HomeMy WebLinkAboutHOME2 SUITES AT HARMONY VILLAGE - PDP - PDP150031 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTGeotechnical Engineering Report
Home2 Suites at Harmony Village
Lot 11A, Harmony Village P.U.D. Replat No. 1
Southwest of East Harmony Road and South Timberline Road
Fort Collins, Colorado
December 11, 2015
Terracon Project No. 20155061
Prepared for:
East Avenue Development, LLC
Ceder Park, Texas
Prepared by:
Terracon Consultants, Inc.
Fort Collins, Colorado
TABLE OF CONTENTS
EXECUTIVE SUMMARY ............................................................................................................ i
1.0 INTRODUCTION ............................................................................................................ 1
2.0 PROJECT INFORMATION ............................................................................................ 1
2.1 Project Description .............................................................................................. 1
2.2 Site Location and Description ............................................................................. 2
3.0 SUBSURFACE CONDITIONS ....................................................................................... 3
3.1 Typical Subsurface Profile .................................................................................. 3
3.2 Laboratory Testing .............................................................................................. 3
3.3 Corrosion Protection (Water-Soluble Sulfates) .................................................... 3
3.4 Groundwater ....................................................................................................... 3
4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION ..................................... 4
4.1 Geotechnical Considerations .............................................................................. 4
4.1.1 Shallow Groundwater .............................................................................. 4
4.1.2 Expansive Soils ....................................................................................... 5
4.1.3 Foundation and Floor Slab Recommendations ........................................ 5
4.2 Earthwork ........................................................................................................... 5
4.2.1 Site Preparation........................................................................................ 5
4.2.2 Excavation ............................................................................................... 6
4.2.3 Subgrade Preparation .............................................................................. 6
4.2.4 Fill Materials and Placement ..................................................................... 7
4.2.5 Compaction Requirements ....................................................................... 8
4.2.6 Utility Trench Backfill ............................................................................... 8
4.2.7 Grading and Drainage .............................................................................. 9
4.3 Foundations .......................................................................................................10
4.3.1 Drilled Piers Bottomed in Bedrock - Design Recommendations ..............10
4.3.2 Drilled Piers Bottomed in Bedrock - Construction Considerations ...........11
4.4 Seismic Considerations......................................................................................12
4.5 Floor Systems ....................................................................................................12
4.5.1 Floor System - Design Recommendations ..............................................12
4.5.2 Floor Systems - Construction Considerations .........................................13
4.6 Swimming Pool Recommendations ....................................................................13
4.7 Lateral Earth Pressures .....................................................................................14
4.8 Elevator Pit ........................................................................................................16
4.8.1 Elevator Pit Design Recommendations ...................................................16
4.8.2 Elevator Pit Construction Considerations ................................................17
4.9 Pavements .........................................................................................................17
4.9.1 Pavements – Subgrade Preparation .......................................................17
4.9.2 Pavements – Design Recommendations ................................................18
4.9.3 Pavements – Construction Considerations .............................................20
4.9.4 Pavements – Maintenance .....................................................................20
5.0 GENERAL COMMENTS ...............................................................................................21
TABLE OF CONTENTS (continued)
Appendix A – FIELD EXPLORATION
Exhibit A-1 Site Location Map
Exhibit A-2 Exploration Plan
Exhibit A-3 Field Exploration Description
Exhibits A-4 to A-8 Boring Logs
Appendix B – LABORATORY TESTING
Exhibit B-1 Laboratory Testing Description
Exhibit B-2 Atterberg Limits Test Results
Exhibits B-3 and B-4 Grain-size Distribution Test Results
Exhibits B-5 to B-8 Swell-consolidation Test Results
Appendix C – SUPPORTING DOCUMENTS
Exhibit C-1 General Notes
Exhibit C-2 Unified Soil Classification System
Exhibit C-3 Description of Rock Properties
Exhibit C-4 Laboratory Test Significance and Purpose
Exhibits C-5 and C-6 Report Terminology
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
December 11, 2015 ■ Terracon Project No. 20155061
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EXECUTIVE SUMMARY
A geotechnical investigation has been performed for the proposed Home2 Suites at Harmony
Village to be constructed at Lot 11A, Harmony Village P.U.D. Replat No. 1 located southwest of
East Harmony Road and South Timberline Road in Fort Collins, Colorado. Five (5) borings,
presented as Exhibits A-4 through A-8 and designated as Boring No. 1 through Boring No. 5, were
performed to depths of approximately 5½ to 35½ feet below existing site grades. This report
specifically addresses the recommendations for the proposed 4-story hotel building. Borings
performed in these areas are for informational purposes and will be utilized by others.
Based on the information obtained from our subsurface exploration, the site can be developed for
the proposed project. However, the following geotechnical considerations were identified and will
need to be considered:
Subsurface conditions encountered in the test borings generally consisted of about 3 to 8
feet of stiff lean clay with varying amounts of sand over about 4 to 11 feet of medium stiff lean
clay. Silty clayey sand with gravel was encountered below the clays and these materials
extended to the underlying sedimentary bedrock. Claystone bedrock was encountered
below the silty clayey sands at depths of about 23 to 25 feet below the existing grade and
extended to the maximum depths explored.
Groundwater was measured in the test borings at depths of about 11½ to 12½ feet below
the existing ground surface when check 1 day after completion of drilling. Groundwater levels
can and should be expected to fluctuate with varying seasonal and weather condition and
irrigation demands on or adjacent to the site.
We recommend constructing the proposed building on a drilled pier foundation system
bottomed in bedrock.
A slab-on-grade floor system is recommended for the proposed building provided the floor
slabs are constructed on at least 1 foot of Colorado Department of Transportation (CDOT)
Class 1 structure backfill.
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 4.2.7 Grading and Drainage section of this report be followed to reduce
potential movement.
Design pavement thickness alternatives include 3½ inches of asphalt over 6 inches of
aggregate base course in automobile parking areas and 4½ inches of asphalt over 6 inches
of aggregate base course in drive lanes/truck access areas. Additional pavement section
alternatives and discussion are presented in the report.
Geotechnical Engineering Report
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The 2012 International Building Code, Table 1613.5.2 IBC seismic site classification for this
site is D.
Close monitoring of the construction operations discussed herein will be critical in achieving
the design subgrade support. We therefore recommend that Terracon be retained to
monitor this portion of the work.
This summary should be used in conjunction with the entire report for design purposes. It should
be recognized that details were not included or fully developed in this section, and the report must
be read in its entirety for a comprehensive understanding of the items contained herein. The section
titled GENERAL COMMENTS should be read for an understanding of the report limitations.
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GEOTECHNICAL ENGINEERING REPORT
Home2 Suites at Harmony Village
Lot 11A, Harmony Village P.U.D. Replat No. 1
Southwest of East Harmony Road and South Timberline Road
Fort Collins, Colorado
Terracon Project No. 20155061
December 11, 2015
1.0 INTRODUCTION
This report presents the results of our geotechnical engineering services performed for the
proposed Home2 Suites at Harmony Village to be constructed at Lot 11A, Harmony Village P.U.D.
Replat No. 1 located southwest of the intersection of East Harmony Road and South Timberline
Road in Fort Collins, Colorado. The purpose of these services is to provide information and
geotechnical engineering recommendations relative to:
subsurface soil and bedrock conditions foundation design and construction
groundwater conditions floor slab design and construction
grading and drainage pavement construction
lateral earth pressures earthwork
seismic considerations
Our geotechnical engineering scope of work for this project included the initial site visit, the
advancement of five test borings to depths ranging from approximately 5½ to 35½ feet below
existing site grades, laboratory testing for soil engineering properties and engineering analyses
to provide foundation, floor system and pavement design and construction recommendations.
Logs of the borings along with an Exploration Plan (Exhibit A-2) are included in Appendix A. The
results of the laboratory testing performed on soil and bedrock samples obtained from the site
during the field exploration are included in Appendix B.
2.0 PROJECT INFORMATION
2.1 Project Description
Item Description
Site layout Refer to the Exploration Plan (Exhibit A-2 in Appendix A)
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
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Item Description
Structures
Preliminary plans indicate the project will include a new, 4-story hotel
building with a building footprint of about 64,863 square feet. An
indoor pool is shown in the southeastern portion of the building. New
pavements and concrete flatwork will be constructed on all sides of
the new building, tying into the existing facilities. Permeable pavers
are shown at several locations around the building.
Building construction
We anticipate the building will be wood-framed with some masonry
constructed on a cast-in-place concrete foundation with a slab-on-
grade floor system.
Foundation/floor slab loads
Structural loading conditions were not available at the time of this
report. However, based on the size and type of construction, we
anticipate relatively light to moderate foundation loads. For purposes
of this report, we assume the following loads:
■ Column/Point Loads: 50 to 100 kips (assumed)
■ Wall/Line Loads: 3 to 4 klf (assumed)
■ Slab-On-Grade Floors: 150 to 200 psf max (assumed)
Finished floor elevation
The finished floor elevation was not known at the time of this report.
However, considering the relatively flat existing site topography we
assume the ground floor will be constructed slightly above the
existing ground surface.
Grading
We anticipate minor cuts and fills on the order of 3 feet or less will
be required for the majority of the construction. Deeper cuts may be
necessary for the indoor swimming pool and possibly for utility
installation.
Below-grade areas
No below-grade areas are planned except for the indoor swimming
pool and the assumed elevator pit.
Traffic loading
We anticipate light-duty pavements for parking areas with some
drive lanes accommodating refuse disposal vehicles and truck
traffic.
2.2 Site Location and Description
Item Description
Location
The project site is located southwest of the intersection of East
Harmony Road and South Timberline Road on Lot 11A, Harmony
Village P.U.D. Replat No. 1 in Fort Collins, Colorado.
Existing site features The lot is currently vacant.
Surrounding developments
There is currently a Texas Roadhouse restaurant to north and a
Cinemark Theater to the south. Paved parking is located to the east
with a paved access drive to the west.
Current ground cover Native grasses and weeds.
Existing topography The site is relatively flat.
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
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3.0 SUBSURFACE CONDITIONS
3.1 Typical Subsurface Profile
Specific conditions encountered at each boring location are indicated on the individual boring logs
included in Appendix A. Stratification boundaries on the boring logs represent the approximate
location of changes in soil types; in-situ, the transition between materials may be gradual. 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 (feet)
Consistency/Density/Hardness
Lean clay with varying amounts of
sand
About 3 to 8 feet below existing
site grades.
Stiff
Lean clay
About 11 to 15 feet below
existing site grades.
Medium stiff to stif
Silty clayey sand with gravel
About 23 to 25 feet below
existing site grades.
Medium dense
Claystone bedrock
To the maximum depth of
exploration of about 35½ feet.
Hard
3.2 Laboratory Testing
Representative soil samples were selected for swell-consolidation testing and exhibited -1.1 to
0.1 percent swell when wetted. Samples of site soils and bedrock selected for plasticity testing
exhibited low to high plasticity with liquid limits ranging from 22 to 58 and plasticity indices ranging
from 6 to 34. Laboratory test results are presented in Appendix B.
3.3 Corrosion Protection (Water-Soluble Sulfates)
At the time this report was prepared, the laboratory testing for water-soluble sulfates had not been
completed. We will submit a supplemental letter with the testing results and recommendations
once the testing has been completed.
3.4 Groundwater
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 some borings. The water levels
observed in the boreholes are noted on the attached boring logs, and are summarized below:
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
December 11, 2015 ■ Terracon Project No. 20155061
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Boring Number
Depth to groundwater while
drilling, ft.
Depth to groundwater 1 day
after drilling, ft.
1 14.5 11.6
2 12 12.4
3 12.5 13.1
P-1 Not encountered Backfilled after drilling
P-2 Not encountered Backfilled after drilling
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, 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 building 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.
4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION
4.1 Geotechnical Considerations
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
geotechnical conditions that could impact design and construction of the proposed 4-story hotel
building, pavements, and other site improvements.
4.1.1 Shallow Groundwater
As previously stated, groundwater was measured at depths ranging from about 12 to 14.5 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. We
do not anticipate groundwater will significantly impact the proposed building. However,
groundwater will be encountered during drilled pier construction.
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
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4.1.2 Expansive Soils
Laboratory testing indicates the native clay soils exhibited low expansive potential at the samples
in-situ moisture content. However, it is our opinion these materials will exhibit a higher expansive
potential if the clays undergo a significant loss of moisture.
This report provides recommendations to help mitigate the effects of soil shrinkage and
expansion. However, even if these procedures are followed, some movement and cracking in
the structures, pavements, and flatwork should be anticipated. The severity of cracking and other
damage such as uneven floor slabs will probably increase if any modification of the site results in
excessive wetting or drying of the expansive clays. Eliminating the risk of movement and distress
is generally not feasible, but it may be possible to further reduce the risk of movement if
significantly more expensive measures are used during construction. It is imperative the
recommendations described in section 4.2.7 Grading and Drainage of this report be followed to
reduce movement.
4.1.3 Foundation and Floor Slab Recommendations
The proposed building may be supported on a drilled pier foundation system bottomed in bedrock.
We recommend a slab-on-grade for the interior floor system of the proposed 4-story hotel
provided the floor slabs are constructed on at least 1 foot of CDOT Class 1 structure backfill.
Recommendations for the subgrade preparation prior to floor slab construction are presented in
the subsequent sections of this report. 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.
4.2 Earthwork
The following presents recommendations for site preparation, excavation, subgrade preparation
and placement of engineered fills on the project. All earthwork on the project should be observed
and evaluated by Terracon on a full-time basis. The evaluation of earthwork should include
observation of over-excavation operations, testing of engineered fills, subgrade preparation,
subgrade stabilization, and other geotechnical conditions exposed during the construction of the
project.
4.2.1 Site Preparation
Prior to placing any fill, strip and remove existing vegetation, and any other deleterious materials
from the proposed construction area. Stripped organic materials should be wasted from the site or
used to re-vegetate landscaped areas after completion of grading operations. Prior to the
placement of fills, the site should be graded to create a relatively level surface to receive fill, and to
provide for a relatively uniform thickness of fill beneath proposed structures.
Geotechnical Engineering Report
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4.2.2 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 weak
and/or nearly 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 septic tanks, vaults, basements, and
utilities was not observed during the site reconnaissance, such features could be encountered
during construction. If unexpected fills or underground facilities are encountered, such features
should be removed and the excavation thoroughly cleaned prior to backfill placement and/or
construction.
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.
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
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
4.2.3 Subgrade Preparation
The top 8 inches of the exposed ground surface below stripped areas and at the base of the
recommended over-excavation below floor slabs 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, concrete floor slab or pavement is placed.
After the bottom of the excavation has been compacted, engineered fill can be placed to bring the
concrete floor slab and pavement subgrade to the desired grade. Engineered fill should be placed
in accordance with the recommendations presented in subsequent sections of this report.
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
December 11, 2015 ■ Terracon Project No. 20155061
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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. Use of fly ash, lime or geotextiles could also be
considered as a stabilization technique. Lightweight excavation equipment may also be used to
reduce subgrade pumping.
4.2.4 Fill Materials and Placement
The on-site soils or approved granular and low plasticity cohesive imported materials may be used
as fill material. CDOT Class 1 structure backfill should be used as the upper 1 foot of fill below
proposed floor slabs. The soil removed from this site that is free of organic or objectionable
materials, as defined by a field technician who is qualified in soil material identification and
compaction procedures, can be re-used as fill for the building pad and pavement subgrade. It
should be noted that the lean clay will require reworking to adjust the moisture content to meet
the compaction criteria.
CDOT Class 1 structure backfill should meet the following material property requirements:
Gradation Percent finer by weight (ASTM C136)
2” 100
No. 4 Sieve 30-100
No.50 Sieve 10-60
No. 200 Sieve 5-20
Soil Properties Value
Liquid Limit 35 (max.)
Plastic Limit 6 (max.)
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 15-50
Geotechnical Engineering Report
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Soil Properties Value
Liquid Limit 30 (max.)
Plastic Limit 15 (max.)
Maximum Expansive Potential (%) Non-expansive1
1. Measured on a sample compacted to approximately 95 percent of the maximum dry unit weight as
determined by ASTM D698 at optimum moisture content. The sample is confined under a 100 psf
surcharge and submerged.
4.2.5 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
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
Moisture content cohesionless soil
(sand)
-3 to +2 % 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.
4.2.6 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 structure 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.
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Utility trenches are a common source of water infiltration and migration. All utility trenches that
penetrate beneath the building should be effectively sealed to restrict water intrusion and flow
through the trenches that could migrate below the building. We recommend constructing an
effective clay “trench plug” that extends at least 5 feet out from the face of the building exterior. 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.
4.2.7 Grading and Drainage
All grades must be adjusted to provide effective drainage away from the proposed building 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.
Landscape irrigation adjacent to foundations should be minimized or eliminated. Water permitted
to pond near or adjacent to the perimeter of the structure (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 10 feet
beyond the perimeter of the proposed building, where possible. The use of swales, chases and/or
area drains may be required to facilitate drainage in unpaved areas around the perimeter of the
building. Backfill against exterior walls should be properly compacted and free of all construction
debris to reduce the possibility of moisture infiltration. After construction of the proposed building
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
structure, care should be taken that joints are properly sealed and maintained to prevent the
infiltration of surface water.
Planters located adjacent to structure 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 not be used near the building. Roof drains should
discharge on to pavements or be extended away from the structure 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.
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
December 11, 2015 ■ Terracon Project No. 20155061
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4.3 Foundations
Terracon recommends constructing the proposed 4-story hotel on a drilled pier foundation system
bottomed in bedrock. Design recommendations for foundations for the proposed structures and
related structural elements are presented in the following sections.
4.3.1 Drilled Piers Bottomed in Bedrock - Design Recommendations
Description Value
Minimum pier length 20 feet
Minimum pier diameter 18 inches
Minimum bedrock embedment 1 8 feet
Maximum allowable end-bearing pressure 25,000 psf
Allowable skin friction (for portion of pier embedded into bedrock) 2,000 psf
Uplift force (tension due to soil uplift, kips) 2 6 x Pier diameter (ft.)
Void thickness (beneath grade beams, between piers) 4 inches
1. Drilled piers should be embedded into hard or very hard bedrock materials. Actual structural
loads and pier diameters may dictate embedment deeper than the recommended minimum
penetration.
2. Required pier penetration should be balanced against uplift forces for the portion of the pier in
firm or harder bedrock below a depth of 16 feet to resist axial loads and uplift forces.
Piers should be considered to work in group action if the horizontal spacing is less than three pier
diameters. A minimum practical horizontal clear spacing between piers of at least three diameters
should be maintained, and adjacent piers should bear at the same elevation. The capacity of
individual piers must be reduced when considering the effects of group action. Capacity reduction
is a function of pier spacing and the number of piers within a group. If group action analyses are
necessary, capacity reduction factors can be provided for the analyses.
To satisfy forces in the horizontal direction using LPILE, piers may be designed for the following
lateral load criteria:
Parameters Lean Clay
Silty Clayey
sand with
Gravel
Claystone
Bedrock
LPILE soil type1
Stiff clay
without free
water
Sand
(submerged)
Stiff clay
without free
water
Unit weight (pcf) 120 125 130
Average undrained shear strength (psf) 500 N/A 9,000
Average angle of internal friction, (degrees) N/A 40 N/A
Geotechnical Engineering Report
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Parameters Lean Clay
Silty Clayey
sand with
Gravel
Claystone
Bedrock
Coefficient of subgrade reaction, k (pci)*
500 - static
200 - cyclic
60
2,000- static
800 – cyclic
Strain, 50 (%) 0.007 N/A 0.004
1. For purposes of LPILE analysis, assume a groundwater depth of about 7 feet below existing
ground surface (approximately Elev. 4735 feet).
4.3.2 Drilled Piers Bottomed in Bedrock - Construction Considerations
Drilling to design depth should be possible with conventional single-flight power augers on the
majority of the site; however, specialized drilling equipment may be required for very hard bedrock
layers. In addition, caving soils and groundwater indicate that temporary steel casing will be
required to properly drill the piers prior to concrete placement.
Groundwater should be removed from each pier hole prior to concrete placement. Pier concrete
should be placed immediately after completion of drilling and cleaning. If pier concrete cannot be
placed in dry conditions, a tremie should be used for concrete placement. Free-fall concrete
placement in piers will only be acceptable if provisions are taken to avoid striking the concrete on
the sides of the hole or reinforcing steel. The use of a bottom-dump hopper, or an elephant's
trunk discharging near the bottom of the hole where concrete segregation will be minimized, is
recommended. Due to potential sloughing and raveling, foundation concrete quantities may
exceed calculated geometric volumes.
Casing should be withdrawn in a slow continuous manner maintaining a sufficient head of
concrete to prevent infiltration of water or caving soils or the creation of voids in pier concrete.
Pier concrete should have a relatively high fluidity when placed in cased pier holes or through a
tremie. Pier concrete with slump in the range of 5 to 7 inches is recommended.
We recommend the sides of each pier should be mechanically roughened in the claystone bearing
strata. This should be accomplished by a roughening tooth placed on the auger. Shaft bearing
surfaces must be cleaned prior to concrete placement. A representative of Terracon should
observe the bearing surface and shaft configuration.
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
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4.4 Seismic Considerations
Code Used Site Classification
2012 International Building Code (IBC) 1 D 2
1. In general accordance with the 2012 International Building Code, Table 1613.5.2.
2. The 2012 International Building Code (IBC) requires a site soil profile determination extending a
depth of 100 feet for seismic site classification. The current scope requested does not include the
required 100 foot soil profile determination. The borings completed for this project extended to a
maximum depth of about 25½ feet and this seismic site class definition considers that similar soil and
bedrock conditions exist below the maximum depth of the subsurface exploration. Additional
exploration to deeper depths could be performed to confirm the conditions below the current depth of
exploration. Alternatively, a geophysical exploration could be utilized in order to attempt to justify a
more favorable seismic site class. However, we believe a higher seismic site class for this site is
unlikely.
4.5 Floor Systems
A slab-on-grade may be utilized for the interior floor system for the proposed 4-story hotel
provided the floor slabs are constructed on at least 1 foot of CDOT Class 1 structure backfill.
Subgrade soils at the base of the over-excavation recommended below the proposed floor slab
for the CDOT Class 1 structure backfill should be properly scarified, moisture conditioned and
compacted prior to floor slab construction. If the estimated movement cannot be tolerated, a
structurally-supported floor system, supported independent of the subgrade materials, is
recommended.
Subgrade soils beneath interior slabs and at the base of the over-excavation for removal of
existing fill 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.
4.5.1 Floor System - 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 prepared as presented in the 4.2 Earthwork section of this report.
For structural design of concrete slabs-on-grade subjected to point loadings, a modulus of
subgrade reaction of 200 pounds per cubic inch (pci) may be used for floors supported on at least
1 foot of non-expansive, imported granular fill.
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
December 11, 2015 ■ Terracon Project No. 20155061
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Additional floor slab design and construction recommendations are as follows:
Positive separations and/or isolation joints should be provided between slabs and all
foundations, columns, or utility lines to allow independent movement.
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.
Interior utility trench backfill placed beneath slabs should be compacted in accordance
with the recommendations presented in the 4.2 Earthwork section of this report.
Floor slabs should not be constructed on frozen subgrade.
A minimum 1½-inch void space should be constructed above or below non-bearing
partition walls placed on the floor slab. Special framing details should be provided at
doorjambs and frames within partition walls to avoid potential distortion. Partition walls
should be isolated from suspended ceilings.
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.
Other design and construction considerations, as outlined in the ACI Design Manual,
Section 302.1R are recommended.
4.5.2 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.
4.6 Swimming Pool Recommendations
We understand an indoor swimming pool is conceptually planned near the southeast corner of
the building. Furthermore, we assume the maximum pool depth to be about 5 to 6 feet deep.
Excavation of the pool area by conventional rubber-tired equipment may encounter soft or loose
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
December 11, 2015 ■ Terracon Project No. 20155061
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soils. It may be necessary to excavate the deep portion of the pool with a backhoe or power
shovel.
Groundwater was encountered in the test boring closest to the proposed pool at a depth of about
11½ feet below the existing grade at the time of our field exploration. Groundwater conditions are
not anticipated to significantly impact design, construction and performance of the shallow pool.
A drainage system should be provided around and beneath the pool. The drain should consist of
a minimum 6-inch layer of clean gravel (minimum 3/4-inch size) beneath and along the sides of
the pool. The top of the drain layer should be sealed with 18 inches of relatively impermeable soil
at the surface. The gravel layer beneath the pool should be sloped so that it will drain into tiles
or perforated drainpipe. The layout of the perforated pipe should include at least one pipe running
down the center of the pool lengthwise. Cross-connecting pipes, spanning with the pool, should
be placed at 6-foot centers. The cross-connecting pipes should be joined to the center pipe with
solid “tees” or “cross” connections. The center pipes should be sloped to a positive gravity outlet
or sloped to a sump located in the equipment room, permitting pump discharge.
The bottom of the excavation beneath the gravel layer and the pipe should be lined with an
impervious membrane (polyethylene film or equal) to reduce potential moisture fluctuations in the
subgrade soils. Pressure relief valves should be provided in the base of the pool to prevent
excessive uplift pressures from developing in the event of drain system failure.
The soils that will support deck slabs around the pool could expand with increasing moisture
content. To reduce possible damage that could be caused by expansive soils, we recommend:
Deck slabs be supported on fill with no, or very low, expansion potential;
Strict moisture-density control during placement of subgrade fill;
Placement of effective control joints on relatively close centers and isolation joints between
slabs and other structural elements;
Provision for adequate drainage in areas adjoining the slabs; and
Use of designs which allow vertical movement between the deck slabs and adjoining
structural elements.
Fill, backfill, and surface drainage in the pool area should be place in accordance with the
recommendations presented in the 4.2 Earthwork section of this report. Grading should be
provided for diversion of deck surface runoff away from the pool area. In no case should water be
allowed to pond around the slab perimeter.
4.7 Lateral Earth Pressures
Reinforced concrete walls with unbalanced backfill levels on opposite sides should be designed
for earth pressures at least equal to those indicated in the following table. Earth pressures will be
influenced by structural design of the walls, conditions of wall restraint, methods of construction
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
December 11, 2015 ■ Terracon Project No. 20155061
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and/or compaction and the strength of the materials being restrained. Two wall restraint
conditions are shown. Active earth pressure is commonly used for design of free-standing
cantilever retaining walls and assumes wall movement. The "at-rest" condition assumes no wall
movement. The recommended design lateral earth pressures do not include a factor of safety
and do not provide for possible hydrostatic pressure on the walls.
EARTH PRESSURE COEFFICIENTS
Earth Pressure
Conditions
Coefficient for
Backfill Type
Equivalent Fluid
Density (pcf)
Surcharge
Pressure,
p1 (psf)
Earth
Pressure,
p2 (psf)
Active (Ka)
Imported Fill - 0.27
Lean Clay - 0.41
35
49
(0.27)S
(0.41)S
(35)H
(49)H
At-Rest (Ko)
Imported Fill - 0.43
Lean Clay - 0.58
56
70
(0.43)S
(0.58)S
(56)H
(70)H
Passive (Kp)
Imported Fill - 3.69
Lean Clay - 2.46
480
295
---
---
---
---
Applicable conditions to the above include:
For active earth pressure, wall must rotate about base, with top lateral movements of about
0.002 H to 0.004 H, where H is wall height;
For passive earth pressure to develop, wall must move horizontally to mobilize resistance;
Uniform surcharge, where S is surcharge pressure;
In-situ soil backfill weight a maximum of 120 pcf;
Horizontal backfill, compacted between 95 and 98 percent of maximum dry unit weight as
determined by ASTM D698;
Geotechnical Engineering Report
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Loading from heavy compaction equipment not included;
No hydrostatic pressures acting on wall;
No dynamic loading;
No safety factor included in soil parameters; and
Ignore passive pressure in frost zone.
To control hydrostatic pressure behind the wall we recommend that a drain be installed at the
foundation wall with a collection pipe leading to a reliable discharge. If this is not possible, then
combined hydrostatic and lateral earth pressures should be calculated for lean clay backfill using
an equivalent fluid weighing 90 and 100 pcf for active and at-rest conditions, respectively. For
granular backfill, an equivalent fluid weighing 85 and 90 pcf should be used for active and at-rest,
respectively. These pressures do not include the influence of surcharge, equipment or floor
loading, which should be added. Heavy equipment should not operate within a distance closer
than the exposed height of retaining walls to prevent lateral pressures more than those provided.
4.8 Elevator Pit
We assume an elevator pit will be included in the interior of the building. The elevator pit will likely
consist of reinforced concrete walls with a concrete base slab. Based on our experience with this
type of structure, we anticipate the base slabs will be about 5 feet below the level of the finished
floor slab.
4.8.1 Elevator Pit Design Recommendations
Subsurface conditions in elevator pit excavations are generally anticipated to consist of native clays
and/or sands/gravels. Groundwater was encountered at depths of about 11½ to 14½ feet below
existing site grades at the time of our field exploration. However, groundwater levels can and
should be expected to fluctuate over time.
Depending upon final site grades and elevator pit elevations, groundwater could impact the
performance of the pit base slab. If the pit slab is constructed at or within about 4 feet of the level
of groundwater, the pit/slab should be designed and constructed to resist hydrostatic pressures
and uplift due to the effects of buoyancy or it should be protected by an underdrain system for
permanent dewatering. “Water-proofing” of the pit will also be needed if permanent dewatering is
not used. Terracon should evaluate the groundwater level within each elevator pit area prior to or
during construction.
The elevator pit walls should be designed for the lateral earth pressures imposed by the soil
backfill. Earth pressures will primarily be influenced by structural design of the walls, conditions
of wall restraint and type, compaction and drainage of the backfill. For purposes of design, we
have assumed approximately 5 feet of fill will be retained by the pit walls and backfill will consist of
the on-site lean clays. If taller walls are planned, or if different type of backfill is used, we should
be contacted to review our data and confirm or modify the design criteria presented below.
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
December 11, 2015 ■ Terracon Project No. 20155061
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Active earth pressure is commonly used for design of walls (such as free-standing cantilever
retaining walls) and assumes some wall rotation and deflection. For walls that can deflect and
rotate about the base, with top lateral movements of about ¼ to ½ percent or more of the wall
height, lower “active” earth pressures could be considered for design. Use of the “active” condition
assumes deflection and thus cracking of walls could occur. For rigid walls where negligible or very
little rotation and deflection will occur, "at-rest" lateral earth pressures should be used in the
design.
Reinforced concrete pit walls should be designed for lateral earth pressures and/or combined
hydrostatic and lateral earth pressures at least equal to those indicated in the following table.
Earth Pressure
Conditions
Backfill Soil
Type
Equivalent Fluid Density
(above water, pcf)
Equivalent Fluid Density
(below water, pcf)
Active (Ka) On-site lean clay 49 90
At-Rest (Ko) On-site lean clay 70 100
The lateral earth pressures presented above do not include a factor of safety. As such, appropriate
factors of safety should be applied to these values. Furthermore, the lateral earth pressures do
not include the influence of surcharge, equipment or floor loading, which should be added.
4.8.2 Elevator Pit Construction Considerations
Depending on groundwater conditions at the time of construction and the final depth of the pits,
some method of temporary dewatering may be needed during construction. Dewatering should
continue through the excavation, foundation construction and backfilling operations to ensure
proper construction.
The elevator pit excavations should be observed by the geotechnical engineer to confirm that the
subsurface conditions are consistent with those encountered in our test borings. If the soil
conditions encountered differ from those presented in this report, supplemental recommendations
will be required. Where expansive clays, low strength soils or otherwise unsuitable bearing
materials are encountered in the excavation, these materials should be over-excavated to the
minimum depth determined by the geotechnical engineer and replaced with approved engineered
fill. Terracon should be contacted to evaluate bearing conditions in the elevator pit excavations
well in advance of forming foundations.
4.9 Pavements
4.9.1 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
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
December 11, 2015 ■ Terracon Project No. 20155061
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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.
4.9.2 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:
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
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)
Subgrade Soil Characteristics
USCS Classification – CL, classified by NAPA as poor
We assumed the following design parameters for ACI rigid pavement thickness design based
upon the average daily truck traffic (ADTT):
Automobile Parking Areas
ACI Category A: Automobile parking with an ADTT of 1 over 20 years
Main Traffic Corridors
ACI Category A: Automobile parking area and service lanes with an ADTT of
up to 10 over 20 years
Subgrade Soil Characteristics
USCS Classification – CL
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:
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
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Traffic Area
Alternative
Recommended Pavement Thickness (Inches)
Asphaltic
Concrete
Surface
Aggregate
Base
Course
Portland
Cement
Concrete
Total
Automobile Parking
(NAPA Class I and ACI Category A)
A 3½ 6 -- 9½
B -- -- 5½ 5½
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
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.
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
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Although not required for structural support, a minimum 4-inch thick aggregate base course layer
is recommended for the PCC pavements to help reduce the potential for slab curl, shrinkage
cracking, and subgrade “pumping” through joints. Proper joint spacing will also be required for
PCC pavements to prevent excessive slab curling and shrinkage cracking. All joints should be
sealed to prevent entry of foreign material and dowelled where necessary for load transfer.
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.
4.9.3 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.
4.9.4 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
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
December 11, 2015 ■ Terracon Project No. 20155061
Responsive ■ Resourceful ■ Reliable 21
priority when implementing a planned pavement maintenance program and provides the highest
return on investment for pavements.
5.0 GENERAL COMMENTS
Terracon should be retained to review the final design plans and specifications so comments can
be made regarding interpretation and implementation of our geotechnical recommendations in
the design and specifications. Terracon also should be retained to provide observation and testing
services during grading, excavation, foundation construction and other earth-related construction
phases of the project.
The analysis and recommendations presented in this report are based upon the data obtained
from the borings performed at the indicated locations and from other information discussed in this
report. This report does not reflect variations that may occur between borings, across the site, 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. If variations appear, we should be
immediately notified so that further evaluation and supplemental recommendations can be
provided.
The scope of services for this project does not include either specifically or by implication any
environmental or biological (e.g., mold, fungi, and 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.
This report has been prepared for the exclusive use of our client for specific application to the
project discussed and has been prepared in accordance with generally accepted geotechnical
engineering practices. No warranties, either express or implied, are intended or made. Site
safety, excavation support, and dewatering requirements are the responsibility of others. In the
event that changes in the nature, design, or location of the project as described in this report are
planned, the conclusions and recommendations contained in this report shall not be considered
valid unless Terracon reviews the changes and either verifies or modifies the conclusions of this
report in writing.
APPENDIX A
FIELD EXPLORATION
TOPOGRAPHIC MAP IMAGE COURTESY OF
THE U.S. GEOLOGICAL SURVEY
QUADRANGLES INCLUDE: FORT COLLINS,
CO (1984).
SITE LOCATION MAP
Home2 Suites at Harmony Village
Lot 11A, Harmony Village P.U.D. Replat No. 1 Southwest of East Harmony
Road and South Timberline Road
Fort Collins, CO
1901 Sharp Point Dr Suite C
Ft. Collins, CO 80525
20155061
DIAGRAM IS FOR GENERAL LOCATION ONLY,
AND IS NOT INTENDED FOR CONSTRUCTION
PURPOSES
Project Manager:
Drawn by: MJG
EDB
Checked by:
EDB
EDB
Approved by:
12/9/2015
Project No.
File Name:
Date:
A-1
Exhibit
Scale: 1”=24,000 SF
EXPLORATION PLAN
1901 Sharp Point Dr Suite C
Ft. Collins, CO 80525
AERIAL PHOTOGRAPHY PROVIDED BY 20155061
MICROSOFT BING MAPS
Home2 Suites at Harmony Village
Lot 11A, Harmony Village P.U.D. Replat No. 1 Southwest of East
Harmony Road and South Timberline Road
Fort Collins, CO
Approximate Location of
Temporary Benchmark (Top of
Fire Hydrant– Assumed
Elevation 100.0’)
DIAGRAM IS FOR GENERAL LOCATION ONLY,
AND IS NOT INTENDED FOR CONSTRUCTION
PURPOSES
P-2
MJG
EDB
Project Manager:
EDB
Drawn by:
EDB
2
Checked by:
Approved by:
12/9/2015
1
P-1
0
’
25’ 50’
Scale:
Project No.
File Name:
Date:
AS SHOWN
A-2
Exhibit
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
December 11, 2015 ■ Terracon Project No. 20155061
Responsive ■ Resourceful ■ Reliable Exhibit A-3
Field Exploration Description
The locations of borings were based upon the proposed development shown on the provided site
plan. The borings were located in the field by measuring from property lines and existing site
features. The ground surface elevation was surveyed at each boring location referencing the
temporary benchmark shown on Exhibit A-2 using an engineer’s level.
The borings were drilled with a CME-55 truck-mounted rotary drill rig with solid-stem augers.
During the drilling operations, lithologic logs of the borings were recorded by the field engineer.
Disturbed samples were obtained at selected intervals utilizing a 2-inch outside diameter split-
spoon sampler and a 3-inch outside diameter ring-barrel sampler. Penetration resistance values
were recorded in a manner similar to the standard penetration test (SPT). This test consists of
driving the sampler into the ground with a 140-pound hammer free-falling through a distance of
30 inches. The number of blows required to advance the ring-barrel sampler 12 inches (18 inches
for standard split-spoon samplers, final 12 inches are recorded) or the interval indicated, is
recorded as a standard penetration resistance value (N-value). The blow count values are
indicated on the boring logs at the respective sample depths. Ring-barrel sample blow counts are
not considered N-values.
A CME automatic SPT hammer was used to advance the samplers in the borings performed on this
site. A greater efficiency is typically achieved with the automatic hammer compared to the
conventional safety hammer operated with a cathead and rope. Published correlations between the
SPT values and soil properties are based on the lower efficiency cathead and rope method. This
higher efficiency affects the standard penetration resistance blow count value by increasing the
penetration per hammer blow over what would be obtained using the cathead and rope method. The
effect of the automatic hammer's efficiency has been considered in the interpretation and analysis of
the subsurface information for this report.
The standard penetration test provides a reasonable indication of the in-place density of sandy
type materials, but only provides an indication of the relative stiffness of cohesive materials since
the blow count in these soils may be affected by the moisture content of the soil. In addition,
considerable care should be exercised in interpreting the N-values in gravelly soils, particularly
where the size of the gravel particle exceeds the inside diameter of the sampler.
Groundwater measurements were obtained in the borings at the time of site exploration and
approximately one day after drilling. After subsequent groundwater measurements were obtained,
the borings were backfilled with auger cuttings. Some settlement of the backfill may occur and
should be repaired as soon as possible.
0.5
3.5
15.0
23.0
35.5
VEGETATIVE LAYER - 6 INCHES
SANDY LEAN CLAY, fine grained, dark brown, stiff
LEAN CLAY (CL), fine grained, light brown to orange-brown,
medium stiff to stiff
SILTY CLAYEY SAND WITH GRAVEL, fine to coarse grained,
reddish-brown, medium dense
SEDIMENTARY BEDROCK - CLAYSTONE, gray to light brown,
hard
97
94
82.5
74.5
62
15-13
5-5-5
N=10
5-5
7-5-4
N=9
7-13-13
N=26
10-17-21
N=38
18-30-36
N=66
19-32-36
N=68
15
14
23
21
10
23
21
24
118
-0.1/1000 96 36-19-17
See Exhibit A-2
DEPTH
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
LOCATION
GRAPHIC LOG
Latitude: 40.52137° Longitude: -105.04208°
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TERRACON SMART LOG - INCHES 20155061.GPJ TERRACON2012.GDT 12/11/15
SW of East Harmony Road and South Timberline Road
Fort Collins, Colorado
SITE:
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Borings backfilled with soil cuttings upon completion.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Notes:
0.5
7.0
11.0
23.0
35.5
VEGETATIVE LAYER - 6 INCHES
LEAN CLAY WITH SAND (CL), fine grained, dark brown, stiff
LEAN CLAY, fine grained, light brown to reddish-brown, medium
stiff to stiff
SILTY CLAYEY SAND WITH GRAVEL, fine to coarse grained,
reddish-brown, medium dense
SEDIMENTARY BEDROCK - CLAYSTONE (CH), gray, hard
97.5
91
87
75
62.5
5-7-5
N=12
5-10
1-2-2
N=4
8-12
11-17-18
N=35
16-26-40
N=66
19-19-23
N=42
18-28-31
N=59
14
16
18
12
15
22
22
23
106
129
38-16-22
58-24-34
-1.1/500
See Exhibit A-2
DEPTH
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
LOCATION
GRAPHIC LOG
Latitude: 40.521689° Longitude: -105.042406°
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TERRACON SMART LOG - INCHES 20155061.GPJ TERRACON2012.GDT 12/11/15
SW of East Harmony Road and South Timberline Road
Fort Collins, Colorado
SITE:
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Borings backfilled with soil cuttings upon completion.
1901 Sharp Point Drive, Suite C
0.5
8.0
15.0
25.0
35.5
VEGETATIVE LAYER - 6 INCHES
SANDY LEAN CLAY, fine grained, dark brown, stiff
LEAN CLAY, fine grained, light brown, medium stiff to stiff
SILTY CLAYEY SAND WITH GRAVEL (SC-SM), with gravel, fine to
coarse grained, reddish-brown, medium dense
SEDIMENTARY BEDROCK - CLAYSTONE, gray, hard
97
89.5
82.5
72.5
62
7-12-10
N=22
7-9
2-1
4-3-2
N=5
7-27-23
N=50
13-25-30
N=55
11-15-29
N=44
15-20-30
N=50
13
15
25
17
9
20
25
26
120
100
22-16-6
See Exhibit A-2
DEPTH
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
LOCATION
GRAPHIC LOG
Latitude: 40.52156° Longitude: -105.04256°
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TERRACON SMART LOG - INCHES 20155061.GPJ TERRACON2012.GDT 12/11/15
SW of East Harmony Road and South Timberline Road
Fort Collins, Colorado
SITE:
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Borings backfilled with soil cuttings upon completion.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Notes:
Project No.: 20155061
3.0
5.5
SANDY LEAN CLAY (CL), fine grained, dark brown, stiff
LEAN CLAY WITH SAND, fine grained, light brown, medium stiff
94.5
92
7-16
2-3-2
N=5
16
17
-0.5/150 105 40-17-23
See Exhibit A-2
DEPTH
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
LOCATION
GRAPHIC LOG
Latitude: 40.52163° Longitude: -105.04205°
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TERRACON SMART LOG - INCHES 20155061.GPJ TERRACON2012.GDT 12/11/15
SW of East Harmony Road and South Timberline Road
Fort Collins, Colorado
SITE:
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Borings backfilled with soil cuttings upon completion.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Notes:
Project No.: 20155061
Drill Rig: CME-55
Boring Started: 12/2/2015
BORING LOG NO. P-1
CLIENT: East Avenue Development, LLC
Ceder Park, Texas
Driller: Drilling Engineers Inc.
Boring Completed: 12/2/2015
See Exhibit A-3 for description of field procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
PROJECT: Home2 Suites at Harmony Village
ELEVATION (Ft.)
Surface Elev.: 97.43 (Ft.)
FIELD TEST
RESULTS
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
SWELL- CONSOL /
LOAD (%/psf)
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
0.5
5.5
VEGETATIVE LAYER - 6 INCHES
SANDY LEAN CLAY, fine grained, dark brown, medium stiff to stiff
98
93
6-12
4-6-5
N=11
12
15
0.1/150 108
See Exhibit A-2
DEPTH
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
LOCATION
GRAPHIC LOG
Latitude: 40.521662° Longitude: -105.042885°
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TERRACON SMART LOG - INCHES 20155061.GPJ TERRACON2012.GDT 12/11/15
SW of East Harmony Road and South Timberline Road
Fort Collins, Colorado
SITE:
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Borings backfilled with soil cuttings upon completion.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Notes:
Project No.: 20155061
Drill Rig: CME-55
Boring Started: 12/2/2015
BORING LOG NO. P-2
CLIENT: East Avenue Development, LLC
Ceder Park, Texas
Driller: Drilling Engineers Inc.
Boring Completed: 12/2/2015
See Exhibit A-3 for description of field procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
PROJECT: Home2 Suites at Harmony Village
ELEVATION (Ft.)
Surface Elev.: 98.26 (Ft.)
FIELD TEST
RESULTS
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
SWELL- CONSOL /
LOAD (%/psf)
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
APPENDIX B
LABORATORY TESTING
Geotechnical Engineering Report
Home2 Suites at Harmony Village ■ Fort Collins, Colorado
December 11, 2015 ■ Terracon Project No. 20155061
Responsive ■ Resourceful ■ Reliable Exhibit B-1
Laboratory Testing Description
The soil and bedrock samples retrieved during the field exploration were returned to the laboratory
for observation by the project geotechnical engineer. At that time, the field descriptions were
reviewed and an applicable laboratory testing program was formulated to determine engineering
properties of the subsurface materials.
Laboratory tests were conducted on selected soil and bedrock samples. The results of these
tests are presented on the boring logs and in this appendix. The test results were used for the
geotechnical engineering analyses, and the development of foundation and earthwork
recommendations. The laboratory tests were performed in general accordance with applicable
locally accepted standards. Soil samples were classified in general accordance with the Unified
Soil Classification System described in Appendix C. Rock samples were visually classified in
general accordance with the description of rock properties presented in Appendix C. Procedural
standards noted in this report are for reference to methodology in general. In some cases variations
to methods are applied as a result of local practice or professional judgment.
Water content Plasticity index
Grain-size distribution
Consolidation/swell
Dry density
Water-soluble sulfate content
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
Boring ID Depth PL PI Description
LEAN CLAY
LEAN CLAY with SAND
FAT CLAY
SILTY, CLAYEY SAND with GRAVEL
SANDY LEAN CLAY
CL
CL
CH
SC-SM
CL
Fines
P
L
A
S
T
I
C
I
T
Y
I
N
D
E
X
LIQUID LIMIT
"U" Line
"A" Line
36
38
58
22
40
19
16
24
16
17
17
22
34
6
23
86
73
94
21
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
% FINES % CLAY USCS
1
2
2
0.0
0.0
0.0
0.0
0.1
0.0
14.4
26.6
6.0
DEPTH
GRAIN SIZE
LEAN CLAY(CL)
LEAN CLAY with SAND(CL)
FAT CLAY(CH)
16 20
100
90
80
70
60
50
40
30
20
10
0
REMARKS
COBBLES SILT OR CLAY
GRAVEL SAND
medium
85.6
73.3
94.0
GRAIN SIZE IN MILLIMETERS
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
% FINES % CLAY USCS
3
P-1 0.0
13.8
0.2
46.0
38.1
DEPTH
0.307
3.18
GRAIN SIZE
SILTY, CLAYEY SAND with
GRAVEL(SC-SM)
SANDY LEAN CLAY(CL)
16 20
100
90
80
70
60
50
40
30
20
10
0
REMARKS
COBBLES SILT OR CLAY
GRAVEL SAND
medium
20.8
61.7
GRAIN SIZE IN MILLIMETERS
PERCENT FINER
3/4 1/2
3/8
SIEVE
(size)
-4
-3
-2
-1
0
1
2
3
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 1,000
psf.
PROJECT NUMBER: 20155061
PROJECT: Home2 Suites at Harmony Village
SITE: SW of East Harmony Road and South
Timberline Road
Fort Collins, Colorado
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Specimen Identification Classification , pcf
1 96 23
WC, %
9 - 10 ft LEAN CLAY(CL)
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. CONSOL_STRAIN-USCS 20155061.GPJ TERRACON2012.GDT 12/11/15
CLIENT: East Avenue Development, LLC
Ceder Park, Texas
EXHIBIT: B-5
-4
-3
-2
-1
0
1
2
3
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 1.1 percent compression upon wetting under an applied pressure of 500
psf.
PROJECT NUMBER: 20155061
PROJECT: Home2 Suites at Harmony Village
SITE: SW of East Harmony Road and South
Timberline Road
Fort Collins, Colorado
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Specimen Identification Classification , pcf
2 106 16
WC, %
4 - 5 ft LEAN CLAY with SAND(CL)
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. CONSOL_STRAIN-USCS 20155061.GPJ TERRACON2012.GDT 12/11/15
CLIENT: East Avenue Development, LLC
Ceder Park, Texas
EXHIBIT: B-6
-4
-3
-2
-1
0
1
2
3
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 0.5 percent compression upon wetting under an applied pressure of 150
psf.
PROJECT NUMBER: 20155061
PROJECT: Home2 Suites at Harmony Village
SITE: SW of East Harmony Road and South
Timberline Road
Fort Collins, Colorado
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Specimen Identification Classification , pcf
P-1 105 16
WC, %
2 - 3 ft SANDY LEAN CLAY(CL)
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. CONSOL_STRAIN-USCS 20155061.GPJ TERRACON2012.GDT 12/11/15
CLIENT: East Avenue Development, LLC
Ceder Park, Texas
EXHIBIT: B-7
-4
-3
-2
-1
0
1
2
3
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 0.2 percent swell upon wetting under an applied pressure of 150 psf.
PROJECT NUMBER: 20155061
PROJECT: Home2 Suites at Harmony Village
SITE: SW of East Harmony Road and South
Timberline Road
Fort Collins, Colorado
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Specimen Identification Classification , pcf
P-2 108 12
WC, %
2 - 3 ft
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. CONSOL_STRAIN-USCS 20155061.GPJ TERRACON2012.GDT 12/11/15
CLIENT: East Avenue Development, LLC
Ceder Park, Texas
EXHIBIT: B-8
APPENDIX C
SUPPORTING DOCUMENTS
Exhibit: C-1
Unconfined Compressive Strength
Qu, (psf)
500 to 1,000
2,000 to 4,000
4,000 to 8,000
1,000 to 2,000
less than 500
> 8,000
Non-plastic
Low
Medium
High
DESCRIPTION OF SYMBOLS AND ABBREVIATIONS
SAMPLING
WATER LEVEL
FIELD TESTS
GENERAL NOTES
Over 12 in. (300 mm)
12 in. to 3 in. (300mm to 75mm)
3 in. to #4 sieve (75mm to 4.75 mm)
#4 to #200 sieve (4.75mm to 0.075mm
Passing #200 sieve (0.075mm)
Particle Size
< 5
5 - 12
> 12
Percent of
Dry Weight
Descriptive Term(s)
of other constituents
RELATIVE PROPORTIONS OF FINES
0
1 - 10
11 - 30
> 30
Plasticity Index
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.
LOCATION AND ELEVATION NOTES
Percent of
Dry Weight
Major Component
of Sample
Trace
With
Modifier
RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY
Trace
With
Modifier
DESCRIPTIVE SOIL CLASSIFICATION
Boulders
Cobbles
Gravel
Sand
UNIFIED SOIL CLASSIFICATION SYSTEM
Exhibit C-2
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 sand G,H,I
Fines classify as CL or CH SC Clayey sand G,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 clay K,L,M
PI 4 or plots below “A” line J 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 clay K,L,M
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.
DESCRIPTION OF ROCK PROPERTIES
Exhibit C-3
WEATHERING
Fresh Rock fresh, crystals bright, few joints may show slight staining. Rock rings under hammer if crystalline.
Very slight Rock generally fresh, joints stained, some joints may show thin clay coatings, crystals in broken face show
bright. Rock rings under hammer if crystalline.
Slight Rock generally fresh, joints stained, and discoloration extends into rock up to 1 in. Joints may contain clay. In
granitoid rocks some occasional feldspar crystals are dull and discolored. Crystalline rocks ring under hammer.
Moderate Significant portions of rock show discoloration and weathering effects. In granitoid rocks, most feldspars are dull
and discolored; some show clayey. Rock has dull sound under hammer and shows significant loss of strength
as compared with fresh rock.
Moderately severe All rock except quartz discolored or stained. In granitoid rocks, all feldspars dull and discolored and majority
show kaolinization. Rock shows severe loss of strength and can be excavated with geologist’s pick.
Severe All rock except quartz discolored or stained. Rock “fabric” clear and evident, but reduced in strength to strong
soil. In granitoid rocks, all feldspars kaolinized to some extent. Some fragments of strong rock usually left.
Very severe All rock except quartz discolored or stained. Rock “fabric” discernible, but mass effectively reduced to “soil” with
only fragments of strong rock remaining.
Complete Rock reduced to ”soil”. Rock “fabric” not discernible or discernible only in small, scattered locations. Quartz may
be present as dikes or stringers.
HARDNESS (for engineering description of rock – not to be confused with Moh’s scale for minerals)
Very hard Cannot be scratched with knife or sharp pick. Breaking of hand specimens requires several hard blows of
geologist’s pick.
Hard Can be scratched with knife or pick only with difficulty. Hard blow of hammer required to detach hand specimen.
Moderately hard Can be scratched with knife or pick. Gouges or grooves to ¼ in. deep can be excavated by hard blow of point of
a geologist’s pick. Hand specimens can be detached by moderate blow.
Medium Can be grooved or gouged 1/16 in. deep by firm pressure on knife or pick point. Can be excavated in small
chips to pieces about 1-in. maximum size by hard blows of the point of a geologist’s pick.
Soft Can be gouged or grooved readily with knife or pick point. Can be excavated in chips to pieces several inches in
size by moderate blows of a pick point. Small thin pieces can be broken by finger pressure.
Very soft Can be carved with knife. Can be excavated readily with point of pick. Pieces 1-in. or more in thickness can be
broken with finger pressure. Can be scratched readily by fingernail.
Joint, Bedding, and Foliation Spacing in Rock
a
Spacing Joints Bedding/Foliation
Less than 2 in. Very close Very thin
2 in. – 1 ft. Close Thin
1 ft. – 3 ft. Moderately close Medium
3 ft. – 10 ft. Wide Thick
More than 10 ft. Very wide Very thick
a. Spacing refers to the distance normal to the planes, of the described feature, which are parallel to each other or nearly so.
Rock Quality Designator (RQD) a Joint Openness Descriptors
RQD, as a percentage Diagnostic description Openness Descriptor
Exceeding 90 Excellent No Visible Separation Tight
90 – 75 Good Less than 1/32 in. Slightly Open
75 – 50 Fair 1/32 to 1/8 in. Moderately Open
50 – 25 Poor 1/8 to 3/8 in. Open
Less than 25 Very poor 3/8 in. to 0.1 ft. Moderately Wide
a. RQD (given as a percentage) = length of core in pieces Greater than 0.1 ft. Wide
4 in. and longer/length of run.
References: American Society of Civil Engineers. Manuals and Reports on Engineering Practice - No. 56. Subsurface Investigation for
Design and Construction of Foundations of Buildings. New York: American Society of Civil Engineers, 1976. U.S.
Department of the Interior, Bureau of Reclamation, Engineering Geology Field Manual.
Exhibit C-4
LABORATORY TEST
SIGNIFICANCE AND PURPOSE
Test Significance Purpose
California Bearing
Ratio
Used to evaluate the potential strength of subgrade soil,
subbase, and base course material, including recycled
materials for use in road and airfield pavements.
Pavement Thickness
Design
Consolidation
Used to develop an estimate of both the rate and amount of
both differential and total settlement of a structure.
Foundation Design
Direct Shear
Used to determine the consolidated drained shear strength
of soil or rock.
Bearing Capacity,
Foundation Design,
and Slope Stability
Dry Density
Used to determine the in-place density of natural, inorganic,
fine-grained soils.
Index Property Soil
Behavior
Expansion
Used to measure the expansive potential of fine-grained soil
and to provide a basis for swell potential classification.
Foundation and Slab
Design
Gradation
Used for the quantitative determination of the distribution of
particle sizes in soil.
Soil Classification
Liquid & Plastic Limit,
Plasticity Index
Used as an integral part of engineering classification
systems to characterize the fine-grained fraction of soils, and
to specify the fine-grained fraction of construction materials.
Soil Classification
Permeability
Used to determine the capacity of soil or rock to conduct a
liquid or gas.
Groundwater Flow
Analysis
pH Used to determine the degree of acidity or alkalinity of a soil. Corrosion Potential
Resistivity
Used to indicate the relative ability of a soil medium to carry
electrical currents.
Corrosion Potential
R-Value
Used to evaluate the potential strength of subgrade soil,
subbase, and base course material, including recycled
materials for use in road and airfield pavements.
Pavement Thickness
Design
Soluble Sulfate
Used to determine the quantitative amount of soluble
sulfates within a soil mass.
REPORT TERMINOLOGY
(Based on ASTM D653)
Expansive Potential The potential of a soil to expand (increase in volume) due to absorption of moisture.
Finished Grade The final grade created as a part of the project.
Footing A portion of the foundation of a structure that transmits loads directly to the soil.
Foundation The lower part of a structure that transmits the loads to the soil or bedrock.
Frost Depth The depth at which the ground becomes frozen during the winter season.
Grade Beam
A foundation element or wall, typically constructed of reinforced concrete, used to span between
other foundation elements such as drilled piers.
Groundwater Subsurface water found in the zone of saturation of soils or within fractures in bedrock.
Heave Upward movement.
Lithologic The characteristics which describe the composition and texture of soil and rock by observation.
Native Grade The naturally occurring ground surface.
Native Soil Naturally occurring on-site soil, sometimes referred to as natural soil.
Optimum Moisture
Content
The water content at which a soil can be compacted to a maximum dry unit weight by a given
compactive effort.
Perched Water
Groundwater, usually of limited area maintained above a normal water elevation by the
presence of an intervening relatively impervious continuous stratum.
Scarify To mechanically loosen soil or break down existing soil structure.
Settlement Downward movement.
Skin Friction (Side
Shear)
The frictional resistance developed between soil and an element of the structure such as a
drilled pier.
Soil (Earth)
Sediments or other unconsolidated accumulations of solid particles produced by the physical
and chemical disintegration of rocks, and which may or may not contain organic matter.
Strain The change in length per unit of length in a given direction.
Stress The force per unit area acting within a soil mass.
Strip To remove from present location.
Subbase A layer of specified material in a pavement system between the subgrade and base course.
Subgrade The soil prepared and compacted to support a structure, slab or pavement system.
Exhibit C-5
REPORT TERMINOLOGY
(Based on ASTM D653)
Allowable Soil
Bearing Capacity
The recommended maximum contact stress developed at the interface of the foundation
element and the supporting material.
Alluvium
Soil, the constituents of which have been transported in suspension by flowing water and
subsequently deposited by sedimentation.
Aggregate Base
Course
A layer of specified material placed on a subgrade or subbase usually beneath slabs or
pavements.
Backfill A specified material placed and compacted in a confined area.
Bedrock
A natural aggregate of mineral grains connected by strong and permanent cohesive forces.
Usually requires drilling, wedging, blasting or other methods of extraordinary force for
excavation.
Bench A horizontal surface in a sloped deposit.
Caisson (Drilled
Pier or Shaft)
A concrete foundation element cast in a circular excavation which may have an enlarged base.
Sometimes referred to as a cast-in-place pier or drilled shaft.
Coefficient of
Friction
A constant proportionality factor relating normal stress and the corresponding shear stress at
which sliding starts between the two surfaces.
Colluvium
Soil, the constituents of which have been deposited chiefly by gravity such as at the foot of a
slope or cliff.
Compaction The densification of a soil by means of mechanical manipulation
Concrete Slab-on-
Grade
A concrete surface layer cast directly upon a base, subbase or subgrade, and typically used
as a floor system.
Differential
Movement
Unequal settlement or heave between, or within foundation elements of structure.
Earth Pressure The pressure exerted by soil on any boundary such as a foundation wall.
ESAL
Equivalent Single Axle Load, a criteria used to convert traffic to a uniform standard, (18,000
pound axle loads).
Engineered Fill
Specified material placed and compacted to specified density and/or moisture conditions
under observations of a representative of a geotechnical engineer.
Equivalent Fluid
A hypothetical fluid having a unit weight such that it will produce a pressure against a lateral
support presumed to be equivalent to that produced by the actual soil. This simplified
approach is valid only when deformation conditions are such that the pressure increases
linearly with depth and the wall friction is neglected.
Existing Fill (or
Man-Made Fill)
Materials deposited throughout the action of man prior to exploration of the site.
Existing Grade The ground surface at the time of field exploration.
Exhibit C-6
Corrosion Potential
Unconfined
Compression
To obtain the approximate compressive strength of soils that
possess sufficient cohesion to permit testing in the
unconfined state.
Bearing Capacity
Analysis for
Foundations
Water Content
Used to determine the quantitative amount of water in a soil
mass.
Index Property Soil
Behavior
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.
M If soil contains 30% plus No. 200, predominantly gravel, add
“gravelly” to group name.
N PI 4 and plots on or above “A” line.
O PI 4 or plots below “A” line.
P PI plots on or above “A” line.
Q PI plots below “A” line.
Silt or Clay
Descriptive Term(s)
of other constituents
N
(HP)
(T)
(DCP)
(PID)
(OVA)
< 15
15 - 29
> 30
Term
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.
Water Level After
a Specified Period of Time
Water Level After a
Specified Period of Time
Water Initially
Encountered
Modified
Dames &
Moore Ring
Sampler
Standard
Penetration
Test
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 Test
Resistance (Blows/Ft.)
Hand Penetrometer
Torvane
Dynamic Cone Penetrometer
Photo-Ionization Detector
Organic Vapor Analyzer
STRENGTH TERMS
Standard Penetration or
N-Value
Blows/Ft.
Descriptive Term
(Consistency)
Descriptive Term
(Density)
CONSISTENCY OF FINE-GRAINED SOILS
(50% or more passing the No. 200 sieve.)
Consistency determined by laboratory shear strength testing, field
visual-manual procedures or standard penetration resistance
Standard Penetration or
N-Value
Blows/Ft.
(More than 50% retained on No. 200 sieve.)
Density determined by Standard Penetration Resistance
RELATIVE DENSITY OF COARSE-GRAINED SOILS
Hard > 30
> 50 Very Stiff 15 - 30
Stiff
Medium Stiff
Very Soft 0 - 1
Medium Dense
Loose Soft
Very Dense
Dense 30 - 50 8 - 15
10 - 29 4 - 8
4 - 9 2 - 4
Very Loose 0 - 3
D60
30 40
3 60
U.HYDROMETERS. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
4 4 6 100
3 2
fine coarse
SOIL DESCRIPTION
CU
BORING ID
10 14
6 50
1.5 8 200
1 140
coarse fine
COEFFICIENTS
% COBBLES % GRAVEL % SAND
D30
D10
CC
PERCENT FINER BY WEIGHT
PERCENT COARSER BY WEIGHT
% SILT
1 1/2"
1"
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#100
#200
80.64
80.64
80.64
76.97
66.86
52.07
38.98
32.23
28.61
25.47
20.84
100.0
99.83
98.73
90.06
83.03
78.67
73.38
61.7
GRAIN SIZE DISTRIBUTION
ASTM D422
SC-SM
CL
19 - 20.5
2 - 3
PROJECT NUMBER: 20155061
PROJECT: Home2 Suites at Harmony Village
SITE: SW of East Harmony Road and South
Timberline Road
Fort Collins, Colorado
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS 1 20155061.GPJ TERRACON2012.GDT 12/9/15
CLIENT: East Avenue Development, LLC
Ceder Park, Texas
EXHIBIT: B-4
PERCENT FINER
3/4 1/2
3/8
SIEVE
(size)
D60
30 40
3 60
U.HYDROMETERS. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
4 4 6 100
3 2
fine coarse
SOIL DESCRIPTION
CU
BORING ID
10 14
6 50
1.5 8 200
1 140
coarse fine
COEFFICIENTS
% COBBLES % GRAVEL % SAND
D30
D10
CC
PERCENT FINER BY WEIGHT
PERCENT COARSER BY WEIGHT
% SILT
1 1/2"
1"
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#100
#200
100.0
99.7
99.05
97.87
95.51
85.64
100.0
99.9
99.48
97.19
93.39
88.67
83.25
73.35
100.0
99.88
99.43
98.65
97.66
96.43
94.01
GRAIN SIZE DISTRIBUTION
ASTM D422
CL
CL
CH
9 - 10
4 - 5
34 - 35.5
PROJECT NUMBER: 20155061
PROJECT: Home2 Suites at Harmony Village
SITE: SW of East Harmony Road and South
Timberline Road
Fort Collins, Colorado
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS 1 20155061.GPJ TERRACON2012.GDT 12/9/15
CLIENT: East Avenue Development, LLC
Ceder Park, Texas
EXHIBIT: B-3
62
LL USCS
1
2
2
3
P-1
ATTERBERG LIMITS RESULTS
ASTM D4318
9 - 10
4 - 5
34 - 35.5
19 - 20.5
2 - 3
PROJECT NUMBER: 20155061
PROJECT: Home2 Suites at Harmony Village
SITE: SW of East Harmony Road and South
Timberline Road
Fort Collins, Colorado
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS 20155061.GPJ TERRACON2012.GDT 12/11/15
CL-ML
CLIENT: East Avenue Development, LLC
Ceder Park, Texas
EXHIBIT: B-2
DEPTH (In.)
no free water observed
WATER LEVEL OBSERVATIONS
Exhibit: A-8
DEPTH (In.)
no free water observed
WATER LEVEL OBSERVATIONS
Exhibit: A-7
Drill Rig: CME-55
Boring Started: 12/2/2015
BORING LOG NO. 3
CLIENT: East Avenue Development, LLC
Ceder Park, Texas
Driller: Drilling Engineers Inc.
Boring Completed: 12/2/2015
See Exhibit A-3 for description of field procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
PROJECT: Home2 Suites at Harmony Village
ELEVATION (Ft.)
Surface Elev.: 97.65 (Ft.)
FIELD TEST
RESULTS
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
SWELL- CONSOL /
LOAD (%/psf)
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
DEPTH (In.)
while drilling
water level measured on 12/3/2015
WATER LEVEL OBSERVATIONS
Exhibit: A-6
Fort Collins, Colorado
Notes:
Project No.: 20155061
Drill Rig: CME-55
Boring Started: 12/2/2015
BORING LOG NO. 2
CLIENT: East Avenue Development, LLC
Ceder Park, Texas
Driller: Drilling Engineers Inc.
Boring Completed: 12/2/2015
See Exhibit A-3 for description of field procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
PROJECT: Home2 Suites at Harmony Village
ELEVATION (Ft.)
Surface Elev.: 98.21 (Ft.)
FIELD TEST
RESULTS
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
SWELL- CONSOL /
LOAD (%/psf)
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
DEPTH (In.)
while drilling
water level measured on 12/3/2015
WATER LEVEL OBSERVATIONS
Exhibit: A-5
Project No.: 20155061
Drill Rig: CME-55
Boring Started: 12/2/2015
BORING LOG NO. 1
CLIENT: East Avenue Development, LLC
Ceder Park, Texas
Driller: Drilling Engineers Inc.
Boring Completed: 12/2/2015
See Exhibit A-3 for description of field procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
PROJECT: Home2 Suites at Harmony Village
ELEVATION (Ft.)
Surface Elev.: 97.33 (Ft.)
FIELD TEST
RESULTS
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
SWELL- CONSOL /
LOAD (%/psf)
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
DEPTH (In.)
while drilling
water level measured on 12/3/2015
WATER LEVEL OBSERVATIONS
Exhibit: A-4