HomeMy WebLinkAboutTHE DISTRICT @ CAMPUS WEST - PDP - PDP120003 - SUBMITTAL DOCUMENTS - ROUND 1 - RECOMMENDATION/REPORTGeotechnical Engineering Report
THE DISTRICT AT CSU
East of West Plum Street and City Park Avenue
Fort Collins, Colorado
November 2, 2011
Terracon Project No. 20115026
Prepared for:
Ft. Collins Student Housing, LLC
Houston, Texas
Prepared by:
Terracon Consultants, Inc.
Fort Collins, Colorado
TABLE OF CONTENTS
Page
EXECUTIVE SUMMARY .............................................................................................................. ii
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 Profile ........................................................................................................ 3
3.2 Groundwater .......................................................................................................... 4
4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION ....................................... 5
4.1 Geotechnical Considerations................................................................................. 5
4.1.1 Existing Fill................................................................................................. 5
4.1.2 Structural Recommendations .................................................................... 5
4.2 Earthwork .............................................................................................................. 6
4.2.1 Site Preparation ......................................................................................... 6
4.2.2 Import Material Specifications .................................................................... 7
4.2.3 Compaction Requirements ........................................................................ 7
4.2.4 Excavation and Trench Construction ......................................................... 8
4.2.5 Utility Trench Backfill ................................................................................. 8
4.2.6 Grading and Drainage ............................................................................... 9
4.2.7 Construction Considerations .................................................................... 10
4.2.8 Corrosion Protection ................................................................................ 10
4.3 Foundations ......................................................................................................... 10
4.3.1 Design Recommendations – Spread Footings ........................................ 11
4.3.2 Construction Considerations – Spread Footings ..................................... 11
4.3.3 Design Recommendations – Drilled Piers ............................................... 12
4.3.4 Construction Considerations – Drilled Piers ............................................ 12
4.4 Seismic Considerations ....................................................................................... 13
4.5 Interior Floor Systems ......................................................................................... 14
4.5.1 Design Recommendations – Slabs-on-grade ......................................... 14
4.5.2 Construction Considerations – Slabs-on-grade ...................................... 15
4.6 Below-grade Construction ................................................................................... 15
4.7 Lateral Earth Pressures ....................................................................................... 16
4.8 Pavement Design and Construction .................................................................... 17
4.8.1 Drainage Adjacent to Pavements ............................................................ 19
4.8.2 Compliance .............................................................................................. 19
4.8.3 Pavement Performance ........................................................................... 19
4.8.4 Construction Considerations .................................................................... 20
5.0 GENERAL COMMENTS ................................................................................................. 20
TABLE OF CONTENTS (Cont’d)
APPENDIX A – FIELD EXPLORATION
Exhibit A-1 Field Exploration Description
Exhibit A-2 Boring Location Diagram
Exhibits A-3 to A-9 Logs of Borings from Previous Study (Project No. 20085059)
Exhibits A-10 to A-13 Logs of Borings for Current Study
APPENDIX B – LABORATORY TESTING
Exhibit B-1 Laboratory Testing
Exhibits B-2 to B-23 Laboratory Test Results from Previous Study and Current Study
APPENDIX C – SUPPORTING DOCUMENTS
Exhibit C-1 General Notes
Exhibit C-2 Unified Soil Classification
Exhibit C-3 Rock Classification
Exhibit C-4 Laboratory Test Significance and Purpose
Exhibits C-5 and C-6 Report Terminology
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable ii
EXECUTIVE SUMMARY
A geotechnical engineering exploration has been performed for the proposed student housing
development known as The District at CSU to be constructed east of the intersection of West
Plum Street and City Park Avenue in Fort Collins, Colorado. Four (4) borings, presented as
Exhibits A-3 through A-6 and designated as Boring Nos. 8 through 11, were performed to
depths ranging from about 25 feet to 45 feet below the existing ground surface. These four new
borings were used to supplement seven (7) borings drilled during a previous study on the
project site. This report presents geotechnical recommendations for design and construction of
the proposed student housing development and associated infrastructure.
Based on the information obtained from our subsurface exploration and the laboratory testing
completed, the site appears suitable for the proposed construction; however, the following
geotechnical conditions will need to be considered:
Soils and bedrock encountered during our field exploration generally consisted of up to
about ½ foot of topsoil or gravel paving over clay with varying amounts of sand and
gravel and sand with varying amounts of silt, clay, and gravel underlain by weathered to
unweathered claystone bedrock.
The proposed student housing and clubhouse buildings may be supported on spread
footing foundations bearing upon undisturbed soils, suitable fill materials and/or newly
placed engineered fill. Drilled pier foundations bottomed in bedrock may also be
considered as an alternative foundation system for the student housing and/or
clubhouse buildings if footing foundations are not feasible due to heavy building loads.
The proposed parking garage should be supported on a drilled pier foundation system
bottomed in bedrock.
It is our understanding that the existing structures on the site will be razed. Based on
our limited site observations, we anticipate that some of the existing structures have
basement construction. Care should be taken during site preparation to include
complete removal of the foundation systems and basements as well as backfilling the
resulting excavations within the proposed construction area.
Considering the low swelling soils encountered in our borings on this site, we believe a
slab-on-grade floor system can be used for the proposed buildings provided some
movement can be tolerated. If no or very little movement is desired, structurally-
supported floor systems should be used for the proposed buildings.
Groundwater was measured at depths ranging from about 10 to 25 feet below the
existing ground surface during our field studies conducted at this site. If the project team
elects to extend the proposed parking garage below grade, it is possible the parking
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
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garage will encroach upon groundwater. We recommend a 3-foot separation between
the bottom of the lower floor for the parking garage and groundwater. If this separation
is not maintained, a permanent dewatering system will be required.
The 2009 International Building Code (IBC), Table 1613.5.2 IBC seismic site
classification for this site is C.
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 this 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.
Responsive ■ Resourceful ■ Reliable 1
GEOTECHNICAL ENGINEERING REPORT
The District at CSU
East of West Plum Street and City Park Avenue
Fort Collins, Colorado
Terracon Project No. 20115026
November 2, 2011
1.0 INTRODUCTION
A geotechnical engineering report has been completed for the proposed student housing
development to be located east of the intersection of West Plum Street and City Park Avenue in
Fort Collins, Colorado.
As part of our subsurface exploration, a total of four (4) borings were drilled at the site. The Logs
of Borings and Boring Location Diagram are included in Appendix A of this report. The four new
borings drilled as part of this study were performed to supplement soil test borings drilled during
a previous study conducted at this site. The results of our previous study are presented in our
Geotechnical Engineering Report (Project No. 20085059; report dated August 21, 2008).
Information presented in our previous study was considered during preparation of this report.
The Logs of Borings and laboratory test results are compiled along with the data collected for
this study in the appendices of this report.
The purpose of these services is to provide information and geotechnical engineering
recommendations relative to:
Subsurface soil and bedrock conditions Floor system design and construction
Groundwater conditions
Foundation design and construction
Earthwork
Lateral earth pressures
Seismic considerations
Pavement construction
Grading and Drainage
2.0 PROJECT INFORMATION
2.1 Project Description
Item Dsecription
Site layout See Appendix A, Exhibit A-2, Boring Location Diagram
Proposed construction
Preliminary concepts indicate this project will consist of construction
of several student housing buildings, a six-story parking garage
possibly with ½ to 1 level below-grade, a clubhouse, a swimming
pool, courtyards, and associated infrastructure including buried
utilities, concrete flatwork, and access drives.
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
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Item Dsecription
Building construction
The exact building layouts have not been finalized at this time. We
understand the student housing buildings and clubhouse will be 4
to 5 stories with no basement or below-grade areas. We anticipate
the student housing buildings will be steel-framed and/or wood-
framed structures possibly with structural masonry supported by
cast-in-place concrete foundations. The parking garage is
anticipated to be up to about 60 feet tall and will consist of concrete
foundation walls and/or precast concrete walls.
Finished floor elevation Unknown at the time that this report was prepared
Maximum loads
Student Housing and Clubhouse
Columns: 50 to 250 kips (assumed)
Walls: 2 to 5 klf (assumed)
Parking Garage
Columns: up to 1,200 kips (assumed)
Walls: 5 to 10 klf (assumed)
Grading
Preliminary Site Grading Plans were not available at the time this
report was written. Based upon the existing topography in the area
of proposed construction, we assume cuts and fills of less than
about 6 feet will be necessary to achieve desired grades. Deeper
cuts and fills on the order of 6 to 10 feet will be required to demolish
and remove existing site buildings and associated elements.
Infrastructure
Installation of underground utilities within about 5 feet of finished
site grades. Installation of pavements for drives and parking.
Below-grade areas
No below grade areas are planned for the student housing and
clubhouse buildings. We understand the parking structure may
extend up to about 12 feet below-grade.
Traffic Loading
Light-duty (parking lots): Assumed to not exceed 15,000 ESALs
Heavy-duty (truck traffic): Assumed 75,000 ESALs
2.2 Site Location and Description
Item Description
Location
The project site is located east of the intersection of West Plum
Street and City Park Avenue in Fort Collins, Colorado.
Existing improvements
The site is currently occupied by 4-plex, 8-plex and single-family
residential structures with some existing roadways also occupying
portions of the site between the existing structures. There are
several large clusters of mature trees at various locations on the
property. We understand these structures will be demolished and
removed prior to the new construction.
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
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Item Description
Current ground cover
The lots are landscaped with sod, bushes, and mature deciduous
trees surrounding existing residential buildings. The existing
roadways are paved with asphalt or gravel-surfaced.
Existing topography
The site is relatively flat sloping gently away from the existing
structures and generally down towards to the south and east.
3.0 SUBSURFACE CONDITIONS
3.1 Typical Profile
Based on the results of the borings, subsurface conditions encountered underlying the existing
ground surface on the project site can be generalized as follows:
Material Description Approximate Depth to Bottom
of Stratum (ft.) Consistency/Density/Hardness
Topsoil or gravel paving About ½ foot ---
Fill materials consisting of
sandy lean clay with varying
amounts of gravel
About 3½ to 9 feet in Boring Nos.
3, 6 and 8 only
Stiff to very stiff
Sandy lean clay
About 12 to 17½ feet except in
Boring Nos. 6 and 7
Medium stiff to hard
Silty to clayey sand with
varying amounts of gravel
About 13 to 18½ feet except in
Boring Nos. 1, 4 and 10
Loose to dense
Claystone bedrock
To the maximum explored depths
of about 20 to 45 feet
Weathered to very hard
Subsurface conditions encountered at each boring location are indicated on the individual Logs
of Borings. Stratification boundaries on the Logs of Borings represent the approximate depths
of changes in soil and bedrock type, the transition between materials may be gradual. The Logs
of Borings are attached in Appendix A of this report.
Laboratory testing was conducted on selected samples of the soils and bedrock collected during
our field explorations and the test results for our previous study and this current study are
presented in Appendix B and on the attached Logs of Borings.
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
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3.2 Groundwater
The borings were observed while drilling and after completion for the presence and level of
groundwater. Groundwater levels measured in Boring Nos. 1 through 7 were measured in
August 2008 and groundwater levels measured in Boring Nos. 8 through 11 were measured in
September 2011. The groundwater levels are noted on the attached Logs of Borings, and are
summarized below.
Boring No. Depth to groundwater while
drilling (ft.)
Depth to groundwater one day
after drilling (ft.)
1 15.5 Backfilled
2 Not encountered 16.7
3 Not encountered 25.0
4 12.5 12.5
5 13.5 14.6
6 Not encountered 15.0
7 Not encountered 18.2
8 10.0 Backfilled
9 Not encountered Backfilled
10 11.7 Backfilled
11 12.0 Backfilled
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.
Zones of perched and/or trapped groundwater may also occur at times in the subsurface soils
overlying bedrock, on top of the bedrock surface or within permeable fractures in the bedrock
materials. The location and amount of perched water is dependent upon several factors,
including hydrologic conditions, type of site development, irrigation demands on or adjacent to
the site, fluctuations in water features, seasonal and weather conditions.
Groundwater level fluctuations occur due to seasonal variations in the 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 structures 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.
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 5
4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION
4.1 Geotechnical Considerations
Based on the results of our study, it is our opinion that the site is suitable for the proposed
construction from a geotechnical point of view provided certain precautions and design and
construction recommendations outlined in this report are followed. We have identified
geotechnical conditions that could impact design and construction of the proposed structures
and other site improvements.
4.1.1 Existing Fill
As previously noted, about 3½ to 9 feet of existing, undocumented fill was encountered in the
borings drilled at the site. Deeper fills may be present around basements and within buried utility
trenches for the existing buildings currently occupying the site. We do not possess any
information regarding whether the fill was placed under the observation of a geotechnical
engineer.
Support of foundations, floor slabs, and pavements on or above existing fill soils is discussed in
this report. However, even with the recommended construction testing services, there is an
inherent risk for the owner that compressible fill or unsuitable material within or buried by the fill
will not be discovered. This risk cannot be eliminated without completely removing the existing
fill, but can be minimized by thorough exploration, testing and remedial earthwork. If additional
exploration is not performed, the owner should make allowances for such conditions to exist in
the preparation of the project budget and/or construction plans.
Based upon the field penetration resistance values, in-situ dry densities, moisture contents, and
the laboratory swell/expansion test data, it is our opinion the existing fill can be used for support
of foundations, floor slabs-on-grade and pavements without the need for removal and/or
recompaction. However, the consistency and relative density of the existing fill must be verified
prior to foundation, slab-on-grade and pavement construction to assess that similar conditions
exist across the site with those encountered in the borings.
4.1.2 Structural Recommendations
Based on the geotechnical engineering analyses, subsurface exploration and laboratory test
results, the proposed student housing and clubhouse buildings may be supported on spread
footing foundations bearing upon undisturbed soils, suitable fill materials and/or newly placed
engineered fill. Drilled pier foundations bottomed in bedrock may also be considered as an
alternative foundation system for the student housing and/or clubhouse buildings if footing
foundations are not feasible due to heavy building loads. The proposed parking garage should
be supported on a drilled pier foundation system bottomed in bedrock.
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 6
Considering the low swelling soils encountered in our borings on this site, we believe a slab-on-
grade floor system can be used for the proposed buildings provided some movement can be
tolerated. If very little movement can be tolerated, structural floors, supported independent of
the subgrade materials, are recommended.
Design and construction recommendations for the foundation system and other earth connected
phases of the project are outlined in subsequent sections.
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 and testing of engineered fills, subgrade preparation, proof-rolling, and
other geotechnical conditions exposed during the construction of the project.
4.2.1 Site Preparation
Strip and remove existing concrete, asphalt, vegetation, unsuitable fills and other deleterious
materials from below proposed buildings, pavements, and areas planned to receive fill prior to
construction. All exposed surfaces should be free of mounds and depressions which could
prevent uniform compaction.
Stripped materials consisting of vegetation and organic materials should be wasted from the site
or used to revegetate landscaped areas or exposed slopes after completion of grading
operations.
All exposed areas which will receive fill, once properly cleared and benched, should be scarified
to a minimum depth of 10 inches, moisture conditioned to near optimum moisture content and
compacted.
Demolition of the existing buildings should include complete removal of the foundation systems
within the proposed construction area. This should include removal of any loose backfill found
adjacent to the existing foundations. All materials derived from the demolition of the existing
structure should be removed from the site and should not be allowed for use in any on-site fills.
Abandoned utilities associated with the structures should be completely removed or grouted in-
place. The types of foundation systems supporting the existing residences are not known. If
some or all of the buildings are supported by drilled piers, the existing piers should be truncated
a minimum depth of 3 feet below areas of planned new construction.
Although evidence of significant amounts of unsuitable fills or underground facilities such as
septic tanks, cesspools, basements and utilities was not observed during the site
reconnaissance, such features could be encountered during construction. If significant amounts
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 7
of unsuitable fills or underground facilities are encountered, such features should be removed
and the excavation thoroughly cleaned prior to backfill placement and/or construction.
The stability of the subgrade may be affected by precipitation, repetitive construction traffic or
other factors. If unstable conditions are encountered or develop during construction, workability
may be improved by scarifying and drying; however, allowing the clays to dry below the
optimum moisture content is not recommended. If such conditions occur, the affected area
should be overexcavated and replaced with granular materials and/or non- to low expansive
materials. As an alternative, chemical treatment such as lime, fly ash, kiln dust, cement or
geotextiles could also be considered as a stabilization technique. Laboratory evaluation is
recommended to determine the effect of chemical stabilization on subgrade soils prior to
construction. Lightweight excavation equipment may be required to reduce subgrade pumping.
4.2.2 Import Material Specifications
Clean on-site soils or approved imported materials may be used as fill material. 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
Liquid Limit……………………………………………………30 (max)
Plastic Limit…………………………………………………..15 (max)
Maximum Expansive Potential (%)………………………..non-expansive*
*Measured on a sample compacted to approximately 95 percent of the ASTM D698 maximum dry density at
optimum water content. The sample is confined under a 100 psf surcharge and submerged.
4.2.3 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 8 to 10-inches or less in loose thickness
Compaction requirements (clay)
95 percent of the maximum dry unit weight as determined by
ASTM D 698
Moisture content cohesive soil
(clay)
-2 to +2 % of the optimum moisture content
-1 to +2% of the optimum moisture content in pavement
areas
Moisture content cohesionless soil
(sand)
-3 to +3 % of the optimum moisture content
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
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Item Description
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 proof-rolled.
4.2.4 Excavation and Trench Construction
Excavations into the on-site soils may encounter caving soils and possibly groundwater,
depending upon the final depth of excavation. We believe excavations into on-site soils can
generally be performed using conventional excavation equipment. Excavations into the clays
above groundwater levels below the site can be expected to stand on relatively steep temporary
slopes during construction. However, excavations into clays and sands below the water table
will likely require sloping or shoring of the excavation sides and temporary construction
dewatering. 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.
Soils penetrated by the proposed excavations may vary significantly across the site. The soil
classifications are based solely on the materials encountered in the 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.
As a safety measure, it is recommended that all vehicles and soil piles be kept to a minimum
lateral distance from the crest of the slope equal to no less than the slope height. The exposed
slope face should be protected against the elements.
Depending upon depth of excavation and seasonal conditions, groundwater may be
encountered in excavations on the site. Pumping from sumps and/or sloping of excavations to
collection areas may be utilized to control water within excavations.
4.2.5 Utility Trench Backfill
All trench excavations should be made with sufficient working space to permit construction
including backfill placement and compaction.
All underground piping within or near the proposed structures should be designed with flexible
couplings, so minor deviations in alignment do not result in breakage or distress. Utility
knockouts in foundation walls should be oversized to accommodate differential movements. It is
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 9
imperative that utility trenches be backfilled with relatively clean materials and is properly
backfilled. If utility trenches are backfilled with relatively clean granular material, they should be
capped with at least 18 inches of cohesive fill in non-pavement areas to reduce the infiltration
and conveyance of surface water through the trench backfill.
Utility trenches are a common source of water infiltration and migration. All utility trenches that
penetrate beneath the buildings should be effectively sealed to restrict water intrusion and flow
through the trenches that could migrate below the buildings. We recommend constructing an
effective clay “trench plug” that extends at least 5 feet out from the face of the building exterior.
The plug material should consist of clay compacted at a water content at or above the soils
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 the geotechnical engineer provide full-time
observation and compaction testing of trench backfill within building and pavement areas.
4.2.6 Grading and Drainage
All grades must be adjusted to provide positive drainage away from the buildings during
construction and maintained throughout the life of the proposed project. Infiltration of water into
utility or foundation excavations must be prevented during construction. Landscaped irrigation
adjacent to foundations should be minimized or eliminated. Water permitted to pond near or
adjacent to the perimeter of structures (either during or post-construction) can result in greater
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 should be sloped at a minimum of 10 percent grade for at least 10 feet beyond
the perimeter of the buildings, 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 buildings.
Backfill against exterior walls and in utility and sprinkler line trenches should be well compacted
and free of all construction debris to reduce the possibility of moisture infiltration. After building
construction and prior to project completion, we recommend verification of final grading be
performed to document positive drainage, as described above, has been achieved.
Flatwork and pavements will be subject to post construction movement. Maximum grades
practical should be used for paving and flatwork to prevent areas where water can pond. In
addition, allowances in final grades should take into consideration post-construction movement
of flatwork, particularly if such movement would be critical. Where paving or flatwork abuts the
structures, care should be taken that joints are properly sealed and maintained to prevent the
infiltration of surface water.
Planters located adjacent to structures should preferably be self-contained. Sprinkler mains and
spray heads should be located a minimum of 5 feet away from the building lines. Drip irrigation
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 10
may be considered in these areas. Roof drains should discharge on pavements or be extended
away from the structures a minimum of 10 feet through the use of splash blocks or downspout
extensions. A preferred alternative is to have the roof drains discharge to storm sewers by solid
pipe or daylighted to a detention pond or other appropriate outfall.
4.2.7 Construction Considerations
Upon completion of grading operations, care should be taken to maintain the moisture content
of the subgrade prior to construction of pavements and exterior concrete flatwork. Construction
traffic over prepared subgrade should be minimized and avoided to the extent practical.
The site should also be graded to prevent ponding of surface water on the prepared subgrades
or in excavations. In areas where water is allowed to pond over a period of time, the affected
area should be removed and allowed to dry out; however, allowing the clays to dry out below
the optimum moisture content is not recommended. If such conditions occur, the affected area
should be over-excavated and replaced with granular materials and/or non- to low expansive
materials. As an alternative, chemical treatment such as lime, fly ash, kiln dust, cement or
geotextiles could also be considered as a stabilization technique.
Terracon should be retained during the construction phase of the project to observe earthwork
and to perform necessary tests and observations during site grading operations, excavations,
subgrade preparation, proof-rolling, placement and compaction of controlled compacted fills,
backfilling of excavations into the completed subgrade, and pavement construction.
4.2.8 Corrosion Protection
Results of water-soluble sulfate testing performed on the existing soils indicated negligible
values of 20 mg/l or less. Results of soluble sulfate testing indicate that ASTM Type I Portland
cement is suitable for all project concrete on and below grade. However, if there is no (or
minimal) cost differential, use of ASTM Type II Portland cement is recommended for additional
sulfate resistance of construction concrete. Foundation concrete should be designed in
accordance with the provisions of Section 318, Chapter 4, of the ACI Design Manual.
4.3 Foundations
Several foundation alternatives were considered for the proposed buildings at this site. Based
on the geotechnical engineering analyses, subsurface exploration and laboratory test results,
the proposed student housing and clubhouse buildings may be supported on spread footing
foundations bearing upon undisturbed soils, suitable fill materials and/or newly placed
engineered fill. Drilled pier foundations bottomed in bedrock may also be considered as an
alternative foundation system for the student housing and/or clubhouse buildings if footing
foundations are not feasible due to heavy building loads. The proposed parking garage should
be supported on a drilled pier foundation system bottomed in bedrock. Design
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
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recommendations for spread footings and drilled piers bottomed in bedrock are presented in the
following paragraphs.
4.3.1 Design Recommendations – Spread Footings
Description Value
Maximum allowable soil bearing pressure 1 2,500 psf
Minimum dimensions
Column Wall Footing
24 inches 16 inches
Minimum embedment below finished grade for
frost protection 2
30 inches 30 inches
Estimated post-construction movement 3 about 1 inch about 1 inch
1. The net allowable soil bearing pressure applies to dead loads plus design live load conditions and
is the maximum pressure that should be transmitted to the bearing soils in excess of the minimum
surrounding overburden pressure at the footing base elevation. Assumes footing subgrade will be
judged stable and if unstable conditions are encountered, subgrade will be stabilized prior to
foundation construction.
2. For perimeter footings and footings beneath unheated areas. Interior column pads in heated areas
should bear at least 12 inches below the adjacent grade (or the top of the floor slab) for
confinement of the bearing materials and to develop the recommended bearing pressure.
3. Additional foundation movements could occur if surface water infiltrates the foundation soils;
therefore, proper drainage away from the foundation system should be provided in the final design,
during construction and maintained throughout the life of the structure.
Footings should be proportioned to reduce differential foundation movement. Proportioning on
the basis of relative constant dead-load pressure can provide a means to reduce differential
movement between adjacent footings.
Footings and foundation walls should be reinforced as necessary to reduce the potential for
distress caused by differential foundation movement.
4.3.2 Construction Considerations – Spread Footings
Subgrade soils beneath footings should be moisture conditioned and compacted. The moisture
content and compaction of subgrade soils should be maintained until foundation construction.
Where soils are loosened during excavation or in the forming process for the footings, or if
soft/low strength or otherwise unsuitable soils are present at foundation bearing depth, they
should be removed and replaced with engineered fill or re-compacted to at least 95 percent of
the maximum dry unit weight as determined by ASTM D698 within 2 percent of optimum
moisture content.
Completed foundation excavations should be observed by a representative of Terracon well in
advance of forming footings to confirm satisfactory bearing materials are present and
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 12
subsurface conditions are consistent with those encountered in our borings. If the soil conditions
encountered differ significantly from those presented in this report, supplemental
recommendations will be required.
4.3.3 Design Recommendations – Drilled Piers
Drilled pier and grade beam foundation systems are considered a suitable deep foundation
system for support of the proposed student housing and/or clubhouse buildings. We recommend
constructing the proposed parking garage on a drilled pier foundation system bottomed in
bedrock.
Description Value
Minimum pier length 25 feet
Minimum pier diameter 18 inches
Minimum bedrock embedment 1 8 feet
Maximum end-bearing pressure 30,000 psf
Skin friction (for portion of pier embedded in bedrock) 2,500 psf
Void Thickness (beneath grade beams, between piers) 4 inches
1. Drilled piers should be embedded into firm or harder bedrock materials.
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 L-pile, piers may be designed for the following
lateral load criteria:
Parameter Clay Sand Bedrock
Unit weight (pci) 0.0694 0.0723 0.0752
Average undrained shear strength (psf) 2,500 N/A 8,000
Average angle of internal friction,
(degrees) N/A 30 N/A
Coefficient of subgrade reaction, k (pci)* 100- static
40 - cyclic
90 (above water)
60 (submerged)
2,000- static
800 – cyclic
Strain, 50 (%) 0.007 N/A 0.004
4.3.4 Construction Considerations – Drilled Piers
Drilling to design depth should be possible with conventional single-flight power augers. However,
very moist to wet clays and sands encountered in our borings on the site will require temporary
steel casing to properly drill the piers prior to concrete placement.
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 13
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. 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 the
geotechnical engineer should observe the bearing surface and shaft configuration of every
drilled pier.
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.
Pier-bearing surfaces must be cleaned prior to concrete placement. A representative of
Terracon should observe the bearing surface and pier configuration.
4.4 Seismic Considerations
Code Used Site Classification
2009 International Building Code (IBC) 1 C 2
1. In general accordance with the 2009 International Building Code, Table 1613.5.2.
2. The 2009 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 performed at this site extended to a
maximum depth of about 45 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
higher seismic site class; however, we believe this is unlikely.
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 14
4.5 Interior Floor Systems
Considering the low swelling soils encountered in our borings on this site, we believe a slab-on-
grade floor system can be used for the proposed buildings provided some movement can be
tolerated. If very little movement can be tolerated, structural floors, supported independent of
the subgrade materials, are recommended.
Subgrade soils beneath interior and exterior slabs and beneath pavements should be scarified,
moisture conditioned and compacted to a minimum depth of 8 inches. The moisture content and
compaction of subgrade soils should be maintained until slab or pavement construction.
4.5.1 Design Recommendations – Slabs-on-Grade
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 or less 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 outlined in the 4.2 Earthwork section of this report.
For structural design of concrete slabs-on-grade, a modulus of subgrade reaction of 100 pounds
per cubic inch (pci) may be used for floors supported on existing or compacted soils at the site.
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 provided in slabs to control the location and extent of cracking.
A minimum 2-inch void space should be constructed above or below non-bearing
partition walls (if any) 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.
Interior trench backfill placed beneath slabs should be compacted in accordance with
recommended specifications outlined below.
The use of a vapor retarder should be considered beneath concrete slabs on grade that
will be covered with wood, tile, carpet or other moisture sensitive or impervious
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.
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 15
Floor slabs should not be constructed on frozen subgrade.
Other design and construction considerations, as outlined in Section 302.1R of the ACI
Design Manual, are recommended.
4.5.1 Construction Considerations – Slabs-on-Grade
Movements of slab-on-grades using the above outlined alternatives will likely be reduced and
tend to be more uniform. The estimates outlined 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 outlined in the 4.2.6 Grading and
Drainage section of this report be followed.
4.6 Below-grade Construction
We understand the proposed student housing and clubhouse buildings will not have basements.
The proposed parking garage may extend ½ to 1 level below grade which may results in about
10 feet of the parking garage constructed below grade. Groundwater was encountered at
depths of about 10 to 25 feet below existing site grade in the test borings at the time of field
exploration. Terracon recommends providing at least 3 feet of separation between the bottom
of the parking garage lower level and measured groundwater levels. If the project team desires
to extend the parking garage closer to groundwater below this site, a permanent dewatering
system will be necessary. Terracon should be contacted if more detailed plans for the parking
garage result in below-grade construction encroaching on groundwater below this site.
To help control the water level behind below-grade walls for the proposed parking garage,
installation of a perimeter drainage system is recommended. The drainage system should be
constructed around the exterior perimeter of the parking garage foundation and sloped at a
minimum 1/8 inch per foot to a suitable outlet(s), such as a sump(s) and pump system(s).
Considering the large footprint anticipated for the proposed parking garage, lateral drains and
multiple collection systems may be necessary.
The drainage system should consist of a minimum 4-inch diameter perforated or slotted pipe,
embedded in free-draining gravel, placed in a trench at least 12 inches in width. The edge of
the trench should be sloped at a 1:1 slope beginning at the bottom outside edge of the grade
beams between drilled piers. The trench should not be cut vertically at the edge of the
foundation to avoid undermining the parking garage floor slab.
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 16
The drainage system should consist of a properly sized, perforated pipe that is embedded in
free-draining gravel and placed in a trench at least 12 inches in width. Gravel should extend a
minimum of 3 inches beneath the bottom of the pipe and at least 2 feet above the bottom of the
foundation wall. The system should be underlain with a polyethylene moisture barrier that is
sealed to the foundation walls and extended to at least the edge of the backfill zone. The gravel
should be covered with drainage fabric prior to placement of foundation backfill.
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 and/or compaction and the strength of the materials being restrained. Two wall
restraint conditions are shown. 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)
At-Rest (Ko)
Granular - 0.50
Lean Clay - 0.64
60
75
(0.50)S
(0.64)S
(60)H
(75)H
Passive (Kp)
Granular - 3.0
Lean Clay - 2.1
360
250
---
---
---
---
Foundation Wall
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 17
Applicable conditions to the above include:
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 to at least 95 percent of maximum dry unit weight as
determined by ASTM D 698
Loading from heavy compaction equipment not included
No hydrostatic pressures acting on wall
No dynamic loading
No safety factor included in soil parameters
Ignore passive pressure in frost zone
4.8 Pavement Design and Construction
Design of privately maintained pavements for the project has been based on the procedures
outlined by the Asphalt Institute (AI) and the American Concrete Institute (ACI). If improvements
to public roadways are anticipated, a pavement design report meeting the City of Fort Collins
specifications (Larimer County Urban Area Street Standards) will need to be prepared for
submittal, subsequent to final grading.
We assumed the following design parameters for Asphalt Institute flexible pavement thickness
design:
Automobile Parking Areas
Parking stalls and parking lots for cars and pick-up trucks, up to 200 stalls
Main Traffic Corridors
Parking lots with a maximum of 25 trucks per day
Subgrade Soil Characteristics
USCS Classification – CL (Poor Subgrade)
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-1: Automobile parking with an ADTT of 1 over 20 years
Main Traffic Corridors
ACI Category B: Commercial entrance and service lanes with an ADTT of
25 over 20 years
Subgrade Soil Characteristics
USCS Classification – CL
Concrete modulus of rupture value of 600 psi
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 18
Traffic patterns and anticipated loading conditions for the site pavements were not available at
the time of this study. We should be contacted to confirm and/or modify the recommendations
contained herein if actual traffic volumes differ from the assumed values shown above.
In our opinion, a full depth asphalt concrete section over a prepared clay subgrade should not
be used on this site. Recommended alternatives for flexible and rigid pavements are
summarized for each traffic area as follows:
Traffic Area
Alternative
Recommended Pavement Thickness (Inches)
Asphalt
Concrete
Surface
Aggregate
Base
Course
Portland
Cement
Concrete
Total
Automobile Parking
(AI Class I and ACI Category A)
A 4 6 10
B 6 6
Main Traffic Corridors
(AI Class III and ACI Category B)
A 5 6 11
B 6 6
The placement of a partial pavement thickness for use during construction is not suggested
without a detailed pavement analysis incorporating construction traffic. In addition, we should
be contacted to confirm the traffic assumptions outlined above. If the actual traffic varies from
the assumptions outlined above, modification of the pavement section thickness will be
required.
For areas subject to concentrated and repetitive loading conditions 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 7 inches underlain by at least 4 inches of
crushed stone. Prior to placement of the crushed stone, the areas should be thoroughly proof-
rolled. For dumpster pads, the concrete pavement area should be large enough to support the
container and tipping axle of the refuse truck.
For analysis of pavement costs, the following specifications should be considered for each
pavement component:
Colorado Department of
Pavement Component Transportation Criteria
Asphalt Concrete Surface ......................................................................... Grading S or SX
Aggregate Base Course ................................................................................... Class 5 or 6
Portland Cement Concrete ...................................................................................... Class P
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 19
4.8.1 Drainage Adjacent to Pavements
The clay soils will likely lose stability with increases in moisture content. Therefore, to reduce
pavement distress due to wetting of the subgrade in areas of water intensive landscaping or
other nearby water sources (or if aggregate base course is used) located adjacent to
pavements, we recommend shoulder drains be considered. The drain system should consist of
a properly sized pipe embedded in free-draining material directed to a suitable outfall such as
an underdrain or storm sewer.
4.8.2 Compliance
Recommendations for pavement design and construction presented depend upon compliance
with recommended material specifications. To assess compliance, observation and testing
should be performed under the observation of the geotechnical engineer.
4.8.3 Pavement Performance
The performance of all pavements can be enhanced by minimizing excess moisture which can
reach the subgrade soils. Future performance of pavements at this site will be dependent upon
several factors, including:
Maintaining stable moisture content of the subgrade soils both before and after
pavement construction; and
Providing for a planned program of preventative maintenance.
Since the clay soils on the site have shrink/swell characteristics, pavements could crack in the
future primarily because of expansion of the soils and bedrock when subjected to an increase in
moisture content to the subgrade. The cracking, while not desirable, does not necessarily
constitute structural failure of the pavement, provided that timely maintenance, such as crack
sealing is performed. Excessive movement and cracking could result if the subgrade soils are
allowed to dry out before paving and subsequently become rewetted.
The performance of all pavements can be enhanced by minimizing excess moisture, which can
reach the subgrade soils. The following recommendations should be considered at minimum:
Site grading at a minimum 2 percent grade onto or away from the pavements;
Water should not be allowed to pond behind curbs;
Compaction of any utility trenches for landscaped areas to the same criteria as the
pavement subgrade;
Sealing all landscaped areas in or adjacent to pavements to minimize or prevent
moisture migration to subgrade soils;
Placing compacted backfill against the exterior side of curb and gutter; and
Placing shoulder or edge drains in pavement areas adjacent to water sources.
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 20
Preventative maintenance should be planned and provided for an ongoing pavement
management program in order to enhance future pavement performance. Preventative
maintenance activities are intended to slow the rate of pavement deterioration and to preserve
the pavement investment.
Preventative maintenance consists of both localized maintenance (e.g. crack sealing and
patching) and global maintenance (e.g. surface sealing). Preventative maintenance is usually
the first priority when implementing a planned pavement maintenance program and provides the
highest return on investment for pavements.
4.8.4 Construction Considerations
Site grading is generally accomplished early in the construction phase. However, as
construction proceeds, the subgrade may be disturbed due to utility excavations, construction
traffic, desiccation, or rainfall. As a result, the pavement subgrade may not be suitable for
pavement construction and corrective action will be required. The subgrade should be carefully
evaluated at the time of pavement construction for signs of disturbance or excessive rutting. If
disturbance has occurred, pavement subgrade areas should be reworked, moisture conditioned,
and properly compacted to the recommendations in this report immediately prior to paving.
We recommend the pavement areas be rough graded and then thoroughly proof-rolled with a
loaded tandem axle dump truck prior to final grading and paving. Particular attention should be
paid to high traffic areas that were rutted and disturbed earlier and to areas where backfilled
trenches are located. Areas where unsuitable conditions are located should be repaired by
removing and replacing the materials with properly compacted fills. All pavement areas should
be moisture conditioned and properly compacted to the recommendations in this report
immediately prior to paving.
The placement of a partial pavement thickness for use during construction is not recommended
without a detailed pavement analysis incorporating construction traffic. In addition, if the actual
traffic varies from the assumptions outlined above, we should be contacted to confirm and/or
modify the pavement thickness recommendations outlined above.
.
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 should also be retained to provide testing and
observation during site grading, excavation, fill placement, as well as foundation and
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
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Responsive ■ Resourceful ■ Reliable 21
this report. This report does not reflect variations that may occur between borings, across the
site, or due to the modifying effects of 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, 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 are planned in the nature, design, or location of the project as outlined in
this report, 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
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Exhibit A-1
Field Exploration Description
The location of borings was based upon the proposed development shown on the provided site
plan. The borings were located in the field by Terracon personnel measuring from property
lines and existing site features. Test boring surface elevations were within approximately 2 feet
of adjacent street grades.
Boring Nos. 1 through 7 were drilled on August 8, 2008 with a CME-55 truck-mounted drill rig
with solid-stem augers. Boring Nos. 8 and 11 were drilled on September 22, 2011 with a limited
access mini rig with solid-stem augers. Boring Nos. 9 and 10 were drilled on September 28,
2011 with a CME-55 truck-mounted drill rig with solid-stem augers. During the drilling
operations, lithologic logs of the borings were recorded by the field engineer. Relatively
undisturbed samples were obtained at selected intervals utilizing a 2-inch outside diameter split-
spoon sampler (RS) and a 3-inch outside diameter ring-barrel sampler (RS). 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 and can be correlated to the 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 Boring Nos. 1 through 7,
9 and 10 performed on this site. A manual safety hammer was used to advance the samplers in
Boring No. 8 and 11. 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 soils moisture content. 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
several days 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’ 50’ 100’
LEGEND
APPROXIMATE SCALE
Scale:
301 North Howes Street Fort Collins, Colorado 80521
PH. (970) 484-0359 FAX. (970) 484-0454
EDB
EDB
EDB
DJJ
Project Manager:
Drawn by:
Checked by:
Approved by:
BORING LOCATION DIAGRAM
THE DISTRICT AT CSU
West Plum Street and City Park Avenue
Fort Collins, Colorado
A-2
20115026 Exhibit
10/28/2011
1=100’
Project No.
File Name:
Date:
DIAGRAM IS FOR GENERAL LOCATION ONLY, AND
IS NOT INTENDED FOR CONSTRUCTION PURPOSES
1
Approximate Boring Location for Previous Study
(Terracon Project No. 20085059; report dated 8/21/08)
8 Approximate Boring Location for Current Study
(Terracon Project No. 20115026)
8
9
10
11
7
6
5
4
2 3
1
RS
111
SS
116
RS
RS
RS
SS
RS
50/0.5
11
12
12
12
12
12
12
115
50/0.3
112
50
45
14
15
14
CL
CL
CL 12
2.3%
500psf
30
15
0.5
BOTTOM OF BORING
7
6
5
4
3
2
1
CLAYSTONE
Firm to hard, brown, gray
SANDY LEAN CLAY
Stiff to very stiff, reddish brown
TOPSOIL
12
The stratification lines represent the approximate boundary lines
Proposed Student Housing Project
CME55
8-8-08
18
BOREHOLE_99 20085059.GPJ BORING.GDT 8/22/08
15.5
% SWELL
SURCHARGE
JOB #
CLIENT
9
PROJECT
CL
127
124
118
102
25
RS
RS
RS
RS 9
RIG FOREMAN PG
BORING STARTED
11
CL 12
18
4
12
12
12
50/0.4
3 30 13
20
0.2%
500psf
17
13
0.5
SANDY LEAN CLAY
Stiff to very stiff, reddish brown
WATER LEVEL OBSERVATIONS, ft
2
1
BOTTOM OF BORING
CLAYEY SAND
Medium dense, brown
4
TOPSOIL
CLAYSTONE
Hard, brown, gray
JOB #
UNCONFINED
STRENGTH, psf
The stratification lines represent the approximate boundary lines
Proposed Student Housing Project
CME55
8-8-08
PROJECT
16.7
5
10
15
20
BLOWS / ft.
WATER
CONTENT, %
USCS SYMBOL
SAMPLES
BOREHOLE_99 20085059.GPJ BORING.GDT 8/22/08
% SWELL
SURCHARGE
SS
SS
RS
SS
RS
RS 11
6
5
4
3
2 16
12
12
12
12
50/0.9
50
24
21
SM
CL
CL
130
118
111
50/0.5
30
1
1.9%
500psf
16.5
13
5
0.5
12
BOTTOM OF BORING
CLAYSTONE
Firm to hard, brown, gray
SILTY SAND WITH GRAVEL
Medium dense, brown
SANDY LEAN CLAY
Stiff, reddish brown
FILL, SANDY LEAN CLAY
Very stiff, brown
TOPSOIL
The stratification lines represent the approximate boundary lines
Proposed Student Housing Project
CME55
8-8-08
UNCONFINED
STRENGTH, psf
Dry
% SWELL
SURCHARGE
JOB #
CLIENT
12
13
PROJECT
5
14
CL
CL
117
25 113
108
RS 50/0.5
RS
RS
RS
114
15
12.5
RIG FOREMAN
23
BORING STARTED
17
17
14
6
12
12
12
PG
0.5%
500psf
0.7%
500psf
20
13
0.5
CLAYSTONE
Weathered to hard, brown, gray
TESTS
4
3
2
1
BOTTOM OF BORING
SANDY LEAN CLAY
Stiff to very stiff, brown
GRAVEL PAVING
CME55
BOREHOLE_99 20085059.GPJ BORING.GDT 8/22/08
UNCONFINED
STRENGTH, psf
The stratification lines represent the approximate boundary lines
8-8-08
TYPE
8-8-08
PROJECT
WATER LEVEL OBSERVATIONS, ft
Proposed Student Housing Project
5
10
15
20
BLOWS / ft.
WATER
CONTENT, %
SS
CL
CL
120
119
21
SS
RS
RS 11
RIG FOREMAN PG
BORING STARTED
13
SM
13
33
6
12
12
12
50/0.5
28
2
13
20 4
0.4%
500psf
18
13
0.5 TOPSOIL
WATER LEVEL OBSERVATIONS, ft
1
BOTTOM OF BORING
CLAYSTONE
Hard, brown, gray
SANDY LEAN CLAY
Very stiff, reddish brown, calcareous
3
SILTY SAND WITH GRAVEL
Medium dense, brown, fine to medium
grained
JOB #
UNCONFINED
STRENGTH, psf
The stratification lines represent the approximate boundary lines
Proposed Student Housing Project
CME55
8-8-08
PROJECT
14.6
5
10
15
20
BLOWS / ft.
WATER
CONTENT, %
USCS SYMBOL
SAMPLES
BOREHOLE_99 20085059.GPJ BORING.GDT 8/22/08
% SWELL
CL
123
127
113
103
SC
18
RS
RS
RS
RS
WATER LEVEL OBSERVATIONS, ft
9
FOREMAN PG
BORING STARTED
13
SC 7
4 6
12
12
12
50/0.5
42
54
9
20
0.2%
500psf
17
9
0.5
FILL, SANDY LEAN CLAY WITH GRAVEL
Stiff, reddish brown
3
2
1
BOTTOM OF BORING
CLAYEY SAND WITH GRAVEL
Medium dense, brown, fine to medium
grained
GRAVEL PAVING
CLAYSTONE
Hard, brown, gray
JOB #
UNCONFINED
STRENGTH, psf
The stratification lines represent the approximate boundary lines
Proposed Student Housing Project
CME55
8-8-08
PROJECT
RIG
15.0
5
10
15
20
BLOWS / ft.
WATER
CONTENT, %
SC
SC
122
124
110
33
25
RS
RS
SS
RS
RS 9
FOREMAN PG
BORING STARTED
11
12
11
11
6
12
12
12
12
50/0.5
41
16
30
14
0.5
0.1%
500psf
BOTTOM OF BORING
5
4
3
2
1
CLAYSTONE
Firm to hard, brown, gray
CLAYEY SAND
Loose to medium dense, brown, fine to
medium grained, trace gravel
GRAVEL PAVING
WATER LEVEL OBSERVATIONS, ft
UNCONFINED
STRENGTH, psf
The stratification lines represent the approximate boundary lines
Proposed Student Housing Project
CME55
8-8-08
PROJECT
Dry
RIG
% SWELL
SURCHARGE
5
10
15
20
25
0.5
3.5
17.5
18.5
29.5
TOPSOIL - 6 inches
FILL
lean clay with sand, stiff, moist, reddish
brown
SANDY LEAN CLAY
medium stiff to very stiff, slightly moist,
reddish brown
very moist at 8.5 feet
SILTY SAND with GRAVEL
dense, wet, brown, reddish brown
CLAYSTONE BEDROCK
hard to very hard, slightly moist, olive,
brown, gray
BOTTOM OF BORING
-200 = 73
LL = 50
PI = 21
-200 = 55
1
2
3
4
5
6
RS
RS
RS
RS
RS
SS
CL
CL
17
26
8
17
50/6
50/6
15
9
19
21
15
18
92
114
108
107
BORING STARTED 9-22-11
10 WD AD
SITE
CLIENT
WL
WL
APPROVED
0.5
13
14.5
29.4
TOPSOIL - 6 inches
SANDY LEAN CLAY
medium stiff to stiff, moist, brown, dark
brown
varying amounts of gravel
SILTY SAND with GRAVEL
dense, wet, brown, reddish brown
CLAYSTONE BEDROCK
weathered to very hard, slightly moist, light
brown, brown
BOTTOM OF BORING
-200 = 61
LL = 36
PI = 18
1
2
3
4
5
6
7
RS
RS
RS
RS
RS
RS
SS
CL 15
8
25
30
45
50/3
50/5
11
9
15
18
13
9
10
105
107
119
112
122
BORING STARTED 9-28-11
None WD AD
SITE
CLIENT
WL
WL
APPROVED
The stratification lines represent the approximate boundary lines
Page 1 of 1
0.5
14
44.1
TOPSOIL - 6 inches
SANDY LEAN CLAY
stiff to very stiff, moist, brown, dark brown
CLAYSTONE BEDROCK
medium hard to very hard, moist, black,
gray
Auger refusal at 45 feet.
BOTTOM OF BORING
-200 = 59
-200 = 99
LL = 54
PI = 34
1
2
3
4
5
6
7
8
9
10
RS
RS
RS
RS
RS
RS
SS
SS
SS
SS
CL
CH
34
30
12
11
48
88
87
50/6
50/5
50/1
11
8
14
17
17
14
15
13
14
13
105
108
116
0.2
12
13
24.8
TOPSOIL - 3 inches
SANDY LEAN CLAY
very stiff to hard, slightly moist, dark brown,
reddish brown
Gravel interlayered with clayey sand
SILTY SAND with GRAVEL
dense, wet, brown, reddish brown
CLAYSTONE BEDROCK
hard to very hard, brown, olive, rust
BOTTOM OF BORING
1
2
3
4
5
6
RS
RS
RS
RS
SS
SS
26
50
43
19
85/15
50/9
13
14
13
21
19
20
97
111
116
106
BORING STARTED 9-22-11
12 WD AD
SITE
CLIENT
WL
WL
APPROVED
The stratification lines represent the approximate boundary lines
Page 1 of 1
UNCONFINED
STRENGTH, psf
TESTS
9-22-11
DESCRIPTION
Exhibit A-13
WATER LEVEL OBSERVATIONS, ft
Ft. Collins Student Housing, LLC
20115026
APPENDIX B
LABORATORY TESTING
Geotechnical Engineering Report
The District at CSU ■ Fort Collins, Colorado
November 2, 2011 ■ Terracon Project No. 20115026
Exhibit B-1
Laboratory Testing
Samples retrieved during the field exploration were returned to the laboratory for observation by
the project geotechnical engineer, and were classified in general accordance with the Unified
Soil Classification System described in Appendix C. Samples of bedrock were classified in
accordance with the general notes for Rock Classification.
At this time, an applicable laboratory-testing program was formulated to determine engineering
properties of the subsurface materials. Following the completion of the laboratory testing, the
field descriptions were confirmed or modified as necessary, and Logs of Borings were prepared.
These logs are presented in Appendix A.
Laboratory test results for our previous study conducted at this site as well as for the current
study are presented in Appendix B. These results were used for the geotechnical engineering
analyses and the development of foundation and earthwork recommendations. All laboratory
tests were performed in general accordance with the applicable local or other accepted
standards.
Selected soil and bedrock samples were tested for the following engineering properties:
Water content
Dry density
Expansion/Consolidation
Grain-size distribution
Atterberg limits
Water-soluble sulfate content
2
4
5
7
SANDY LEAN CLAY(CL)
LEAN CLAY with SAND(CL)
SANDY LEAN CLAY(CL)
68
70
68
46 CLAYEY SAND(SC)
100
50
40
30
20
10
0 20 40 80
60
0
60
9.0ft 17
15
15
16
22
18
15
11
LL PL
Job #: 20085059
Site: West of Int. of Plum St. and S. Shields Fort Collins, Colorado
Project: Proposed Student Housing Project
%Fines Classification
ATTERBERG LIMITS RESULTS
4.0ft
4.0ft
4.0ft 33
27
Specimen Identification
CL
PI
MH
TC_ATTERBERG_LIMITS 20085059.GPJ BORING.GDT 8/22/08
39
LIQUID LIMIT
CL-ML ML
30
CH
P
L
A
S
T
I
C
I
T
Y
I
0
10
20
30
40
50
60
0 20 40 60 80 100
Specimen Identification
ML
CL
MH
CH
CL-ML
P
L
A
S
T
I
C
I
T
Y
I
N
D
E
X
2.0ft
2.0ft
19.0ft
LIQUID LIMIT
8
9
10
50
36
54
29
18
20
21
18
34
LL PL %Fines
ATTERBERG LIMITS RESULTS
SANDY CLAY FILL WITH GRAVEL (CL)
SANDY LEAN CLAY(CL)
CLAYSTONE BEDROCK
73
61
99
PI Classification
Project: The District at CSU
Proj. No. 20115026
Site: West Plum Street and City Park Avenue, Fort Collins, Colorado
TC_ATTERBERG_LIMITS 20115026.GPJ DENVER 031610.GDT 11/1/11
-2
100 1,000
Notes:
1 5.0ft SANDY LEAN CLAY 111 11
4
0
-4
-6
-8
-10
2
TC_CONSOL_STRAIN 20085059.GPJ BORING.GDT 8/22/08
SWELL CONSOLIDATION TEST
PRESSURE, psf
AXIAL STRAIN, %
Project: Proposed Student Housing Project
Site: West of Int. of Plum St. and S. Shields Fort Collins, Colorado
10,000
Specimen Identification Classification , pcf WC,%
Job #: 20085059
-2
100 1,000
Notes:
2 4.0ft SANDY LEAN CLAY 102 9
4
0
-4
-6
-8
-10
2
TC_CONSOL_STRAIN 20085059.GPJ BORING.GDT 8/22/08
SWELL CONSOLIDATION TEST
PRESSURE, psf
AXIAL STRAIN, %
Project: Proposed Student Housing Project
Site: West of Int. of Plum St. and S. Shields Fort Collins, Colorado
10,000
Specimen Identification Classification , pcf WC,%
Job #: 20085059
-2
100 1,000
Notes:
3 9.0ft SANDY LEAN CLAY 118 13
4
0
-4
-6
-8
-10
2
TC_CONSOL_STRAIN 20085059.GPJ BORING.GDT 8/22/08
SWELL CONSOLIDATION TEST
PRESSURE, psf
AXIAL STRAIN, %
Project: Proposed Student Housing Project
Site: West of Int. of Plum St. and S. Shields Fort Collins, Colorado
10,000
Specimen Identification Classification , pcf WC,%
Job #: 20085059
-2
100 1,000
Notes:
4 4.0ft LEAN CLAY with SAND(CL) 108 14
4
0
-4
-6
-8
-10
2
TC_CONSOL_STRAIN 20085059.GPJ BORING.GDT 8/22/08
SWELL CONSOLIDATION TEST
PRESSURE, psf
AXIAL STRAIN, %
Project: Proposed Student Housing Project
Site: West of Int. of Plum St. and S. Shields Fort Collins, Colorado
10,000
Specimen Identification Classification , pcf WC,%
Job #: 20085059
-2
100 1,000
Notes:
4 9.0ft SANDY LEAN CLAY 114 17
4
0
-4
-6
-8
-10
2
TC_CONSOL_STRAIN 20085059.GPJ BORING.GDT 8/22/08
SWELL CONSOLIDATION TEST
PRESSURE, psf
AXIAL STRAIN, %
Project: Proposed Student Housing Project
Site: West of Int. of Plum St. and S. Shields Fort Collins, Colorado
10,000
Specimen Identification Classification , pcf WC,%
Job #: 20085059
-2
100 1,000
Notes:
5 4.0ft SANDY LEAN CLAY(CL) 119 11
4
0
-4
-6
-8
-10
2
TC_CONSOL_STRAIN 20085059.GPJ BORING.GDT 8/22/08
SWELL CONSOLIDATION TEST
PRESSURE, psf
AXIAL STRAIN, %
Project: Proposed Student Housing Project
Site: West of Int. of Plum St. and S. Shields Fort Collins, Colorado
10,000
Specimen Identification Classification , pcf WC,%
Job #: 20085059
-2
100 1,000
Notes:
6 4.0ft SANDY LEAN CLAY WITH GRAVEL 103 9
4
0
-4
-6
-8
-10
2
TC_CONSOL_STRAIN 20085059.GPJ BORING.GDT 8/22/08
SWELL CONSOLIDATION TEST
PRESSURE, psf
AXIAL STRAIN, %
Project: Proposed Student Housing Project
Site: West of Int. of Plum St. and S. Shields Fort Collins, Colorado
10,000
Specimen Identification Classification , pcf WC,%
Job #: 20085059
-2
100 1,000
Notes:
7 4.0ft CLAYEY SAND(SC) 110 9
4
0
-4
-6
-8
-10
2
TC_CONSOL_STRAIN 20085059.GPJ BORING.GDT 8/22/08
SWELL CONSOLIDATION TEST
PRESSURE, psf
AXIAL STRAIN, %
Project: Proposed Student Housing Project
Site: West of Int. of Plum St. and S. Shields Fort Collins, Colorado
10,000
Specimen Identification Classification , pcf WC,%
Job #: 20085059
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
Exhibit B-12
Project: The District at CSU
Proj. No. 20115026
Site: West Plum Street and City Park Avenue, Fort Collins, Colorado
, pcf WC,%
107 9
SpecimenClassification Identification
9 4.0 ft SANDY LEAN CLAY (CL)
Notes: Water added at 1,000 psf.
TC_CONSOL_STRAIN 20115026.GPJ DENVER 031610.GDT 11/1/11
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
Exhibit B-13
Project: The District at CSU
Proj. No. 20115026
Site: West Plum Street and City Park Avenue, Fort Collins, Colorado
, pcf WC,%
115 17
SpecimenClassification Identification
10 19.0 ft CLAYSTONE BEDROCK
Notes: Water added at 1,000 psf.
TC_CONSOL_STRAIN 20115026.GPJ DENVER 031610.GDT 11/1/11
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
Exhibit B-14
Project: The District at CSU
Proj. No. 20115026
Site: West Plum Street and City Park Avenue, Fort Collins, Colorado
, pcf WC,%
120 14
SpecimenClassification Identification
10 24.0 ft CLAYSTONE BEDROCK
Notes: Water added at 1,000 psf.
TC_CONSOL_STRAIN 20115026.GPJ DENVER 031610.GDT 11/1/11
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
Exhibit B-15
Project: The District at CSU
Proj. No. 20115026
Site: West Plum Street and City Park Avenue, Fort Collins, Colorado
, pcf WC,%
97 13
SpecimenClassification Identification
11 2.0 ft SANDY LEAN CLAY (CL)
Notes: Water added at 200 psf.
TC_CONSOL_STRAIN 20115026.GPJ DENVER 031610.GDT 11/1/11
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
Exhibit B-16
Project: The District at CSU
Proj. No. 20115026
Site: West Plum Street and City Park Avenue, Fort Collins, Colorado
, pcf WC,%
111 14
SpecimenClassification Identification
11 4.0 ft SANDY LEAN CLAY (CL)
Notes: Water added at 500 psf.
TC_CONSOL_STRAIN 20115026.GPJ DENVER 031610.GDT 11/1/11
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
Exhibit B-17
Project: The District at CSU
Proj. No. 20115026
Site: West Plum Street and City Park Avenue, Fort Collins, Colorado
, pcf WC,%
116 13
SpecimenClassification Identification
11 9.0 ft SANDY LEAN CLAY (CL)
Notes: Water added at 1,000 psf.
TC_CONSOL_STRAIN 20115026.GPJ DENVER 031610.GDT 11/1/11
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
Exhibit B-18
Project: The District at CSU
Proj. No. 20115026
Site: West Plum Street and City Park Avenue, Fort Collins, Colorado
, pcf WC,%
106 21
SpecimenClassification Identification
11 14.0 ft CLAYSTONE BEDROCK
Notes: Water added at 1,750 psf.
TC_CONSOL_STRAIN 20115026.GPJ DENVER 031610.GDT 11/1/11
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
GRAIN SIZE DISTRIBUTION
26.2 73.0
8
9.5
50 60 100
coarse
1.5
GRAIN SIZE IN MILLIMETERS
PERCENT FINER BY WEIGHT
Classification
coarse
SAND
SILT OR CLAY
200
LL PL
D10
fine
6 1 6
3/4 1/2
3/8
PI Cc Cu
0.8
4 3 14
2 8
COBBLES
GRAVEL
29
Specimen Identification D100
4
21
10
D30
16 20
30 40
U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
SANDY CLAY FILL WITH GRAVEL (CL)
fine
Exhibit B-19
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
GRAIN SIZE DISTRIBUTION
32.5 61.3
9
19
50 60 100
coarse
1.5
GRAIN SIZE IN MILLIMETERS
PERCENT FINER BY WEIGHT
Classification
coarse
SAND
SILT OR CLAY
200
LL PL
D10
fine
6 1 6
3/4 1/2
3/8
PI Cc Cu
6.2
4 3 14
2 8
COBBLES
GRAVEL
18
Specimen Identification D100
4
18
10
D30
16 20
30 40
U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
SANDY LEAN CLAY(CL)
fine
Exhibit B-20
3
4 4.0
3 29.0 10.3
3 24.0 10.5
129.8
10.6
19.0
70
3 14.0 3.5
3 9.0 13.0 117.8 1.9/500
1
8.0
114.1
5 4.0
4 19.0 15.4 116.7
14.0 17.4 112.5
33
0.5/500
18
4 9.0 17.3
100 A-6 CL 14.3 108.2 0.7/500
4.0
4
11.9
1 29.0 14.5
1 24.0 14.9
14.0 17.5 112.3
111.0
115.0
4.0
1 9.0
1 5.0 10.8 111.2 2.3/500
0.5 8.8
1
CL
3
2 19.0 10.6 127.4
2 14.0 13.4 123.9
116.0
12.0
2
2 9.0 39 22 68 A-6
9.5 102.1 0.2/500
68
117.8
11.1
Water
Soluble
Sulfates
(ppm)
Plasticity
Index
USCS
Class-
ification
Dry Unit
Weight
(pcf)
Depth
ft
8 2 CL A-7-6 (14) 92 15 100 99 97 91 73 50 21 4
8 4 CL 114 9 55 4,5
8 9 108 19 4
8 14 107 21 4
8 19 15 4
8 29 18 4
9 2 CL A-6 (8) 105 11 100 94 89 76 61 36 18 4
9 4 107 9 1.0 -0.4 3,4
9 9 119 15 4
9 14 112 18 4
9 19 122 13 4
9 24 9 4
9 29 10 4
10 2 105 11 4
10 4 108 8 <1 4
10 9 CL 116 14 59 4,5
10 14 116 17 4
10 19 CH A-7-6 (19) 115 17 1.0 +3.9 99 54 34 3,4,5
10 24 120 14 1.0 +3.2 3,4
10 29 15 4
10 34 13 4
Exhibit B-22
Initial Dry Density, Initial Water Content and Swell values obtained from undisturbed samples unless otherwise noted
* = partially disturbed sample
- = compression/settlement
Notes:
REMARKS:
1. Remolded compacted density (approximately between 95 to 100% of ASTM D698 maximum dry density near optimum)
2. Remolded compacted density (approximately between 95 to 100% of ASTM D1557 maximum dry density near optimum)
3. Submerged to approximate saturation
4. Density/water content determined from one-ring of a multi-ring sample
5. Minus #200 only
6. Moisture-Density Relations Test Method ASTM D698/AASHTO T99
7. Moisture-Density Relations Test Method ASTM D1557/AASHTO T180
8. Indicates composite sample
Initial
Dry
Density
(pcf)
Initial
Water
Content
(%)
SUMMARY OF LABORATORY TEST RESULTS
Terracon Project No. 20115026
The District at CSU, Fort Collins, Colorado
A - STANDARD SUMMARY 20115026.GPJ DENVER 031610.GDT 11/1/11
AASHTO
Class-
ification
USCS Soil
DepthClassification
Boring
No. Swell #4
(%)
Swell/Consolidation
Surcharge
(ksf)
3/4" #10 #40
Particle Size Distribution
10 39 14 4
10 44 13 4
11 2 97 13 0.2 +3.6 3,4
11 4 111 14 0.5 +1.1 3,4
11 9 116 13 1.0 +0.4 20 3,4
11 14 106 21 1.8 +0.3 3,4
11 19 19 4
11 24 20 4
Exhibit B-23
Initial Dry Density, Initial Water Content and Swell values obtained from undisturbed samples unless otherwise noted
* = partially disturbed sample
- = compression/settlement
Notes:
REMARKS:
1. Remolded compacted density (approximately between 95 to 100% of ASTM D698 maximum dry density near optimum)
2. Remolded compacted density (approximately between 95 to 100% of ASTM D1557 maximum dry density near optimum)
3. Submerged to approximate saturation
4. Density/water content determined from one-ring of a multi-ring sample
5. Minus #200 only
6. Moisture-Density Relations Test Method ASTM D698/AASHTO T99
7. Moisture-Density Relations Test Method ASTM D1557/AASHTO T180
8. Indicates composite sample
Initial
Dry
Density
(pcf)
Initial
Water
Content
(%)
SUMMARY OF LABORATORY TEST RESULTS
Terracon Project No. 20115026
The District at CSU, Fort Collins, Colorado
A - STANDARD SUMMARY 20115026.GPJ DENVER 031610.GDT 11/1/11
AASHTO
Class-
ification
USCS Soil
DepthClassification
Boring
No. Swell #4
(%)
Swell/Consolidation
Surcharge
(ksf)
3/4" #10 #40
Particle Size Distribution
Percent Passing by Weight
#200
Liquid
Limit
Plasticity
Index
Water
Soluble
Sulfates
(mg/L)
Remarks
NV = no value
NP = non-plastic
APPENDIX C
SUPPORTING DOCUMENTS
GENERAL NOTES
DRILLING & SAMPLING SYMBOLS:
SS: Split Spoon - 1-3/8" I.D., 2" O.D., unless otherwise noted HS: Hollow Stem Auger
ST: Thin-Walled Tube - 2" O.D., unless otherwise noted PA: Power Auger
RS: Ring Sampler - 2.42" I.D., 3" O.D., unless otherwise noted HA: Hand Auger
DB: Diamond Bit Coring - 4", N, B RB: Rock Bit
BS: Bulk Sample or Auger Sample WB: Wash Boring or Mud Rotary
The number of blows required to advance a standard 2-inch O.D. split-spoon sampler (SS) the last 12 inches of the total 18-inch
penetration with a 140-pound hammer falling 30 inches is considered the “Standard Penetration” or “N-value”. For 3” O.D. ring
samplers (RS) the penetration value is reported as the number of blows required to advance the sampler 12 inches using a 140-
pound hammer falling 30 inches, reported as “blows per foot,” and is not considered equivalent to the “Standard Penetration” or
“N-value”.
WATER LEVEL MEASUREMENT SYMBOLS:
WL: Water Level WS: While Sampling
WCI: Wet Cave in WD: While Drilling
DCI: Dry Cave in BCR: Before Casing Removal
AB: After Boring ACR: After Casing Removal
Water levels indicated on the boring logs are the levels measured in the borings at the times indicated. Groundwater levels at
other times and other locations across the site could vary. In pervious soils, the indicated levels may reflect the location of
groundwater. In low permeability soils, the accurate determination of groundwater levels may not be possible with only short-
term observations.
DESCRIPTIVE SOIL CLASSIFICATION: Soil classification is based on the Unified 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.
FINE-GRAINED SOILS COARSE-GRAINED SOILS BEDROCK
(RS)
Blows/Ft.
(SS)
Blows/Ft.
Consistency
(RS)
Blows/Ft.
(SS)
Blows/Ft.
Relative
Density
(RS)
Blows/Ft.
(SS)
Blows/Ft. Consistency
< 3 0-2 Very Soft 0-6 < 3 Very Loose < 30 < 20 Weathered
3-4 3-4 Soft 7-18 4-9 Loose 30-49 20-29 Firm
5-9 5-8 Medium Stiff 19-58 10-29 Medium Dense 50-89 30-49 Medium Hard
10-18 9-15 Stiff 59-98 30-50 Dense 90-119 50-79 Hard
19-42 16-30 Very Stiff > 98 > 50 Very Dense > 119 > 79 Very Hard
> 42 > 30 Hard
RELATIVE PROPORTIONS OF SAND AND
GRAVEL
GRAIN SIZE TERMINOLOGY
Descriptive Terms of
Other Constituents
Percent of
Dry Weight
Major Component
of Sample Particle Size
Trace < 15 Boulders Over 12 in. (300mm)
With 15 – 29 Cobbles 12 in. to 3 in. (300mm to 75 mm)
UNIFIED SOIL CLASSIFICATION SYSTEM
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests Soil Classification
Group
Symbol
Group NameB
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% finesC
Cu 4 and 1 Cc 3E GW Well graded gravelF
Cu 4 and/or 1 Cc 3E GP Poorly graded gravelF
Gravels with Fines More
than 12% finesC
Fines classify as ML or MH GM Silty gravelF,G, H
Fines classify as CL or CH GC Clayey gravelF,G,H
Sands
50% or more of coarse
fraction passes
No. 4 sieve
Clean Sands
Less than 5% finesD
Cu 6 and 1 Cc 3E SW Well graded sandI
Cu 6 and/or 1 Cc 3E SP Poorly graded sandI
Sands with Fines
More than 12% finesD
Fines classify as ML or MH SM Silty sandG,H,I
Fines classify as CL or CH SC Clayey sandG,H,I
Fine-Grained Soils
50% or more passes the
No. 200 sieve
Silts and Clays
Liquid limit less than 50
Inorganic PI 7 and plots on or above “A” lineJ CL Lean clayK,L,M
PI 4 or plots below “A” lineJ ML SiltK,L,M
Organic
Liquid limit - oven
dried
0.75 OL
Organic clayK,L,M,N
Liquid limit - not
dried
Organic siltK,L,M,O
Silts and Clays
Liquid limit 50 or more
Inorganic PI plots on or above “A” line CH Fat clayK,L,M
PI plots below “A” line MH Elastic siltK,L,M
Organic Liquid limit - oven dried
0.75 OH
Organic clayK,L,M,P
Liquid limit - not dried Organic siltK,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-in. (75-mm) sieve
B If field sample contained cobbles or boulders, or both, add “with cobbles
or boulders, or both” to group name.
C Gravels with 5 to 12% fines require dual symbols: GW-GM well graded
ROCK CLASSIFICATION
(Based on ASTM C-294)
Sedimentary Rocks
Sedimentary rocks are stratified materials laid down by water or wind. The sediments may
be composed of particles or pre-existing rocks derived by mechanical weathering,
evaporation or by chemical or organic origin. The sediments are usually indurated by
cementation or compaction.
Chert Very fine-grained siliceous rock composed of micro-crystalline or
cyrptocrystalline quartz, chalcedony or opal. Chert is various colored,
porous to dense, hard and has a conchoidal to splintery fracture.
Claystone Fine-grained rock composed of or derived by erosion of silts and clays or
any rock containing clay. Soft massive and may contain carbonate
minerals.
Conglomerate Rock consisting of a considerable amount of rounded gravel, sand and
cobbles with or without interstitial or cementing material. The cementing
or interstitial material may be quartz, opal, calcite, dolomite, clay, iron
oxides or other materials.
Dolomite A fine-grained carbonate rock consisting of the mineral dolomite
[CaMg(CO3)2]. May contain noncarbonate impurities such as quartz,
chert, clay minerals, organic matter, gypsum and sulfides. Reacts with
hydrochloric acid (HCL).
Limestone A fine-grained carbonate rock consisting of the mineral calcite (CaCO3).
May contain noncarbonate impurities such as quartz, chert, clay minerals,
organic matter, gypsum and sulfides. Reacts with hydrochloric acid
(HCL).
Sandstone Rock consisting of particles of sand with or without interstitial and
cementing materials. The cementing or interstitial material may be
quartz, opal, calcite, dolomite, clay, iron oxides or other material.
Shale Fine-grained rock composed of or derived by erosion of silts and clays or
any rock containing clay. Shale is hard, platy, of fissile may be gray,
black, reddish or green and may contain some carbonate minerals
(calcareous shale).
Siltstone Fine grained rock composed of or derived by erosion of silts or rock
containing silt. Siltstones consist predominantly of silt sized particles
(0.0625 to 0.002 mm in diameter) and are intermediate rocks between
claystones and sandstones and may contain carbonate minerals.
Exhibit C-3
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 Sulphate Used to determine the quantitative amount of soluble
sulfates within a soil mass.
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
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-5
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-6
Analysis for
Foundations
Water Content Used to determine the quantitative amount of water in a soil
mass.
Index Property Soil
Behavior
Exhibit C-4
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.
HIf fines are organic, add “with organic fines” to group name.
I If soil contains 15% gravel, add “with gravel” to group name.
J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay.
K If soil contains 15 to 29% plus No. 200, add “with sand” or “with
gravel,” whichever is predominant.
L If soil contains 30% plus No. 200 predominantly sand, add
“sandy” to group name.
MIf soil contains 30% plus No. 200, predominantly gravel, add
“gravelly” to group name.
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.
Exhibit C-2
Modifier > 30 Gravel 3 in. to #4 sieve (75mm to 4.75 mm)
Sand
Silt or Clay
#4 to #200 sieve (4.75mm to 0.075mm)
Passing #200 Sieve (0.075mm)
RELATIVE PROPORTIONS OF FINES PLASTICITY DESCRIPTION
Descriptive Terms of
Other Constituents
Percent of
Dry Weight Term Plasticity Index
Trace
With
Modifiers
< 5
5 – 12
> 12
Non-plastic
Low
Medium
High
0
1-10
11-30
30+
Exhibit C-1
Atterberg
Limits
Percent Passing by Weight
#200
Liquid
Limit
Plasticity
Index
Water
Soluble
Sulfates
(mg/L)
Remarks
NV = no value
NP = non-plastic
Atterberg
Limits
SUMMARY OF LABORATORY RESULTS
30
7 29.0
7 19.0 11.8 122.3
7 14.0 16.2
Sheet 1 of 1
Job #: 20085059
Site: West of Int. of Plum St. and S. Shields Fort Collins, Colorado
Project: Proposed Student Housing Project
Unconfined
Comp.
Strength
(psf)
Borehole
Water
Content
(%)
AASHTO
Class-
ification
% <#200
Sieve
Liquid
Limit
9.0
Swell (%)/
Surcharge
(psf)
5
123.6
6 4.0 8.9 103.0 0.2/500
5 19.0 13.4
9.0
14.0
6.6
5 9.0 12.8 120.5
A-6 CL 10.9 119.2 0.4/500
TC_LAB_SUMMARY 20085059.GPJ BORING.GDT 8/22/08
12.8
4.0
15
7
46 200 A-6 SC 9.0 110.4 0.1/500
6
27
10.7
7
6 19.0 12.9 123.0
6 14.0 9.3 127.0
112.5
11
3
%Gravel %Sand %Silt
Specimen Identification
140
%Clay
HYDROMETER
9
D60
medium
2.0ft
2.0 ft 36
Project: The District at CSU
Proj. No. 20115026
Site: West Plum Street and City Park Avenue, Fort Collins, Colorado
TC_GRAIN_SIZE 20115026.GPJ DENVER 031610.GDT 11/1/11
3
%Gravel %Sand %Silt
Specimen Identification
140
%Clay
HYDROMETER
8
D60
medium
2.0ft
2.0 ft 50
Project: The District at CSU
Proj. No. 20115026
Site: West Plum Street and City Park Avenue, Fort Collins, Colorado
TC_GRAIN_SIZE 20115026.GPJ DENVER 031610.GDT 11/1/11
N
D
E
X
Mini Rig
EDB PROJ. NO.
LOGGED
PROJECT
BORING COMPLETED
* 140lb. SPT manual hammer
3" diameter solid stem auger
Backfilled
RIG EDB
between soil and rock types: in-situ, the transition may be gradual.
The District at CSU
West Plum Street and City Park Avenue
Fort Collins, Colorado
GRAPHIC LOG
BORING LOG NO. 11
PERCENT FINES
ATTERBERG LIMITS,
%
BOREHOLE WITH ATTERBERG LIMITS 20115026.GPJ DENVER TEMPLATE 8-5-11.GDT 11/1/11
TYPE
NUMBER
DEPTH, ft.
SAMPLES
USCS SYMBOL
5
10
15
20
BLOWS / ft.*
RECOVERY, in.
WATER
CONTENT, %
DRY UNIT WT, pcf
116
115
120
BORING STARTED 9-28-11
11.7 WD AD
SITE
CLIENT
WL
WL
APPROVED
The stratification lines represent the approximate boundary lines
Page 1 of 1
UNCONFINED
STRENGTH, psf
TESTS
9-28-11
DESCRIPTION
Exhibit A-12
WATER LEVEL OBSERVATIONS, ft
Ft. Collins Student Housing, LLC
20115026
CME 55
EDB PROJ. NO.
LOGGED
PROJECT
BORING COMPLETED
* 140lb. SPT automatic hammer
4" diameter solid stem auger
Backfilled
RIG BCJ
between soil and rock types: in-situ, the transition may be gradual.
The District at CSU
West Plum Street and City Park Avenue
Fort Collins, Colorado
GRAPHIC LOG
BORING LOG NO. 10
PERCENT FINES
ATTERBERG LIMITS,
%
BOREHOLE WITH ATTERBERG LIMITS 20115026.GPJ DENVER TEMPLATE 8-5-11.GDT 11/1/11
TYPE
NUMBER
DEPTH, ft.
SAMPLES
USCS SYMBOL
5
10
15
20
25
30
35
40
45
BLOWS / ft.*
RECOVERY, in.
WATER
CONTENT, %
DRY UNIT WT, pcf
UNCONFINED
STRENGTH, psf
TESTS
9-28-11
DESCRIPTION
Exhibit A-11
WATER LEVEL OBSERVATIONS, ft
Ft. Collins Student Housing, LLC
20115026
CME 55
EDB PROJ. NO.
LOGGED
PROJECT
BORING COMPLETED
* 140lb. SPT automatic hammer
4" diameter solid stem auger
Backfilled
RIG BCJ
between soil and rock types: in-situ, the transition may be gradual.
The District at CSU
West Plum Street and City Park Avenue
Fort Collins, Colorado
GRAPHIC LOG
BORING LOG NO. 9
PERCENT FINES
ATTERBERG LIMITS,
%
BOREHOLE WITH ATTERBERG LIMITS 20115026.GPJ DENVER TEMPLATE 8-5-11.GDT 11/1/11
TYPE
NUMBER
DEPTH, ft.
SAMPLES
USCS SYMBOL
5
10
15
20
25
BLOWS / ft.*
RECOVERY, in.
WATER
CONTENT, %
DRY UNIT WT, pcf
The stratification lines represent the approximate boundary lines
Page 1 of 1
UNCONFINED
STRENGTH, psf
TESTS
9-22-11
DESCRIPTION
Exhibit A-10
WATER LEVEL OBSERVATIONS, ft
Ft. Collins Student Housing, LLC
20115026
Mini Rig
EDB PROJ. NO.
LOGGED
PROJECT
BORING COMPLETED
* 140lb. SPT manual hammer
3" diameter solid stem auger
Backfilled
RIG EDB
between soil and rock types: in-situ, the transition may be gradual.
The District at CSU
West Plum Street and City Park Avenue
Fort Collins, Colorado
GRAPHIC LOG
BORING LOG NO. 8
PERCENT FINES
ATTERBERG LIMITS,
%
BOREHOLE WITH ATTERBERG LIMITS 20115026.GPJ DENVER TEMPLATE 8-5-11.GDT 11/1/11
TYPE
NUMBER
DEPTH, ft.
SAMPLES
USCS SYMBOL
5
10
15
20
25
BLOWS / ft.*
RECOVERY, in.
WATER
CONTENT, %
DRY UNIT WT, pcf
30
BLOWS / ft.
WATER
CONTENT, %
USCS SYMBOL
SAMPLES
BOREHOLE_99 20085059.GPJ BORING.GDT 8/22/08
JOB #
DRY UNIT WT
pcf
RECOVERY, in.
DEPTH, ft.
NUMBER
TYPE
20085059
Page 1 of 1
between soil and rock types: in-situ, the transition may be gradual.
West of Int. of Plum St. and S. Shields
Fort Collins, Colorado
LOG OF BORING NO. 7
WD AB 8-8-08
TESTS
18.2
CLIENT
DESCRIPTION
Water Level Reading 8/9/08
Glenwood Intermountain Properties
SITE
WL
WL
WL
BORING COMPLETED
GRAPHIC LOG
USCS SYMBOL
SAMPLES
BOREHOLE_99 20085059.GPJ BORING.GDT 8/22/08
% SWELL
SURCHARGE
DRY UNIT WT
pcf
RECOVERY, in.
DEPTH, ft.
NUMBER
TYPE
West of Int. of Plum St. and S. Shields
Fort Collins, Colorado
Dry
Page 1 of 1
between soil and rock types: in-situ, the transition may be gradual.
Glenwood Intermountain Properties
LOG OF BORING NO. 6
20085059
WD AB 8-8-08
TESTS
CLIENT
Water Level Reading 8/9/08
GRAPHIC LOG
SITE
WL
WL
WL
BORING COMPLETED
DESCRIPTION
SURCHARGE
DRY UNIT WT
pcf
RECOVERY, in.
DEPTH, ft.
NUMBER
TYPE
West of Int. of Plum St. and S. Shields
Fort Collins, Colorado
13.5
Page 1 of 1
between soil and rock types: in-situ, the transition may be gradual.
Glenwood Intermountain Properties
LOG OF BORING NO. 5
20085059
WD AB 8-8-08
TESTS
CLIENT
Water Level Reading 8/9/08
GRAPHIC LOG
SITE
WL
WL
WL
BORING COMPLETED
DESCRIPTION
USCS SYMBOL
SAMPLES
DRY UNIT WT
pcf
RECOVERY, in.
DEPTH, ft.
NUMBER
% SWELL
SURCHARGE
Glenwood Intermountain Properties
12.5
Water Level Reading 8/9/08 JOB #
between soil and rock types: in-situ, the transition may be gradual.
West of Int. of Plum St. and S. Shields
Fort Collins, Colorado
20085059
WD AB
Page 1 of 1
GRAPHIC LOG
CLIENT
LOG OF BORING NO. 4
DESCRIPTION
SITE
WL
WL
WL
BORING COMPLETED
10
15
20
25
30
BLOWS / ft.
WATER
CONTENT, %
USCS SYMBOL
SAMPLES
DRY UNIT WT
pcf
RECOVERY, in.
DEPTH, ft.
NUMBER
TYPE
BOREHOLE_99 20085059.GPJ BORING.GDT 8/22/08
DESCRIPTION
20085059
WD AB 8-8-08
TESTS
WATER LEVEL OBSERVATIONS, ft
West of Int. of Plum St. and S. Shields
Fort Collins, Colorado
RIG FOREMAN PG
BORING STARTED
10
11
8
4
25
GRAPHIC LOG
SITE
WL
WL
WL
BORING COMPLETED
Glenwood Intermountain Properties
LOG OF BORING NO. 3
between soil and rock types: in-situ, the transition may be gradual.
Water Level Reading 8/9/08
Page 1 of 1
DRY UNIT WT
pcf
RECOVERY, in.
DEPTH, ft.
NUMBER
TYPE
West of Int. of Plum St. and S. Shields
Fort Collins, Colorado
Dry
Page 1 of 1
between soil and rock types: in-situ, the transition may be gradual.
Glenwood Intermountain Properties
LOG OF BORING NO. 2
20085059
WD AB 8-8-08
TESTS
CLIENT
Water Level Reading 8/9/08
GRAPHIC LOG
SITE
WL
WL
WL
BORING COMPLETED
DESCRIPTION
5
10
15
20
25
30
BLOWS / ft.
WATER
CONTENT, %
USCS SYMBOL
SAMPLES
UNCONFINED
STRENGTH, psf
DRY UNIT WT
pcf
RECOVERY, in.
DEPTH, ft.
NUMBER
TYPE
WATER LEVEL OBSERVATIONS, ft
20085059
WD FILLED IN AB 8-8-08
RIG FOREMAN PG
BORING STARTED
14
15
TESTS
DESCRIPTION
GRAPHIC LOG
SITE
WL
WL
WL
West of Int. of Plum St. and S. Shields
Fort Collins, Colorado
BORING COMPLETED
between soil and rock types: in-situ, the transition may be gradual.
Glenwood Intermountain Properties
LOG OF BORING NO. 1
Water Level Reading 8/9/08
Page 1 of 1