loose, or otherwise unsuitable materials are encountered at the bottom of the
foundation excavations and it is inconvenient to lower the foundations, the proposed foundation
elevations may be reestablished by over-excavating the unsuitable soils and backfilling with
compacted engineered fill or lean concrete.
After the bottom of the excavation has been compacted, engineered fill can be placed to bring the
building pad and pavement subgrade to the desired grade. Engineered fill should be placed in
accordance with the recommendations presented in subsequent sections of this report.
The stability of the subgrade may be affected by precipitation, repetitive construction traffic or
other factors. If unstable conditions develop, workability may be improved by scarifying and
drying. Alternatively, over-excavation of wet zones and replacement with granular materials may
be used, or crushed gravel and/or rock can be tracked or “crowded” into the unstable surface soil
until a stable working surface is attained. Lightweight excavation equipment may also be used to
reduce subgrade pumping.
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
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Fill Materials
The on-site soils or approved granular and low plasticity cohesive imported materials may be used
as fill material. Bedrock excavated during site development and construction can be reused as fill
provided the material is broken down and thoroughly processed to a “soil-like” consistency, with
no particles greater than 2 inches in size. The earthwork contractor should expect significant
mechanical processing and moisture conditioning of the site soils and/or bedrock will be needed
to achieve proper compaction
Imported soils (if required) should meet the following material property requirements:
Gradation Percent finer by weight (ASTM C136)
4” 100
3” 70-100
No. 4 Sieve 50-100
No. 200 Sieve 50 (max.)
Soil Properties Values
Liquid Limit 35 (max.)
Plastic Limit 6 (max.)
Other import fill materials types may be suitable for use on the site depending upon proposed
application and location on the site, and could be tested and approved for use on a case-by-base
basis.
Compaction Requirements
Engineered fill should be placed and compacted in horizontal lifts, using equipment and procedures
that will produce recommended moisture contents and densities throughout the lift.
Item Description
Fill lift thickness
9 inches or less in loose thickness when heavy, self-
propelled compaction equipment is used
4 to 6 inches in loose thickness when hand-guided
equipment (i.e. jumping jack or plate compactor) is used
Minimum compaction requirements 95 percent of the maximum dry unit weight as determined by
ASTM D698.
Moisture content cohesive soil (clay) -1 to +3 % of the optimum moisture content
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
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Item Description
Moisture content cohesionless soil
(sand) -3 to +3 % of the optimum moisture content
1. We recommend engineered fill be tested for moisture content and compaction during placement.
Should the results of the in-place density tests indicate the specified moisture or compaction limits
have not been met, the area represented by the test should be reworked and retested as required
until the specified moisture and compaction requirements are achieved.
2. Specifically, moisture levels should be maintained low enough to allow for satisfactory compaction to
be achieved without the fill material pumping when proofrolled.
3. Moisture conditioned clay materials should not be allowed to dry out. A loss of moisture within these
materials could result in an increase in the material’s expansive potential. Subsequent wetting of these
materials could result in undesirable movement.
Utility Trench Backfill
All trench excavations should be made with sufficient working space to permit construction including
backfill placement and compaction.
All underground piping within or near the proposed structures should be designed with flexible
couplings, so minor deviations in alignment do not result in breakage or distress. Utility knockouts
in foundation walls should be oversized to accommodate differential movements. It is imperative
that utility trenches be properly backfilled with relatively clean materials. If utility trenches are
backfilled with relatively clean granular material, they should be capped with at least 18 inches of
cohesive fill in non-pavement areas to reduce the infiltration and conveyance of surface water
through the trench backfill.
Utility trenches are a common source of water infiltration and migration. All utility trenches that
penetrate beneath the buildings should be effectively sealed to restrict water intrusion and flow
through the trenches that could migrate below the buildings. We recommend constructing an
effective clay “trench plug” that extends at least 5 feet out from the face of the building exteriors.
The plug material should consist of clay compacted at a water content at or above the soil’s optimum
water content. The clay fill should be placed to completely surround the utility line and be compacted
in accordance with recommendations in this report.
It is strongly recommended that a representative of Terracon provide full-time observation and
compaction testing of trench backfill within building and pavement areas.
Grading and Drainage
Grades must be adjusted to provide effective drainage away from the proposed building(s) and
existing buildings during construction and maintained throughout the life of the proposed project.
Infiltration of water into foundation excavations must be prevented during construction.
Preliminary Geotechnical Engineering Report
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Landscape irrigation adjacent to foundations should be minimized or eliminated. Water permitted
to pond near or adjacent to the perimeter of the structures (either during or post-construction) can
result in significantly higher soil movements than those discussed in this report. As a result, any
estimations of potential movement described in this report cannot be relied upon if positive
drainage is not obtained and maintained, and water is allowed to infiltrate the fill and/or subgrade.
Exposed ground (if any) should be sloped at a minimum of 10 percent grade for at least 5 feet
beyond the perimeter of the proposed buildings, where possible. Locally, flatter grades may be
necessary to transition ADA access requirements for flatwork. The use of swales, chases and/or
area drains may be required to facilitate drainage in unpaved areas around the perimeter of the
buildings. Backfill against foundations and exterior walls should be properly compacted and free
of all construction debris to reduce the possibility of moisture infiltration. After construction of the
proposed buildings and prior to project completion, we recommend verification of final grading be
performed to document positive drainage, as described above, has been achieved.
Flatwork and pavements will be subject to post-construction movement. Maximum grades
practical should be used for paving and flatwork to prevent areas where water can pond. In
addition, allowances in final grades should take into consideration post-construction movement
of flatwork, particularly if such movement would be critical. Where paving or flatwork abuts the
structures, care should be taken that joints are properly sealed and maintained to prevent the
infiltration of surface water.
Planters located adjacent to structures should preferably be self-contained. Sprinkler mains and
spray heads should be located a minimum of 5 feet away from the building line(s). Low-volume,
drip style landscaped irrigation should be used sparingly near the building. Roof drains should
discharge on to pavements or be extended away from the structures a minimum of 10 feet through
the use of splash blocks or downspout extensions. A preferred alternative is to have the roof
drains discharge by solid pipe to storm sewers or to a detention pond or other appropriate outfall.
Exterior Slab Design and Construction
Exterior slabs on-grade, exterior architectural features, and utilities founded on, or in backfill or
the site soils will likely experience some movement due to the volume change of the material.
Potential movement could be reduced by:
n Minimizing moisture increases in the backfill;
n Controlling moisture-density during placement of the backfill;
n Using designs which allow vertical movement between the exterior features and
adjoining structural elements; and
n Placing control joints on relatively close centers.
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
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Construction Observation and Testing
The earthwork efforts should be monitored under the direction of Terracon. Monitoring should
include documentation of adequate removal of vegetation and topsoil, proof-rolling and mitigation
of areas delineated by the proof-roll to require mitigation.
Each lift of compacted fill should be tested, evaluated, and reworked as necessary until approved
by Terracon prior to placement of additional lifts. Each lift of fill should be tested for density and
water content at a frequency of at least one test for every 2,500 square feet of compacted fill in
the structure areas and 5,000 square feet in pavement areas. One density and water content test
for every 50 linear feet of compacted utility trench backfill.
In areas of foundation excavations, the bearing subgrade and exposed conditions at the base of
the recommended over-excavation should be evaluated under the direction of Terracon. In the
event that unanticipated conditions are encountered, Terracon should prescribe mitigation
options.
In addition to the documentation of the essential parameters necessary for construction, the
continuation of Terracon into the construction phase of the project provides the continuity to
maintain the Terracon’s evaluation of subsurface conditions, including assessing variations and
associated design changes.
SHALLOW FOUNDATIONS
If the site has been prepared in accordance with the requirements noted in Earthwork, the
following preliminary design parameters for shallow foundations can be used for planning
purposes.
Spread Footings – Preliminary Design Recommendations
Description Values
Bearing material Properly prepared on-site soil, or new, properly
placed engineered fill.
Maximum net allowable bearing pressure
1 2,000 to 2,500 psf
Minimum embedment depth below finished
grade
2 30 inches
Estimated total movement About 1 inch
Estimated differential movement About ½ to ¾ of total movement
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Description Values
1. The recommended preliminary maximum net allowable bearing ranges pressure assumes any unsuitable fill
or loose soils, if encountered, will be over-excavated and replaced with properly compacted engineered fill.
The design bearing pressure applies to a dead load plus design live load condition. The design bearing
pressure may be increased by one-third when considering total loads that include wind or seismic conditions.
2. For frost protection and to reduce the effects of seasonal moisture variations in the subgrade soils. The
minimum embedment depth is for perimeter footings beneath unheated areas and is relative to lowest
adjacent finished grade, typically exterior grade. Interior column pads in heated areas should bear at least
12 inches below the adjacent grade (or top of the floor slab) for confinement of the bearing materials and to
develop the recommended bearing pressure.
Footings should be proportioned to reduce differential foundation movement. As discussed, total
movement resulting from the assumed structural loads is estimated to be on the order of about 1
inch. Additional foundation movements could occur if water from any source infiltrates the
foundation soils; therefore, proper drainage should be provided in the final design and during
construction and throughout the life of the structure. Failure to maintain the proper drainage as
recommended in the Grading and Drainage section in the Earthwork section of this report will
nullify the movement estimates provided above.
Spread Footings – Preliminary Construction Considerations
To reduce the potential of “pumping” and softening of the foundation soils at the foundation
bearing level and the requirement for corrective work, we suggest the foundation excavation for
the control building be completed remotely with a track-hoe operating outside of the excavation
limits.
Spread footing construction should only be considered if the estimated foundation movement can
be tolerated. Subgrade soils beneath footings should be moisture conditioned and compacted as
described in the Earthwork section of this report. The moisture content and compaction of
subgrade soils should be maintained until foundation construction.
Footings and foundation walls should be reinforced as necessary to reduce the potential for distress
caused by differential foundation movement.
Unstable subgrade conditions are anticipated as excavations approach the groundwater surface.
Unstable surfaces will need to be stabilized prior to backfilling excavations and/or constructing
the building foundation, floor slab and/or project pavements. The use of angular rock, recycled
concrete and/or gravel pushed or “crowded” into the yielding subgrade is considered suitable
means of stabilizing the subgrade. The use of geogrid materials in conjunction with gravel could
also be considered and could be more cost effective.
Unstable subgrade conditions should be observed by Terracon to assess the subgrade and
provide suitable alternatives for stabilization. Stabilized areas should be proof-rolled prior to
continuing construction to assess the stability of the subgrade.
Preliminary Geotechnical Engineering Report
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March 7, 2018 ■ Terracon Project No. 20175058
Responsive ■ Resourceful ■ Reliable 13
Foundation excavations should be observed by Terracon. If the soil conditions encountered differ
significantly from those presented in this report, supplemental recommendations will be required.
FLOOR SYSTEMS
Preliminary study indicated a slab-on-grade will likely be appropriate for the interior floor systems
for the proposed buildings provided the soils are properly prepared as described in the Earthwork
section of this report. If the estimated movement cannot be tolerated, a structurally-supported
floor system, supported independent of the subgrade materials, is recommended.
Subgrade soils beneath interior and exterior slabs should be scarified to a depth of at least 8
inches, moisture conditioned and compacted. The moisture content and compaction of subgrade
soils should be maintained until slab construction. Shallow over-excavation, likely on the order of
1 to 3 feet, may be necessary below several of the buildings to reduce risk for settlement and
enhance performance.
Floor System – Preliminary Design Recommendations
Even when bearing on properly prepared soils, movement of the slab-on-grade floor system is
possible should the subgrade soils undergo an increase in moisture content. We estimate
movement of about 1 inch is possible. If the owner cannot accept the risk of slab movement, a
structural floor should be used. If conventional slab-on-grade is utilized, the subgrade soils should
be over-excavated and prepared as presented in the Earthwork section of this report.
For structural design of concrete slabs-on-grade subjected to point loadings, a modulus of
subgrade reaction of 200 to 250 pounds per cubic inch (pci) will likely be recommended for floors
supported on re-compacted existing soils at the site.
Additional floor slab design and construction recommendations are as follows:
n Positive separations and/or isolation joints should be provided between slabs and all
foundations, columns, or utility lines to allow independent movement.
n Control joints should be saw-cut in slabs in accordance with ACI Design Manual, Section
302.1R-37 8.3.12 (tooled control joints are not recommended) to control the location and
extent of cracking.
n Interior utility trench backfill placed beneath slabs should be compacted in accordance
with the recommendations presented in the Earthwork section of this report.
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
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n Floor slabs should not be constructed on frozen subgrade.
n The use of a vapor retarder should be considered beneath concrete slabs that will be
covered with wood, tile, carpet or other moisture sensitive or impervious floor coverings,
or when the slab will support equipment sensitive to moisture. When conditions warrant
the use of a vapor retarder, the slab designer and slab contractor should refer to ACI
302 for procedures and cautions regarding the use and placement of a vapor retarder.
n Other design and construction considerations, as outlined in the ACI Design Manual,
Section 302.1R are recommended.
Floor Systems - Construction Considerations
Movements of slabs-on-grade using the recommendations discussed in previous sections of this
report will likely be reduced and tend to be more uniform. The estimates discussed above assume
that the other recommendations in this report are followed. Additional movement could occur
should the subsurface soils become wetted to significant depths, which could result in potential
excessive movement causing uneven floor slabs and severe cracking. This could be due to over
watering of landscaping, poor drainage, improperly functioning drain systems, and/or broken utility
lines. Therefore, it is imperative that the recommendations presented in this report be followed.
SEISMIC CONSIDERATIONS
The seismic design requirements for buildings and other structures are based on Seismic Design
Category. Site Classification is required to determine the Seismic Design Category for a structure.
The Site Classification is based on the upper 100 feet of the site profile defined by a weighted
average value of either shear wave velocity, standard penetration resistance, or undrained shear
strength in accordance with Section 20.4 of ASCE 7-10.
Description Value
2015 International Building Code Site Classification
1
C
2
Site Latitude 40.60208°N
Site Longitude 105.06342°W
SDS Spectral Acceleration for a Short Period
3 0.147g
SD1 Spectral Acceleration for a 1-Second Period
3 0.066g
Preliminary Geotechnical Engineering Report
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March 7, 2018 ■ Terracon Project No. 20175058
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Description Value
1. Seismic site classification in general accordance with the 2015 International Building Code, which refers to
ASCE 7-10.
2. The 2015 International Building Code (IBC) uses a site profile extending to a depth of 100 feet for seismic
site classification. Borings at this site were extended to a maximum depth of 29 feet. The site properties
below the boring depth to 100 feet were estimated based on our experience and knowledge of geologic
conditions of the general area. Additional deeper borings or geophysical testing may be performed to confirm
the conditions below the current boring depth.
3. These values were obtained using online seismic design maps and tools provided by the USGS
(http://earthquake.usgs.gov/hazards/designmaps/).
PAVEMENTS
Pavements – Subgrade Preparation
On most project sites, the site grading is accomplished relatively early in the construction phase.
Fills are typically placed and compacted in a uniform manner. However, as construction
proceeds, the subgrade may be disturbed due to utility excavations, construction traffic,
desiccation, or rainfall/snow melt. As a result, the pavement subgrade may not be suitable for
pavement construction and corrective action will be required. The subgrade should be carefully
evaluated at the time of pavement construction for signs of disturbance or instability. We
recommend the pavement subgrade be thoroughly proofrolled with a loaded tandem-axle dump
truck prior to final grading and paving. All pavement areas should be moisture conditioned and
properly compacted to the recommendations in this report immediately prior to paving.
Pavements – Design Recommendations
Design of new privately-maintained pavements for the project has been based on the procedures
described by the National Asphalt Pavement Associations (NAPA) and the American Concrete
Institute (ACI).
We assumed the following design parameters for NAPA flexible pavement thickness design:
n Automobile Parking Areas
• Class I - Parking stalls and parking lots for cars and pick-up trucks, with
Equivalent Single Axle Load (ESAL) up to 7,000 over 20 years
n Main Traffic Corridors
• Class II – Parking lots with a maximum of 10 trucks per day with Equivalent
Single Axle Load (ESAL) up to 27,000 over 20 years (Including trash trucks)
n Subgrade Soil Characteristics
• USCS Classification – SM, classified by NAPA as poor
Preliminary Geotechnical Engineering Report
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We assumed the following design parameters for ACI rigid pavement thickness design based
upon the average daily truck traffic (ADTT):
n Automobile Parking Areas
• ACI Category A: Automobile parking with an ADTT of 1 over 20 years
n Main Traffic Corridors
• ACI Category A: Automobile parking area and service lanes with an ADTT of
up to 10 over 20 years
n Subgrade Soil Characteristics
• USCS Classification – SM
n Concrete modulus of rupture value of 600 psi
We should be contacted to confirm and/or modify the recommendations contained herein if actual
traffic volumes differ from the assumed values shown above.
Recommended alternatives for flexible and rigid pavements are summarized for each traffic area
as follows:
Traffic Area Alternative
Recommended Pavement Thicknesses (Inches)
Asphaltic
Concrete
Surface
Aggregate
Base Course
Portland
Cement
Concrete
Total
Automobile Parking
(NAPA Class I and
ACI Category A)
A 4 4 - 8
B - - 5 5
Service Lanes
(NAPA Class II and
ACI Category A)
A 4½ 6 - 10½
B - - 6 6
Aggregate base course (if used on the site) should consist of a blend of sand and gravel which
meets strict specifications for quality and gradation. Use of materials meeting Colorado
Department of Transportation (CDOT) Class 5 or 6 specifications is recommended for aggregate
base course. Aggregate base course should be placed in lifts not exceeding 6 inches and
compacted to a minimum of 95 percent of the maximum dry unit weight as determined by ASTM
D698.
Asphaltic concrete should be composed of a mixture of aggregate, filler and additives (if required)
and approved bituminous material. The asphalt concrete should conform to approved mix
designs stating the Superpave properties, optimum asphalt content, job mix formula and
recommended mixing and placing temperatures. Aggregate used in asphalt concrete should
meet particular gradations. Material meeting CDOT Grading S or SX specifications or equivalent
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
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is recommended for asphalt concrete. Mix designs should be submitted prior to construction to
verify their adequacy. Asphalt material should be placed in maximum 3-inch lifts and compacted
within a range of 92 to 96 percent of the theoretical maximum (Rice) density (ASTM D2041).
Where rigid pavements are used, the concrete should be produced from an approved mix design
with the following minimum properties:
Properties Value
Compressive strength 4,000 psi
Cement type Type I or II portland cement
Entrained air content (%) 5 to 8
Concrete aggregate ASTM C33 and CDOT section 703
Concrete should be deposited by truck mixers or agitators and placed a maximum of 90 minutes
from the time the water is added to the mix. Longitudinal and transverse joints should be provided
as needed in concrete pavements for expansion/contraction and isolation per ACI 325. The
location and extent of joints should be based upon the final pavement geometry.
For areas subject to concentrated and repetitive loading conditions (if any) such as dumpster
pads, truck delivery docks and ingress/egress aprons, we recommend using a portland cement
concrete pavement with a thickness of at least 6 inches underlain by at least 4 inches of granular
base. Prior to placement of the granular base, the areas should be thoroughly proofrolled. For
dumpster pads, the concrete pavement area should be large enough to support the container and
tipping axle of the refuse truck.
Pavement performance is affected by its surroundings. In addition to providing preventive
maintenance, the civil engineer should consider the following recommendations in the design and
layout of pavements:
■ Site grades should slope a minimum of 2 percent away from the pavements;
■ The subgrade and the pavement surface have a minimum 2 percent slope to promote proper
surface drainage;
■ Consider appropriate edge drainage and pavement under drain systems;
■ Install pavement drainage surrounding areas anticipated for frequent wetting;
■ Install joint sealant and seal cracks immediately;
■ Seal all landscaped areas in, or adjacent to pavements to reduce moisture migration to
subgrade soils; and
■ Placing compacted, low permeability backfill against the exterior side of curb and gutter.
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
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Pavements – Construction Considerations
Openings in pavement, such as landscape islands, are sources for water infiltration into
surrounding pavements. Water collects in the islands and migrates into the surrounding subgrade
soils thereby degrading support of the pavement. This is especially applicable for islands with
raised concrete curbs, irrigated foliage, and low permeability near-surface soils. The civil design
for the pavements with these conditions should include features to restrict or to collect and
discharge excess water from the islands. Examples of features are edge drains connected to the
storm water collection system or other suitable outlet and impermeable barriers preventing lateral
migration of water such as a cutoff wall installed to a depth below the pavement structure.
Pavements – Maintenance
Preventative maintenance should be planned and provided for an ongoing pavement
management program in order to enhance future pavement performance. Preventive
maintenance consists of both localized maintenance (e.g. crack and joint sealing and patching)
and global maintenance (e.g. surface sealing). Preventative maintenance is usually the first
priority when implementing a planned pavement maintenance program and provides the highest
return on investment for pavements.
CORROSIVITY
At the time this report was prepared, the laboratory testing for water-soluble sulfates had not been
completed. We will submit a supplemental section with the testing results and recommendations
once the testing has been completed.
GENERAL COMMENTS
As the project progresses, we address assumptions by incorporating information provided by the
design team, if any. Revised project information that reflects actual conditions important to our
services is reflected in the final report. The design team should collaborate with Terracon to
confirm these assumptions and to prepare the final design plans and specifications. This facilitates
the incorporation of our opinions related to implementation of our geotechnical recommendations.
Any information conveyed prior to the final report is for informational purposes only and should
not be considered or used for decision-making purposes.
Our analysis and opinions are based upon our understanding of the project, the geotechnical
conditions in the area, and the data obtained from our site exploration. Natural variations will occur
between exploration point locations or due to the modifying effects of construction or weather.
The nature and extent of such variations may not become evident until during or after construction.
Terracon should be retained as the Geotechnical Engineer, where noted in the final report, to
Preliminary Geotechnical Engineering Report
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
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provide observation and testing services during pertinent construction phases. If variations
appear, we can provide further evaluation and supplemental recommendations. If variations are
noted in the absence of our observation and testing services on-site, we should be immediately
notified so that we can provide evaluation and supplemental recommendations.
Our scope of services does not include either specifically or by implication any environmental or
biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of
pollutants, hazardous materials or conditions. If the owner is concerned about the potential for
such contamination or pollution, other studies should be undertaken.
Our services and any correspondence or collaboration through this system are intended for the
sole benefit and exclusive use of our client for specific application to the project discussed and
are accomplished in accordance with generally accepted geotechnical engineering practices with
no third party beneficiaries intended. Any third party access to services or correspondence is
solely for information purposes to support the services provided by Terracon to our client. Reliance
upon the services and any work product is limited to our client, and is not intended for third parties.
Any use or reliance of the provided information by third parties is done solely at their own risk. No
warranties, either express or implied, are intended or made.
Site characteristics as provided are for design purposes and not to estimate excavation cost. Any
use of our report in that regard is done at the sole risk of the excavating cost estimator as there
may be variations on the site that are not apparent in the data that could significantly impact
excavation cost. Any parties charged with estimating excavation costs should seek their own site
characterization for specific purposes to obtain the specific level of detail necessary for costing.
Site safety, and cost estimating including, excavation support, and dewatering
requirements/design are the responsibility of others. If changes in the nature, design, or location
of the project are planned, our conclusions and recommendations shall not be considered valid
unless we review the changes and either verify or modify our conclusions in writing.
ATTACH MENTS
ATTACHMENTS
SITE LOCA TION AND EXPLORATION PLANS
SITE LOCATION AND EXPLORATION PLANS
SITE LOCATION
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March 7, 2018 ■ Terracon Project No. 20175058
EXHIBIT D LANDSCAPE
DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS
EXPLORATION PLAN
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March 7, 2018 ■ Terracon Project No. 20175058
EXHIBIT D PORTRAIT
DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS
EXPLORATION PLAN WITH SITE PLAN
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March 7, 2018 ■ Terracon Project No. 20175058
EXHIBIT E LANDSCAPE
DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS
EXPLORATION RESULTS
EXPLORATION RESULTS
EXPLORATION AND TESTING PROCEDURES
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
EXPLORATION AND TESTING PROCEDURES
The field exploration program consists of the following:
Number of Borings Planned Boring Depth (feet)
1 Planned Location
6 30 or auger refusal Planned building envelope
1. Proposed borings will be completed to the planned depths below existing site grades or practical auger
refusal, if shallower.
Boring Layout and Elevations: We use handheld GPS equipment to locate borings with an
estimated horizontal accuracy of +/-20 feet. A ground surface elevation at each boring location
is obtained by Terracon using an engineer’s level, referencing a fire hydrant located west of the
site as a temporary on-site benchmark with an assumed elevation of 100 feet.
Subsurface Exploration Procedures: We advance soil borings with a truck-mounted drill rig
using continuous-flight augers (solid-stem and/or hollow-stem, as necessary, depending on
subsurface conditions). Three samples are obtained in the upper 10 feet of each boring and at
intervals of 5 feet thereafter. Soil sampling is typically performed using, ring-lined split-barrel,
and/or standard split-barrel sampling procedures. For the standard split-barrel sampling
procedure, a standard 2-inch outer diameter split-barrel sampling spoon is driven into the ground
by a 140-pound automatic hammer falling a distance of 30 inches. The number of blows required
to advance the sampling spoon the last 12 inches of a normal 18-inch penetration is recorded as
the Standard Penetration Test (SPT) resistance value. The SPT resistance values, also referred
to as N-values, are indicated on the boring logs at the test depths. For the ring-lined split-barrel
sampling procedure, a 3-inch outer diameter split-barrel sampling spoon is used for sampling.
Ring-lined, split-barrel sampling procedures are similar to standard split-barrel sampling
procedures; however, blow counts are typically recorded for 6-inch intervals for a total of 12 inches
of penetration. The samples are placed in appropriate containers, taken to our soil laboratory for
testing, and classified by a geotechnical engineer.
In addition, we observe and record groundwater levels during drilling observations and several
days after drilling.
Our exploration team prepares field boring logs as part of standard drilling operations including
sampling depths, penetration distances, and other relevant sampling information. Field logs include
visual classifications of materials encountered during drilling, and our interpretation of subsurface
conditions between samples. Final boring logs, prepared from field logs, represent the
geotechnical engineer's interpretation, and include modifications based on observations and
laboratory test results.
Property Disturbance: Upon completion of our drilling operations, we install hand-stalled PVC
pipe into completed boreholes to facilitate delayed groundwater measurements. After completion
EXPLORATION AND TESTING PROCEDURES
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
of delayed groundwater measurements, we remove the hand-slotted PVC pipe and backfill the
borings. We backfill borings with auger cuttings backfill after completion. Our services do not
include repair of the site beyond backfilling our boreholes. Excess auger cuttings are dispersed
in the general vicinity of the boreholes. Because backfill material often settles below the surface
after a period, we recommend checking boreholes periodically and backfilling, if necessary. We
can provide this service, or grout the boreholes for additional fees, at your request.
Laboratory Testing
The project engineer reviews field data and assigns various laboratory tests to better understand
the engineering properties of various soil and bedrock strata. Exact types and number of tests
cannot be defined until completion of field work. Laboratory testing is conducted in general
accordance with applicable or other locally recognized standards. Testing is performed under the
direction of a geotechnical engineer and may include the following:
■ Visual classification ■ Moisture content
■ Dry density ■ Atterberg limits
■ Grain-size analysis ■ One-dimensional swell
■ Water-soluble sulfates
Our laboratory testing program often includes examination of soil samples by an engineer. Based
on the material’s texture and plasticity, we describe and classify soil samples in accordance with
the Unified Soil Classification System (USCS). Soil and bedrock samples obtained during our
field work will be disposed of after laboratory testing is complete unless a specific request is made
to temporarily store the samples for a longer period of time.
If bedrock samples are obtained, rock classification is conducted using locally accepted practices
for engineering purposes; petrographic analysis (if performed) may reveal other rock types. Rock
core samples typically provide an improved specimen for this classification. Boring log rock
classification is determined using the Description of Rock Properties.
16
5
12
17
27
24
NP
95
91.5
77
66
3-3-2
N=5
12-21-30
N=51
19-21
No recovery
7-6-5
N=11
11-33-50/3"
25-50/6"
50/6"
0.5
4.0
18.5
29.5
TOPSOIL: VEGETATIVE LAYER, approximately 6 inches
SILTY SAND (SM), brown to orange brown, loose
WELL GRADED SAND WITH SILT AND GRAVEL, light
brown to orange brown, medium dense to dense
SEDIMENTARY BEDROCK - CLAYSTONE, dark gray, hard
to very hard
Boring Terminated at 29.5 Feet
GRAPHIC LOG
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20175058 RETREAT AT FORT C.GPJ TERRACON_DATATEMPLATE.GDT 3/2/18
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
LL-PL-PI
ATTERBERG
LIMITS
ELEVATION (Ft.)
Surface Elev.: 95.73 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
25
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL / LOAD
(%/psf)
DEPTH
LOCATION See Exploration Plan
14
13
26
NP
95.5
93
78
74
12-21
No recovery
12-22-27
N=49
50/6"
22-50/4"
0.5
3.0
18.0
22.0
TOPSOIL: VEGETATIVE LAYER, approximately 6 inches
SILTY SAND, brown to orange brown
WELL GRADED SAND WITH SILT AND GRAVEL
(SW-SM), light brown to orange brown, dense to very dense
SEDIMENTARY BEDROCK - CLAYSTONE, dark gray, very
hard
Auger Refusal at 22 Feet
GRAPHIC LOG
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20175058 RETREAT AT FORT C.GPJ TERRACON_DATATEMPLATE.GDT 3/2/18
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
LL-PL-PI
ATTERBERG
LIMITS
ELEVATION (Ft.)
Surface Elev.: 96.12 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL / LOAD
(%/psf)
DEPTH
LOCATION See Exploration Plan
Latitude: 40.6023° Longitude: -105.0646°
Page 1 of 1
Advancement Method:
6-inch hollow-stem augers
Abandonment Method:
Temporary piezometer installed to facilitate delayed
groundwater readings. Boring backfilled with auger cuttings
upon completion of delayed water levels reading.
1901 Sharp Point Dr Ste C
8
6
9
10
11
17
122 NP
93.5
91.5
71
65
8-19
11-20-12
N=32
28-50/4"
50/6"
17-21-15
N=36
50/3"
-0.1/500
0.5
2.5
23.0
29.2
TOPSOIL: VEGETATIVE LAYER, approximately 6 inches
SILTY SAND WITH GRAVEL (SM), brown to orange brown,
medium dense
WELL GRADED SAND WITH SILT AND GRAVEL, light
brown to orange brown, dense to very dense
SEDIMENTARY BEDROCK - CLAYSTONE, dark gray, very
hard
Boring Terminated at 29.2 Feet
GRAPHIC LOG
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20175058 RETREAT AT FORT C.GPJ TERRACON_DATATEMPLATE.GDT 3/2/18
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
LL-PL-PI
ATTERBERG
LIMITS
ELEVATION (Ft.)
Surface Elev.: 94.01 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
25
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL / LOAD
(%/psf)
DEPTH
LOCATION See Exploration Plan
Latitude: 40.6017° Longitude: -105.0626°
29
8
11
17
35-20-15
94
88.5
78.5
71.5
1-3-3
N=6
11-20-21
N=41
50/6"
15-50/5"
0.5
6.0
16.0
23.0
TOPSOIL: VEGETATIVE LAYER, approximately 6 inches
LEAN CLAY (CL), organics, dark brown to gray/black,
medium stiff
WELL GRADED SAND WITH SILT AND GRAVEL, light
brown to orange brown, dense
SEDIMENTARY BEDROCK - CLAYSTONE, dark gray, very
hard
Auger Refusal at 23 Feet
3.3
GRAPHIC LOG
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20175058 RETREAT AT FORT C.GPJ TERRACON_DATATEMPLATE.GDT 3/2/18
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
LL-PL-PI
ATTERBERG
LIMITS
ELEVATION (Ft.)
Surface Elev.: 94.37 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL / LOAD
(%/psf)
DEPTH
LOCATION See Exploration Plan
Latitude: 40.6004° Longitude: -105.0645°
Page 1 of 1
Advancement Method:
6-inch hollow-stem augers
Abandonment Method:
Temporary piezometer installed to facilitate delayed
18
10
5
9
18
17
99
NP
96
89.5
76.5
67.5
10-16
6-5-4
N=9
17-18-19
N=37
17-25-27
N=52
21-50/6"
50/4"
-2.2/500
0.5
7.0
20.0
29.3
TOPSOIL: VEGETATIVE LAYER, approximately 6 inches
SILTY SAND, brown to orange brown, loose to medium
dense
SILTY SAND WITH GRAVEL (SM), reddish brown, dense to
very dense
SEDIMENTARY BEDROCK - CLAYSTONE, dark gray, very
hard
Boring Terminated at 29.3 Feet
GRAPHIC LOG
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20175058 RETREAT AT FORT C.GPJ TERRACON_DATATEMPLATE.GDT 3/2/18
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
LL-PL-PI
ATTERBERG
LIMITS
ELEVATION (Ft.)
Surface Elev.: 96.59 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
25
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL / LOAD
(%/psf)
DEPTH
22
23
5
7
12
19
96 30-13-17
92.5
77
72.5
7-10
2-2-2
N=4
13-28-34
N=62
17-28-31
N=59
13-27-50/5"
50/4"
0.5
4.0
19.5
24.3
TOPSOIL: VEGETATIVE LAYER, approximately 6 inches
SANDY LEAN CLAY (CL), brown to dark brown, stiff
WELL GRADED SAND WITH SILT AND GRAVEL, orange
brown with white, loose to very dense
SEDIMENTARY BEDROCK - CLAYSTONE, dark gray, very
hard
Boring Terminated at 24.3 Feet
GRAPHIC LOG
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20175058 RETREAT AT FORT C.GPJ TERRACON_DATATEMPLATE.GDT 3/2/18
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
LL-PL-PI
ATTERBERG
LIMITS
ELEVATION (Ft.)
Surface Elev.: 96.71 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL / LOAD
(%/psf)
DEPTH
LOCATION See Exploration Plan
Latitude: 40.5986° Longitude: -105.0668°
Page 1 of 1
Advancement Method:
4-inch solid-stem augers
0
10
20
30
40
50
60
0 20 40 60 80 100
CL or OL CH or OH
ML or OL
MH or OH
"U" Line
"A" Line
ATTERBERG LIMITS RESULTS
ASTM D4318
P
L
A
S
T
I
C
I
T
Y
I
N
D
E
X
LIQUID LIMIT
1901 Sharp Point Dr Ste C
Fort Collins, CO
PROJECT NUMBER: 20175058
SITE: SE of Redwood Street and Conifer Street
Fort Collins, Colorado
PROJECT: Retreat at Fort Collins
CLIENT: LCD Acquisitions, LLC
Athens, GA
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS 20175058 RETREAT AT FORT C.GPJ TERRACON_DATATEMPLATE.GDT 3/1/18
B1
B2
B3
B4
B5
B6
SM
SW-SM
SM
CL
SM
CL
35
8
19
86
12
68
NP
NP
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
100 10 1 0.1 0.01 0.001
30 40
1.5 50
6 8 200
4 10 14
1 3/4
1/2 60
GRAIN SIZE IN MILLIMETERS
PERCENT FINER BY WEIGHT
U.HYDROMETERS. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
4 3/8
3 3 100 140
2
GRAIN SIZE DISTRIBUTION
ASTM D422 / ASTM C136
6 16
20
1901 Sharp Point Dr Ste C
Fort Collins, CO
PROJECT NUMBER: 20175058
SITE: SE of Redwood Street and Conifer Street
Fort Collins, Colorado
PROJECT: Retreat at Fort Collins
CLIENT: LCD Acquisitions, LLC
Athens, GA
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 20175058 RETREAT AT FORT C.GPJ TERRACON_DATATEMPLATE.GDT 3/1/18
SILTY SAND (SM)
WELL-GRADED SAND with SILT and GRAVEL (SW-SM)
SILTY SAND with GRAVEL (SM)
LEAN CLAY (CL)
SILTY SAND with GRAVEL (SM)
0.277
2.858
2.922
3.897
19
25
25
4.75
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
100 10 1 0.1 0.01 0.001
30 40
1.5 50
6 8 200
4 10 14
1 3/4
1/2 60
GRAIN SIZE IN MILLIMETERS
PERCENT FINER BY WEIGHT
U.HYDROMETERS. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
4 3/8
3 3 100 140
2
GRAIN SIZE DISTRIBUTION
ASTM D422 / ASTM C136
6 16
20
1901 Sharp Point Dr Ste C
Fort Collins, CO
PROJECT NUMBER: 20175058
SITE: SE of Redwood Street and Conifer Street
Fort Collins, Colorado
PROJECT: Retreat at Fort Collins
CLIENT: LCD Acquisitions, LLC
Athens, GA
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 20175058 RETREAT AT FORT C.GPJ TERRACON_DATATEMPLATE.GDT 3/1/18
SANDY LEAN CLAY (CL)
9.5
30
1.2 68.0
22
0 - 1 30.8
0 - 1
WC (%) LL
D30 D10 %Gravel %Fines %Clay
B6 13 17
Boring ID Depth USCS Classification PL PI Cc Cu
Boring ID Depth D100 D60 %Sand %Silt
medium
-14
-12
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 0.1 percent compression upon wetting under an applied pressure of 500 psf.
1901 Sharp Point Dr Ste C
Fort Collins, CO
PROJECT NUMBER: 20175058
SITE: SE of Redwood Street and Conifer Street
Fort Collins, Colorado
PROJECT: Retreat at Fort Collins
CLIENT: LCD Acquisitions, LLC
Athens, GA
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20175058 RETREAT AT FORT C.GPJ TERRACON_DATATEMPLATE.GDT 3/2/18
B3 2 - 3 ft SILTY SAND with GRAVEL(SM) 122 8
Specimen Identification Classification , pcf WC, %
-14
-12
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 2.2 percent compression upon wetting under an applied pressure of 500 psf.
1901 Sharp Point Dr Ste C
Fort Collins, CO
PROJECT NUMBER: 20175058
SITE: SE of Redwood Street and Conifer Street
Fort Collins, Colorado
PROJECT: Retreat at Fort Collins
CLIENT: LCD Acquisitions, LLC
Athens, GA
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20175058 RETREAT AT FORT C.GPJ TERRACON_DATATEMPLATE.GDT 3/2/18
B5 2 - 3 ft SILTY SAND 99 18
Specimen Identification Classification , pcf WC, %
SUPPORTING INFORMA TION
SUPPORTING INFORMATION
Retreat at Fort Collins Fort Collins, Colorado
3/7/2018 Terracon Project No. 20175058
500 to 1,000
> 8,000
4,000 to 8,000
2,000 to 4,000
1,000 to 2,000
less than 500
Unconfined Compressive Strength
Qu, (psf)
Modified
Dames &
Moore Ring
Sampler
Standard
Penetration
Test
Trace
PLASTICITY DESCRIPTION
Water levels indicated on the soil boring logs are
the levels measured in the borehole at the times
indicated. Groundwater level variations will occur
over time. In low permeability soils, accurate
determination of groundwater levels is not possible
with short term water level observations.
DESCRIPTION OF SYMBOLS AND ABBREVIATIONS
GENERAL NOTES
> 30
11 - 30
Low 1 - 10
Non-plastic
Plasticity Index
#4 to #200 sieve (4.75mm to 0.075mm
Boulders
Cobbles 12 in. to 3 in. (300mm to 75mm)
Gravel 3 in. to #4 sieve (75mm to 4.75 mm)
Sand
Silt or Clay Passing #200 sieve (0.075mm)
Particle Size
Water Level After
a Specified Period of Time
Water Level After a
Specified Period of Time
Water Initially
Encountered
Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have more than 50% of their dry
weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less
than 50% of their dry weight retained on a #200 sieve; they are principally 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 in-place relative density and fine-grained soils on the basis of their consistency.
GRAIN SIZE TERMINOLOGY
RELATIVEFINES PROPORTIONS OF SAND AND GRAVEL RELATIVE PROPORTIONS OF
DESCRIPTIVE SOIL CLASSIFICATION
LOCATION AND ELEVATION NOTES
SAMPLING WATER LEVEL FIELD TESTS
N
(HP)
(T)
(DCP)
UNIFIED SOIL CLASSIFICATION SYSTEM
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
UNIFIED SOI L CLASSI FICATI ON SYSTEM
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A
Soil Classification
Group
Symbol Group Name
B
Coarse-Grained Soils:
More than 50% retained
on No. 200 sieve
Gravels:
More than 50% of
coarse fraction
retained on No. 4 sieve
Clean Gravels:
Less than 5% fines C
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
Gravels with Fines:
More than 12% fines C
Fines classify as ML or MH GM Silty gravel F, G, H
Fines classify as CL or CH GC Clayey gravel F, G, H
Sands:
50% or more of coarse
fraction passes No. 4
sieve
Clean Sands:
Less than 5% fines D
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
Sands with Fines:
More than 12% fines D
Fines classify as ML or MH SM Silty sandG, H, I
Fines classify as CL or CH SC Clayey sandG, H, I
Fine-Grained Soils:
50% or more passes the
No. 200 sieve
Silts and Clays:
Liquid limit less than 50
Inorganic:
PI > 7 and plots on or above “A”
line J
CL Lean clayK, L, M
PI < 4 or plots below “A” lineJ ML Silt
K, L, M
Organic:
Liquid limit - oven dried
< 0.75 OL Organic clay
K, L, M, N
Liquid limit - not dried Organic silt K, L, M, O
Silts and Clays:
Liquid limit 50 or more
Inorganic:
PI plots on or above “A” line CH Fat clayK, L, M
DESCRIPTION OF ROCK PROPERTIES
Retreat at Fort Collins ■ Fort Collins, Colorado
March 7, 2018 ■ Terracon Project No. 20175058
ROCK VERSION 1
WEATHERING
Term Description
Unweathered No visible sign of rock material weathering, perhaps slight discoloration on major discontinuity surfaces.
Slightly
weathered
Discoloration indicates weathering of rock material and discontinuity surfaces. All the rock material may be
discolored by weathering and may be somewhat weaker externally than in its fresh condition.
Moderately
weathered
Less than half of the rock material is decomposed and/or disintegrated to a soil. Fresh or discolored rock is
present either as a continuous framework or as corestones.
Highly
weathered
More than half of the rock material is decomposed and/or disintegrated to a soil. Fresh or discolored rock is
present either as a discontinuous framework or as corestones.
Completely
weathered All rock material is decomposed and/or disintegrated to soil. The original mass structure is still largely intact.
Residual soil All rock material is converted to soil. The mass structure and material fabric are destroyed. There is a large
change in volume, but the soil has not been significantly transported.
STRENGTH OR HARDNESS
Description Field Identification Uniaxial Compressive
Strength, psi (MPa)
Extremely weak Indented by thumbnail 40-150 (0.3-1)
Very weak Crumbles under firm blows with point of geological hammer, can be
peeled by a pocket knife 150-700 (1-5)
Weak rock Can be peeled by a pocket knife with difficulty, shallow indentations
made by firm blow with point of geological hammer 700-4,000 (5-30)
Medium strong Cannot be scraped or peeled with a pocket knife, specimen can be
fractured with single firm blow of geological hammer 4,000-7,000 (30-50)
Strong rock Specimen requires more than one blow of geological hammer to
fracture it 7,000-15,000 (50-100)
Very strong Specimen requires many blows of geological hammer to fracture it 15,000-36,000 (100-250)
Extremely strong Specimen can only be chipped with geological hammer >36,000 (>250)
DISCONTINUITY DESCRIPTION
Fracture Spacing (Joints, Faults, Other Fractures) Bedding Spacing (May Include Foliation or Banding)
Description Spacing Description Spacing
Extremely close < ¾ in (<19 mm) Laminated < ½ in (<12 mm)
Very close ¾ in – 2-1/2 in (19 - 60 mm) Very thin ½ in – 2 in (12 – 50 mm)
Close 2-1/2 in – 8 in (60 – 200 mm) Thin 2 in – 1 ft. (50 – 300 mm)
Moderate 8 in – 2 ft. (200 – 600 mm) Medium 1 ft. – 3 ft. (300 – 900 mm)
Wide 2 ft. – 6 ft. (600 mm – 2.0 m) Thick 3 ft. – 10 ft. (900 mm – 3 m)
Very Wide 6 ft. – 20 ft. (2.0 – 6 m) Massive > 10 ft. (3 m)
Discontinuity Orientation (Angle): Measure the angle of discontinuity relative to a plane perpendicular to the longitudinal axis of the
core. (For most cases, the core axis is vertical; therefore, the plane perpendicular to the core axis is horizontal.) For example, a
horizontal bedding plane would have a 0-degree angle.
ROCK QUALITY DESIGNATION (RQD) 1
Description RQD Value (%)
Very Poor 0 - 25
Poor 25 – 50
Fair 50 – 75
Good 75 – 90
Excellent 90 - 100
1. The combined length of all sound and intact core segments equal to or greater than 4 inches in length, expressed as a
percentage of the total core run length.
Reference: U.S. Department of Transportation, Federal Highway Administration, Publication No FHWA-NHI-10-034, December 2009
Technical Manual for Design and Construction of Road Tunnels – Civil Elements
PI plots below “A” line MH Elastic Silt K, L, M
Organic:
Liquid limit - oven dried
< 0.75 OH Organic clay
K, L, M, P
Liquid limit - not dried Organic silt K, L, M, Q
Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat
A Based on the material passing the 3-inch (75-mm) sieve
B If field sample contained cobbles or boulders, or both, add “with cobbles
or boulders, or both” to group name.
C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded
gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly
graded gravel with silt, GP-GC poorly graded gravel with clay.
D Sands with 5 to 12% fines require dual symbols: 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
E Cu = D60/D10 Cc =
10 60
2
30
D x D
(D )
F If soil contains ‡ 15% sand, add “with sand” to group name.
G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.
H If fines are organic, add “with organic fines” to group name.
I If soil contains ‡ 15% gravel, add “with gravel” to group name.
J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay.
K If soil contains 15 to 29% plus No. 200, add “with sand” or “with
gravel,” whichever is predominant.
L If 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.
NPI‡ 4 and plots on or above “A” line.
OPI< 4 or plots below “A” line.
P PI plots on or above “A” line.
QPI plots below “A” line.
UC
(PID)
(OVA)
Standard Penetration Test
Resistance (Blows/Ft.)
Hand Penetrometer
Torvane
Dynamic Cone Penetrometer
Unconfined Compressive
Strength
Photo-Ionization Detector
Organic Vapor Analyzer
Medium
Over 12 in. (300 mm) 0
>12
5-12
<5
Percent of
Dry Weight
Major Component of Sample Term
Modifier
With
Trace
Descriptive Term(s) of
other constituents
Modifier >30
<15
Percent of
Dry Weight
Descriptive Term(s) of
other constituents
With 15-29
High
Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. The accuracy of
such devices is variable. Surface elevation data annotated with +/- indicates that no actual topographical survey was conducted
to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic maps of the
area.
Standard Penetration or
N-Value
Blows/Ft.
Descriptive Term
(Density)
CONSISTENCY OF FINE-GRAINED SOILS
Hard
Very Dense > 50 Very Stiff 15 - 30
Dense 30 - 50 Stiff 8 - 15
Medium Dense 10 - 29 Medium Stiff 4 - 8
Loose 4 - 9 Soft 2 - 4
Very Loose 0 - 3 Very Soft 0 - 1
(50% or more passing the No. 200 sieve.)
Consistency determined by laboratory shear strength testing, field visual-manual
procedures or standard penetration resistance
STRENGTH TERMS
> 30
Descriptive Term
(Consistency)
Standard Penetration or
N-Value
Blows/Ft.
RELATIVE DENSITY OF COARSE-GRAINED SOILS
(More than 50% retained on No. 200 sieve.)
Density determined by Standard Penetration Resistance
B6
coarse fine coarse fine
COBBLES GRAVEL SAND
SILT OR CLAY
25
19
NP
NP
35
NP
34.9
7.6
18.8
85.8
12.5
0.147
12.0
30.6
30.4
0.0
37.2
0.724
0.306
0.468
16
14
8
29
5
53.2
61.7
50.8
14.2
50.3
2 - 3.5
9 - 10.5
2 - 3
4 - 5.5
9 - 10.5
2 - 3.5
9 - 10.5
2 - 3
4 - 5.5
9 - 10.5
WC (%) LL
D30 D10 %Gravel %Fines %Clay
B1
B2
B3
B4
B5
1.25
1.08
NP
NP
NP
15
NP
19
NP
NP
20
NP
19.49
74.99
Boring ID Depth USCS Classification PL PI Cc Cu
Boring ID Depth D100 D60 %Sand %Silt
medium
B1
B2
B3
B4
B5
coarse fine coarse fine
COBBLES GRAVEL SAND
SILT OR CLAY
NP
15
NP
17
19
NP
NP
20
NP
13
19
NP
NP
35
NP
30
2 - 3.5
9 - 10.5
2 - 3
4 - 5.5
9 - 10.5
0 - 1
SILTY SAND
WELL-GRADED SAND with SILT and GRAVEL
SILTY SAND with GRAVEL
LEAN CLAY
SILTY SAND with GRAVEL
SANDY LEAN CLAY
CL-ML
Boring ID Depth LL PL PI Fines USCS Description
Abandonment Method:
Temporary piezometer installed to facilitate delayed
groundwater readings. Boring backfilled with auger cuttings
upon completion of delayed water levels reading.
1901 Sharp Point Dr Ste C
Fort Collins, CO
Notes:
Project No.: 20175058
Drill Rig: CME-55
Boring Started: 02-23-2018
BORING LOG NO. B6
CLIENT: LCD Acquisitions, LLC
Athens, GA
Driller: Drilling Engineers, Inc.
Boring Completed: 02-23-2018
PROJECT: Retreat at Fort Collins
Elevations were measured in the field using an
engineer's level and grade rod.
See Exploration and Testing Procedures for a
description of field and laboratory procedures used
and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
SE of Redwood Street and Conifer Street
Fort Collins, Colorado
SITE:
12' while drilling
9.5' on 2/27/2018
WATER LEVEL OBSERVATIONS
ORGANIC
CONTENT (%)
LOCATION See Exploration Plan
Latitude: 40.5998° Longitude: -105.0665°
Page 1 of 1
Advancement Method:
4-inch solid-stem augers
Abandonment Method:
Temporary piezometer installed to facilitate delayed
groundwater readings. Boring backfilled with auger cuttings
upon completion of delayed water levels reading.
1901 Sharp Point Dr Ste C
Fort Collins, CO
Notes:
Project No.: 20175058
Drill Rig: CME-55
Boring Started: 02-23-2018
BORING LOG NO. B5
CLIENT: LCD Acquisitions, LLC
Athens, GA
Driller: Drilling Engineers, Inc.
Boring Completed: 02-23-2018
PROJECT: Retreat at Fort Collins
Elevations were measured in the field using an
engineer's level and grade rod.
See Exploration and Testing Procedures for a
description of field and laboratory procedures used
and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
SE of Redwood Street and Conifer Street
Fort Collins, Colorado
SITE:
11' while drilling
13.5' on 2/27/2018
WATER LEVEL OBSERVATIONS
ORGANIC
CONTENT (%)
groundwater readings. Boring backfilled with auger cuttings
upon completion of delayed water levels reading.
1901 Sharp Point Dr Ste C
Fort Collins, CO
Notes:
Project No.: 20175058
Drill Rig: CME-75
Boring Started: 02-20-2018
BORING LOG NO. B4
CLIENT: LCD Acquisitions, LLC
Athens, GA
Driller: Drilling Engineers, Inc.
Boring Completed: 02-20-2018
PROJECT: Retreat at Fort Collins
Elevations were measured in the field using an
engineer's level and grade rod.
See Exploration and Testing Procedures for a
description of field and laboratory procedures used
and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
SE of Redwood Street and Conifer Street
Fort Collins, Colorado
SITE:
8' while drilling
8.1' on 2/27/2018
WATER LEVEL OBSERVATIONS
ORGANIC
CONTENT (%)
Page 1 of 1
Advancement Method:
4-inch solid-stem augers
Abandonment Method:
Temporary piezometer installed to facilitate delayed
groundwater readings. Boring backfilled with auger cuttings
upon completion of delayed water levels reading.
1901 Sharp Point Dr Ste C
Fort Collins, CO
Notes:
Project No.: 20175058
Drill Rig: CME-55
Boring Started: 02-23-2018
BORING LOG NO. B3
CLIENT: LCD Acquisitions, LLC
Athens, GA
Driller: Drilling Engineers, Inc.
Boring Completed: 02-23-2018
PROJECT: Retreat at Fort Collins
Elevations were measured in the field using an
engineer's level and grade rod.
See Exploration and Testing Procedures for a
description of field and laboratory procedures used
and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
SE of Redwood Street and Conifer Street
Fort Collins, Colorado
SITE:
7' while drilling
7' on 2/27/2018
WATER LEVEL OBSERVATIONS
ORGANIC
CONTENT (%)
Fort Collins, CO
Notes:
Project No.: 20175058
Drill Rig: CME-75
Boring Started: 02-20-2018
BORING LOG NO. B2
CLIENT: LCD Acquisitions, LLC
Athens, GA
Driller: Drilling Engineers, Inc.
Boring Completed: 02-20-2018
PROJECT: Retreat at Fort Collins
Elevations were measured in the field using an
engineer's level and grade rod.
See Exploration and Testing Procedures for a
description of field and laboratory procedures used
and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
SE of Redwood Street and Conifer Street
Fort Collins, Colorado
SITE:
7' while drilling
6.3' on 2/27/2018
WATER LEVEL OBSERVATIONS
ORGANIC
CONTENT (%)
Latitude: 40.6029° Longitude: -105.0627°
Page 1 of 1
Advancement Method:
6-inch hollow-stem augers
Abandonment Method:
Temporary piezometer installed to facilitate delayed
groundwater readings. Boring backfilled with auger cuttings
upon completion of delayed water levels reading.
1901 Sharp Point Dr Ste C
Fort Collins, CO
Notes:
Project No.: 20175058
Drill Rig: CME-75
Boring Started: 02-20-2018
BORING LOG NO. B1
CLIENT: LCD Acquisitions, LLC
Athens, GA
Driller: Drilling Engineers, Inc.
Boring Completed: 02-20-2018
PROJECT: Retreat at Fort Collins
Elevations were measured in the field using an
engineer's level and grade rod.
See Exploration and Testing Procedures for a
description of field and laboratory procedures used
and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
SE of Redwood Street and Conifer Street
Fort Collins, Colorado
SITE:
8' while drilling
7.8' on 2/27/2018
WATER LEVEL OBSERVATIONS
ORGANIC
CONTENT (%)