HomeMy WebLinkAboutSOUTHEAST FORT COLLINS COMMUNITY PARK - PDP - PDP140014 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTGeotechnical Engineering Report
Southeast Community Park
Northeast of Ziegler Road and Kechter Road
Fort Collins, Colorado
June 18, 2014
Terracon Project No. 20135017
Prepared for:
Civitas, Inc.
Denver, Colorado
Prepared by:
Terracon Consultants, Inc.
Fort Collins, Colorado
TABLE OF CONTENTS
Page
EXECUTIVE SUMMARY ............................................................................................................ i
1.0 INTRODUCTION .............................................................................................................1
2.0 PROJECT INFORMATION .............................................................................................2
2.1 Project Description ...............................................................................................2
2.2 Site Location and Description...............................................................................3
3.0 SUBSURFACE CONDITIONS ........................................................................................3
3.1 Typical Subsurface Profile ...................................................................................3
3.2 Laboratory Testing ...............................................................................................4
3.3 Groundwater ........................................................................................................4
4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION ......................................5
4.1 Geotechnical Considerations ...............................................................................5
4.1.1 Existing Fill ...............................................................................................5
4.1.2 Shallow Groundwater ...............................................................................5
4.1.3 Expansive Soils and Bedrock ...................................................................5
4.1.4 Foundation Recommendations .................................................................6
4.2 Earthwork.............................................................................................................6
4.2.1 Site Preparation ........................................................................................6
4.2.2 Excavation ................................................................................................7
4.2.3 Subgrade Preparation ...............................................................................8
4.2.4 Fill Materials and Placement ......................................................................8
4.2.5 Compaction Requirements ........................................................................9
4.2.6 Utility Trench Backfill ..............................................................................10
4.2.7 Grading and Drainage .............................................................................10
4.2.8 Exterior Slab Design and Construction ...................................................11
4.2.9 Corrosion Protection ...............................................................................11
4.3 Foundations .......................................................................................................11
4.3.1 Spread Footings - Design Recommendations .........................................12
4.3.2 Spread Footings - Construction Considerations ......................................13
4.3.3 Helical Pile Foundations .........................................................................14
4.3.4 Drilled Piers Bottomed in Bedrock - Design Recommendations ..............15
4.3.5 Drilled Piers Bottomed in Bedrock - Construction Considerations ...........16
4.4 Seismic Considerations......................................................................................16
4.5 Floor Systems ....................................................................................................17
4.5.1 Floor System - Design Recommendations ..............................................17
4.5.2 Floor Systems - Construction Considerations .........................................18
4.6 Lateral Earth Pressures .....................................................................................18
4.7 Pavements .........................................................................................................20
4.7.1 Pavements – Subgrade Preparation .......................................................20
4.7.2 Pavements – Permeable Pavements Subgrade Preparation .....................20
4.7.3 Pavements – Design Recommendations ................................................21
4.7.4 Pavements – Construction Considerations .............................................24
4.7.5 Pavements – Maintenance .....................................................................24
5.0 GENERAL COMMENTS ...............................................................................................24
TABLE OF CONTENTS (continued)
Appendix A – FIELD EXPLORATION
Exhibit A-1 Site Location Map
Exhibit A-2 Exploration Plan
Exhibit A-3 Field Exploration Description
Exhibits A-4 to A-11 Boring Logs
Appendix B – LABORATORY TESTING
Exhibit B-1 Laboratory Testing Description
Exhibit B-2 Atterberg Limits Test Results
Exhibit B-3 Grain-size Distribution Test Results
Exhibits B-6 to B-7 Swell-consolidation Test Results
Exhibit B-8 Corrosion Testing Results
Exhibits B-9 to B-14 Topsoil Analysis Test Results
Appendix C – SUPPORTING DOCUMENTS
Exhibit C-1 General Notes
Exhibit C-2 Unified Soil Classification System
Exhibit C-3 Description of Rock Properties
Exhibit C-4 Laboratory Test Significance and Purpose
Exhibits C-5 and C-6 Report Terminology
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable i
EXECUTIVE SUMMARY
A geotechnical investigation has been performed for the proposed Southeast Community Park to
be constructed northeast of Ziegler Road and Kechter Road in Fort Collins, Colorado. Eight (8)
borings, presented as Exhibits A-4 through A-11 and designated as Boring No. 1 through Boring
No. 8, were performed to depths of approximately 20½ feet below existing site grades. This report
specifically addresses the recommendations for the proposed restrooms, pedestrian bridges,
shelters, play field/courts, and landscaping. Borings performed in these areas are for informational
purposes and will be utilized by others.
Based on the information obtained from our subsurface exploration, the site can be developed for
the proposed project. However, the following geotechnical considerations were identified and will
need to be considered:
The proposed pedestrian bridges may be supported on a shallow footing foundation
system bearing on compacted, moisture conditioned native soils or on imported fill. A
helical pile foundation system bottomed in bedrock is also considered an appropriate
alternative for support of the proposed pedestrian bridges.
The proposed restrooms and shelters may be supported on shallow spread footing
foundations bearing on compacted, moisture conditioned native soils or on newly placed
engineered fill.
A slab-on-grade floor system is recommended for the proposed buildings and shelters.
The sports field lighting may be supported on drilled piers bottomed in bedrock.
We understand traditional and permeable pavements are planned for this site. As required
by Larimer County Urban Areas Street Standards (LCUASS), the Final Pavement
Design Report for city-maintained roadways should occur after grading for roadways and
utility installation is complete. We recommend field infiltration rate testing be completed in
areas of the site planned for permeable pavements.
The amount of movement of foundations, floor slabs, pavements, etc. will be related to the
wetting of underlying supporting soils. Therefore, it is imperative the recommendations
discussed in the 4.2.7 Grading and Drainage section of this report be followed to reduce
potential movement.
The 2012 International Building Code, Table 1613.5.2 IBC seismic site classification for this
site is C.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable ii
Close monitoring of the construction operations discussed herein will be critical in
achieving the design subgrade support. We therefore recommend that Terracon be
retained to monitor this portion of the work.
This summary should be used in conjunction with the entire report for design purposes. It
should be recognized that details were not included or fully developed in this section, and the
report must be read in its entirety for a comprehensive understanding of the items contained
herein. The section titled GENERAL COMMENTS should be read for an understanding of the
report limitations.
Responsive Ŷ Resourceful Ŷ Reliable 1
GEOTECHNICAL ENGINEERING REPORT
Southeast Community Park
Northeast of Ziegler Road and Kechter Road
Fort Collins, Colorado
Terracon Project No. 20135017
June 18, 2014
1.0 INTRODUCTION
This report presents the results of our geotechnical engineering services performed for the
proposed Southeast Community Park to be located at northeast of Ziegler Road and Kechter
Road in Fort Collins, Colorado. The purpose of these services is to provide information and
geotechnical engineering recommendations relative to:
subsurface soil and bedrock conditions foundation design and construction
groundwater conditions floor slab design and construction
grading and drainage pavement construction
lateral earth pressures earthwork
seismic considerations
Our geotechnical engineering scope of work for this project included the initial site visit, the
advancement of eight (8) test borings to depths of approximately 20½ feet below existing site
grades, laboratory testing for soil engineering properties and engineering analyses to provide
foundation, floor system and pavement design and construction recommendations.
Logs of the borings along with an Exploration Plan (Exhibit A-2) are included in Appendix A.
The results of the laboratory testing performed on soil and bedrock samples obtained from the
site during the field exploration are included in Appendix B.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 2
2.0 PROJECT INFORMATION
2.1 Project Description
Item Description
Site layout Refer to the Boring Location Plan (Exhibit A-2 in Appendix A)
Proposed construction
We understand the park improvements will include restroom
facilities, shade shelters, pedestrian bridge creek crossings, sports
fields with dugouts and bleachers, a dog park, a spray park,
playgrounds with various equipment, barbeque and bench areas,
pedestrian paths, new parking areas, and field lighting. The
existing BMX track and timing booth will be relocated west of the
current location. Traditional and permeable pavements are also
planned for this project.
Building construction
We anticipate the restrooms and shelters will be constructed of
wood and/or steel framing and masonry walls. The pedestrian
bridges will likely be prefabricated steel frame with a wood deck.
Dug out walls, bleachers, and other various site features will be
cast in place concrete.
Maximum loads
Pedestrian bridges:
20 kips max (assumed)
Restrooms, shelters, dugouts, and bleachers:
Column Load – 10 kips max (assumed)
Wall Loads – 2 to 5 klf (assumed)
Floor Slab Load – 125 psf
Playground equipment:
10 kips max (assumed)
Sports field lighting:
20 kips max (assumed)
Grading in building area
Grading details were not fully developed at the time this report was
prepared. However, we understand cuts and fills on the order of 5
to 10 feet will be necessary for development at the site including
areas planned for borrow materials. Deeper cuts and fills may be
required for the installation of deep utilities.
Below-grade areas No below-grade areas are planned for this site.
Traffic loading
At the time this report was prepared, traffic loading was not
available. We designed the areas of the site planned for parking
areas with a 20-year design life and an equivalent single-axle load
(ESAL) of 73,000.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 3
2.2 Site Location and Description
Item Description
Location The project site is located at northeast of Ziegler Road and Kechter
Road in Fort Collins, Colorado.
Existing site features
An existing BMX course with timing booth is located at the northern
portion of the site, west of the baseball field. A creek divides the
northern portion of the site from the southern portion of the site
with a pedestrian bridge for creek crossing located at the western
portion of the site. A pedestrian path follows the creek east and
west. A pump house is located on the eastern side of the site west
of the existing pond.
Surrounding developments The site is bordered to the south by Kechter Road with residential
housing development beyond.
Current ground cover The ground surface is covered with native grasses and weeds,
bare ground, and areas of irrigated grass.
Existing topography
The site gently slopes from west to east with the northern and
southern portions of the site sloping towards the center of the site
where the creek is located.
3.0 SUBSURFACE CONDITIONS
3.1 Typical Subsurface Profile
Specific conditions encountered at each boring location are indicated on the individual boring
logs included in Appendix A. Stratification boundaries on the boring logs represent the
approximate location of changes in soil types; in-situ, the transition between materials may be
gradual. Based on the results of the borings, subsurface conditions on the project site can be
generalized as follows:
Material Description Approximate Depth to
Bottom of Stratum (feet) Consistency/Density/Hardness
Lean clay with varying amounts of
sand
About 2½ to 16 feet below
existing site grades.
Stiff to very stiff
Clayey sand
About 6 feet below existing
grades in Boring No. 5 only.
Loose to medium dense
Sand with clay, silt, and gravel
About 10 to 20 feet below
existing site grades.
Loose to dense
Claystone bedrock
To the maximum depth of
exploration of about 20½ feet.
Firm to hard
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 4
3.2 Laboratory Testing
Representative soil samples were selected for swell-consolidation testing and exhibited 2.4
compression to 0.4 percent swell when wetted. Samples of site soils and bedrock selected for
plasticity testing exhibited medium plasticity with liquid limits ranging from non-plastic to 49 and
plasticity indices ranging from 18 to 35. Three topsoil samples were collected in areas planned
for borrow materials. The topsoil samples were tested by Colorado State University for topsoil
nutrients applicable to use for turf and other landscape vegetation. Laboratory test results are
presented in Appendix B.
3.3 Groundwater
The boreholes were observed while drilling and after completion for the presence and level of
groundwater. In addition, delayed water levels were also obtained in the borings. The water levels
observed in the boreholes are noted on the attached boring logs, and are summarized below:
Boring
Number
Depth to groundwater
while drilling, ft.
Depth to groundwater
several days after drilling, ft.
Elevation of groundwater
several days after drilling, ft.
1 10 11.0 4889.8
2 16 18.9 4886.1
3 7 6.9 4890.3
4 12 8.9 4884.6
5 11 11.4 4889.5
6 12 11.0 4887.1
7 12 12.6 4895.6
8 8 7.6 4894.8
These observations represent groundwater conditions at the time of the field exploration, and
may not be indicative of other times or at other locations. Groundwater levels can be expected
to fluctuate with varying seasonal and weather conditions, and other factors.
Groundwater level fluctuations occur due to seasonal variations in the water levels present in
the creek, 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
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 5
4.0 RECOMMENDATIONS FOR DESIGN AND CONSTRUCTION
4.1 Geotechnical Considerations
Based on subsurface conditions encountered in the borings, the site appears suitable for the
proposed construction from a geotechnical point of view provided certain precautions and
design and construction recommendations described in this report are followed. We have
identified geotechnical conditions that could impact design and construction of the proposed
structures, pavements, and other site improvements.
4.1.1 Existing Fill
As previously noted, an existing BMX track and timing booth is located near at the northern
portion of the site. We understand the track and timing booth will be relocated to the
northwestern portion of the site. Our scope of services did not include sampling or laboratory
testing of the fill placed during construction of the BMX track. We recommend thorough
evaluation of the BMX track fill materials.
During our site visits, we observed the ground surface in the southwestern portion of the site to
seemingly be unnaturally flat. The subsurface materials in the southwestern portion of the site
were consistent with the subsurface materials encountered at the other borings we completed at
this site. We are not sure if this portion of the site was used for borrow materials for the
surrounding development or was previously placed fill. If it is determined that this portion of the
site is composed of previously placed fill, the compaction test records will need to be provided to
Terracon for review.
Support of footings, 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 of unforeseen conditions cannot be eliminated without completely
removing the existing fill, but can be reduced by performing additional testing and evaluation.
4.1.2 Shallow Groundwater
As previously stated, groundwater was measured at depths ranging from about 6.9 to 18.9 feet
below existing site grades. Terracon recommends maintaining a separation of at least 3 feet
between the bottom of proposed foundations and measured groundwater levels. It is also
possible and likely that groundwater levels below this site may rise as water levels in the creek
rise.
4.1.3 Expansive Soils and Bedrock
Laboratory testing indicates the native clay soils exhibited slight compression to 0.4 percent
swell at the sample’s in-situ moisture content. However, it is our opinion these materials will
exhibit a higher expansive potential if the clays and claystone undergo a significant loss of
moisture.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 6
This report provides recommendations to help mitigate the effects of soil shrinkage and
expansion. However, even if these procedures are followed, some movement and cracking in
the structures, pavements, and flatwork should be anticipated. The severity of cracking and
other damage such as uneven floor slabs will probably increase if any modification of the site
results in excessive wetting or drying of the expansive clays and/or claystone bedrock.
Eliminating the risk of movement and distress is generally not feasible, but it may be possible to
further reduce the risk of movement if significantly more expensive measures are used during
construction. It is imperative the recommendations described in section 4.2.7 Grading and
Drainage of this report be followed to reduce movement.
4.1.4 Foundation Recommendations
The proposed restrooms, shade shelters, pedestrian bridges, BMX timing booth, playground
equipment, dugouts, bleachers, barbeque grills, and benches may be supported on shallow
spread footing foundation systems. A helical pile foundation system bottomed in bedrock is also
considered an appropriate alternative for support of the proposed pedestrian bridges.
We recommend the sport fields lights be supported on drilled pier foundation systems bottomed
in bedrock or a reinforced concrete mat foundation. We can provide shallow, reinforced
concrete mat foundation system recommendations upon request.
As required by Larimer County Urban Areas Street Standards (LCUASS), the Final Pavement
Design Report for city-maintained roadways should occur after grading for roadways and utility
installation is complete. We recommend double-ring infiltrometer testing be performed in areas
planned for permeable pavements. Terracon is available to provide additional testing upon
request.
4.2 Earthwork
The following presents recommendations for site preparation, excavation, subgrade preparation
and placement of engineered fills on the project. All earthwork on the project should be
observed and evaluated by Terracon on a full-time basis. The evaluation of earthwork should
include observation of over-excavation operations, testing of engineered fills, subgrade
preparation, subgrade stabilization, and other geotechnical conditions exposed during the
construction of the project.
4.2.1 Site Preparation
Prior to placing any fill, strip and remove existing vegetation and any other deleterious materials
from the proposed construction areas.
Stripped organic materials should be wasted from the site or used to re-vegetate landscaped
areas or exposed slopes after completion of grading operations. Prior to the placement of fills, the
site should be graded to create a relatively level surface to receive fill, and to provide for a
relatively uniform thickness of fill beneath proposed structures.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 7
Demolition of the existing concrete curbs and pavements should include complete removal of all
foundation components within the proposed construction area. This should include removal of
any utilities to be abandoned along with any loose utility trench backfill or loose backfill. All
materials derived from the demolition of existing pavements and curbs should be removed from
the site, and not be allowed for use in any on-site fills.
4.2.2 Excavation
It is anticipated that excavations for the proposed construction can be accomplished with
conventional earthmoving equipment. Excavations approaching the level of groundwater will
encounter weak and/or saturated soil conditions with possible caving conditions.
The soils to be excavated can vary significantly across the site as their classifications are based
solely on the materials encountered in widely-spaced exploratory test borings. The contractor
should verify that similar conditions exist throughout the proposed area of excavation. If different
subsurface conditions are encountered at the time of construction, the actual conditions should be
evaluated to determine any excavation modifications necessary to maintain safe conditions.
Although evidence of fills or underground facilities such as septic tanks, vaults, and basements
was not observed during the site reconnaissance, such features could be encountered during
construction. If unexpected fills or underground facilities are encountered, such features should
be removed and the excavation thoroughly cleaned prior to backfill placement and/or construction.
Any over-excavation that extends below the bottom of foundation elevation should extend laterally
beyond all edges of the footings at least 8 inches per foot of over-excavation depth below the
footing base elevation. The over-excavation should be backfilled to the footing base elevation in
accordance with the recommendations presented in this report.
Depending upon depth of excavation and seasonal conditions, surface water infiltration and/or
groundwater may be encountered in excavations on the site. It is anticipated that pumping from
sumps may be utilized to control water within excavations. Well points may be required for
significant groundwater flow, or where excavations penetrate groundwater to a significant depth.
The subgrade soil conditions should be evaluated during the excavation process and the stability
of the soils determined at that time by the contractors’ Competent Person. Slope inclinations
flatter than the OSHA maximum values may have to be used. The individual contractor(s) should
be made responsible for designing and constructing stable, temporary excavations as required to
maintain stability of both the excavation sides and bottom. All excavations should be sloped or
shored in the interest of safety following local, and federal regulations, including current OSHA
excavation and trench safety standards.
As a safety measure, it is recommended that all vehicles and soil piles be kept a minimum lateral
distance from the crest of the slope equal to the slope height. The exposed slope face should be
protected against the elements
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 8
4.2.3 Subgrade Preparation
After the deleterious materials been removed from the construction areas, the top 10 inches of
the exposed ground surface should be scarified, moisture conditioned, and recompacted to at
least 95 percent of the maximum dry unit weight as determined by ASTM D698 before any new
fill, foundation, or pavement is placed.
If pockets of soft, loose, or otherwise unsuitable materials are encountered at the bottom of the
footing excavations and it is inconvenient to lower the footings, the proposed footing elevations
may be reestablished by over-excavating the unsuitable soils and backfilling with compacted
engineered fill or lean concrete. Any over-excavation should be performed in accordance with
the excavation recommendations given below.
The stability of the subgrade may be affected by precipitation, repetitive construction traffic or
other factors. If unstable conditions develop, workability may be improved by scarifying and
drying. Alternatively, over-excavation of wet zones and replacement with granular materials
may be used, or crushed gravel and/or rock can be tracked or “crowded” into the unstable
surface soil until a stable working surface is attained. Use of lime, fly ash, cement or geotextiles
could also be considered as a stabilization technique. Lightweight excavation equipment may
also be used to reduce subgrade pumping.
4.2.4 Fill Materials and Placement
The on-site soils or approved granular and low plasticity cohesive imported materials may be used
as fill material. The soil removed from this site that is free of organic or objectionable materials,
as defined by a field technician who is qualified in soil material identification and compaction
procedures, can be re-used as fill for the foundation support, slabs-on-grade and pavement
subgrade. It should be noted that on-site soils will require reworking to adjust the moisture
content to meet the compaction criteria.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 9
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
Soil Properties Value
Liquid Limit 30 (max.)
Plastic Limit 15 (max.)
Maximum Expansive Potential (%) Non-expansive1
1. Measured on a sample compacted to approximately 95 percent of the maximum dry unit weight as
determined by ASTM D698 at optimum moisture content. The sample is confined under a 100 psf
surcharge and submerged.
4.2.5 Compaction Requirements
Engineered fill should be placed and compacted in horizontal lifts, using equipment and
procedures that will produce recommended moisture contents and densities throughout the lift.
Item Description
Fill lift thickness
9 inches or less in loose thickness when heavy, self-
propelled compaction equipment is used
4 to 6 inches in loose thickness when hand-guided
equipment (i.e. jumping jack or plate compactor) is used
Minimum compaction requirements
95 percent of the maximum dry unit weight as determined
by ASTM D698
Moisture content cohesive soil (clay) -1 to +3 % of the optimum moisture content
Moisture content cohesionless soil
(sand)
-3 to +2 % of the optimum moisture content
1. We recommend engineered fill be tested for moisture content and compaction during placement.
Should the results of the in-place density tests indicate the specified moisture or compaction limits
have not been met, the area represented by the test should be reworked and retested as required
until the specified moisture and compaction requirements are achieved.
2. Specifically, moisture levels should be maintained low enough to allow for satisfactory compaction
to be achieved without the fill material pumping when proofrolled.
3. Moisture conditioned clay materials should not be allowed to dry out. A loss of moisture within
these materials could result in an increase in the material’s expansive potential. Subsequent
wetting of these materials could result in undesirable movement.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 10
4.2.6 Utility Trench Backfill
All trench excavations should be made with sufficient working space to permit construction
including backfill placement and compaction.
All underground piping within or near the proposed structures should be designed with flexible
couplings, so minor deviations in alignment do not result in breakage or distress. Utility knockouts
in foundation walls should be oversized to accommodate differential movements. It is imperative
that utility trenches be properly backfilled with relatively clean materials. If utility trenches are
backfilled with relatively clean granular material, they should be capped with at least 18 inches of
cohesive fill in non-pavement areas to reduce the infiltration and conveyance of surface water
through the trench backfill.
Utility trenches are a common source of water infiltration and migration. All utility trenches that
penetrate beneath the buildings should be effectively sealed to restrict water intrusion and flow
through the trenches that could migrate below the buildings. We recommend constructing an
effective clay “trench plug” that extends at least 5 feet out from the face of the building exteriors.
The plug material should consist of clay compacted at a water content at or above the soil’s
optimum water content. The clay fill should be placed to completely surround the utility line and be
compacted in accordance with recommendations in this report.
It is strongly recommended that a representative of Terracon provide full-time observation and
compaction testing of trench backfill within building and pavement areas.
4.2.7 Grading and Drainage
All grades must be adjusted to provide effective drainage away from the proposed structures
during construction and maintained throughout the life of the proposed project. Infiltration of
water into foundation excavations must be prevented during construction. Landscape irrigation
adjacent to foundations should be minimized or eliminated. Water permitted to pond near or
adjacent to the perimeter of the structures (either during or post-construction) can result in
significantly higher soil movements than those discussed in this report. As a result, any
estimations of potential movement described in this report cannot be relied upon if positive
drainage is not obtained and maintained, and water is allowed to infiltrate the fill and/or
subgrade.
Exposed ground (if any) should be sloped at a minimum of 10 percent grade for at least 10 feet
beyond the perimeter of the proposed structures, 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 structures. Backfill against footings and exterior walls should be properly compacted and
free of all construction debris to reduce the possibility of moisture infiltration. After construction
of the proposed structures and prior to project completion, we recommend verification of final
grading be performed to document positive drainage, as described above, has been achieved.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 11
Flatwork and pavements will be subject to post-construction movement. Maximum grades
practical should be used for paving and flatwork to prevent areas where water can pond. In
addition, allowances in final grades should take into consideration post-construction movement
of flatwork, particularly if such movement would be critical. Where paving or flatwork abuts the
structures, care should be taken that joints are properly sealed and maintained to prevent the
infiltration of surface water.
Planters located adjacent to structures should preferably be self-contained. Sprinkler mains and
spray heads should be located a minimum of 5 feet away from the building line(s). Low-volume,
drip style landscaped irrigation should not be used near the building. Roof drains should
discharge on to pavements or be extended away from the structures a minimum of 10 feet
through the use of splash blocks or downspout extensions. A preferred alternative is to have
the roof drains discharge by solid pipe to storm sewers or to a detention pond or other
appropriate outfall.
4.2.8 Exterior Slab Design and Construction
Exterior slabs on-grade, exterior architectural features, and utilities founded on, or in backfill or
the site soils will likely experience some movement due to the volume change of the material.
Potential movement could be reduced by:
Minimizing moisture increases in the backfill;
Controlling moisture-density during placement of the backfill;
Using designs which allow vertical movement between the exterior features
and adjoining structural elements; and
Placing control joints on relatively close centers.
4.2.9 Corrosion Protection
Results of water-soluble sulfate testing indicate that ASTM Type I portland cement should be
specified for all project concrete on and below grade. Foundation concrete should be designed
for low sulfate exposure in accordance with the provisions of the ACI Design Manual, Section
318, Chapter 4.
4.3 Foundations
The proposed restrooms, shade shelters, pedestrian bridges, BMX timing booth, playground
equipment, dugouts, bleachers, barbeque grills, and benches may be supported on shallow
spread footing foundation systems. Footings may bear on properly prepared on-site soils or
newly placed imported fill. A helical pile foundation system bottomed in bedrock is also
considered an appropriate alternative for support of the proposed pedestrian bridges. The
proposed sports field lighting may be supported by drilled pier foundation systems bottomed in
bedrock.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 12
Design recommendations for foundations for the proposed structures and related structural
elements are presented in the following paragraphs.
4.3.1 Spread Footings - Design Recommendations
Description Value
Bearing material On-site soil or imported granular fill
Maximum allowable bearing pressure 1
On-site soil: 2,000 psf
At least 12 inches of imported granular fill: 2,500 psf
Lateral earth pressure coefficients 2
On-site soil:
Active, Ka = 0.41
Passive, Kp = 2.46
At-rest, Ko = 0.58
Imported granular fill:
Active, Ka = 0.28
Passive, Kp = 3.69
At-rest, Ko = 0.43
Sliding coefficient 2
On-site soil:
µ = 0.37
Imported granular fill:
µ = 0.56
Moist soil unit weight
On-site soil:
ܵ = 120 pcf
Imported granular fill:
ܵ = 135 pcf
Minimum embedment depth below finished
grade 3
30 inches
Estimated total movement 4 About 1 inch
Estimated differential movement 4 About ½ to ¾ of total movement
1. The recommended maximum allowable bearing pressure assumes any unsuitable fill or soft soils,
if encountered, will be over-excavated and replaced with properly compacted engineered fill.
The design bearing pressure applies to a dead load plus design live load condition. The design
bearing pressure may be increased by one-third when considering total loads that include wind or
seismic conditions.
2. The lateral earth pressure coefficients and sliding coefficients are ultimate values and do not
include a factor of safety. The foundation designer should include the appropriate factors of
safety.
3. For frost protection and to reduce the effects of seasonal moisture variations in the subgrade
soils. The minimum embedment depth is for perimeter footings beneath unheated areas and is
relative to lowest adjacent finished grade, typically exterior grade.
4. The estimated movements presented above are based on the assumption that the maximum
footing size is 4 feet for column footings and 1.5 feet for continuous footings.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 13
Footings should be proportioned to reduce differential foundation movement. As discussed,
total movement resulting from the assumed structural loads is estimated to be on the order of
about 1 inch. Additional foundation movements could occur if water from any source infiltrates
the foundation soils; therefore, proper drainage should be provided in the final design and
during construction and throughout the life of the structures. Failure to maintain the proper
drainage as recommended in the 4.2.7 Grading and Drainage section of this report will nullify
the movement estimates provided above.
4.3.2 Spread Footings - Construction Considerations
Spread footing construction should only be considered if the estimated foundation movement
can be tolerated. Subgrade soils beneath footings should be moisture conditioned and
compacted as described in the 4.2 Earthwork section of this report. The moisture content and
compaction of subgrade soils should be maintained until foundation construction.
Footings and foundation walls should be reinforced as necessary to reduce the potential for
distress caused by differential foundation movement.
Unstable subgrade conditions are anticipated as excavations approach the groundwater
surface. Unstable surfaces will need to be stabilized prior to backfilling excavations and/or
constructing the building foundation, floor slab and/or project pavements. The use of angular
rock, recycled concrete and/or gravel pushed or “crowded” into the yielding subgrade is
considered suitable means of stabilizing the subgrade. The use of geogrid materials in
conjunction with gravel could also be considered and could be more cost effective.
Unstable subgrade conditions should be observed by Terracon to assess the subgrade and
provide suitable alternatives for stabilization. Stabilized areas should be proof-rolled prior to
continuing construction to assess the stability of the subgrade.
Foundation excavations should be observed by Terracon. If the soil conditions encountered
differ significantly from those presented in this report, supplemental recommendations will be
required.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 14
4.3.3 Helical Pile Foundations
We believe helical piles bottomed in bedrock are an appropriate alternative for support of the
proposed pedestrian bridges. Design recommendations for helical pile foundations and related
structural elements are presented in the following paragraphs.
Description Value
Bearing material Claystone bedrock
Anticipated pile length About 18 to 25 feet from existing grade
Net allowable end-bearing pressure 1 25,000 psf
Individual pile settlement About ½ inch
Void thickness (between piles and below pile
caps) 2 inches
1. The design bearing pressure applies to dead loads plus design live load conditions. The design
bearing pressure may be increased by one-third when considering total loads that include wind or
seismic conditions.
We do not recommend using vertically installed helical piles to resist lateral loads without
approved lateral load test data, as these types of foundations are typically designed to resist
axial loads. Only the horizontal component of the allowable axial load should be considered to
resist the lateral loading and only in the direction of the batter. Terracon should be retained to
observe helical pile installation to verify that proper bearing materials have been encountered
during installation.
If a helical pile foundation system is selected by the project team, we recommend the helical pile
designer follow the recommendations presented in Chapter 18 of the 2009/2012 International
Building Code (IBC). We recommend the helical bearing plates for each helical pile bear in the
claystone bedrock encountered below the site. We do not recommend helical bearing plates
bottomed in native clay soils. The helical pile designer should select the size and number of
helical bearing plates for each helical pile based on planned loads and bearing materials
described in our exploratory boring logs. Torque measurements during installation of helical piles
should be used to verify the axial capacity of the helical piles. We recommend the helical pile
installation contractor provide confirmation that the installation equipment has been calibrated
within one year of installation at this project. The helical foundations should be installed per the
manufacturer’s recommendations.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 15
4.3.4 Drilled Piers Bottomed in Bedrock - Design Recommendations
Description Value
Minimum pier length 30 feet
Minimum pier diameter 18 inches
Minimum bedrock embedment 1 10 feet
Maximum allowable end-bearing pressure 25,000 psf
Allowable skin friction (for portion of pier embedded into bedrock) 2,000 psf
Uplift force (tension due to soil uplift, kips) 2 8 x Pier diameter (ft.)
Void thickness (beneath grade beams) 4 inches
1. Drilled piers should be embedded into hard or very hard bedrock materials. Actual structural
loads and pier diameters may dictate embedment deeper than the recommended minimum
penetration.
2. Required pier penetration should be balanced against uplift forces for the portion of the pier in
firm or harder bedrock below a depth of 16 feet to resist axial loads and uplift forces.
Piers should be considered to work in group action if the horizontal spacing is less than three
pier diameters. A minimum practical horizontal clear spacing between piers of at least three
diameters should be maintained, and adjacent piers should bear at the same elevation. The
capacity of individual piers must be reduced when considering the effects of group action.
Capacity reduction is a function of pier spacing and the number of piers within a group. If group
action analyses are necessary, capacity reduction factors can be provided for the analyses.
To satisfy forces in the horizontal direction using LPILE, piers may be designed for the following
lateral load criteria:
Parameters Clay Sand and
Gravel
Claystone
Bedrock
LPILE soil type1
Stiff clay
without free
water
Sand
(submerged)
Stiff clay
without free
water
Unit weight (pcf) 120 125 130
Average undrained shear strength (psf) 500 N/A 9,000
Average angle of internal friction, ) (degrees) N/A 35 N/A
Coefficient of subgrade reaction, k (pci)*
100 - static
30 - cyclic
60
2,000- static
800 – cyclic
Strain, H50 (%) 0.010 N/A 0.004
1. For purposes of LPILE analysis, assume a groundwater elevation of approximately 4891 feet.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 16
4.3.5 Drilled Piers Bottomed in Bedrock - Construction Considerations
Drilling to design depth should be possible with conventional single-flight power augers on the
majority of the site; however, specialized drilling equipment may be required for very hard bedrock
layers. In addition, caving soils and groundwater indicate that temporary steel casing will be
required to properly drill the piers prior to concrete placement.
Groundwater should be removed from each pier hole prior to concrete placement. Pier concrete
should be placed immediately after completion of drilling and cleaning. If pier concrete cannot
be placed in dry conditions, a tremie should be used for concrete placement. Free-fall concrete
placement in piers will only be acceptable if provisions are taken to avoid striking the concrete
on the sides of the hole or reinforcing steel. The use of a bottom-dump hopper, or an elephant's
trunk discharging near the bottom of the hole where concrete segregation will be minimized, is
recommended. Due to potential sloughing and raveling, foundation concrete quantities may
exceed calculated geometric volumes.
Casing should be withdrawn in a slow continuous manner maintaining a sufficient head of
concrete to prevent infiltration of water or caving soils or the creation of voids in pier concrete.
Pier concrete should have a relatively high fluidity when placed in cased pier holes or through a
tremie. Pier concrete with slump in the range of 5 to 7 inches is recommended.
We recommend the sides of each pier should be mechanically roughened in the claystone
bearing strata. This should be accomplished by a roughening tooth placed on the auger. Shaft
bearing surfaces must be cleaned prior to concrete placement. A representative of Terracon
should observe the bearing surface and shaft configuration.
4.4 Seismic Considerations
Code Used Site Classification
2012 International Building Code (IBC) 1 C 2
1. In general accordance with the 2012 International Building Code, Table 1613.5.2.
2. The 2012 International Building Code (IBC) requires a site soil profile determination extending a
depth of 100 feet for seismic site classification. The current scope requested does not include the
required 100 foot soil profile determination. The borings completed for this project extended to a
maximum depth of about 20½ feet and this seismic site class definition considers that similar soil and
bedrock conditions exist below the maximum depth of the subsurface exploration. Additional
exploration to deeper depths could be performed to confirm the conditions below the current depth of
exploration. Alternatively, a geophysical exploration could be utilized in order to attempt to justify a
more favorable seismic site class. However, we believe a higher seismic site class for this site is
unlikely.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 17
4.5 Floor Systems
A slab-on-grade may be utilized for the interior floor system for the proposed restrooms, shelters
and other site structures. If very little movement can be tolerated, a structurally-supported floor
system, supported independent of the subgrade materials, is recommended.
Subgrade soils beneath interior and exterior slabs should be scarified to a depth of at least 10
inches, moisture conditioned and compacted. The moisture content and compaction of
subgrade soils should be maintained until slab construction.
4.5.1 Floor System - Design Recommendations
Even when bearing on properly prepared soils, movement of the slab-on-grade floor system is
possible should the subgrade soils undergo an increase in moisture content. We estimate
movement of about 1 inch is possible. If the owner cannot accept the risk of slab movement, a
structural floor should be used. If conventional slab-on-grade is utilized, the subgrade soils
should be prepared as described in the 4.2 Earthwork section of this report.
For structural design of concrete slabs-on-grade subjected to point loadings, a modulus of
subgrade reaction of 100 pounds per cubic inch (pci) may be used for floors supported on re-
compacted existing soils at the site. A modulus of 200 pci may be used for floors supported on
at least 1 foot of non-expansive, imported granular fill.
Additional floor slab design and construction recommendations are as follows:
Positive separations and/or isolation joints should be provided between slabs and all
foundations, columns, or utility lines to allow independent movement.
Control joints should be saw-cut in slabs in accordance with ACI Design Manual,
Section 302.1R-37 8.3.12 (tooled control joints are not recommended) to control the
location and extent of cracking.
Interior utility trench backfill placed beneath slabs should be compacted in accordance
with the recommendations presented in the 4.2 Earthwork section of this report.
Floor slabs should not be constructed on frozen subgrade.
A minimum 2-inch void space should be constructed below non-bearing partition walls
placed on the floor slab. Special framing details should be provided at doorjambs and
frames within partition walls to avoid potential distortion. Partition walls should be
isolated from suspended ceilings.
The use of a vapor retarder should be considered beneath concrete slabs that will be
covered with wood, tile, carpet or other moisture sensitive or impervious floor
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 18
coverings, or when the slab will support equipment sensitive to moisture. When
conditions warrant the use of a vapor retarder, the slab designer and slab contractor
should refer to ACI 302 for procedures and cautions regarding the use and placement
of a vapor retarder.
Other design and construction considerations, as outlined in the ACI Design Manual,
Section 302.1R are recommended.
4.5.2 Floor Systems - Construction Considerations
Movements of slabs-on-grade using the recommendations discussed in previous sections of this
report will likely be reduced and tend to be more uniform. The estimates discussed above
assume that the other recommendations in this report are followed. Additional movement could
occur should the subsurface soils become wetted to significant depths, which could result in
potential excessive movement causing uneven floor slabs and severe cracking. This could be
due to over watering of landscaping, poor drainage, improperly functioning drain systems,
and/or broken utility lines. Therefore, it is imperative that the recommendations presented in
this report be followed.
Some differential movement of a slab-on-grade floor system is possible if the moisture content
of the subgrade soils is increased. To reduce potential slab movements, the subgrade soils
should be prepared as described in section 4.2 Earthwork of this report.
4.6 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. Active earth pressure is commonly used for design of
free-standing cantilever retaining walls and assumes wall movement. The "at-rest" condition
assumes no wall movement. The recommended design lateral earth pressures do not include a
factor of safety and do not provide for possible hydrostatic pressure on the walls.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 19
EARTH PRESSURE COEFFICIENTS
Earth Pressure
Conditions
Coefficient for
Backfill Type
Equivalent Fluid
Density (pcf)
Surcharge
Pressure,
p1 (psf)
Earth
Pressure,
p2 (psf)
Active (Ka)
Import Fill - 0.28
Sandy lean Clay - 0.41
38
49
(0.28)S
(0.41)S
(38)H
(49)H
At-Rest (Ko)
Import Fill - 0.43
Sandy lean Clay - 0.58
58
70
(0.43)S
(0.58)S
(58)H
(70)H
Passive (Kp)
Import Fill - 3.69
Sandy lean Clay - 2.46
498
295
---
---
---
---
Applicable conditions to the above include:
For active earth pressure, wall must rotate about base, with top lateral movements of about
0.002 H to 0.004 H, where H is wall height;
For passive earth pressure to develop, wall must move horizontally to mobilize resistance;
Uniform surcharge, where S is surcharge pressure;
In-situ soil backfill weight a maximum of 120 pcf;
Horizontal backfill, compacted between 95 and 98 percent of maximum dry unit weight as
determined by ASTM D698;
Loading from heavy compaction equipment not included;
No hydrostatic pressures acting on wall;
No dynamic loading;
No safety factor included in soil parameters; and
Ignore passive pressure in frost zone.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 20
To control hydrostatic pressure behind the wall we recommend that a drain be installed at the
foundation wall with a collection pipe leading to a reliable discharge. If this is not possible, then
combined hydrostatic and lateral earth pressures should be calculated for lean clay backfill
using an equivalent fluid weighing 90 and 100 pcf for active and at-rest conditions, respectively.
For granular backfill, an equivalent fluid weighing 85 and 90 pcf should be used for active and
at-rest, respectively. These pressures do not include the influence of surcharge, equipment or
floor loading, which should be added. Heavy equipment should not operate within a distance
closer than the exposed height of retaining walls to prevent lateral pressures more than those
provided.
4.7 Pavements
4.7.1 Pavements – Subgrade Preparation
On most project sites, the site grading is accomplished relatively early in the construction phase.
Fills are typically placed and compacted in a uniform manner. However as construction
proceeds, the subgrade may be disturbed due to construction traffic, desiccation, or
rainfall/snow melt. As a result, the pavement subgrade may not be suitable for pavement
construction and corrective action will be required. The subgrade should be carefully evaluated
at the time of pavement construction for signs of disturbance or instability. We recommend the
pavement subgrade for conventional pavements be thoroughly proofrolled with a loaded
tandem-axle dump truck prior to final grading and paving. All conventional pavement areas
should be moisture conditioned and properly compacted to the recommendations in this report
immediately prior to paving.
As required by Larimer County Urban Areas Street Standards (LCUASS), the Final Pavement
Design Report for city-maintained roadways should occur after grading for roadways and utility
installation is complete. Terracon can assist with final design of city-maintained roadways
following roadway grading and utility installation, upon your request.
4.7.2 Pavements – Permeable Pavements Subgrade Preparation
Unlike conventional pavements, permeable pavement subgrades are not compacted. When
preparing the subgrade for permeable pavements, care should be taken to excavate the
required reservoir storage volume without disturbing the underlying soils. It may be prudent to
scarify the subgrade soils prior to placement of the materials for the rock reservoir.
Groundwater was encountered at depths of about 6.9 to 18.9 feet below existing site grades in
the portion of the site planned for permeable pavements. Shallow groundwater will reduce
infiltration rates as the water stored within the rock reservoir layer infiltrates into the ground.
We recommend infiltration testing be completed in the areas of the site planned for permeable
pavements. The City of Fort Collins prefers double-ring infiltrometer testing for permeable
placements. Terracon is available to conduct double-ring infiltrometer testing upon your
request.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 21
4.7.3 Pavements – Design Recommendations
Design of pavements for the project have been based on the procedures outlined in the 1993
Guideline for Design of Pavement Structures prepared by the American Association of State
Highway and Transportation Officials (AASHTO) and the Larimer County Urban Area Street
Standards (LCUASS).
Traffic patterns and anticipated loading conditions were not available at the time that this report
was prepared. However, we anticipate that the new parking areas (i.e., light-duty) will be
primarily used by personal vehicles (cars and pick-up trucks). Delivery trucks and refuse
disposal vehicles will be expected in the drive lanes and loading areas (i.e., medium-duty). For
our pavement thicknesses design recommendations, we assumed a 18-kip equivalent single-
axle load (ESAL) of 73,000 for automobile parking areas and an ESAL of 150,000 for heavy
truck traffic areas. These assumed traffic design values should be verified by the civil engineer
or owner prior to final design and construction. If the actual traffic values vary from the
assumed values, the pavement thickness recommendations may not be applicable. When the
actual traffic design information is available Terracon should be contacted so that the design
recommendations can be reviewed and revised if necessary.
For flexible pavement design, a terminal serviceability index of 2.0 was utilized along with an
inherent reliability of 85 percent and a design life of 20 years. Using the correlated design R-value
of 5, appropriate ESAL, environmental criteria and other factors, the structural numbers (SN) of the
pavement sections were determined on the basis of the 1993 AASHTO design equation.
In addition to the flexible pavement design analyses, a rigid pavement design analysis was
completed based upon AASHTO design procedures. Rigid pavement design is based on an
evaluation of the Modulus of Subgrade Reaction of the soils (k-value), the Modulus of Rupture
of the concrete, and other factors previously outlined. The design k-value of 63 for the
subgrade soil was determined by correlation to the laboratory test results. A modulus of rupture
of 580 psi (working stress 435 psi) was used for pavement concrete. The rigid pavement
thickness for each traffic category was determined on the basis of the AASHTO design
equation.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 22
Recommended minimum pavement sections are provided in the table below.
Traffic
Area
Alternative
Recommended Pavement Thicknesses (Inches)
Asphaltic
Concrete
Surface
Aggregate Base
Course
Portland
Cement
Concrete
Porous
Pavers Total
Automobile
parking
areas
(light-duty)
A 4 8 -- -- 12
B -- -- 6 -- 6
C -- 3 -- ǩ “ ǩ”
Heavy
truck traffic
areas
(heavy-
duty)
A 5 8 -- -- 13
B -- -- 6½ -- 6½
Terracon recommends the design and construction of porous pavers should be completed by a
specialty contractor who has demonstrated experience with placing, compacting, finishing,
edging, jointing, and protecting porous pavers. There are several choices for base course
depending upon which type of porous paver is chosen. Terracon recommends constructing
perimeter curbing around porous pavers and between conventional and porous pavers to
reduce infiltration of water below moisture sensitive subgrades.
Aggregate base course below traditional pavements (if used on the site) should consist of a
blend of sand and gravel which meets strict specifications for quality and gradation. Use of
materials meeting Colorado Department of Transportation (CDOT) Class 5 or 6 specifications is
recommended for aggregate base course. Aggregate base course should be placed in lifts not
exceeding 6 inches and compacted to a minimum of 95 percent of the maximum dry unit weight
as determined by ASTM D698.
Asphaltic concrete should be composed of a mixture of aggregate, filler and additives (if
required) and approved bituminous material. The asphalt concrete should conform to approved
mix designs stating the Superpave properties, optimum asphalt content, job mix formula and
recommended mixing and placing temperatures. Aggregate used in asphalt concrete should
meet particular gradations. We recommend using a Superpave asphalt mix for this project
consisting of Grading S, Ndesign=75 gyrations with a PG 64-22 binder. Mix designs should be
submitted prior to construction to verify their adequacy. Asphalt material should be placed in
maximum 3-inch lifts and compacted within a range of 92 to 96 percent of the theoretical
maximum (Rice) density (ASTM D2041).
Where rigid pavements are used, the concrete should be obtained from an approved mix design
with the following minimum properties (Class “P”, refer to LCUASS Chapter 22 and 23):
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 23
Properties Value
Compressive strength 4,000 psi
Cement type Type I or II portland cement
Entrained air content (%) 4 to 8
Concrete aggregate ASTM C33 and CDOT Section 703
Concrete used for trails, flatwork, and general use should be obtained from an approved mix
design that meets the CDOT Class B Concrete, Class P may also be substituted for the Class B
concrete.
Concrete should be deposited by truck mixers or agitators and placed a maximum of 90 minutes
from the time the water is added to the mix. Longitudinal and transverse joints should be
provided as needed in concrete pavements for expansion/contraction and isolation per ACI 325.
The location and extent of joints should be based upon the final pavement geometry. Joints
should be sealed to prevent entry of foreign material and doweled where necessary for load
transfer.
Although not required for structural support, a minimum 4-inch thick aggregate base course
layer is recommended for the PCC pavements to help reduce the potential for slab curl,
shrinkage cracking, and subgrade “pumping” through joints. Proper joint spacing will also be
required for PCC pavements to prevent excessive slab curling and shrinkage cracking. All joints
should be sealed to prevent entry of foreign material and dowelled where necessary for load
transfer.
For areas subject to concentrated and repetitive loading conditions such as dumpster pads and
ingress/egress aprons, we recommend using a portland cement concrete pavement with a
thickness of at least 6 inches underlain by at least 4 inches of granular base. Prior to placement
of the granular base, the areas should be thoroughly proofrolled. For dumpster pads, the
concrete pavement area should be large enough to support the container and tipping axle of the
refuse truck.
Pavement performance is affected by its surroundings. In addition to providing preventive
maintenance, the civil engineer should consider the following recommendations in the design
and layout of pavements:
Site grades should slope a minimum of 2 percent away from the pavements;
The subgrade and the pavement surface have a minimum 2 percent slope to promote proper
surface drainage;
Consider appropriate edge drainage and pavement under drain systems;
Install pavement drainage surrounding areas anticipated for frequent wetting;
Install joint sealant and seal cracks immediately;
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 24
Seal all landscaped areas in, or adjacent to pavements to reduce moisture migration to
subgrade soils; and
Placing compacted, low permeability backfill against the exterior side of curb and gutter.
4.7.4 Pavements – Construction Considerations
Openings in pavement, such as landscape islands, are sources for water infiltration into
surrounding pavements. Water collects in the islands and migrates into the surrounding
subgrade soils thereby degrading support of the pavement. This is especially applicable for
islands with raised concrete curbs, irrigated foliage, and low permeability near-surface soils. The
civil design for the pavements with these conditions should include features to restrict or to
collect and discharge excess water from the islands. Examples of features are edge drains
connected to the storm water collection system or other suitable outlet and impermeable
barriers preventing lateral migration of water such as a cutoff wall installed to a depth below the
pavement structure.
4.7.5 Pavements – Maintenance
Preventative maintenance should be planned and provided for an ongoing pavement
management program in order to enhance future pavement performance. Preventive
maintenance consists of both localized maintenance (e.g. crack and joint sealing and patching)
and global maintenance (e.g. surface sealing). Preventative maintenance is usually the first
priority when implementing a planned pavement maintenance program and provides the highest
return on investment for pavements.
Permeable pavements require periodic inspection and cleaning. Consideration should be given
to installing signage to restrict heavily loaded vehicles (i.e. trash trucks, delivery trucks, etc.)
from driving on permeable pavement areas. Also, maintenance of permeable pavements should
be completed by properly trained workers.
5.0 GENERAL COMMENTS
Terracon should be retained to review the final design plans and specifications so comments
can be made regarding interpretation and implementation of our geotechnical recommendations
in the design and specifications. Terracon also should be retained to provide observation and
testing services during grading, excavation, foundation construction and other earth-related
construction phases of the project.
The analysis and recommendations presented in this report are based upon the data obtained
from the borings performed at the indicated locations and from other information discussed in
this report. This report does not reflect variations that may occur between borings, across the
site, or due to the modifying effects of construction or weather. The nature and extent of such
variations may not become evident until during or after construction. If variations appear, we
should be immediately notified so that further evaluation and supplemental recommendations
can be provided.
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable 25
The scope of services for this project does not include either specifically or by implication any
environmental or biological (e.g., mold, fungi, and bacteria) assessment of the site or
identification or prevention of pollutants, hazardous materials or conditions. If the owner is
concerned about the potential for such contamination or pollution, other studies should be
undertaken.
This report has been prepared for the exclusive use of our client for specific application to the
project discussed and has been prepared in accordance with generally accepted geotechnical
engineering practices. No warranties, either express or implied, are intended or made. Site
safety, excavation support, and dewatering requirements are the responsibility of others. In the
event that changes in the nature, design, or location of the project as described in this report are
planned, the conclusions and recommendations contained in this report shall not be considered
valid unless Terracon reviews the changes and either verifies or modifies the conclusions of this
report in writing.
APPENDIX A
FIELD EXPLORATION
TOPOGRAPHIC MAP IMAGE COURTESY OF SITE LOCATION MAP
THE U.S. GEOLOGICAL SURVEY
QUADRANGLES INCLUDE: FORT COLLINS,
CO (1/1/1984), TIMNATH, CO (1/1/1971),
LOVELAND, CO (1/1/1984) and WINDSOR, CO
(1/1/1969). Southeast Community Park
Northeast of Ziegler Road and Kechter Road
Fort Collins, CO
1901 Sharp Point Dr Suite C
Ft. Collins, CO
20135017
DIAGRAM IS FOR GENERAL LOCATION ONLY,
AND IS NOT INTENDED FOR CONSTRUCTION
PURPOSES
Project Manager:
Drawn by:
Checked by:
Approved by:
BCR
EDB
EDB
EDB
1:24,000
5/13/2014
Project No.
Scale:
File Name:
Date:
A-1
Exhibit
0’ 100’ 200’
APPROXIMATE SCALE
Scale:
EDB
BCR
EDB
EDB
Project Manager:
Drawn by:
Checked by:
Approved by:
EXPLORATION PLAN
A-2
20135017Exhibit
5/13/2014
1=200’
Project No.
File Name:
Date:
DIAGRAM IS FOR GENERAL LOCATION ONLY, AND
IS NOT INTENDED FOR CONSTRUCTION PURPOSES
1 APPROXIMATE BORING LOCATION
LEGEND
3
4
5
7 6
8
1
2
1901 Sharp Point Drive, Suite C Fort Collins, Colorado 80525
PH. (970) 484-0359 FAX. (970) 484-0454
Southeast Community Park
Northeast of Ziegler Road and Kechter Road
Fort Collins, CO
APPROXIMATE TOPSOIL SAMPLING
LOCATION
1
2
3
1
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable Exhibit A-3
Field Exploration Description
The locations of borings were based upon the proposed development shown on the provided
site plan. The borings were located in the field by measuring from existing site features. The
ground surface elevation was interpolated at each boring location from the grading plans
provided to us by the client.
The borings were drilled with a CME-75 truck-mounted rotary drill rig with solid-stem augers.
During the drilling operations, lithologic logs of the borings were recorded by the field engineer.
Disturbed samples were obtained at selected intervals utilizing a 2-inch outside diameter split-
spoon sampler and a 3-inch outside diameter ring-barrel sampler. Penetration resistance
values were recorded in a manner similar to the standard penetration test (SPT). This test
consists of driving the sampler into the ground with a 140-pound hammer free-falling through a
distance of 30 inches. The number of blows required to advance the ring-barrel sampler 12
inches (18 inches for standard split-spoon samplers, final 12 inches are recorded) or the interval
indicated, is recorded as a standard penetration resistance value (N-value). The blow count
values are indicated on the boring logs at the respective sample depths. Ring-barrel sample
blow counts are not considered N-values.
A CME automatic SPT hammer was used to advance the samplers in the borings performed on
this site. A greater efficiency is typically achieved with the automatic hammer compared to the
conventional safety hammer operated with a cathead and rope. Published correlations between
the SPT values and soil properties are based on the lower efficiency cathead and rope method.
This higher efficiency affects the standard penetration resistance blow count value by increasing
the penetration per hammer blow over what would be obtained using the cathead and rope
method. The effect of the automatic hammer's efficiency has been considered in the interpretation
and analysis of the subsurface information for this report.
The standard penetration test provides a reasonable indication of the in-place density of sandy
type materials, but only provides an indication of the relative stiffness of cohesive materials
since the blow count in these soils may be affected by the moisture content of the soil. In
addition, considerable care should be exercised in interpreting the N-values in gravelly soils,
particularly where the size of the gravel particle exceeds the inside diameter of the sampler.
Groundwater measurements were obtained in the borings at the time of site exploration and
several days after drilling. After subsequent groundwater measurements were obtained, the
borings were backfilled with auger cuttings and sand (if needed). Some settlement of the
backfill and/or patch may occur and should be repaired as soon as possible.
Grab samples of topsoil materials were obtained at the locations selected by other members of
the project team. The topsoil samples were placed in sealed baggies and delivered to Colorado
State University for nutrient analysis.
0.3
7.0
10.0
13.0
20.5
VEGETATIVE LAYER - 4 inches
LEAN CLAY WITH SAND (CL), trace calcareous
nodules, brown and white, very stiff
SILTY CLAYEY SAND, fine to medium grained,
brown rust and olive, loose
WEATHERED SEDIMENTARY BEDROCK -
CLAYSTONE, gray rust and olive
SEDIMENTARY BEDROCK - CLAYSTONE, brown
gray and rust, firm to medium hard
Boring Terminated at 20.5 Feet
15-17
4-4-5
N=9
9-11-14
N=25
18-17-25
N=42
0.029
15 73
17
20
18
101 48-21-27
4900.5
4894
4891
4888
4880.5
0.4
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
LOCATION
DEPTH
Latitude: 40.511464° Longitude: -105.018661°
GRAPHIC LOG
See Exhibit A-2
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20135017.GPJ TEMPLATE UPDATE 3-31-14.GPJ 6/3/14
Northeast of Ziegler Road and Kechter Road
Fort Collins, Colorado
SITE:
PROJECT: Southeast Community Park
Page 1 of 1
Advancement Method:
4-inch solid stem augers
Abandonment Method:
Borings backfilled with soil cuttings upon completion.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Notes:
Project No.: 20135017
Drill Rig: CME-75
Boring Started: 4/7/2014
BORING LOG NO. 1
CLIENT: Civitas, Inc.
Denver, Colorado
Driller: Drilling Engineers, Inc.
0.4
16.0
20.0
20.5
VEGETATIVE LAYER - 5 inches
SANDY LEAN CLAY (CL), trace gravel, brown to
reddish-brown to olive, stiff to very stiff
WELL GRADED SAND WITH GRAVEL, fine to
coarse grained, brown, dense
SANDY LEAN CLAY, brown, stiff
Boring Terminated at 20.5 Feet
10-8
7-7
7-8
8-14
15-15-5
N=20
55
10
11
10
19
16
86
96
101
105
36-18-18
4904.5
4889
4885
4884.5
-2.4
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
LOCATION
DEPTH
Latitude: 40.511823° Longitude: -105.014733°
GRAPHIC LOG
See Exhibit A-2
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20135017.GPJ TEMPLATE UPDATE 3-31-14.GPJ 6/3/14
Northeast of Ziegler Road and Kechter Road
Fort Collins, Colorado
SITE:
PROJECT: Southeast Community Park
Page 1 of 1
Advancement Method:
4-inch solid stem augers
Abandonment Method:
Borings backfilled with soil cuttings upon completion.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Notes:
Project No.: 20135017
Drill Rig: CME-75
Boring Started: 4/7/2014
BORING LOG NO. 2
CLIENT: Civitas, Inc.
Denver, Colorado
Driller: Drilling Engineers, Inc.
Boring Completed: 4/7/2014
0.4
7.0
17.0
20.5
VEGETATIVE LAYER - 5 inches
SANDY LEAN CLAY, trace calcareous nodules,
brown dark brown and white, very stiff
WELL GRADED SAND WITH SILT AND GRAVEL
(SW-SM), fine to coarse grained, brown, medium
dense
A 6-inch lean clay lense was encountered at a depth
of approximately 14.5 feet below the ground surface.
SEDIMENTARY BEDROCK - CLAYSTONE, trace
sand, brown gray and olive, firm
Boring Terminated at 20.5 Feet
13-26
15-25
6-14-15
N=29
7-14-15
N=29
10-14-13
N=27
6
13
16
18
13
22
113
108
NP
4897
4890
4880
4876.5
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
LOCATION
DEPTH
Latitude: 40.510775° Longitude: -105.014684°
GRAPHIC LOG
See Exhibit A-2
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20135017.GPJ TEMPLATE UPDATE 3-31-14.GPJ 6/3/14
Northeast of Ziegler Road and Kechter Road
Fort Collins, Colorado
SITE:
PROJECT: Southeast Community Park
Page 1 of 1
Advancement Method:
4-inch solid stem augers
Abandonment Method:
Borings backfilled with soil cuttings upon completion.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Notes:
Project No.: 20135017
Drill Rig: CME-75
Boring Started: 4/7/2014
BORING LOG NO. 3
CLIENT: Civitas, Inc.
0.3
9.0
12.0
19.0
20.5
VEGETATIVE LAYER - 4 inches
SANDY LEAN CLAY, light brown, stiff
LEAN CLAY, trace sand, brown, stiff
WELL GRADED SAND WITH SILT AND GRAVEL,
fine to coarse grained, brown, medium dense
LEAN CLAY WITH SAND, brown rust and gray, stiff
Boring Terminated at 20.5 Feet
7-8
5-6
3-4-4
N=8
13-14-10
N=24
3-4-4
N=8
13
16
23
13
21
118
105
4893
4884.5
4881.5
4874.5
4873
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
LOCATION
DEPTH
Latitude: 40.510156° Longitude: -105.012061°
GRAPHIC LOG
See Exhibit A-2
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20135017.GPJ TEMPLATE UPDATE 3-31-14.GPJ 6/3/14
Northeast of Ziegler Road and Kechter Road
Fort Collins, Colorado
SITE:
PROJECT: Southeast Community Park
Page 1 of 1
Advancement Method:
4-inch solid stem augers
Abandonment Method:
Borings backfilled with soil cuttings upon completion.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Notes:
Project No.: 20135017
Drill Rig: CME-75
Boring Started: 4/7/2014
BORING LOG NO. 4
CLIENT: Civitas, Inc.
Denver, Colorado
Driller: Drilling Engineers, Inc.
Boring Completed: 4/7/2014
Exhibit: A-7
0.4
6.0
11.0
13.0
17.0
20.5
VEGETATIVE LAYER - 5 inches
CLAYEY SAND, trace calcareous nodules, fine
grained, light brown to reddish-brown, loose to
medium dense
SANDY LEAN CLAY (CL), olive and gray, very stiff
WELL GRADED SAND WITH GRAVEL, fine to
coarse grained, brown
SILTY SAND, fine grained, brown, medium dense
SEDIMENTARY BEDROCK - CLAYSTONE, olive
rust and gray, firm
Boring Terminated at 20.5 Feet
9-11
8-10
9-13
11-13-6
N=19
10-14-13
N=27
70
7
9
19
21
22
101
94
105 41-19-22
4900.5
4895
4890
4888
4884
4880.5
-0.4
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
LOCATION
DEPTH
Latitude: 40.509633° Longitude: -105.014667°
GRAPHIC LOG
See Exhibit A-2
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20135017.GPJ TEMPLATE UPDATE 3-31-14.GPJ 6/3/14
Northeast of Ziegler Road and Kechter Road
Fort Collins, Colorado
SITE:
PROJECT: Southeast Community Park
Page 1 of 1
Advancement Method:
4-inch solid stem augers
Abandonment Method:
Borings backfilled with soil cuttings upon completion.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Notes:
Project No.: 20135017
0.4
2.5
4.0
12.0
19.0
20.5
VEGETATIVE LAYER - 5 inches
SANDY LEAN CLAY, light brown, stiff
SILTY SAND, trace gravel, fine to medium grained,
white, medium dense
LEAN CLAY WITH SAND (CL), trace sand, brown,
stiff to very stiff
WELL GRADED SAND WITH SILT, trace gravel,
fine to coarse grained, brown, dense
SEDIMENTARY BEDROCK - CLAYSTONE, gray
olive and brown, hard
Boring Terminated at 20.5 Feet
8-13
14-11
8-7
7-14-23
N=37
12-23-27
N=50
0.014
74
12
9
22
15
19
91
105
107 49-14-35
4897.5
4895.5
4894
4886
4879
4877.5
0.0
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
LOCATION
DEPTH
Latitude: 40.509987° Longitude: -105.01501°
GRAPHIC LOG
See Exhibit A-2
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20135017.GPJ TEMPLATE UPDATE 3-31-14.GPJ 6/3/14
Northeast of Ziegler Road and Kechter Road
Fort Collins, Colorado
SITE:
PROJECT: Southeast Community Park
Page 1 of 1
Advancement Method:
4-inch solid stem augers
Abandonment Method:
Borings backfilled with soil cuttings upon completion.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Notes:
0.5
4.0
14.0
16.0
20.5
VEGETATIVE LAYER - 6 inches
LEAN CLAY, trace gravel, brown, very stiff
SANDY LEAN CLAY, light brown, stiff to very stiff
SILTY SAND (SM), fine to medium grained, brown,
medium dense
LEAN CLAY, brown, stiff
Boring Terminated at 20.5 Feet
8-12
7-8
7-12
5-5-12
N=17
2-4-6
N=10
0.014
29
14
11
11
16
24
102
82
117
NP
4907.5
4904
4894
4892
4887.5
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
LOCATION
DEPTH
Latitude: 40.509891° Longitude: -105.018101°
GRAPHIC LOG
See Exhibit A-2
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20135017.GPJ TEMPLATE UPDATE 3-31-14.GPJ 6/3/14
Northeast of Ziegler Road and Kechter Road
Fort Collins, Colorado
SITE:
PROJECT: Southeast Community Park
Page 1 of 1
Advancement Method:
4-inch solid stem augers
Abandonment Method:
Borings backfilled with soil cuttings upon completion.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Notes:
Project No.: 20135017
Drill Rig: CME-75
Boring Started: 4/7/2014
BORING LOG NO. 7
CLIENT: Civitas, Inc.
Denver, Colorado
0.5
8.0
13.0
20.5
VEGETATIVE LAYER - 6 inches
SANDY LEAN CLAY, trace gravel, light brown white
and rust, very stiff
WELL GRADED SAND WITH SILT AND GRAVEL,
fine to coarse grained, brown, dense
SEDIMENTARY BEDROCK - CLAYSTONE, gray
olive and brown, medium hard
Boring Terminated at 20.5 Feet
12-17
10-22
12-23
9-13-19
N=32
11-19-27
N=46
0.029
8
10
12
19
18
99
113
114
4902
4894.5
4889.5
4882
Stratification lines are approximate. In-situ, the transition may be gradual. Hammer Type: Automatic
LOCATION
DEPTH
Latitude: 40.510791° Longitude: -105.018266°
GRAPHIC LOG
See Exhibit A-2
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20135017.GPJ TEMPLATE UPDATE 3-31-14.GPJ 6/3/14
Northeast of Ziegler Road and Kechter Road
Fort Collins, Colorado
SITE:
PROJECT: Southeast Community Park
Page 1 of 1
Advancement Method:
4-inch solid stem augers
Abandonment Method:
Borings backfilled with soil cuttings upon completion.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
Notes:
Project No.: 20135017
Drill Rig: CME-75
Boring Started: 4/7/2014
BORING LOG NO. 8
CLIENT: Civitas, Inc.
Denver, Colorado
Driller: Drilling Engineers, Inc.
Boring Completed: 4/7/2014
Exhibit: A-11
APPENDIX B
LABORATORY TESTING
Geotechnical Engineering Report
Southeast Community Park Ŷ Fort Collins, Colorado
June 18, 2014 Ŷ Terracon Project No. 20135017
Responsive Ŷ Resourceful Ŷ Reliable Exhibit B-1
Laboratory Testing Description
The soil and bedrock samples retrieved during the field exploration were returned to the
laboratory for observation by the project geotechnical engineer. At that time, the field
descriptions were reviewed and an applicable laboratory testing program was formulated to
determine engineering properties of the subsurface materials.
Laboratory tests were conducted on selected soil and bedrock samples. The results of these
tests are presented on the boring logs and in this appendix. The test results were used for the
geotechnical engineering analyses, and the development of foundation and earthwork
recommendations. The laboratory tests were performed in general accordance with applicable
locally accepted standards. Soil samples were classified in general accordance with the Unified
Soil Classification System described in Appendix C. Rock samples were visually classified in
general accordance with the description of rock properties presented in Appendix C.
Water content Plasticity index
Grain-size distribution
Consolidation/swell
Water-soluble sulfate content
Dry density
pH
Topsoil nutrients
0
10
20
30
40
50
60
0 20 40 60 80 100
CL or OL CH or OH
ML or OL
MH or OH
PL PI
4.0
4.0
9.0
9.0
9.0
14.0
Boring ID Depth Description
LEAN CLAY with SAND
SANDY LEAN CLAY
WELL-GRADED SAND with SILT and GRAVEL
SANDY LEAN CLAY
LEAN CLAY with SAND
SILTY SAND
CL
CL
SW-SM
CL
CL
SM
Fines
P
L
A
S
T
I
C
I
T
Y
I
N
D
E
X
LIQUID LIMIT
"U" Line
"A" Line
48
36
NP
41
49
NP
21
18
NP
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
6 16
20 30
40 50
1.5 6 200
810
0.133 21.2 5.8
14
LL PL PI
%Silt %Clay
1 4
3/4 1/2
60
fine
U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS HYDROMETER
NP NP 1.09
D100
Cc Cu
SILT OR CLAY
4
D30 D10 %Gravel %Sand
3 WELL-GRADED SAND with SILT and GRAVEL(SW-SM) NP
3 19 2.501 0.601
9.0 18.85
GRAIN SIZE IN MILLIMETERS
PERCENT FINER BY WEIGHT
coarse fine
3/8 3 100
3 2 140
COBBLES
GRAVEL SAND
USCS Classification
73.1
D60
coarse medium
9.0
Boring ID Depth
Boring ID Depth
GRAIN SIZE DISTRIBUTION
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 0.4 percent swell upon wetting under an applied pressure of 500 psf.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
PROJECT NUMBER: 20135017
PROJECT: Southeast Community Park
SITE: Northeast of Ziegler Road and Kechter
Road
Fort Collins, Colorado
CLIENT: Civitas, Inc.
Denver, Colorado
EXHIBIT: B-4
Specimen Identification
4.0 ft
Classification , pcf
1 101 15
WC, %
LEAN CLAY with SAND(CL)
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. CONSOL_STRAIN-USCS 20135017.GPJ TERRACON2012.GDT 6/3/14
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 2.4 percent compression under an applied pressure of 500 psf.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
PROJECT NUMBER: 20135017
PROJECT: Southeast Community Park
SITE: Northeast of Ziegler Road and Kechter
Road
Fort Collins, Colorado
CLIENT: Civitas, Inc.
Denver, Colorado
EXHIBIT: B-5
Specimen Identification
4.0 ft
Classification , pcf
2 96 7
WC, %
SANDY LEAN CLAY(CL)
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. CONSOL_STRAIN-USCS 20135017.GPJ TERRACON2012.GDT 6/3/14
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 0.4 percent compression upon wetting under an applied pressure of
500 psf.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
PROJECT NUMBER: 20135017
PROJECT: Southeast Community Park
SITE: Northeast of Ziegler Road and Kechter
Road
Fort Collins, Colorado
CLIENT: Civitas, Inc.
Denver, Colorado
EXHIBIT: B-6
Specimen Identification
9.0 ft
Classification , pcf
5 105 16
WC, %
SANDY LEAN CLAY(CL)
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. CONSOL_STRAIN-USCS 20135017.GPJ TERRACON2012.GDT 6/3/14
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited no movement upon wetting under an applied pressure of 1,000 psf.
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
PROJECT NUMBER: 20135017
PROJECT: Southeast Community Park
SITE: Northeast of Ziegler Road and Kechter
Road
Fort Collins, Colorado
CLIENT: Civitas, Inc.
Denver, Colorado
EXHIBIT: B-7
Specimen Identification
9.0 ft
Classification , pcf
6 107 17
WC, %
LEAN CLAY with SAND(CL)
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. CONSOL_STRAIN-USCS 20135017.GPJ TERRACON2012.GDT 6/3/14
APPENDIX C
SUPPORTING DOCUMENTS
Exhibit: C-1
Unconfined
Compressive
Strength
Qu, (tsf)
0.25 to 0.50
1.00 to 2.00
> 4.00
less than 0.25
0.50 to 1.00
2.00 to 4.00
Non-plastic
Low
Medium
High
DESCRIPTION OF SYMBOLS AND ABBREVIATIONS
Hand Penetrometer
Torvane
Dynamic Cone Penetrometer
Photo-Ionization Detector
Organic Vapor Analyzer
SAMPLING
WATER LEVEL
FIELD TESTS
(HP)
(T)
(DCP)
(PID)
(OVA)
GENERAL NOTES
Over 12 in. (300 mm)
12 in. to 3 in. (300mm to 75mm)
3 in. to #4 sieve (75mm to 4.75 mm)
#4 to #200 sieve (4.75mm to 0.075mm
Passing #200 sieve (0.075mm)
Particle Size
< 5
5 - 12
> 12
Percent of
Dry Weight
Descriptive Term(s)
of other constituents
RELATIVE PROPORTIONS OF FINES
0
1 - 10
11 - 30
> 30
Plasticity Index
Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have more than 50% of their dry
weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have
less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, and
silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents may be
added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are defined
on the basis of their in-place relative density and fine-grained soils on the basis of their consistency.
LOCATION AND ELEVATION NOTES
Percent of
Dry Weight
Major Component
of Sample
UNIFIED SOIL CLASSIFICATION SYSTEM
Exhibit C-2
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A
Soil Classification
Group
Symbol Group Name B
Coarse Grained Soils:
More than 50% retained
on No. 200 sieve
Gravels:
More than 50% of
coarse fraction retained
on No. 4 sieve
Clean Gravels:
Less than 5% fines C
Cu 4 and 1 Cc 3 E GW Well-graded gravel F
Cu 4 and/or 1 Cc 3 E GP Poorly graded gravel F
Gravels with Fines:
More than 12% fines C
Fines classify as ML or MH GM Silty gravel F,G,H
Fines classify as CL or CH GC Clayey gravel F,G,H
Sands:
50% or more of coarse
fraction passes No. 4
sieve
Clean Sands:
Less than 5% fines D
Cu 6 and 1 Cc 3 E SW Well-graded sand I
Cu 6 and/or 1 Cc 3 E SP Poorly graded sand I
Sands with Fines:
More than 12% fines D
Fines classify as ML or MH SM Silty sand G,H,I
Fines classify as CL or CH SC Clayey sand G,H,I
Fine-Grained Soils:
50% or more passes the
No. 200 sieve
Silts and Clays:
Liquid limit less than 50
Inorganic:
PI 7 and plots on or above “A” line J CL Lean clay K,L,M
PI 4 or plots below “A” line J ML Silt K,L,M
Organic:
Liquid limit - oven dried
0.75 OL
Organic clay K,L,M,N
Liquid limit - not dried Organic silt K,L,M,O
Silts and Clays:
Liquid limit 50 or more
Inorganic:
PI plots on or above “A” line CH Fat clay K,L,M
PI plots below “A” line MH Elastic Silt K,L,M
Organic:
Liquid limit - oven dried
0.75 OH
Organic clay K,L,M,P
Liquid limit - not dried Organic silt K,L,M,Q
Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat
A Based on the material passing the 3-inch (75-mm) sieve
B If field sample contained cobbles or boulders, or both, add “with cobbles
or boulders, or both” to group name.
DESCRIPTION OF ROCK PROPERTIES
Exhibit C-3
WEATHERING
Fresh Rock fresh, crystals bright, few joints may show slight staining. Rock rings under hammer if crystalline.
Very slight Rock generally fresh, joints stained, some joints may show thin clay coatings, crystals in broken face show
bright. Rock rings under hammer if crystalline.
Slight Rock generally fresh, joints stained, and discoloration extends into rock up to 1 in. Joints may contain clay. In
granitoid rocks some occasional feldspar crystals are dull and discolored. Crystalline rocks ring under hammer.
Moderate Significant portions of rock show discoloration and weathering effects. In granitoid rocks, most feldspars are dull
and discolored; some show clayey. Rock has dull sound under hammer and shows significant loss of strength
as compared with fresh rock.
Moderately severe All rock except quartz discolored or stained. In granitoid rocks, all feldspars dull and discolored and majority
show kaolinization. Rock shows severe loss of strength and can be excavated with geologist’s pick.
Severe All rock except quartz discolored or stained. Rock “fabric” clear and evident, but reduced in strength to strong
soil. In granitoid rocks, all feldspars kaolinized to some extent. Some fragments of strong rock usually left.
Very severe All rock except quartz discolored or stained. Rock “fabric” discernible, but mass effectively reduced to “soil” with
only fragments of strong rock remaining.
Complete Rock reduced to ”soil”. Rock “fabric” not discernible or discernible only in small, scattered locations. Quartz may
be present as dikes or stringers.
HARDNESS (for engineering description of rock – not to be confused with Moh’s scale for minerals)
Very hard Cannot be scratched with knife or sharp pick. Breaking of hand specimens requires several hard blows of
geologist’s pick.
Hard Can be scratched with knife or pick only with difficulty. Hard blow of hammer required to detach hand specimen.
Moderately hard Can be scratched with knife or pick. Gouges or grooves to ¼ in. deep can be excavated by hard blow of point of
a geologist’s pick. Hand specimens can be detached by moderate blow.
Medium Can be grooved or gouged 1/16 in. deep by firm pressure on knife or pick point. Can be excavated in small
chips to pieces about 1-in. maximum size by hard blows of the point of a geologist’s pick.
Soft Can be gouged or grooved readily with knife or pick point. Can be excavated in chips to pieces several inches in
size by moderate blows of a pick point. Small thin pieces can be broken by finger pressure.
Very soft Can be carved with knife. Can be excavated readily with point of pick. Pieces 1-in. or more in thickness can be
broken with finger pressure. Can be scratched readily by fingernail.
Joint, Bedding, and Foliation Spacing in Rock
a
Spacing Joints Bedding/Foliation
Less than 2 in. Very close Very thin
2 in. – 1 ft. Close Thin
1 ft. – 3 ft. Moderately close Medium
3 ft. – 10 ft. Wide Thick
More than 10 ft. Very wide Very thick
a. Spacing refers to the distance normal to the planes, of the described feature, which are parallel to each other or nearly so.
Rock Quality Designator (RQD) a Joint Openness Descriptors
RQD, as a percentage Diagnostic description Openness Descriptor
Exceeding 90 Excellent No Visible Separation Tight
90 – 75 Good Less than 1/32 in. Slightly Open
75 – 50 Fair 1/32 to 1/8 in. Moderately Open
50 – 25 Poor 1/8 to 3/8 in. Open
Less than 25 Very poor 3/8 in. to 0.1 ft. Moderately Wide
a. RQD (given as a percentage) = length of core in pieces Greater than 0.1 ft. Wide
4 in. and longer/length of run.
References: American Society of Civil Engineers. Manuals and Reports on Engineering Practice - No. 56. Subsurface Investigation for
Design and Construction of Foundations of Buildings. New York: American Society of Civil Engineers, 1976. U.S.
Department of the Interior, Bureau of Reclamation, Engineering Geology Field Manual.
Exhibit C-4
LABORATORY TEST
SIGNIFICANCE AND PURPOSE
Test Significance Purpose
California Bearing
Ratio
Used to evaluate the potential strength of subgrade soil,
subbase, and base course material, including recycled
materials for use in road and airfield pavements.
Pavement Thickness
Design
Consolidation
Used to develop an estimate of both the rate and amount of
both differential and total settlement of a structure. Foundation Design
Direct Shear
Used to determine the consolidated drained shear strength
of soil or rock.
Bearing Capacity,
Foundation Design,
and Slope Stability
Dry Density
Used to determine the in-place density of natural, inorganic,
fine-grained soils.
Index Property Soil
Behavior
Expansion
Used to measure the expansive potential of fine-grained
soil and to provide a basis for swell potential classification.
Foundation and Slab
Design
Gradation
Used for the quantitative determination of the distribution of
particle sizes in soil. Soil Classification
Liquid & Plastic Limit,
Plasticity Index
Used as an integral part of engineering classification
systems to characterize the fine-grained fraction of soils,
and to specify the fine-grained fraction of construction
materials.
Soil Classification
Permeability
Used to determine the capacity of soil or rock to conduct a
liquid or gas.
Groundwater Flow
Analysis
pH
Used to determine the degree of acidity or alkalinity of a
soil. Corrosion Potential
Resistivity
Used to indicate the relative ability of a soil medium to carry
electrical currents. Corrosion Potential
R-Value
Used to evaluate the potential strength of subgrade soil,
subbase, and base course material, including recycled
materials for use in road and airfield pavements.
Pavement Thickness
Design
Soluble Sulfate
Used to determine the quantitative amount of soluble
sulfates within a soil mass. Corrosion Potential
Exhibit C-5
REPORT TERMINOLOGY
(Based on ASTM D653)
Allowable Soil
Bearing Capacity
The recommended maximum contact stress developed at the interface of the foundation
element and the supporting material.
Alluvium
Soil, the constituents of which have been transported in suspension by flowing water and
subsequently deposited by sedimentation.
Aggregate Base
Course
A layer of specified material placed on a subgrade or subbase usually beneath slabs or
pavements.
Backfill A specified material placed and compacted in a confined area.
Bedrock
A natural aggregate of mineral grains connected by strong and permanent cohesive forces.
Usually requires drilling, wedging, blasting or other methods of extraordinary force for
excavation.
Bench A horizontal surface in a sloped deposit.
Caisson (Drilled
Pier or Shaft)
A concrete foundation element cast in a circular excavation which may have an enlarged
base. Sometimes referred to as a cast-in-place pier or drilled shaft.
Coefficient of
Friction
A constant proportionality factor relating normal stress and the corresponding shear stress
at which sliding starts between the two surfaces.
Colluvium
Soil, the constituents of which have been deposited chiefly by gravity such as at the foot of a
slope or cliff.
Compaction The densification of a soil by means of mechanical manipulation
Concrete Slab-on-
Grade
A concrete surface layer cast directly upon a base, subbase or subgrade, and typically used
as a floor system.
Differential
Movement Unequal settlement or heave between, or within foundation elements of structure.
Earth Pressure The pressure exerted by soil on any boundary such as a foundation wall.
ESAL
Equivalent Single Axle Load, a criteria used to convert traffic to a uniform standard, (18,000
pound axle loads).
Engineered Fill
Specified material placed and compacted to specified density and/or moisture conditions
under observations of a representative of a geotechnical engineer.
Equivalent Fluid
A hypothetical fluid having a unit weight such that it will produce a pressure against a lateral
support presumed to be equivalent to that produced by the actual soil. This simplified
approach is valid only when deformation conditions are such that the pressure increases
linearly with depth and the wall friction is neglected.
Existing Fill (or
Man-Made Fill) Materials deposited throughout the action of man prior to exploration of the site.
Existing Grade The ground surface at the time of field exploration.
Exhibit C-6
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.
Unconfined
Compression
To obtain the approximate compressive strength of soils
that possess sufficient cohesion to permit testing in the
unconfined state.
Bearing Capacity
Analysis for
Foundations
Water Content
Used to determine the quantitative amount of water in a soil
mass.
Index Property Soil
Behavior
C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded
gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly
graded gravel with silt, GP-GC poorly graded gravel with clay.
D Sands with 5 to 12% fines require dual symbols: SW-SM well-graded
sand with silt, SW-SC well-graded sand with clay, SP-SM poorly graded
sand with silt, SP-SC poorly graded sand with clay
E Cu = D60/D10 Cc =
10 60
2
30
D x D
(D )
F If soil contains 15% sand, add “with sand” to group name.
G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.
H If fines are organic, add “with organic fines” to group name.
I If soil contains 15% gravel, add “with gravel” to group name.
J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay.
K If soil contains 15 to 29% plus No. 200, add “with sand” or “with gravel,”
whichever is predominant.
L If soil contains 30% plus No. 200 predominantly sand, add “sandy” to
group name.
M If soil contains 30% plus No. 200, predominantly gravel, add
“gravelly” to group name.
N PI 4 and plots on or above “A” line.
O PI 4 or plots below “A” line.
P PI plots on or above “A” line.
Q PI plots below “A” line.
Trace
With
Modifier
RELATIVE PROPORTIONS OF SAND AND GRAVEL GRAIN SIZE TERMINOLOGY
Trace
With
Modifier
DESCRIPTIVE SOIL CLASSIFICATION
Boulders
Cobbles
Gravel
Sand
Silt or Clay
Descriptive Term(s)
of other constituents
< 15
15 - 29
> 30
Term
PLASTICITY DESCRIPTION
Water levels indicated on the soil boring
logs are the levels measured in the
borehole at the times indicated.
Groundwater level variations will occur
over time. In low permeability soils,
accurate determination of groundwater
levels is not possible with short term
water level observations.
Water Level After
a Specified Period of Time
Water Level After a
Specified Period of Time
Water Initially
Encountered
Modified
Dames &
Moore Ring
Sampler
Standard
Penetration
Test
Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. The accuracy
of such devices is variable. Surface elevation data annotated with +/- indicates that no actual topographical survey was
conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic
maps of the area.
STRENGTH TERMS
BEDROCK
Loose
Medium Dense
Dense
0 - 3
4 - 9
10 - 29
30 - 50
7 - 18
19 - 58
Very Soft
Soft
Medium-Stiff
Stiff
Very Stiff
Standard
Penetration or
N-Value
Blows/Ft.
2 - 4
4 - 8
8 - 15
< 3
5 - 9
19 - 42
> 42
30 - 49
50 - 89
20 - 29
Medium Hard
Very Dense
RELATIVE DENSITY OF COARSE-GRAINED
SOILS
Descriptive
Term
(Density)
Very Loose
> 50
Ring
Sampler
Blows/Ft.
0 - 6
59 - 98
> 99
Descriptive
Term
(Consistency)
Hard
0 - 1
Ring
Sampler
Blows/Ft.
3 - 4
10 - 18
Ring
Sampler
Blows/Ft.
< 30
90 - 119
Standard
Penetration or
N-Value
Blows/Ft.
Descriptive
Term
(Consistency)
Weathered
Firm
Very Hard
CONSISTENCY OF FINE-GRAINED SOILS
(More than 50% retained on No. 200 sieve.)
Density determined by
Standard Penetration Resistance
(50% or more passing the No. 200 sieve.)
Consistency determined by laboratory shear strength testing, field
visual-manual procedures or standard penetration resistance
Standard
Penetration or
N-Value
Blows/Ft.
_ 15 - 30
> 30
> 119
< 20
30 - 49
50 - 79
>79
Hard
ASTM D422
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
PROJECT NUMBER: 20135017
PROJECT: Southeast Community Park
SITE: Northeast of Ziegler Road and Kechter
Road
Fort Collins, Colorado
CLIENT: Civitas, Inc.
Denver, Colorado
EXHIBIT: B-3
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS-2 20135017.GPJ TERRACON2012.GDT 6/3/14
14
NP
27
18
NP
22
35
NP
73
55
6
70
74
29
LL USCS
1
2
3
5
6
7
ATTERBERG LIMITS RESULTS
ASTM D4318
1901 Sharp Point Drive, Suite C
Fort Collins, Colorado
PROJECT NUMBER: 20135017
PROJECT: Southeast Community Park
SITE: Northeast of Ziegler Road and Kechter
Road
Fort Collins, Colorado
CLIENT: Civitas, Inc.
Denver, Colorado
EXHIBIT: B-2
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS 20135017.GPJ TERRACON2012.GDT 6/3/14
CL-ML
See Exhibit A-3 for description of field
procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
FIELD TEST
RESULTS
SULFATES (%)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 4902.4 (Ft.)
DEPTH (Ft.)
5
10
15
20
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
SWELL (%)
While drilling
4/9/14
WATER LEVEL OBSERVATIONS
Driller: Drilling Engineers, Inc.
Boring Completed: 4/7/2014
Exhibit: A-10
See Exhibit A-3 for description of field
procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
FIELD TEST
RESULTS
SULFATES (%)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 4908.2 (Ft.)
DEPTH (Ft.)
5
10
15
20
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
SWELL (%)
While drilling
4/9/14
WATER LEVEL OBSERVATIONS
Project No.: 20135017
Drill Rig: CME-75
Boring Started: 4/7/2014
BORING LOG NO. 6
CLIENT: Civitas, Inc.
Denver, Colorado
Driller: Drilling Engineers, Inc.
Boring Completed: 4/7/2014
Exhibit: A-9
See Exhibit A-3 for description of field
procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
FIELD TEST
RESULTS
SULFATES (%)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 4898.1 (Ft.)
DEPTH (Ft.)
5
10
15
20
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
SWELL (%)
While drilling
4/9/14
WATER LEVEL OBSERVATIONS
Drill Rig: CME-75
Boring Started: 4/7/2014
BORING LOG NO. 5
CLIENT: Civitas, Inc.
Denver, Colorado
Driller: Drilling Engineers, Inc.
Boring Completed: 4/7/2014
Exhibit: A-8
See Exhibit A-3 for description of field
procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
FIELD TEST
RESULTS
SULFATES (%)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 4900.9 (Ft.)
DEPTH (Ft.)
5
10
15
20
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
SWELL (%)
While drilling
4/9/14
WATER LEVEL OBSERVATIONS
See Exhibit A-3 for description of field
procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
FIELD TEST
RESULTS
SULFATES (%)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 4893.5 (Ft.)
DEPTH (Ft.)
5
10
15
20
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
SWELL (%)
While drilling
4/9/14
WATER LEVEL OBSERVATIONS
Denver, Colorado
Driller: Drilling Engineers, Inc.
Boring Completed: 4/7/2014
Exhibit: A-6
See Exhibit A-3 for description of field
procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
FIELD TEST
RESULTS
SULFATES (%)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 4897.2 (Ft.)
DEPTH (Ft.)
5
10
15
20
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
SWELL (%)
While drilling
4/9/14
WATER LEVEL OBSERVATIONS
Exhibit: A-5
See Exhibit A-3 for description of field
procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
FIELD TEST
RESULTS
SULFATES (%)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 4905.0 (Ft.)
DEPTH (Ft.)
5
10
15
20
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
SWELL (%)
While drilling
4/9/14
WATER LEVEL OBSERVATIONS
Boring Completed: 4/7/2014
Exhibit: A-4
See Exhibit A-3 for description of field
procedures.
See Appendix B for description of laboratory
procedures and additional data (if any).
See Appendix C for explanation of symbols and
abbreviations.
FIELD TEST
RESULTS
SULFATES (%)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 4900.8 (Ft.)
DEPTH (Ft.)
5
10
15
20
SAMPLE TYPE
WATER LEVEL
OBSERVATIONS
SWELL (%)
While drilling
4/9/14
WATER LEVEL OBSERVATIONS