HomeMy WebLinkAboutSAINT JOHN XXIII CATHOLIC CHURCH AND LOMBARDY STUDENT HOUSING - PDP190001 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTREPORT COVER PAGE
Geotechnical Engineering Report
Lombardy Student Housing
Fort Collins, Colorado
November 6, 2018
Revised December 3, 2018
Terracon Project No. 20185115 (revised)
Prepared for:
Blackbird Investments, LLC
Des Moines, Iowa
Prepared by:
Terracon Consultants, Inc.
Fort Collins, Colorado
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REPORT TOPICS
REPORT TOPICS
REPORT SUMMARY ....................................................................................................... i
INTRODUCTION ............................................................................................................. 1
SITE CONDITIONS ......................................................................................................... 1
PHOTOGRAPHY LOG ................................................................................................... 2
PROJECT DESCRIPTION .............................................................................................. 4
GEOTECHNICAL CHARACTERIZATION ...................................................................... 5
GEOTECHNICAL OVERVIEW ....................................................................................... 6
CORROSIVITY.............................................................................................................. 10
EARTHWORK............................................................................................................... 11
SHALLOW FOUNDATIONS ......................................................................................... 17
DEEP FOUNDATIONS ................................................................................................. 22
SEISMIC CONSIDERATIONS ...................................................................................... 24
FLOOR SYSTEMS........................................................................................................ 25
BELOW-GRADE STRUCTURES ................................................................................. 26
PAVEMENTS ................................................................................................................ 29
GENERAL COMMENTS ............................................................................................... 32
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ATTACHMENTS
SITE LOCATION AND EXPLORATION PLANS
EXPLORATION RESULTS (EXPLORATION AND TESTING PROCEDURES, Boring
Logs and Laboratory Data)
SUPPORTING INFORMATION (General Notes and Unified Soil Classification System)
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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REPORT SUMMARY
Topic
1
Overview Statement
2
Project
Overview
A geotechnical exploration has been performed for the proposed Lombardy Student
Housing project to be constructed at 1220 University Avenue in Fort Collins,
Colorado. Thirteen (13) borings were performed to depths of approximately 25 to 40
feet below existing site grades.
Subsurface
Conditions
Subsurface conditions encountered in our exploratory borings generally consisted of
about 2 to 7 inches of asphalt or aggregate surfacing material or an approximately 6-
inch thick vegetative layer over about 3 to 19 feet of lean clay with varying amounts of
sand, silt, and gravel. Claystone/siltstone bedrock was encountered below the
overburden soils in all of the borings at depths of approximately 3 to 19 feet below
existing site grades. The upper approximately 4.5 to 11 feet of bedrock was highly
weathered in some of the borings. Boring logs are presented in the Exploration
Results section of this report.
Groundwater
Conditions
Groundwater was encountered in all of our test borings at depths of about 4.6 to 16.2
feet below existing site grades at the time of drilling and at depths of about 4 to 11.3
feet when checked several days after drilling. Groundwater levels can fluctuate in
response to site development and to varying seasonal and weather conditions,
irrigation on or adjacent to the site and fluctuations in nearby water features.
Geotechnical
Concerns
■ Expansive clays and bedrock are present on this site. This report provides
recommendations to help mitigate the effects of soil movement/heave associated
with these materials. The risk can be mitigated by careful design, construction and
maintenance practices; however, it should be recognized these procedures will not
eliminate risk. The owner should be aware and understand that on-grade slabs,
pavements and, in some instances foundations, may be affected to some degree by
the expansive soils and bedrock on this site.
■ Although not encountered in our boring logs, Joseph Aikne, with JA Environment
indicated that existing, undocumented fill is present on site. Terracon was informed
three (3) gas storage tanks were removed and backfilled on the northeast portion of
this site to depths ranging from about 12 to 14 feet below existing site grades. The
existing fill soils should be removed and replaced with engineered fill beneath
proposed foundations and floor slabs.
■ Comparatively soft sandy lean clay soils were encountered at depths of up to about
5 feet in two of the borings completed at the site and is likely present below other
areas of the site. These materials can be susceptible to disturbance and loss of
strength under repeated construction traffic loads and unstable conditions could
develop. Stabilization of soft soils may be required at some locations to provide
adequate support for construction equipment and proposed structures. Terracon
should be contacted if these conditions are encountered to observe the conditions
exposed and to provide guidance regarding stabilization (if needed).
■ Shallow bedrock was encountered at depths of about 4 to 8 feet in two of the borings
completed at the site. Excavation penetrating the bedrock may require the use of
specialized heavy-duty equipment, together with ripping or jack-hammering drilling
to advance the excavation and facilitate rock break-up and removal. Consideration
should be given to obtaining a unit price for difficult excavation in the contract
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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Topic
1
Overview Statement
2
Earthwork
On-site soils typically appear suitable for use as general engineered fill and backfill on
the site provided they are placed and compacted as described in this report. Import
materials (if needed) should be evaluated and approved by Terracon prior to delivery
to the site. Earthwork recommendations are presented in the Earthwork section of
this report.
Grading and
Drainage
The amount of movement of foundations, floor slabs, pavements, etc. will be related to
the wetting of underlying supporting soils. Therefore, it is imperative the
recommendations discussed in the Grading and Drainage section of the Earthwork
section this report be followed to reduce potential movement. As discussed in the
Grading and Drainage section of this report, surface drainage should be designed,
constructed and maintained to provide rapid removal of surface water runoff away from
the proposed buildings and pavements. Water should not be allowed to pond adjacent
to foundations or on pavements and conservative irrigation practices should be followed
to avoid wetting foundation/slab soils and pavement subgrade. Excessive wetting of
foundations/slab soils and subgrade can cause movement and distress to foundations,
floor slabs, concrete flatwork and pavements.
Foundations
We believe the proposed parking structure and relatively heavily-loaded structures
with low tolerance for movement can be supported on either drilled piers bottomed
in bedrock or helical piles bottomed in bedrock. We believe the two multi-story
student housing buildings can be supported by a spread footing or posttension slab
foundation system bearing on properly prepared on-site soils or properly placed
engineered fill as described in the Earthwork section of this report.
Recommendations for design and construction of foundations are presented in the
Shallow Foundation and Deep Foundation sections of this report.
Floor Systems
A slab-on-grade Floor System is recommended for the proposed buildings provided
the soils and/or bedrock are over-excavated to a depth of at least 3 feet below the
proposed floor slab and replaced with moisture conditioned, properly compacted
engineered fill. On-site soils are suitable as over-excavation backfill below floor slabs.
Pavements
Recommended Pavement thicknesses for this project include 4 inches of asphalt over
6 inches of aggregate base course in light-duty parking areas and 5 inches of asphalt
over 8 inches of aggregate base course in heavy-duty drive lanes and loading areas.
Additional pavement section alternatives and discussion are presented in the report.
Seismic
Considerations
As presented in the Seismic Considerations section of this report, the 2015
International Building Code, which refers to Section 20 of ASCE 7-10, indicates the
seismic site classification for this site is D.
Construction
Observation
and Testing
Close monitoring of the construction operations and implementing drainage
recommendations discussed herein will be critical in achieving the intended
foundation, slab and pavement performance. We therefore recommend that Terracon
be retained to monitor this portion of the work.
General
Comments
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INTRODUCTION
Geotechnical Engineering Report
Lombardy Student Housing
1220 University Avenue
Fort Collins, Colorado
Terracon Project No. 20185115 (revised)
December 3, 2018
INTRODUCTION
This report presents the results of our subsurface exploration and geotechnical engineering
services performed for the proposed Lombardy Student Housing project to be located at 1220
University Avenue in Fort Collins, Colorado. The purpose of these services is to provide
information and geotechnical engineering recommendations relative to:
■ Subsurface soil and rock conditions ■ Foundation design and construction
■ Groundwater conditions ■ Floor system design and construction
■ Site preparation and earthwork ■ Seismic considerations
■ Demolition considerations ■ Lateral earth pressures
■ Excavation considerations ■ Pavement design and construction
■ Dewatering considerations
The geotechnical engineering scope of services for this project included the advancement of
thirteen test borings to depths ranging from approximately 25 to 40 feet below existing site grades.
Maps showing the site and boring locations are shown in the Site Location and Exploration
Plan sections, respectively. The results of the laboratory testing performed on soil and bedrock
samples obtained from the site during the field exploration are included on the boring logs and as
separate graphs in the Exploration Results section of this report.
SITE CONDITIONS
The following description of site conditions is derived from our site visit in association with the
field exploration and our review of publicly available geologic and topographic maps.
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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Item Description
Parcel Information
The project site is located northwest of the intersection of University Avenue
and South Shields Street in Fort Collins, Colorado. The approximate
Latitude/Longitude of the center of the site is 40.57359 ° N/-105.09892 °W
(Please refer to See Site Location).
Existing
Improvements
The site currently contains of a single-story church, asphalt parking areas,
moderate to heavily vegetated landscaping with mature trees, two multi-story
residential homes, flagstone walkway, and a previously demolished gas
station.
Surrounding
Development
The site is surrounded by asphalt parking lots, followed by two-story
commercial buildings to the east and north of site. To the south and west of
the site are University Avenue and City Park Avenue, respectively, followed
by multi-story residential housing.
Current Ground
Cover
Current ground cover of the site includes: moderately to heavily vegetated
landscaping, asphalt paved parking lot, and single-story church.
Existing Topography The site is relatively flat.
We also collected photographs at the time of our field exploration program. Representative photos
are provided in our Photography Log.
PHOTOGRAPHY LOG
Boring No. 5 Boring No. 12
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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Boring No. 11 and 10 Boring No. 13
Boring No. 2 Boring No. 3 and 4
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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PROJECT DESCRIPTION
Our initial understanding of the project was provided in our proposal and was discussed in the
project planning stage. A period of collaboration has transpired since the project was initiated,
and our final understanding of the project conditions is as follows:
Item Description
Information Provided
Terracon was provided with a proposed site plan layout for the buildings
and parking structure dated September 14, 2018. As part of the proposal
revision, we were also provided with a site plan showing the locations of
the four (4) additional borings within the church area.
Project Description
We understand the proposed project will include demolition of existing
structures and surrounding site features and the construction of two multi-
story student housing buildings, a parking garage with one level of
underground parking and a fire lane. We anticipate new underground
utilities and a pool may also be included in the proposed construction.
Project Understanding
Terracon’s proposed scope of services presented in this project has been
provided under the belief that this site will be used as apartments. As such,
Terracon would like to inform the Client that if this apartment project is
converted at any time to another purpose such as condominiums, the
Client understands the services Terracon is proving are not applicable for
a condominium project and that a separate consultant will need to be
retained for such services. Terracon will have no liability for any such
unintended use of our services and Client agrees to defend, indeminify,
and hold harmless Terracon for any such unintended usage.
Finished Floor Elevation
The provided Site Plan indicates the finished floor elevations (FFE) will be
5,039.00 feet for a student housing building, 5,033.17 feet for a student
housing building, 5,031.9 feet for the parking garage, and 5,031.29 feet for
the church.
Maximum Loads
(assumed)
■ Columns: 50 to 500 kips
■ Walls: 2 to 5 kips per linear foot (klf)
■ Slabs: 150 pounds per square foot (psf)
Grading/Slopes
Grading plans indicate up to about 3 to 5 feet of cut and about 3 to 5 feet
of fill will be required to develop final grades. Deeper cuts and fills will likely
be required for buried utility construction, below-grade parking (if chosen),
and removal and recompaction of existing fill
Below-grade Structures
Plans indicate a proposed below-grade parking level extending
approximately 15 feet below the ground surface.
Pavements
Based on our understanding of the project and our experience with similar
projects we have anticipated the following traffic conditions:
■ Automobile Parking Areas: Class I - Parking stalls and parking lots
for cars and pick-up trucks, with Equivalent Single Axle Load
(ESAL) up to 7,000 over 20 years
■ Main Traffic Corridors: Class II – Parking lots with a maximum of
10 trucks per day with Equivalent Single Axle Load (ESAL) up to
27,000 over 20 years (Including trash trucks)
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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GEOTECHNICAL CHARACTERIZATION
Subsurface Profile
Specific conditions encountered at each boring location are indicated on the individual boring logs.
Stratification boundaries on the boring logs represent the approximate location of changes in soil
types; in situ, the transition between materials may be gradual. Details for each of the borings can
be found in Exploration Results. A discussion of field sampling and laboratory testing procedures
and test results are presented in Exploration and Testing Procedures. Based on the results of
the borings, subsurface conditions on the project site can be generalized as follows:
Material Description
Approximate Depth to
Bottom of Stratum
Consistency/Density/Hardness
Surface material: Asphalt or
aggregate surfacing or vegetative
layer
About 2 to 7 inches thick -
Lean clay with varying amounts of
sand, silt and gravel
About 0 to 10 feet below
existing site grades.
Soft to medium stiff
Clayey to silty sand with varying
amounts of gravel
About 9 to 19 feet below
existing site grades.
Very loose to very dense
Claystone/siltstone bedrock
To the maximum depth of
exploration of about 39.5 feet.
Weathered to very hard
Groundwater Conditions
The boreholes were observed while drilling and after completion for the presence and level of
groundwater. In addition, delayed water levels were also obtained in some borings. Groundwater
was observed in all of the boring and water levels are noted on the attached boring logs, and are
summarized below:
Boring
Number
Depth to
groundwater
while drilling,
ft.
Depth to
groundwater
after drilling,
ft.
Elevation of
groundwater
after drilling,
ft..
Depth of
groundwater 2 to 3
days after drilling,
ft.
Elevation of
groundwater 2
to 3 days after
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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Boring
Number
Depth to
groundwater
while drilling,
ft.
Depth to
groundwater
after drilling,
ft.
Elevation of
groundwater
after drilling,
ft..
Depth of
groundwater 2 to 3
days after drilling,
ft.
Elevation of
groundwater 2
to 3 days after
drilling, ft.
7 10 5.9 5024.1 Backfilled Backfilled
8 9 8.7 5021.3 Backfilled Backfilled
9 7 4.6 5020.4 4.0 5021.0
10 13 9.3 5018.7 9.4 5018.6
11 12 9.6 5018.4 9.5 5018.5
12 4 9.6 5019.4 9.5 5019.5
13 13 11.8 5018.2 11.3 5018.7
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
nearby water features, 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.
Laboratory Testing
Representative soil and bedrock samples selected for swell-consolidation testing and exhibited
approximately 0.2 percent compression to 1.6 percent swell when wetted. Samples of
claystone/siltstone bedrock exhibited unconfined compressive strengths of approximately 5,700
to 16,020 psf. Samples of site soils and bedrock selected for plasticity testing exhibited low to
moderate plasticity with liquid limits ranging from non-plastic to 39 and plasticity indices ranging
from non-plastic to 19. Laboratory test results are presented in the Exploration Results section
of this report.
GEOTECHNICAL OVERVIEW
Based on subsurface conditions encountered in the borings, the site appears suitable for the
proposed construction from a geotechnical point of view provided certain precautions and design
and construction recommendations described in this report are followed and the owner
understands the inherent risks associated with construction on sites underlain by expansive soils
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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and bedrock. We have identified several geotechnical conditions that could impact design,
construction and performance of the proposed structures, pavements, and other site
improvements. These included existing, undocumented fill, shallow groundwater, shallow
bedrock, expansive soils and bedrock, and potentially soft, low strength clay soils. These
conditions will require particular attention in project planning, design and during construction and
are discussed in greater detail in the following sections.
Existing, Undocumented Fill
As previously stated, we understand existing undocumented fill is present on site. Terracon was
informed by Joseph Aikne, with JA Environmental that three (3) gas storage tanks were removed
and backfilled on the northeast portion of this site to depths ranging from about 12 to 14 feet below
existing site grades. Existing fill could exist at other locations on the site and extend to greater
depths. We do not possess any information regarding whether the fill was placed under the
observation of a geotechnical engineer. Undocumented fill can present a greater than normal
risk of post-construction movement of foundations, slabs, pavements and other site improvements
supported on or above these materials. Consequently, it is our opinion existing fill on the site
should not be relied upon for support and should be removed down to native soil, moisture
conditioned and recompacted prior to new fill placement and/or construction.
Shallow Groundwater
As previously stated, groundwater was measured at depths ranging from about 4 to 11.3 feet
below existing site grades. In general, measured groundwater levels were shallowest on the west
to center portion of the site in the vicinity of Boring Nos. 2, 4, 3 and 9. Terracon recommends
maintaining a separation of at least 3 feet between the bottom of proposed below-grade
foundations and measured groundwater levels. It is also possible and likely that groundwater
levels below this site may rise as water levels in the nearby water features rise. Final site grading
should be planned and designed to avoid cuts where shallow groundwater is known to exist, and
also in areas where such grading would create shallow groundwater conditions. If deeper cuts
are unavoidable, installation of a subsurface drainage system will be needed.
Shallow Bedrock
Shallow bedrock was encountered at depths of about 4 to 8 feet in two of the borings completed at
the site. Excavation penetrating the bedrock may require the use of specialized heavy-duty
equipment, together with ripping or jack-hammering drilling to advance the excavation and facilitate
rock break-up and removal. Consideration should be given to obtaining a unit price for difficult
excavation in the contract documents for the project.
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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Expansive Soils and Bedrock
Expansive soils and bedrock are present on this site and these conditions constitute a geologic
hazard. 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 is possible. The severity of cracking and other damage
such as uneven floor slabs and flat work will probably increase if modification of the site results in
excessive wetting or drying of the expansive clays and claystone/siltstone bedrock. Eliminating
the risk of movement and cosmetic 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 Grading and Drainage
section of the Earthwork section of this report be followed to reduce potential movement.
Low Strength Soils
Comparatively soft lean clay with sand soils were encountered within the upper approximately 4
to 6 feet of the borings completed at this site. In general, these materials were encountered in
the upper 5 feet on the southeast and center portion of the site in the vicinity of Boring Nos. 4, 12,
and 13. These materials can be susceptible to disturbance and loss of strength under repeated
construction traffic loads and unstable conditions could develop. Stabilization of soft soils may
be required at some locations to provide adequate support for construction equipment and
proposed structures. Terracon should be contacted if these conditions are encountered to
observe the conditions exposed and to provide guidance regarding stabilization (if needed).
Permanent Dewatering
Preliminary site concepts indicate the proposed below-grade areas will extend below the
observed groundwater levels. Thus, permanent dewatering may be needed to lower groundwater
levels below permanent excavations. We recommend that on a long term basis, groundwater
levels be maintained at least 3 feet below the floor slab and any below-grade areas.
If a permanent dewatering system is judged necessary by the project team, we suggest that the
dewatering system consist of a combination of drains and sumps. The configuration of the system
will depend on the size of the below-grade areas. The locations of the drains and/or sumps must
consider maintenance accessibility. Our services did not include design of construction and/or
permeant dewatering systems.
A possible configuration would be a subsurface drain around the exterior of the below-grade
perimeter wall. The drain pipe should be properly-sized, perforated PVC or other type of hard
pipe embedded in properly graded drainage gravel. The invert of the drain pipe should be at least
3 feet below the bottom of the floor slab for below-grade areas. The drain pipe should discharge
into a sump(s) accessible within the base of the below-grade area.
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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The drainage gravel should extend vertically over the drain pipes to at least 2 feet above the
highest groundwater levels observed in the soil borings. Thus, the drain gravel will extend into
the below-grade area foundation wall backfill. The foundation walls for the below-grade areas
adjacent to the drain gravel should be properly water-proofed.
Provisions must be made to prevent migration or piping of the native soils into the drainage gravel.
Ideally this would be by a properly graded sand filter. Alternatively, a filter fabric could be used.
If a filter fabric is used, we strongly recommend that installation be in the dry. That is, the
Contractor should dewater the excavation so that it is free of standing water during installation of
the drain components.
Other issues to be considered include:
Disposition of the developed water, which could be to a storm water detention basin.
Evaluation of the amount of water likely to be discharged from a permanent dewatering
system was not included in our scope of services for this study but should be evaluated,
if a permanent dewatering system is selected.
Possible permitting requirements. If the dewatering system is considered to be a well,
permits would be required at a minimum from the Colorado State Engineer’s Office and
the State of Colorado Department of Public Health and Environment. The permits, should
they be needed, will require regular reporting of discharge water quality. Adequate time
should be included in the project schedule to obtain the permits.
Maintenance. All permanent dewatering systems require regular maintenance to assure
the drains and pumps are in proper operating condition. Underground drains associated
with the system should have cleanouts so that the system can be flushed/ cleaned
periodically as underground dewatering systems can become clogged with anaerobic
microbial and other growth. The cleanout locations should be readily accessible and a
source of high pressure (water main pressure) water available to flush the drains.
Monitoring. By their nature, permanent dewatering systems tend to be “out of sight and
out of mind”. Therefore, we recommend that there be a monitoring system to alert
maintenance personnel if the pumps have failed and water levels are rising in the sumps.
A simple monitoring system would be to install a water detector in a sump about 2 feet
below the bottom of the below-grade area floor slab that would activate a flashing warning
light in the control building.
Foundation and Floor System Recommendations
We believe the proposed parking structure and relatively heavily-loaded structures with low
tolerance for movement can be supported on either drilled piers bottomed in bedrock or helical
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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piles bottomed in bedrock. We believe the two multi-story buildings can be supported by a spread
footing or posttension slab foundation system bearing on properly prepared on-site soils or
properly placed engineered fill as described in the Earthwork section of this report.
Recommendations for design and construction of foundations are presented in the Shallow
Foundation and Deep Foundation sections of this report.
A slab-on-grade floor system is recommended for the proposed buildings provided the soils and/or
bedrock are over-excavated to a depth of at least 3 feet below the proposed floor slab and replaced
with moisture conditioned, properly compacted engineered fill. On-site soils are suitable as over-
excavation backfill below floor slabs. Design and construction recommendation for floor slabs are
presented in the Floor Systems section of this report.
The General Comments section provides an understanding of the report limitations.
CORROSIVITY
Results of water-soluble sulfate testing indicate Exposure Class S0 according to ACI 318. ASTM
Type I or II 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.
Terracon was requested to perform laboratory testing on soil samples collected from the site to
determine the potential corrosive characteristics of the on-site soils and bedrock with respect to
contact with the various underground materials that will be used for project construction.
Laboratory test results for select samples tested exhibited the following properties:
Sample
Identification
Water-soluble
Sulfate
Redox
Potential
Sulfide
Water-soluble
chloride
Electrical
Resistivity1 pH
(%) (mV) (Presence) (%) (ohm-cm)
Boring No. 7 at
2 feet
0.0061 678 Negative 0.0035 1,649 8.8
Boring No. 1 at
2 feet
0.011 - - - - -
Boring No. 4 at
4 feet
0.0074 - - - - -
Boring No. 9 at
4 feet
0.0083 - - - - -
Boring No. 12
at 2 feet
0.0074 - - - - -
1. Resistivity determined on saturated samples.
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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EARTHWORK
The following presents recommendations for site preparation, demolition, excavation, subgrade
preparation, fill materials, compaction requirements, utility trench backfill, grading and drainage
and exterior slab design and construction. Earthwork on the project should be observed and
evaluated by Terracon. Evaluation of earthwork should include observation and/or testing of over-
excavation, removal of existing fill, subgrade preparation, placement of engineered fills, subgrade
stabilization and other geotechnical conditions exposed during the construction of the project.
Site Preparation
Prior to placing any fill, strip and remove existing surface material or vegetation, topsoil, and any
other deleterious materials from the proposed construction areas. As previously stated, we also
recommend complete removal of existing, undocumented fill within proposed building areas.
Existing fill is reportedly located to be in the northeast portion of the proposed church location and
extends to depths of about 12 to14 feet below existing site grades.
Stripped organic materials should be wasted from the site or used to re-vegetate landscaped areas
after completion of grading operations. Prior to the placement of fills, the site should be graded to
create a relatively level surface to receive fill, and to provide for a relatively uniform thickness of fill
beneath proposed structures.
If fill is placed in areas of the site where existing slopes are steeper than 5:1 (horizontal:vertical),
the area should be benched to reduce the potential for slippage between existing slopes and fills.
Benches should be wide enough to accommodate compaction and earth moving equipment, and
to allow placement of horizontal lifts of fill.
Demolition
Demolition of the existing Church and multi-story student housing should include complete removal
of all foundation systems, below-grade structural elements, pavements, and exterior flat work 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 found adjacent to existing foundations. All
materials derived from the demolition of existing structures and pavements should be removed from
the site. The types of foundation systems supporting the existing church and student housing
buildings are not known. If some or all of the existing buildings are supported by drilled piers, the
existing piers should be truncated a minimum depth of 3 feet below areas of planned new
construction.
Consideration could be given to re-using the asphalt and concrete provided the materials are
processed and uniformly blended with the on-site soils. Asphalt and/or concrete materials should
be processed to a maximum size of 2 inches and blended at a ratio of 30 percent asphalt/concrete
Geotechnical Engineering Report
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to 70 percent of on-site soils. Asphalt or concrete crushed to meet the gradation specifications for
CDOT Class 1 structural backfill, Class 5 or 6 aggregate base course, or similar can be used as a
uniform lift of fill below floor slabs, exterior foundations or pavements.
Excavation
It is anticipated that excavations for the proposed construction can be accomplished with
conventional earthmoving equipment. Excavations into the on-site soils may encounter weak
and/or saturated soil conditions with possible caving conditions.
Excavation penetrating the bedrock may require the use of specialized heavy-duty equipment,
together with ripping or jack-hammering drilling to advance the excavation and facilitate rock break-
up and removal. Consideration should be given to obtaining a unit price for difficult excavation in
the contract documents for the project.
The soils to be excavated can vary significantly across the site as their classifications are based
solely on the materials encountered in widely-spaced exploratory test borings. The contractor
should verify that similar conditions exist throughout the proposed area of excavation. If different
subsurface conditions are encountered at the time of construction, the actual conditions should be
evaluated to determine any excavation modifications necessary to maintain safe conditions.
Although evidence of fills or underground facilities such as grease pits, septic tanks, vaults,
basements, and utilities was not observed during the site reconnaissance, such features could be
encountered during construction. If unexpected underground facilities are encountered, such
features should be removed, and the excavation thoroughly cleaned prior to backfill placement
and/or construction.
Any over-excavation that extends below the bottom of foundation elevation should extend laterally
beyond all edges of the foundations at least 8 inches per foot of over-excavation depth below the
foundation base elevation. The over-excavation should be backfilled to the foundation base
elevation in accordance with the recommendations presented in this report.
Depending upon depth of excavation and seasonal conditions, surface water infiltration and/or
groundwater may be encountered in excavations on the site. It is anticipated that pumping from
sumps may be utilized to control water within excavations. Well points may be required for
significant groundwater flow, or where excavations penetrate groundwater to a significant depth.
Groundwater seepage should be anticipated for excavations approaching the level of bedrock.
The subgrade soil conditions should be evaluated during the excavation process and the stability
of the soils determined at that time by the contractors’ Competent Person. Slope inclinations flatter
than the OSHA maximum values may have to be used. The individual contractor(s) should be
made responsible for designing and constructing stable, temporary excavations as required to
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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. If any excavation, including a utility trench, is extended to
a depth of more than 20 feet, it will be necessary to have the side slopes and/or shoring system
designed by a professional engineer.
As a safety measure, it is recommended that all vehicles and soil piles be kept a minimum lateral
distance from the crest of the slope equal to the slope height. The exposed slope face should be
protected against the elements
Subgrade Preparation
After site preparation and demolition, 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
foundation excavations and it is inconvenient to lower the foundations, the proposed foundation
elevations may be reestablished by over-excavating the unsuitable soils and backfilling with
compacted engineered fill or lean concrete.
After the bottom of the excavation has been compacted, engineered fill can be placed to bring the
building pad and pavement subgrade to the desired grade. Engineered fill should be placed in
accordance with the recommendations presented in subsequent sections of this report.
The stability of the subgrade may be affected by precipitation, repetitive construction traffic or
other factors. If unstable conditions develop, workability may be improved by scarifying and
drying. Alternatively, over-excavation of wet zones and replacement with granular materials may
be used, or crushed gravel and/or rock can be tracked or “crowded” into the unstable surface soil
until a stable working surface is attained. Use of fly ash or geotextiles could also be considered
as a stabilization technique. Laboratory evaluation is recommended to determine the effect of
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chemical stabilization on subgrade soils prior to construction. Lightweight excavation equipment
may also be used to reduce subgrade pumping.
Fill Materials
The on-site soils or approved granular and low plasticity cohesive imported materials may be used
as fill material. Bedrock excavated during site development and construction can be reused as fill
provided the material is broken down and thoroughly processed to a “soil-like” consistency, with
no particles greater than 2 inches in size. The earthwork contractor should expect significant
mechanical processing and moisture conditioning of the site soils and/or bedrock will be needed
to achieve proper compaction
Imported soils (if required) should meet the following material property requirements:
Gradation Percent finer by weight (ASTM C136)
4” 100
3” 70-100
No. 4 Sieve 50-100
No. 200 Sieve 15-60
Soil Properties Values
Liquid Limit 35 (max.)
Plastic Limit 6 (max.)
Other import fill materials types may be suitable for use on the site depending upon proposed
application and location on the site and could be tested and approved for use on a case-by-case
basis.
Compaction Requirements
Engineered fill should be placed and compacted in horizontal lifts, using equipment and procedures
that will produce recommended moisture contents and densities throughout the lift.
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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 +3 % of the optimum moisture content
1. We recommend engineered fill be tested for moisture content and compaction during placement.
Should the results of the in-place density tests indicate the specified moisture or compaction limits
have not been met, the area represented by the test should be reworked and retested as required
until the specified moisture and compaction requirements are achieved.
2. Specifically, moisture levels should be maintained low enough to allow for satisfactory compaction to
be achieved without the fill material pumping when proofrolled.
3. Moisture conditioned clay materials should not be allowed to dry out. A loss of moisture within these
materials could result in an increase in the material’s expansive potential. Subsequent wetting of these
materials could result in undesirable movement.
Utility Trench Backfill
All trench excavations should be made with sufficient working space to permit construction including
backfill placement and compaction.
All underground piping within or near the proposed structures should be designed with flexible
couplings, so minor deviations in alignment do not result in breakage or distress. Utility knockouts
in foundation walls should be oversized to accommodate differential movements. It is imperative
that utility trenches be properly backfilled with relatively clean materials. If utility trenches are
backfilled with relatively clean granular material, they should be capped with at least 18 inches of
cohesive fill in non-pavement areas to reduce the infiltration and conveyance of surface water
through the trench backfill.
Utility trenches are a common source of water infiltration and migration. All utility trenches that
penetrate beneath the buildings should be effectively sealed to restrict water intrusion and flow
through the trenches that could migrate below the buildings. We recommend constructing an
effective clay “trench plug” that extends at least 5 feet out from the face of the building exteriors.
The plug material should consist of clay compacted at a water content at or above the soil’s optimum
water content. The clay fill should be placed to completely surround the utility line and be compacted
in accordance with recommendations in this report.
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It is strongly recommended that a representative of Terracon provide full-time observation and
compaction testing of trench backfill within building and pavement areas.
Grading and Drainage
Grades must be adjusted to provide effective drainage away from the proposed buildings during
construction and maintained throughout the life of the proposed project. Infiltration of water into
foundation excavations must be prevented during construction. Landscape irrigation adjacent to
foundations should be minimized or eliminated. Water permitted to pond near or adjacent to the
perimeter of the 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 buildings, where possible. Locally, flatter grades may be
necessary to transition ADA access requirements for flatwork. The use of swales, chases and/or
area drains may be required to facilitate drainage in unpaved areas around the perimeter of the
buildings. Backfill against foundations and exterior walls should be properly compacted and free
of all construction debris to reduce the possibility of moisture infiltration. After construction of the
proposed buildings and prior to project completion, we recommend verification of final grading be
performed to document positive drainage, as described above, has been achieved.
Flatwork and pavements will be subject to post-construction movement. Maximum grades
practical should be used for paving and flatwork to prevent areas where water can pond. In
addition, allowances in final grades should take into consideration post-construction movement
of flatwork, particularly if such movement would be critical. Where paving or flatwork abuts the
structures, care should be taken that joints are properly sealed and maintained to prevent the
infiltration of surface water.
Planters located adjacent to structures should preferably be self-contained. Sprinkler mains and
spray heads should be located a minimum of 5 feet away from the building line(s). Low-volume,
drip style landscaped irrigation should be used sparingly near the buildings. Roof drains should
discharge on to pavements or be extended away from the structures a minimum of 10 feet through
the use of splash blocks or downspout extensions. A preferred alternative is to have the roof
drains discharge by solid pipe to storm sewers or to a detention pond or other appropriate outfall.
Exterior Slab Design and Construction
Exterior slabs on-grade, exterior architectural features, and utilities founded on, or in backfill or
the site soils will likely experience some movement due to the volume change of the material.
Potential movement could be reduced by:
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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.
Construction Observation and Testing
The earthwork efforts should be monitored under the direction of Terracon. Monitoring should
include documentation of adequate removal of vegetation and topsoil, proof-rolling and mitigation
of areas delineated by the proof-roll to require mitigation.
Each lift of compacted fill should be tested, evaluated, and reworked as necessary until approved
by Terracon prior to placement of additional lifts. Each lift of fill should be tested for density and
water content at a frequency of at least one test for every 2,500 square feet of compacted fill in
the structure areas and 5,000 square feet in pavement areas. One density and water content test
for every 50 linear feet of compacted utility trench backfill.
In areas of foundation excavations, the bearing subgrade and exposed conditions at the base of
the recommended over-excavation should be evaluated under the direction of Terracon. In the
event that unanticipated conditions are encountered, Terracon should prescribe mitigation
options.
In addition to the documentation of the essential parameters necessary for construction, the
continuation of Terracon into the construction phase of the project provides the continuity to
maintain the Terracon’s evaluation of subsurface conditions, including assessing variations and
associated design changes.
SHALLOW FOUNDATIONS
If the site has been prepared in accordance with the requirements noted in Earthwork, the
following deign parameters are applicable for shallow foundations.
Spread Footings - Design Recommendations
Description Values
Bearing material
Properly prepared on-site soil, or new, properly
placed engineered fill.
Maximum net allowable bearing pressure
1 2,500 psf
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Description Values
Lateral earth pressure coefficients
2
Active, Ka = 0.33
Passive, Kp = 3.00
At-rest, Ko = 0.50
Sliding coefficients
2
µ = 0.46
Moist soil unit weight ɣ = 125 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 net 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. Interior column pads in heated areas should bear at least
12 inches below the adjacent grade (or top of the floor slab) for confinement of the bearing materials and to
develop the recommended bearing pressure.
4. The estimated movements presented above are based on the assumption that the maximum footing size is
9 feet for column footings and 3 feet for continuous footings. Larger foundation footprints will likely require
reduced net allowable soil bearing pressures to reduce risk for potential settlement.
Footings should be proportioned to reduce differential foundation movement. As discussed, total
movement resulting from the assumed structural loads is estimated to be on the order of about 1
inch. Additional foundation movements could occur if water from any source infiltrates the
foundation soils; therefore, proper drainage should be provided in the final design and during
construction and throughout the life of the structure. Failure to maintain the proper drainage as
recommended in the Grading and Drainage section of the Earthwork section of this report will
nullify the movement estimates provided above.
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 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.
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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.
Frost Protected Post-Tensioned Slabs
A frost protected shallow foundation is a foundation that does not extend below the design frost
depth but is protected against effects of frost. Protection from frost heave is achieved by insulating
to retard frost penetration below the foundation and to retard heat flow from beneath the
foundation. Installation of insulation will allow shallower foundation bearing depths to be possible
with significantly reduced risk of frost damage. Recommendations for design and construction of
frost protected shallow foundations are presented in Design and Construction of Frost-Protected
Shallow Foundations prepared by the American Society of Civil Engineers (ASCE 32-01).
Post-Tensioned Slabs – Design Recommendations
Based on the subsurface conditions encountered, use of post-tensioned slabs is feasible for
support of the structures provided some foundation movement can be tolerated and:
The post-tensioned slab foundations are properly designed and constructed;
Approved materials supporting the foundation are properly placed and compacted;
Proper surface drainage is maintained throughout the life of the structures; and
Prudent landscaping measures are used.
In our opinion, total foundation movements on the order of about 1 inch should be expected.
Provided foundations are properly designed, foundation movements could result in periodic, and
possibly seasonal, cosmetic distress to drywall, window frames, door frames and other features.
We would anticipate that the frequency of distress and amount of movement would generally
diminish with time provided proper drainage is established and/or maintained. Assuming at least
3 feet of imported granular engineered fill is placed directly below the post-tensioned slab
foundations. The granular fill should consist of materials within the specified limits presented in
the Fill Materials section of the Earthwork section of this report.
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Based on the subsurface conditions, post-tensioned slabs should be designed using criteria
presented by the Post-Tensioning Institute1 based on the following:
Post-tensioned Slab Design Parameters
PTI, Third Edition
2015 IBC/IRC
Edge Moisture Variation Distance, em
(feet)
Center Lift Condition 9
Edge Lift Condition 4.5
Differential Soil Movement, ym (inches)
Center Lift Condition 1¼
Edge Lift Condition ¾
Maximum Net Allowable Bearing Pressure: ……………………………………………...2,000 psf
Slab-Subgrade Friction Coefficient,
on polyethylene sheeting……………………………………………………………0.75
on cohesionless soils………………………………………………………………..1.00
on cohesive soils……………………………………………………………………..2.00
The maximum net allowable bearing pressure may be increased by 1/3 for transient wind or
seismic loading.
It should be noted that ym is the estimated vertical movement at the edges of a uniformly loaded
slab. These are theoretical values that are used in the design of post-tensioned slabs-on-grade
and do not represent the movements that would be expected from the actual loading conditions.
As previously discussed, the use of post-tensioned slabs assumes that some potential movement
is considered acceptable.
Post-Tensioned Slabs – Construction Considerations
Post-tensioned slabs, thickened or turndown edges and/or interior beams should be designed
and constructed in accordance with the requirements of the PTI and the American Concrete
Institute (ACI).
As previously discussed, foundations should be protected from frost heave using insulation. If
traditional post-tensioned slab foundations are selected, exterior slab edges should be placed a
minimum of 30 inches below finished grade for frost protection. Finished grade is the lowest
adjacent grade for perimeter beams. Extending exterior slab edges to depths of at least 30 inches
will likely encroach upon soft to very loose and nearly saturated to wet soils requiring stabilization
of subgrade prior to construction.
1 (2004, Third Edition, reprinted with 2008 Supplement), Design of Post-Tensioned Slabs-on-Ground, Post-
Tensioning Institute.
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If portions of the building floor slab will be unheated, such as patios and entryways, consideration
should be given to structurally separating these areas of the slab from the remaining interior
portion of the slab. Exterior slab areas may be cantilevered portions of the slab which are subject
to uplift from frost heave and swelling of the expansive soils, sometimes beyond those used for
design, due to over watering of adjacent to landscaped areas. Such movement in the exterior
slabs can result in change in slab grade to the point where negative grade results and water ponds
adjacent to the interior areas of the slab. Repairs of such conditions are difficult and costly,
particularly if the floor slabs are post-tensioned slabs.
Exterior slabs in unheated areas are subject to frost heave beneath the slab. Therefore, in design
of the exterior slabs, potential movement from frost heave should be considered in the design.
It should be noted that the presences of 1 to 2-foot steps within long spans of post-tensioned
slabs could create a situation where the slabs at different elevations perform independently of
one another unless the steps are properly reinforced and designed to tie the slabs together to act
as one rigid structure. We strongly recommend that joints be designed within the full height of
the structure of the building over each step-in order to help the structure be capable of
withstanding movements on the order of 1 inch.
The estimated movement should also be considered as the potential amount of tilting of the
structure, which could be caused by non-uniform, significant wetting of the subsurface materials
below the post-tensioned slab, resulting in potential movement. Failure to maintain soil water
content below the slab and to maintain proper drainage around the structure will nullify the
movement estimates provided above.
If the site has been prepared in accordance with the requirements noted in Earthwork, the
following design parameters are applicable for shallow foundations.
BRAB Type II Post-Tensioned Slabs – Design Recommendations
We understand the project team is considering a BRAB Type II post-tensioned slab. If this
foundation system is chosen, we recommend 5 feet of over-excavation below the proposed
foundation to reduce potential movement and allow for BRAB Type II. On-site soils are suitable
for the lower 2 feet of over-excavation backfill below BRAB Type II foundation systems. We
recommend imported granular fill be used for the upper 3 feet of the over-excavation backfill.
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DEEP FOUNDATIONS
Drilled Piers Bottomed in Bedrock - Design Recommendations
Description Value
Minimum pier length (upper level) 20 feet
Minimum pier length (basement/lower level) 15 feet
Minimum pier diameter 18 inches
Minimum bedrock embedment
1 10 feet
Maximum allowable end-bearing pressure 40,000 psf
Allowable skin friction (for portion of pier embedded into bedrock) 3,500 psf
Void thickness (beneath grade beams or below pier caps) 4 inches
Uplift force (tension due to soil uplift, kips)
2 9 x Pier diameter
(ft.)
1. Drilled piers should be embedded into competent bedrock materials. Actual structural loads and pier
diameters may dictate embedment deeper than the recommended minimum bedrock embedment.
2. Required bedrock embedment should be balanced against uplift forces for the portion of the pier in competent
bedrock below a depth of 6 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 type
Stiff clay
(Reese)
Sand
(Reese)
Stiff clay w/o
free water
(Reese)
Effective unit weight above groundwater (pcf) 120 125 135
Undrained cohesion (psf) 2,000 - 8,000
Friction angle, (degrees) - 35 -
Coefficient of subgrade, k (pci) - 90 -
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Parameters Clay
Sand and
Gravel
Claystone
Bedrock
Strain factor, 50 (%) 0.007 - 0.004
For purposes of LPILE analysis, assume a groundwater depth of about 4 to 9 feet below existing ground surface
(approximately Elev. 5019 to 5021 feet).
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.
Groundwater/caving soil conditions indicate temporary steel casing may be required to properly
drill and clean 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/siltstone 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.
Helical Pile Foundations
We believe helical piles bottomed in bedrock are a viable alternative appropriate for support of
the proposed project. The helical pile foundation system will offer reduced drilling lengths
(compared to conventional drilled piers) by anchoring into the upper portions of the bedrock
versus competent bedrock. In addition, the installation torque can be used to verify the capacity
of a helical pile, which will provide an indication of allowable bearing pressure and may result in
reduced pile lengths. Design recommendations for helical pile foundations and related structural
elements are presented in the following paragraphs.
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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.
In accordance with local building code requirements, a load test should be performed by the
helical pile installer to validate achieving the allowable design load. Load tests should be
performed using helical piles consistent in size and materials with those piles planned for use
during construction. Similarly, the same installation techniques and equipment planned for use
during installation of production piles should be used when installing piles for load testing.
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. Terracon should be provided with the torque to capacity
relationships for each type of pile used on the project for our review and comment prior to
mobilization to the site. 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 by a qualified specialty contractor per the manufacturer’s
recommendations.
SEISMIC CONSIDERATIONS
The seismic design requirements for buildings and other structures are based on Seismic Design
Category. Site Classification is required to determine the Seismic Design Category for a structure.
The Site Classification is based on the upper 100 feet of the site profile defined by a weighted
average value of either shear wave velocity, standard penetration resistance, or undrained shear
strength in accordance with Section 20.4 of ASCE 7 and the International Building Code (IBC).
Based on the soil/bedrock properties encountered at the site and as described on the exploration
logs and results, it is our professional opinion that the Seismic Site Classification is D.
Subsurface explorations at this site were extended to a maximum depth of 40 feet. The site
properties below the boring depth to 100 feet were estimated based on our experience and
knowledge of geologic conditions of the general area. Additional deeper borings or geophysical
testing may be performed to confirm the conditions below the current boring depth.
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FLOOR SYSTEMS
A slab-on-grade may be utilized for the interior floor system for the proposed buildings provided
the native soils are over-excavated to a depth of at least 3 feet below floor slab, moisture
conditioned, and compacted on-site soils. If the estimated movement cannot be tolerated, a
structurally-supported floor system, supported independent of the subgrade materials, is
recommended.
Subgrade soils beneath interior and exterior slabs and at the base of the over-excavation for
removal of existing fill 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.
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 over-excavated and prepared as presented in the Earthwork section of this report.
For structural design of concrete slabs-on-grade subjected to point loadings, a modulus of
subgrade reaction of 200 pounds per cubic inch (pci) may be used for floors supported on at least
12 inches of imported granular fill and a modulus of subgrade reaction of 150 pci may be used for
floors supported on native lean clay soils.
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 Earthwork section of this report.
Floor slabs should not be constructed on frozen subgrade.
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
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The use of a vapor retarder should be considered beneath concrete slabs that will be
covered with wood, tile, carpet or other moisture sensitive or impervious floor coverings,
or when the slab will support equipment sensitive to moisture. When conditions warrant
the use of a vapor retarder, the slab designer and slab contractor should refer to ACI
302 for procedures and cautions regarding the use and placement of a vapor retarder.
Other design and construction considerations, as outlined in the ACI Design Manual,
Section 302.1R are recommended.
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.
BELOW-GRADE STRUCTURES
Lateral Earth Pressures
Below grade structures or 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
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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Earth Pressure Coefficients
Earth Pressure
Conditions
Coefficient for Backfill
Type
Equivalent
Fluid Density
(pcf)
Surcharge
Pressure, p1
(psf)
Earth Pressure,
p2 (psf)
Active (Ka)
Imported Fill - 0.27
Lean Clay with sand - 0.33
34
41
(0.27)S
(0.33)S
(34)H
(41)H
At-Rest (Ko)
Imported Fill - 0.43
Lean Clay with sand - 0.50
54
62
(0.43)S
(0.50)S
(54)H
(62)H
Passive (Kp)
Imported Fill - 3.69
Lean Clay with sand – 3.00
461
375
---
---
---
---
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 125 pcf
■ Horizontal backfill, compacted between 95 and 98 percent of standard Proctor maximum
dry density
■ Loading from heavy compaction equipment not included
■ No hydrostatic pressures acting on wall
■ No dynamic loading
■ No safety factor included
■ Ignore passive pressure in frost zone
Backfill placed against structures should consist of granular soils or low plasticity cohesive soils.
For the granular values to be valid, the granular backfill must extend out and up from the base of
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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the wall at an angle of at least 45 and 60 degrees from vertical for the active and passive cases,
respectively. To calculate the resistance to sliding, a value of 0.32 should be used as the ultimate
coefficient of friction between the footing and the underlying soil.
Swimming Pool Recommendations
We understand a swimming pool is conceptually planned near the student housing buildings of
the project site. The construction and performance of the pool will be highly affected by the
presence of groundwater encountered at depths ranging from approximately 4.9 to 5.7 feet below
existing site grades. Construction and/or permanent dewatering will be required for swimming
pool construction and service. Excavation of the pool area by conventional rubber-tired
equipment may encounter soft or very loose soils and/or severe pumping when nearing
groundwater level. It may be necessary to excavate the deep portion of the pool with a backhoe
or power shovel.
If the excavation extends into the groundwater, a one-piece fiberglass or similar pool should be
installed. As a precaution, pressure relief valves should be placed in the deep end of any pool
constructed to prevent flotation should groundwater rise when the pool is empty. We recommend
coordination with a qualified swimming pool specialty contractor to discuss alternatives to address
the effects of shallow groundwater on the proposed swimming pool.
If needed, a drainage system should be provided around and beneath the pool. The drain should
consist of a minimum 6-inch layer of clean gravel (minimum 3/4-inch size) beneath and along the
sides of the pool. The top of the drain layer should be sealed with 18 inches of relatively
impermeable soil at the surface. The gravel layer beneath the pool should be sloped so that it
will drain into tiles or perforated drainpipe. The layout of the perforated pipe should include at
least one pipe running down the center of the pool lengthwise. Cross-connecting pipes, spanning
with the pool, should be placed at 6-foot centers. The cross-connecting pipes should be joined to
the center pipe with solid “tees” or “cross” connections. The center pipes should be sloped to a
positive gravity outlet or sloped to a sump located in the equipment room, permitting pump
discharge.
The bottom of the excavation beneath the gravel layer and the pipe should be lined with an
impervious membrane (polyethylene film or equal) to reduce potential moisture fluctuations in the
subgrade soils. Pressure relief valves should be provided in the base of the pool to prevent
excessive uplift pressures from developing in the event of drain system failure.
The soils that will support deck slabs around the pool could expand with increasing moisture
content. To reduce possible damage that could be caused by expansive soils, we recommend:
Deck slabs be supported on fill with no, or very low, expansion potential;
Strict moisture-density control during placement of subgrade fill;
Geotechnical Engineering Report
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Placement of effective control joints on relatively close centers and isolation joints between
slabs and other structural elements;
Provision for adequate drainage in areas adjoining the slabs; and
Use of designs which allow vertical movement between the deck slabs and adjoining
structural elements.
Fill, backfill, and surface drainage in the pool area should be place in accordance with the
recommendations presented in the Earthwork section of this report. Grading should be provided
for diversion of deck surface runoff away from the pool area. In no case should water be allowed
to pond around the slab perimeter.
PAVEMENTS
Pavements – Subgrade Preparation
On most project sites, the site grading is accomplished relatively early in the construction phase.
Fills are typically placed and compacted in a uniform manner. However, as construction
proceeds, the subgrade may be disturbed due to utility excavations, construction traffic,
desiccation, or rainfall/snow melt. As a result, the pavement subgrade may not be suitable for
pavement construction and corrective action will be required. The subgrade should be carefully
evaluated at the time of pavement construction for signs of disturbance or instability. We
recommend the pavement subgrade be thoroughly proofrolled with a loaded tandem-axle dump
truck prior to final grading and paving. All pavement areas should be moisture conditioned and
properly compacted to the recommendations in this report immediately prior to paving.
Pavements – Design Recommendations
Design of new privately-maintained pavements for the project has been based on the procedures
described by the National Asphalt Pavement Associations (NAPA) and the American Concrete
Institute (ACI).
We assumed the following design parameters for NAPA flexible pavement thickness design:
Automobile Parking Areas
• Class I - Parking stalls and parking lots for cars and pick-up trucks, with
Equivalent Single Axle Load (ESAL) up to 7,000 over 20 years
Main Traffic Corridors
• Class II – Parking lots with a maximum of 10 trucks per day with Equivalent
Single Axle Load (ESAL) up to 27,000 over 20 years (Including trash trucks)
Subgrade Soil Characteristics
• USCS Classification – CL, classified by NAPA as poor
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Lombardy Student Housing ■ Fort Collins, Colorado
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We assumed the following design parameters for ACI rigid pavement thickness design based
upon the average daily truck traffic (ADTT):
Automobile Parking Areas
• ACI Category A: Automobile parking with an ADTT of 1 over 20 years
Main Traffic Corridors
• ACI Category A: Automobile parking area and service lanes with an ADTT of
up to 10 over 20 years
Subgrade Soil Characteristics
• USCS Classification – CL
Concrete modulus of rupture value of 600 psi
We should be contacted to confirm and/or modify the recommendations contained herein if actual
traffic volumes differ from the assumed values shown above.
Recommended alternatives for flexible and rigid pavements are summarized for each traffic area
as follows:
Traffic Area Alternative
Recommended Pavement Thicknesses (Inches)
Asphaltic
Concrete
Surface
Aggregate
Base Course
Portland
Cement
Concrete
Total
Automobile Parking
(NAPA Class I and
ACI Category A)
A 4 6 - 10
B - - 5 5
Service Lanes
(NAPA Class II and
ACI Category A)
A 5 8 - 13
B - - 6 6
Aggregate base course (if used on the site) should consist of a blend of sand and gravel which
meets strict specifications for quality and gradation. Use of materials meeting Colorado
Department of Transportation (CDOT) Class 5 or 6 specifications is recommended for aggregate
base course. Aggregate base course should be placed in lifts not exceeding 6 inches and
compacted to a minimum of 95 percent of the maximum dry unit weight as determined by ASTM
D698.
Asphaltic concrete should be composed of a mixture of aggregate, filler and additives (if required)
and approved bituminous material. The asphalt concrete should conform to approved mix
designs stating the Superpave properties, optimum asphalt content, job mix formula and
recommended mixing and placing temperatures. Aggregate used in asphalt concrete should
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Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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meet particular gradations. Material meeting CDOT Grading S or SX specifications or equivalent
is recommended for asphalt concrete. Mix designs should be submitted prior to construction to
verify their adequacy. Asphalt material should be placed in maximum 3-inch lifts and compacted
within a range of 92 to 96 percent of the theoretical maximum (Rice) density (ASTM D2041).
Where rigid pavements are used, the concrete should be produced from an approved mix design
with the following minimum properties:
Properties Value
Compressive strength 4,000 psi
Cement type Type I or II portland cement
Entrained air content (%) 5 to 8
Concrete aggregate ASTM C33 and CDOT section 703
Concrete should be deposited by truck mixers or agitators and placed a maximum of 90 minutes
from the time the water is added to the mix. Longitudinal and transverse joints should be provided
as needed in concrete pavements for expansion/contraction and isolation per ACI 325. The
location and extent of joints should be based upon the final pavement geometry.
For areas subject to concentrated and repetitive loading conditions (if any) such as dumpster
pads, truck delivery docks and ingress/egress aprons, we recommend using a portland cement
concrete pavement with a thickness of at least 6 inches underlain by at least 4 inches of granular
base. Prior to placement of the granular base, the areas should be thoroughly proofrolled. For
dumpster pads, the concrete pavement area should be large enough to support the container and
tipping axle of the refuse truck.
Pavement performance is affected by its surroundings. In addition to providing preventive
maintenance, the civil engineer should consider the following recommendations in the design and
layout of pavements:
Site grades should slope a minimum of 2 percent away from the pavements;
The subgrade and the pavement surface have a minimum 2 percent slope to promote proper
surface drainage;
Consider appropriate edge drainage and pavement under drain systems;
Install pavement drainage surrounding areas anticipated for frequent wetting;
Install joint sealant and seal cracks immediately;
Seal all landscaped areas in, or adjacent to pavements to reduce moisture migration to
subgrade soils; and
Placing compacted, low permeability backfill against the exterior side of curb and gutter.
Geotechnical Engineering Report
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Pavements – Construction Considerations
Openings in pavement, such as landscape islands, are sources for water infiltration into
surrounding pavements. Water collects in the islands and migrates into the surrounding subgrade
soils thereby degrading support of the pavement. This is especially applicable for islands with
raised concrete curbs, irrigated foliage, and low permeability near-surface soils. The civil design
for the pavements with these conditions should include features to restrict or to collect and
discharge excess water from the islands. Examples of features are edge drains connected to the
storm water collection system or other suitable outlet and impermeable barriers preventing lateral
migration of water such as a cutoff wall installed to a depth below the pavement structure.
Pavements – Maintenance
Preventative maintenance should be planned and provided for an ongoing pavement
management program in order to enhance future pavement performance. Preventive
maintenance consists of both localized maintenance (e.g. crack and joint sealing and patching)
and global maintenance (e.g. surface sealing). Preventative maintenance is usually the first
priority when implementing a planned pavement maintenance program and provides the highest
return on investment for pavements.
GENERAL COMMENTS
As the project progresses, we address assumptions by incorporating information provided by the
design team, if any. Revised project information that reflects actual conditions important to our
services is reflected in the final report. The design team should collaborate with Terracon to
confirm these assumptions and to prepare the final design plans and specifications. This facilitates
the incorporation of our opinions related to implementation of our geotechnical recommendations.
Any information conveyed prior to the final report is for informational purposes only and should
not be considered or used for decision-making purposes.
Our analysis and opinions are based upon our understanding of the project, the geotechnical
conditions in the area, and the data obtained from our site exploration. Natural variations will occur
between exploration point locations or due to the modifying effects of construction or weather.
The nature and extent of such variations may not become evident until during or after construction.
Terracon should be retained as the Geotechnical Engineer, where noted in the final report, to
provide observation and testing services during pertinent construction phases. If variations
appear, we can provide further evaluation and supplemental recommendations. If variations are
noted in the absence of our observation and testing services on-site, we should be immediately
notified so that we can provide evaluation and supplemental recommendations.
Our scope of services does not include either specifically or by implication any environmental or
biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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pollutants, hazardous materials or conditions. If the owner is concerned about the potential for
such contamination or pollution, other studies should be undertaken.
Our services and any correspondence or collaboration through this system are intended for the
sole benefit and exclusive use of our client for specific application to the project discussed and
are accomplished in accordance with generally accepted geotechnical engineering practices with
no third-party beneficiaries intended. Any third-party access to services or correspondence is
solely for information purposes to support the services provided by Terracon to our client. Reliance
upon the services and any work product is limited to our client and is not intended for third parties.
Any use or reliance of the provided information by third parties is done solely at their own risk. No
warranties, either express or implied, are intended or made.
Site characteristics as provided are for design purposes and not to estimate excavation cost. Any
use of our report in that regard is done at the sole risk of the excavating cost estimator as there
may be variations on the site that are not apparent in the data that could significantly impact
excavation cost. Any parties charged with estimating excavation costs should seek their own site
characterization for specific purposes to obtain the specific level of detail necessary for costing.
Site safety, and cost estimating including, excavation support, and dewatering
requirements/design are the responsibility of others. If changes in the nature, design, or location
of the project are planned, our conclusions and recommendations shall not be considered valid
unless we review the changes and either verify or modify our conclusions in writing.
ATTACH MENTS
ATTACHMENTS
SITE LOCA TION AND EXPLORATION PLANS
SITE LOCATION AND EXPLORATION PLANS
SITE LOCATION and NEARBY GEOTECHNICAL DATA
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
SITE LOCA TION P LAN
DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS
EXPLORATION PLAN
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
EXHIBIT E LANDSCAPE
B1
EXPLORATION PLAN
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS
B1
Geotechnical Engineering Report
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EXPLORATION AND TESTING PROCEDURES
Our scope of services consisted of field exploration, laboratory testing, and engineering/project
delivery. These services are described in the following sections.
Field Exploration
The field exploration program consisted of the following:
Number of Borings Planned Boring Depth (feet)
1
Planned Location
4 40 or auger refusal Planned parking garage
9 25 to 30 or auger refusal
Student housing buildings and church
area
1. Borings were completed to the planned depths below existing site grades or practical auger refusal, if
shallower.
Boring Layout and Elevations: We used handheld GPS equipment to locate borings with an
estimated horizontal accuracy of +/-20 feet. An approximate ground surface elevation at each
boring location was obtained by interpolation from a site specific, surveyed topographic map.
Subsurface Exploration Procedures: We advanced soil borings with a truck-mounted drill rig
using solid-stem, continuous-flight augers. Three samples were obtained in the upper 10 feet of
each boring and at intervals of 5 feet thereafter. Soil sampling was performed using modified
California barrel and/or standard split-barrel sampling procedures. For the standard split-barrel
sampling procedure, a standard 2-inch outer diameter split-barrel sampling spoon was driven into
the ground by a 140-pound automatic hammer falling a distance of 30 inches. The number of
blows required to advance the sampling spoon the last 12 inches of a normal 18-inch penetration
was recorded as the Standard Penetration Test (SPT) resistance value. The SPT resistance
values, also referred to as N-values, are indicated on the boring logs at the test depths. For the
modified California barrel sampling procedure, a 2½-inch outer diameter split-barrel sampling
spoon was used for sampling. Modified California barrel sampling procedures are similar to
standard split-barrel sampling procedures; however, blow counts were recorded for 6-inch
intervals for a total of 12 inches of penetration. The samples were placed in appropriate containers,
and taken to our soil laboratory for testing, and classified by a geotechnical engineer.
In addition, we observed and record groundwater levels during drilling observations and 2 to 3
days after drilling. Eight of the borings were left open for delayed water readings. Three of the
eight borings had PVC pipe installed for more accurate delayed water readings.
Our exploration team prepared field boring logs as part of standard drilling operations including
sampling depths, penetration distances, and other relevant sampling information. Field logs include
visual classifications of materials encountered during drilling, and our interpretation of subsurface
Geotechnical Engineering Report
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
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conditions between samples. Final boring logs, prepared from field logs, represent the
geotechnical engineer's interpretation, and include modifications based on observations and
laboratory test results.
Property Disturbance: We backfilled borings with a mixture of auger cuttings and cement-
bentonite grout after completion or delayed water readings. Pavements were patched with cold-
mix asphalt. Our services did not include repair of the site beyond backfilling our boreholes, and
cold patching existing pavements. Excess auger cuttings were removed from the site.
Laboratory Testing
The project engineer reviewed field data and assigned various laboratory tests to better
understand the engineering properties of various soil and bedrock strata. Laboratory testing was
conducted in general accordance with applicable or other locally recognized standards. Testing
was performed under the direction of a geotechnical engineer and included the following:
■ Visual classification ■ Moisture content
■ Dry density ■ Atterberg limits
■ Grain-size analysis ■ One-dimensional swell
■ Corrosive properties ■ Unconfined compressive strength
Our laboratory testing program included examination of soil samples by an engineer. Based on
the material’s texture and plasticity, we described and classified soil samples in accordance with
the Unified Soil Classification System (USCS). Soil and bedrock samples obtained during our
field work are disposed of after laboratory testing is complete unless a specific request is made
to temporarily store the samples for a longer period of time
EXPLORATION RESULTS
EXPLORATION RESULTS
14170
28
92
18
7
23
10
13
13
123
122
27-21-6
38-22-16
5037
5036.5
5034
5029
5023
5018
5012.5
3-4-6
N=10
3-9
3-3-7
N=10
4-13
16,50/6"
N=66/12"
50/6"
ASPHALT, about 3 inches thick
AGGREGATE SURFACING, brown
SANDY LEAN CLAY, light brown, stiff
SILTY CLAYEY SAND WITH GRAVEL (SC-SM),
red to brown, stiff
LEAN CLAY (CL), tan to light brown, stiff
SANDY LEAN CLAY WITH VARYING AMOUTNS
OF GRAVEL, brown, stiff
INTERBEDDED SILTSTONE CLAYSTONE, gray to
tan, very hard, trace FeOx
Boring Terminated at 24.5 Feet
0.2
0.4
3.0
8.0
14.0
19.0
24.5
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
UNCONFINED
COMPRESSIVE
STRENGTH (psf)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
80
15
15
16
16
22
14
14
109
106
101
118
34-15-19
NP
5031.5
5023
5017
5007.5
10-9
5-8
9-6-6
N=12
50/6"
50/5"
50/6"
-0.1/500
TOPSOIL, brown, about 7 inches thick
LEAN CLAY WITH SAND (CL), brown to light
brown, stiff
SILTY SAND WITH GRAVEL (SM), tan, medium
dense
INTERBEDDED SILTSTONE CLAYSTONE, gray to
brown, very hard, trace FeOx
Boring Terminated at 24.5 Feet
0.6
9.0
15.0
24.5
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
UNCONFINED
COMPRESSIVE
STRENGTH (psf)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 5032 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
76
87
14
17
23
14
14
13
12
111
117
112
120
37-22-15
39-23-16
5031.5
5027.5
5023
5018
5017
5002.5
5-6-6
N=12
5-8
2-5-7
N=12
50/6"
50/6"
50/5"
50/4"
+1.6/500
TOPSOIL, brown, about 7 inches thick
LEAN CLAY WITH SAND (CL), brown, stiff
LEAN CLAY (CL), gray to white, medium stiff to stiff
CLAYEY SAND, brown, medium dense
SANDY GRAVEL, brown, very dense
INTERBEDDED SILTSTONE CLAYSTONE, gray to
brown, very hard
Boring Terminated at 29.3 Feet
0.6
4.5
9.0
14.0
15.0
29.3
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
UNCONFINED
COMPRESSIVE
STRENGTH (psf)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 5032 (Ft.)
32 79
22
16
18
17
13
104
117
39-26-13
5028.5
5026
5015
4999.5
1-1-1
N=2
0-1
3-11-17
N=28
50/5"
30, 50/6"
N=80/12"
50/6"
TOPSOIL, brown, about 7 inches thick
SILTY SAND (ML), brown to light brown, loose
WEATHERED INTERBEDDED SILTSTONE
CLAYSTONE, gray to brown, weathered
INTERBEDDED SILTSTONE CLAYSTONE, gray to
brown, very hard, trace FeOx
Boring Terminated at 29.5 Feet
0.6
3.0
14.0
29.5
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
UNCONFINED
COMPRESSIVE
STRENGTH (psf)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 5029 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
25
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL-CONSOL
16020
90
9
21
13
14
12
13
119
106
121
123
33-21-12
5026.5
5026
5022.5
5018
5002
4-6
2-5
16, 50/6"
N=66/12"
25,50/2
N=75/8"
50/6"
15, 50/5"
N=75/11"
ASPHALT, about 5 inches thick
AGGREGATE SURFACING, brown
SILTY SAND WITH VARYING AMOUTNS OF
GRAVEL, brown to white/pink, loose
LEAN CLAY (CL), tan to gray, medium stiff
INTERBEDDED SILTSTONE CLAYSTONE, gray to
tan, very hard
Boring Terminated at 24.9 Feet
0.4
0.8
4.5
9.0
24.9
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
UNCONFINED
COMPRESSIVE
STRENGTH (psf)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 5027 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
5690
72
26
81
22
12
13
14
12
16
17
101
122
111
26-18-8
22-16-6
31-21-10
5025.5
5025
5021.5
5016
5012
4986.5
8-11
5-13-14
N=27
5-10
15, 50/6"
N=65/12"
25, 50/3"
N=75/9"
50/6"
50/5"
ASPHALT, about 4 inches thick
AGGREGATE SURFACING, brown
LEAN CLAY WITH SAND (CL), brown to black, very
stiff
SAND WITH VARYING AMOUTNS OF GRAVEL,
tan to brown/pink, medium dense
SILTY CLAYEY SAND WITH GRAVEL (SC-SM),
brown to light brown, medium dense
INTERBEDDED SILTSTONE CLAYSTONE (CL),
gray to tan, very hard
Boring Terminated at 39.4 Feet
0.3
0.8
4.5
10.0
14.0
39.4
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
UNCONFINED
COMPRESSIVE
STRENGTH (psf)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
49
26
21
13
23
14
14
11
14
122
35-23-12
NP
5029.5
5029
5020
5011
4990
2-4-3
N=7
6-8
7-4-8
N=12
7-11
19, 33, 50/3"
N=83/9"
50/6"
15, 50/4"
N=65/10"
0/1,000
ASPHALT, black, about 6 inches thick
AGGREGATE SURFACING, brown
CLAYEY SAND WITH GRAVEL (SC), gray to black,
loose to medium dense
SILTY SAND WITH GRAVEL (SM), brown to
white/pink, medium dense
INTERBEDDED SILTSTONE CLAYSTONE, gray to
tan, very hard
Boring Terminated at 39.8 Feet
0.5
0.8
10.0
19.0
39.8
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
UNCONFINED
COMPRESSIVE
STRENGTH (psf)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 5030 (Ft.)
WATER LEVEL
OBSERVATIONS
8770
55
43
14
8
14
18
20
12
12
130
111
119
28-16-12
31-14-17
5029.5
5029
5028
5020.5
5016
5011
4990.5
4-4-6
N=10
3-4
6-6-4
N=10
7-16
7, 30, 50/5"
N=80/11"
50/6"
50/4"
-0.1/500
ASPHALT, black, about 4 inches thick
AGGREGATE SURFACING, brown
SAND WITH VARYING AMOUTNS OF GRAVEL,
brown to red, medium dense
SANDY LEAN CLAY (CL), brown to black/red,
medium stiff
CLAYEY SAND WITH GRAVEL (SC), brown,
medium dense
WEATHERED INTERBEDDED SILTSTONE
CLAYSTONE, gray to brown, weathered
INTERBEDDED SILTSTONE CLAYSTONE, gray to
tan, very hard
Boring Terminated at 39.3 Feet
0.3
0.9
2.0
9.5
14.0
19.0
39.3
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
UNCONFINED
COMPRESSIVE
STRENGTH (psf)
PERCENT FINES
WATER
15
16
19
11
18
30
15
13
114
119
NP
5024.5
5022
5011
4985.5
4-12
8, 50/1"
N=58/7"
7-20
22, 32, 50/6"
N=82/12"
50/6"
50/6"
50/4"
+0.4/250
TOPSOIL, brown, about 7 inches thick
LEAN CLAY WITH SAND, brown, stiff
SILTY SAND WITH GRAVEL (SM), brown to
tan/white, medium dense to very dense
INTERBEDDED SILTSTONE CLAYSTONE, gray to
tan/green, very hard
Boring Terminated at 39.3 Feet
0.6
3.0
14.0
39.3
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
UNCONFINED
COMPRESSIVE
STRENGTH (psf)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 5025 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
25
30
6940
13 53
13
19
22
15
15
123
105
117
23-16-7
5027.5
5018.5
5013.5
5009
5003
3-4-3
N=7
4-7
3-5-7
N=12
10-10
21, 50/6"
N=71/12"
33,50/5"
N=83/11"
-0.2/500
TOPSOIL, brown, about 7 inches thick
SANDY SILTY CLAY (CL-ML), with clay, brown,
medium stiff to stiff
CLAYEY SAND, trace gravel, brown to tan, medium
dense
WEATHERED INTERBEDDED SILTSTONE
CLAYSTONE, gray to brown, weathered
INTERBEDDED SILTSTONE CLAYSTONE, gray to
tan, very hard, trace FeOx
Boring Terminated at 24.9 Feet
0.6
9.5
14.5
19.0
24.9
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
UNCONFINED
COMPRESSIVE
STRENGTH (psf)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 5028 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
23
17
6
19
18
16
97
107
5027.5
5020
5018
5014
5009
4998
2-4
2-3-7
N=10
7-7
6-9-20
N=29
50/6"
37, 50/4"
N=87/10"
+0.7/150
AGGREGATE SURFACING, brown to black, about
7 inches thick
LEAN CLAY WITH SAND, brown to light brown,
medium stiff
GRAVEL WITH SAND, brown to tan, loose
LEAN CLAY, brown, stiff
WEATHERED INTERBEDDED SILTSTONE
CLAYSTONE, gray to brown, weathered
INTERBEDDED SILTSTONE CLAYSTONE, gray to
tan, very hard
Boring Terminated at 29.8 Feet
0.6
8.0
10.0
14.0
19.0
29.8
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
UNCONFINED
COMPRESSIVE
STRENGTH (psf)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 5028 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
71
20
21
11
19
15
19
15
102
116
117
32-16-16
5028.5
5026
5020
5014.5
5010
5005
4999.5
3-3
2-3-3
N=6
6-6
7-6-3
N=9
12-35
20, 50/6"
N=70/12"
50/6"
TOPSOIL, brown, about 7 inches thick
CLAYEY SAND, brown, loose
LEAN CLAY WITH SAND (CL-ML), brown, stiff
SAND WITH VARYING AMOUTNS OF GRAVEL,
trace clay, brown to white, loose
CLAYEY SAND, trace gravel, brown to tan, loose
WEATHERED INTERBEDDED SILTSTONE
CLAYSTONE, gray to brown, weathered
INTERBEDDED SILTSTONE CLAYSTONE, gray to
tan, very hard, trace FeOx
Boring Terminated at 29.5 Feet
0.6
3.0
9.0
14.5
19.0
24.0
29.5
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
UNCONFINED
COMPRESSIVE
STRENGTH (psf)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
87
27
21
20
23
20
19
18
101
31-22-9
NP
5029.5
5025
5019.5
5010.5
5006
5005.5
2-1-1
N=2
2-3
2-3-3
N=6
5-8
5-7-29
N=36
50/4"
TOPSOIL, brown, about 7 inches thick
CLAYEY SAND, trace gravel, brown, very loose to
loose
LEAN CLAY (CL), brown to light brown, medium
stiff
SILTY SAND WITH GRAVEL (SM), trace clay,
brown to white, loose
WEATHERED INTERBEDDED SILTSTONE
CLAYSTONE, gray to brown, weathered
INTERBEDDED SILTSTONE CLAYSTONE, gray to
tan, weathered to very hard
Boring Terminated at 24.3 Feet
0.6
5.0
10.5
19.5
24.0
24.3
StratificationAutomatic lines are approximate. In-situ, the transition may be gradual. Hammer Type:
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
UNCONFINED
COMPRESSIVE
STRENGTH (psf)
PERCENT FINES
WATER
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 5030 (Ft.)
WATER LEVEL
0
10
20
30
40
50
60
0 20 40 60 80 100
CL or OL CH or OH
ML or OL
MH or OH
"U" Line
"A" Line
ATTERBERG LIMITS RESULTS
ASTM D4318
P
L
A
S
T
I
C
I
T
Y
I
N
D
E
X
LIQUID LIMIT
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
27
38
34
NP
37
39
39
33
26
22
31
35
NP
28
31
NP
23
32
31
NP
v
0 v
10
20
30
40
50
60
0 20 40 60 80 100
CL or OL CH or OH
ML or OL
MH or OH
"U" Line
"A" Line
ATTERBERG LIMITS RESULTS
ASTM D4318
P
L
A
S
T
I
C
I
T
Y
I
N
D
E
X
LIQUID LIMIT
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. ATTERBERG LIMITS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
35 38 NP ML SILT with SAND
Boring ID Depth LL PL PI Fines USCS Description
BULK 0 - 5 70
CL-ML
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
100 10 1 0.1 0.01 0.001
GRAIN SIZE IN MILLIMETERS
3/4 1/2
3/8 30
3 40
60
U.S. SIEVE OPENING IN INCHES HYDROMETER
16 20
100
90
80
70
60
50
40
30
20
10
0
U.S. SIEVE NUMBERS
4 4 6 100
3 2 10
14 50
6 200
1.5 1 8
140
PERCENT FINER BY WEIGHT
PERCENT COARSER BY WEIGHT
GRAIN SIZE DISTRIBUTION
ASTM D422 / ASTM C136
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS 1 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
100 10 1 0.1 0.01 0.001
GRAIN SIZE IN MILLIMETERS
3/4 1/2
3/8 30
3 40
60
U.S. SIEVE OPENING IN INCHES HYDROMETER
16 20
100
90
80
70
60
50
40
30
20
10
0
U.S. SIEVE NUMBERS
4 4 6 100
3 2 10
14 50
6 200
1.5 1 8
140
PERCENT FINER BY WEIGHT
PERCENT COARSER BY WEIGHT
GRAIN SIZE DISTRIBUTION
ASTM D422 / ASTM C136
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS 1 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
100 10 1 0.1 0.01 0.001
GRAIN SIZE IN MILLIMETERS
3/4 1/2
3/8 30
3 40
60
U.S. SIEVE OPENING IN INCHES HYDROMETER
16 20
100
90
80
70
60
50
40
30
20
10
0
U.S. SIEVE NUMBERS
4 4 6 100
3 2 10
14 50
6 200
1.5 1 8
140
PERCENT FINER BY WEIGHT
PERCENT COARSER BY WEIGHT
GRAIN SIZE DISTRIBUTION
ASTM D422 / ASTM C136
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS 1 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
100 10 1 0.1 0.01 0.001
GRAIN SIZE IN MILLIMETERS
3/4 1/2
3/8 30
3 40
60
U.S. SIEVE OPENING IN INCHES HYDROMETER
16 20
100
90
80
70
60
50
40
30
20
10
0
U.S. SIEVE NUMBERS
4 4 6 100
3 2 10
14 50
6 200
1.5 1 8
140
PERCENT FINER BY WEIGHT
PERCENT COARSER BY WEIGHT
GRAIN SIZE DISTRIBUTION
ASTM D422 / ASTM C136
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS 1 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
100 10 1 0.1 0.01 0.001
GRAIN SIZE IN MILLIMETERS
3/4 1/2
3/8 30
3 40
60
U.S. SIEVE OPENING IN INCHES HYDROMETER
16 20
100
90
80
70
60
50
40
30
20
10
0
U.S. SIEVE NUMBERS
4 4 6 100
3 2 10
14 50
6 200
1.5 1 8
140
PERCENT FINER BY WEIGHT
PERCENT COARSER BY WEIGHT
GRAIN SIZE DISTRIBUTION
ASTM D422 / ASTM C136
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS 1 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
100 10 1 0.1 0.01 0.001
GRAIN SIZE IN MILLIMETERS
3/4 1/2
3/8 30
3 40
60
U.S. SIEVE OPENING IN INCHES HYDROMETER
16 20
100
90
80
70
60
50
40
30
20
10
0
U.S. SIEVE NUMBERS
4 4 6 100
3 2 10
14 50
6 200
1.5 1 8
140
PERCENT FINER BY WEIGHT
PERCENT COARSER BY WEIGHT
GRAIN SIZE DISTRIBUTION
ASTM D422 / ASTM C136
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS 1 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
100 10 1 0.1 0.01 0.001
GRAIN SIZE IN MILLIMETERS
3/4 1/2
3/8 30
3 40
60
U.S. SIEVE OPENING IN INCHES HYDROMETER
16 20
100
90
80
70
60
50
40
30
20
10
0
U.S. SIEVE NUMBERS
4 4 6 100
3 2 10
14 50
6 200
1.5 1 8
140
PERCENT FINER BY WEIGHT
PERCENT COARSER BY WEIGHT
GRAIN SIZE DISTRIBUTION
ASTM D422 / ASTM C136
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GRAIN SIZE: USCS 1 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 0.1 percent compression upon wetting under an applied pressure of 500 psf.
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
B 02 4 - 5 ft LEAN CLAY WITH SAND 106 16
Specimen Identification Classification , pcf WC, %
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 1.6 percent swell upon wetting under an applied pressure of 500 psf.
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
B 03 4 - 5 ft LEAN CLAY(CL) 111 17
Specimen Identification Classification , pcf WC, %
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited no movement upon wetting under an applied pressure of 1,000 psf.
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
B 07 29SILTSTONE - 29.5 ft CLAYSTONE/121 11
Specimen Identification Classification , pcf WC, %
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 0.1 percent compression upon wetting under an applied pressure of 500 psf.
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
B 08 4 - 5 ft SANDY LEAN CLAY WITH GRAVEL 130 8
Specimen Identification Classification , pcf WC, %
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 0.4 percent swell upon wetting under an applied pressure of 250 psf.
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
B 09 2 - 3 ft LEAN CLAY WITH SAND 126 16
Specimen Identification Classification , pcf WC, %
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 0.2 percent compression upon wetting under an applied pressure of 500 psf.
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
B 10 4 - 5 ft SANDY SILTY CLAY 118 13
Specimen Identification Classification , pcf WC, %
-10
-8
-6
-4
-2
0
2
4
100 1,000 10,000
AXIAL STRAIN, %
PRESSURE, psf
SWELL CONSOLIDATION TEST
ASTM D4546
NOTES: Sample exhibited 0.7 percent swell upon wetting under an applied pressure of 150 psf.
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. TC_CONSOL_STRAIN-USCS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
B 11 2 - 3 ft LEAN CLAY WITH SAND 102 23
Specimen Identification Classification , pcf WC, %
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
AXIAL STRAIN - %
UNCONFINED COMPRESSION TEST
ASTM D2166
COMPRESSIVE STRESS - psf
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. UNCONFINED WITH PHOTOS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
SAMPLEfeet TYPE: CA RING SAMPLER SAMPLE LOCATION: B 01 @ 24 - 24.5
Strain Rate: in/min
Failure Strain: %
Calculated Saturation: %
Height: in.
Diameter: in.
SPECIMEN FAILURE PHOTOGRAPH
Remarks:
LLPLPISieve Percent < #200
7084
DESCRIPTION: CLAYSTONE/SILTSTONE
Dry Density: pcf
Moisture Content: %
2.78
Height / Diameter Ratio: 2.19
Calculated Void Ratio:
Undrained Shear Strength: (psf)
Unconfined Compressive Strength (psf)
Assumed Specific Gravity:
14167
4.24
1.94
SPECIMEN TEST DATA
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
0 1.0 2.0 3.0 4.0
AXIAL STRAIN - %
UNCONFINED COMPRESSION TEST
ASTM D2166
COMPRESSIVE STRESS - psf
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. UNCONFINED WITH PHOTOS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
SAMPLEfeet TYPE: CA RING SAMPLER SAMPLE LOCATION: B 05 @ 24 - 24.9
Strain Rate: in/min
Failure Strain: %
Calculated Saturation: %
Height: in.
Diameter: in.
SPECIMEN FAILURE PHOTOGRAPH
Remarks:
LLPLPISieve Percent < #200
8008
DESCRIPTION: CLAYSTONE/SILTSTONE
Dry Density: pcf
Moisture Content: %
3.35
Height / Diameter Ratio: 2.11
Calculated Void Ratio:
Undrained Shear Strength: (psf)
Unconfined Compressive Strength (psf)
Assumed Specific Gravity:
16017
4.09
1.94
SPECIMEN TEST DATA
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
5,000
5,500
6,000
0 1.0 2.0 3.0 4.0
AXIAL STRAIN - %
UNCONFINED COMPRESSION TEST
ASTM D2166
COMPRESSIVE STRESS - psf
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. UNCONFINED WITH PHOTOS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
SAMPLEfeet TYPE: CA RING SAMPLER SAMPLE LOCATION: B 06 @ 19 - 19.7
Strain Rate: in/min
Failure Strain: %
Calculated Saturation: %
Height: in.
Diameter: in.
SPECIMEN FAILURE PHOTOGRAPH
Remarks: Sample height to diameter ratio does not follow ASTM Standards.
81
LLPLPISieve Percent < #200
2847
DESCRIPTION: CLAYSTONE/SILTSTONE
Dry Density: pcf
Moisture Content: %
2.42
Height / Diameter Ratio: 2.13
Calculated Void Ratio:
Undrained Shear Strength: (psf)
Unconfined Compressive Strength (psf)
31 21 10
Assumed Specific Gravity:
5695
4.09
1.92
SPECIMEN TEST DATA
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
0 1 2 3 4 5 6 7
AXIAL STRAIN - %
UNCONFINED COMPRESSION TEST
ASTM D2166
COMPRESSIVE STRESS - psf
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. UNCONFINED WITH PHOTOS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
SAMPLEfeet TYPE: CA RING SAMPLER SAMPLE LOCATION: B 08 @ 29 - 29.5
Strain Rate: in/min
Failure Strain: %
Calculated Saturation: %
Height: in.
Diameter: in.
SPECIMEN FAILURE PHOTOGRAPH
Remarks:
LLPLPISieve Percent < #200
4383
DESCRIPTION: CLAYSTONE/SILTSTONE
Dry Density: pcf
Moisture Content: %
6.17
Height / Diameter Ratio: 2.28
Calculated Void Ratio:
Undrained Shear Strength: (psf)
Unconfined Compressive Strength (psf)
Assumed Specific Gravity:
8767
4.40
1.93
SPECIMEN TEST DATA
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
0 0.4 0.8 1.2 1.6 2.0 2.4
AXIAL STRAIN - %
UNCONFINED COMPRESSION TEST
ASTM D2166
COMPRESSIVE STRESS - psf
PROJECT NUMBER: 20185115
SITE: NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
PROJECT: Lombardy Student Housing
CLIENT: Blackbird Investments, LLC
Des Moines, IA
1901 Sharp Point Dr, Ste C
Fort Collins, CO
LABORATORY TESTS ARE NOT VALID IF SEPARATED FROM ORIGINAL REPORT. UNCONFINED WITH PHOTOS 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/5/18
SAMPLEfeet TYPE: CA RING SAMPLER SAMPLE LOCATION: B 10 @ 24 - 24.9
Strain Rate: in/min
Failure Strain: %
Calculated Saturation: %
Height: in.
Diameter: in.
SPECIMEN FAILURE PHOTOGRAPH
Remarks:
LLPLPISieve Percent < #200
3468
DESCRIPTION: CLAYSTONE/SILTSTONE
Dry Density: pcf
Moisture Content: %
1.95
Height / Diameter Ratio: 2.13
Calculated Void Ratio:
Undrained Shear Strength: (psf)
Unconfined Compressive Strength (psf)
Assumed Specific Gravity:
6936
4.15
1.95
SPECIMEN TEST DATA
Project Number:
Service Date:
Report Date:
Task:
Client
Date Received:
B-7
2.0
8.80
61
Nil
35
+678
1000
1649
Analyzed By:
The tests were performed in general accordance with applicable ASTM, AASHTO, or DOT test methods. This report is exclusively for the use of the client
indicated above and shall not be reproduced except in full without the written consent of our company. Test results transmitted herein are only applicable to
the actual samples tested at the location(s) referenced and are not necessarily indicative of the properties of other apparently similar or identical materials.
20185115
Sample Submitted By: Terracon (20) 10/25/2018
Results of Corrosion Analysis
Chemist
10/26/18
Lab No.: 18-1300
Sample Number
Sample Location
Sample Depth (ft.)
10/29/18
750 Pilot Road, Suite F
Las Vegas, Nevada 89119
(702) 597-9393
Project
CHEMICAL LABORATORY TEST REPORT
Trisha Campo
pH Analysis, AWWA 4500 H
Water Soluble Sulfate (SO4), ASTM C 1580
(mg/kg)
Sulfides, AWWA 4500-S D, (mg/kg)
Chlorides, ASTM D 512, (mg/kg)
Red-Ox, AWWA 2580, (mV)
Total Salts, AWWA 2520 B, (mg/kg)
Resistivity, ASTM G 57, (ohm-cm)
Blackbird Investments, LLC. Lombardy Student Housing
Project Number:
Service Date:
Report Date:
Task:
Client
Date Received:
B-1 B-4 B-9 B-12
2.0 4.0 4.0 2.0
110 74 83 74
Analyzed By:
CHEMICAL LABORATORY TEST REPORT
Trisha Campo
Water Soluble Sulfate (SO4), ASTM C 1580
(mg/kg)
Blackbird Investments, LLC. Lombardy Student Housing
10/29/18
750 Pilot Road, Suite F
Las Vegas, Nevada 89119
(702) 597-9393
Project
Lab No.: 18-1300
Sample Number
Sample Location
Sample Depth (ft.)
The tests were performed in general accordance with applicable ASTM, AASHTO, or DOT test methods. This report is exclusively for the use of the client
indicated above and shall not be reproduced except in full without the written consent of our company. Test results transmitted herein are only applicable to
the actual samples tested at the location(s) referenced and are not necessarily indicative of the properties of other apparently similar or identical materials.
20185115
Sample Submitted By: Terracon (20) 10/25/2018
Results of Corrosion Analysis
Chemist
10/26/18
4,980
4,985
4,990
4,995
5,000
5,005
5,010
5,015
5,020
5,025
5,030
5,035
4,980
4,985
4,990
4,995
5,000
5,005
5,010
5,015
5,020
5,025
5,030
5,035
N=2
N=28
BT-29.5 Ft.
32 39 26
22
16
18
17
13
B 04
%w LL PL
BT-24.9 Ft.
33 21
16020
9
21
13
14
12
13
B 05
LL PL psf
UC
%w
N=27
BT-39.4 Ft.
18
16
21
26
22
31 5690
22
12
13
14
4,985
4,990
4,995
5,000
5,005
5,010
5,015
5,020
5,025
5,030
5,035
5,040
4,985
4,990
4,995
5,000
5,005
5,010
5,015
5,020
5,025
5,030
5,035
5,040
N=10
N=10
BT-24.5 Ft.
21
22
27
38
14170
18
7
23
10
13
13
B 01
LL PL psf
UC
%w
N=12
BT-24.5 Ft.
15
0
34
0
15
16
16
22
14
14
B 02
%w LL PL
N=12
N=12
BT-29.3 Ft.
22
ELEV APPROXIMATE ELEVATION TO BEDROCK (FEET)
APPROXIMATE LOCATION OF BORING, WITH HAND-WRITTEN ELEVATIONS AND DEPTH TO BEDROCK (FEET)
LEGEND:
ELEV
INDICATES APPROXIMATE ELEVATION TO WATER TABLE (FEET)
APPROXIMATE LOCATION OF BORING, WITH HAND-WRITTEN ELEVATIONS AND DEPTH TO GROUNDWATER (FEET)
APPROXIMATE LOCATION OF UNDOCUMENTED FILL
SUPPORTING INFORMA TION
SUPPORTING INFORMATION
Lombardy Student Housing Fort Collins, CO
December 3, 2018 Terracon Project No. 20185115 (revised)
2,000 to 4,000
Unconfined
Compressive
Strength
Qu, (psf)
less than 500
500 to 1,000
1,000 to 2,000
4,000 to 8,000
> 8,000
Modified
California
Ring
Sampler
Split Spoon
Trace
PLASTICITY DESCRIPTION
Water levels indicated on the soil boring logs are
the levels measured in the borehole at the times
indicated. Groundwater level variations will occur
over time. In low permeability soils, accurate
determination of groundwater levels is not
possible with short term water level
observations.
DESCRIPTION OF SYMBOLS AND ABBREVIATIONS
GENERAL NOTES
> 30
11 - 30
Low 1 - 10
Non-plastic
Plasticity Index
#4 to #200 sieve (4.75mm to 0.075mm
Boulders
Cobbles 12 in. to 3 in. (300mm to 75mm)
Gravel 3 in. to #4 sieve (75mm to 4.75 mm)
Sand
Silt or Clay Passing #200 sieve (0.075mm)
Particle Size
Water Level After
a Specified Period of Time
Water Level After a
Specified Period of Time
Water Initially
Encountered
Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have more than 50% of their
dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils
have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic,
and silts if they are slightly plastic or non-plastic. Major constituents may be added as modifiers and minor constituents
may be added according to the relative proportions based on grain size. In addition to gradation, coarse-grained soils are
defined on the basis of their in-place relative density and fine-grained soils on the basis of their consistency.
GRAIN SIZE TERMINOLOGY
RELATIVE PROPORTIONS OF SAND AND GRAVEL RELATIVE PROPORTIONS OF FINES
DESCRIPTIVE SOIL CLASSIFICATION
LOCATION AND ELEVATION NOTES
SAMPLING WATER LEVEL FIELD TESTS
N
(HP)
(T)
UNIFIED SOIL CLASSIFICATION SYSTEM
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
UNIFIED SOIL CLASSI FICATI ON SYSTEM
Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A
Soil Classification
Group
Symbol
Group Name B
Coarse-Grained Soils:
More than 50% retained
on No. 200 sieve
Gravels:
More than 50% of
coarse fraction
retained on No. 4 sieve
Clean Gravels:
Less than 5% fines C
Cu 4 and 1 Cc 3 E
GW Well-graded gravel F
Cu 4 and/or 1 Cc 3 E
GP Poorly graded gravel F
Gravels with Fines:
More than 12% fines C
Fines classify as ML or MH GM Silty gravel F, G, H
Fines classify as CL or CH GC Clayey gravel F, G, H
Sands:
50% or more of coarse
fraction passes No. 4
sieve
Clean Sands:
Less than 5% fines D
Cu 6 and 1 Cc 3 E
SW Well-graded sand I
Cu 6 and/or 1 Cc 3 E
SP Poorly graded sand I
Sands with Fines:
More than 12% fines D
Fines classify as ML or MH SM Silty 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
DESCRIPTION OF ROCK PROPERTIES
Lombardy Student Housing ■ Fort Collins, Colorado
December 3, 2018 ■ Terracon Project No. 20185115 (revised)
ROCK VERSION 1
WEATHERING
Term Description
Unweathered No visible sign of rock material weathering, perhaps slight discoloration on major discontinuity surfaces.
Slightly
weathered
Discoloration indicates weathering of rock material and discontinuity surfaces. All the rock material may be
discolored by weathering and may be somewhat weaker externally than in its fresh condition.
Moderately
weathered
Less than half of the rock material is decomposed and/or disintegrated to a soil. Fresh or discolored rock is
present either as a continuous framework or as corestones.
Highly
weathered
More than half of the rock material is decomposed and/or disintegrated to a soil. Fresh or discolored rock is
present either as a discontinuous framework or as corestones.
Completely
weathered
All rock material is decomposed and/or disintegrated to soil. The original mass structure is still largely intact.
Residual soil
All rock material is converted to soil. The mass structure and material fabric are destroyed. There is a large
change in volume, but the soil has not been significantly transported.
STRENGTH OR HARDNESS
Description Field Identification
Uniaxial Compressive
Strength, psi (MPa)
Extremely weak Indented by thumbnail 40-150 (0.3-1)
Very weak
Crumbles under firm blows with point of geological hammer, can be
peeled by a pocket knife
150-700 (1-5)
Weak rock
Can be peeled by a pocket knife with difficulty, shallow indentations
made by firm blow with point of geological hammer
700-4,000 (5-30)
Medium strong
Cannot be scraped or peeled with a pocket knife, specimen can be
fractured with single firm blow of geological hammer
4,000-7,000 (30-50)
Strong rock
Specimen requires more than one blow of geological hammer to
fracture it
7,000-15,000 (50-100)
Very strong Specimen requires many blows of geological hammer to fracture it 15,000-36,000 (100-250)
Extremely strong Specimen can only be chipped with geological hammer >36,000 (>250)
DISCONTINUITY DESCRIPTION
Fracture Spacing (Joints, Faults, Other Fractures) Bedding Spacing (May Include Foliation or Banding)
Description Spacing Description Spacing
Extremely close < ¾ in (<19 mm) Laminated < ½ in (<12 mm)
Very close ¾ in – 2-1/2 in (19 - 60 mm) Very thin ½ in – 2 in (12 – 50 mm)
Close 2-1/2 in – 8 in (60 – 200 mm) Thin 2 in – 1 ft. (50 – 300 mm)
Moderate 8 in – 2 ft. (200 – 600 mm) Medium 1 ft. – 3 ft. (300 – 900 mm)
Wide 2 ft. – 6 ft. (600 mm – 2.0 m) Thick 3 ft. – 10 ft. (900 mm – 3 m)
Very Wide 6 ft. – 20 ft. (2.0 – 6 m) Massive > 10 ft. (3 m)
Discontinuity Orientation (Angle): Measure the angle of discontinuity relative to a plane perpendicular to the longitudinal axis of the
core. (For most cases, the core axis is vertical; therefore, the plane perpendicular to the core axis is horizontal.) For example, a
horizontal bedding plane would have a 0-degree angle.
ROCK QUALITY DESIGNATION (RQD) 1
Description RQD Value (%)
Very Poor 0 - 25
Poor 25 – 50
Fair 50 – 75
Good 75 – 90
Excellent 90 - 100
1. The combined length of all sound and intact core segments equal to or greater than 4 inches in length, expressed as a
percentage of the total core run length.
Reference: U.S. Department of Transportation, Federal Highway Administration, Publication No FHWA-NHI-10-034, December 2009
Technical Manual for Design and Construction of Road Tunnels – Civil Elements
PI plots below “A” line MH Elastic Silt K, L, M
Organic:
Liquid limit - oven dried
0.75 OH
Organic clay K, L, M, P
Liquid limit - not dried Organic silt K, L, M, Q
Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat
A Based on the material passing the 3-inch (75-mm) sieve
B If field sample contained cobbles or boulders, or both, add “with cobbles
or boulders, or both” to group name.
C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded
gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly
graded gravel with silt, GP-GC poorly graded gravel with clay.
D Sands with 5 to 12% fines require dual symbols: SW-SM well-graded
sand with silt, SW-SC well-graded sand with clay, SP-SM poorly graded
sand with silt, SP-SC poorly graded sand with clay
E Cu = D60/D10 Cc =
10 60
2
30
D x D
(D )
F If soil contains 15% sand, add “with sand” to group name.
G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM.
H If fines are organic, add “with organic fines” to group name.
I If soil contains 15% gravel, add “with gravel” to group name.
J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay.
K If soil contains 15 to 29% plus No. 200, add “with sand” or “with
gravel,” whichever is predominant.
L If soil contains 30% plus No. 200 predominantly sand, add
“sandy” to group name.
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.
(DCP)
UC
(PID)
(OVA)
Standard Penetration Test
Resistance (Blows/Ft.)
Hand Penetrometer
Torvane
Dynamic Cone Penetrometer
Unconfined Compressive
Strength
Photo-Ionization Detector
Organic Vapor Analyzer
Medium
Over 12 in. (300 mm) 0
>12
5-12
<5
Percent of
Dry Weight
Major Component of Sample Term
Modifier
With
Trace
Descriptive Term(s) of
other constituents
Modifier >30
<15
Percent of
Dry Weight
Descriptive Term(s) of
other constituents
With 15-29
High
Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. The
accuracy of such devices is variable. Surface elevation data annotated with +/- indicates that no actual topographical
survey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from
topographic maps of the area.
30 - 50
> 50
5 - 9
10 - 18
Descriptive
Term
(Consistency)
8 - 15
> 30
Ring
Sampler
Blows/Ft.
10 - 29
> 99
Medium Hard
< 3
3 - 4
19 - 42
2 - 4
BEDROCK
Standard
Penetration
or N-Value
Blows/Ft.
Very Loose 0 - 3
STRENGTH TERMS
Very Soft
(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
RELATIVE DENSITY OF COARSE-GRAINED SOILS
30 - 49
50 - 79
>79
Descriptive
Term
(Consistency)
Firm
< 20 Weathered
Hard
< 30
30 - 49
50 - 89
90 - 119
15 - 30 > 119
Standard
Penetration or
N-Value
Blows/Ft.
0 - 1
4 - 8
Very Hard
Ring
Sampler
Blows/Ft.
Ring
Sampler
Blows/Ft.
Soft
Medium Stiff
Stiff
Very Stiff
Hard
CONSISTENCY OF FINE-GRAINED SOILS
Standard
Penetration
or N-Value
Blows/Ft.
> 42
Loose
Medium Dense
Dense
Very Dense
7 - 18
19 - 58
Descriptive Term
(Density)
0 - 6
4 - 9
59 - 98
_
20 - 29
23
37
39
14
17
23
14
14
13
12
B 03
%w LL PL
N=7
N=12
BT-39.8 Ft.
23
0
35
0
21
13
23
14
14
11
14
B 07
%w LL PL
N=10
N=10
BT-39.3 Ft.
16
14
28
31
8770
14
8
14
18
20
12
12
B 08
LL PL psf
UC
%w
N=6
N=9
BT-29.5 Ft.
32 16
20
21
11
19
15
19
15
B 12
%w LL PL
N=2
N=6
N=36
BT-24.3 Ft.
22
0
31
0
21
20
23
20
19
18
B 13
%w LL PL
NOTES:
Asphalt
Aggregate
Base
Course
Sandy Lean
Clay/Clayey
Sand
Silty Clayey
Sand with
Gravel
Lean Clay
Sandy Lean
Clay with
Gravel
Colorado -
Sandstone/Siltstone Topsoil
Lean Clay
with Sand
Silty Sand
with Gravel
Borehole
Number
Liquid and Plastic Limits
AR
BT
Moisture LL PL
Content %w
B 01
Water Level Reading
at time of drilling.
Water Level Reading
after drilling.
Sampling
(See General Notes)
Elevation - Feet
Distance Along Baseline - Feet
Explanation
Borehole
Lithology
Borehole
Termination Type
See Exploration Plan for orientation of soil profile.
See General Notes in Supporting Information for symbols and soil
classifications.
Soils profile provided for illustration purposes only.
Soils between borings may differ
AR - Auger Refusal
BT - Boring Termination
SUBSURFACE PROFILE
LOMBARDY STUDENT HOUSING
NW OF ELIZABETH ST. AND S. SHIELDS ST.
FORT COLLINS, CO
Project No.: 20185115
Date: 12/3/2018
Scale: N.T.S 1901 Sharp Point Dr, Ste C
Fort Collins, CO
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. SMART FENCE 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
12
16
17
B 06
LL PL psf
UC
%w
BT-39.3 Ft.
0 0
16
19
11
18
30
15
13
B 09
%w LL PL N=7
N=12
BT-24.9 Ft.
23 16
6940
13
13
19
22
15
15
B 10
LL PL psf
UC
%w
N=10
N=29
BT-29.8 Ft.
23
17
6
19
18
16
B 11
%w
NOTES:
Topsoil Silt with
Sand
Weathered
Rock
Colorado -
Sandstone/Siltstone Asphalt
Aggregate
Base
Course
Silty Sand
with Gravel Lean Clay
Lean Clay
with Sand
Well-graded
Sand with
Gravel
Borehole
Number
Liquid and Plastic Limits
AR
BT
Moisture LL PL
Content %w
B 04
Water Level Reading
at time of drilling.
Water Level Reading
after drilling.
Sampling
(See General Notes)
Elevation - Feet
Distance Along Baseline - Feet
Explanation
Borehole
Lithology
Borehole
Termination Type
See Exploration Plan for orientation of soil profile.
See General Notes in Supporting Information for symbols and soil
classifications.
Soils profile provided for illustration purposes only.
Soils between borings may differ
AR - Auger Refusal
BT - Boring Termination
SUBSURFACE PROFILE
LOMBARDY STUDENT HOUSING
NW OF ELIZABETH ST. AND S. SHIELDS ST.
FORT COLLINS, CO
Project No.: 20185115
Date: 12/3/2018
Scale: N.T.S 1901 Sharp Point Dr, Ste C
Fort Collins, CO
THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. SMART FENCE 20185115 LOMBARDY STUDENT .GPJ TERRACON_DATATEMPLATE.GDT 11/6/18
coarsemediumfine fine coarse
LEAN CLAY (CL)
SILTY SAND with GRAVEL (SM)
D10 SILT with SAND (ML)
% Finer
COEFFICIENTS
REMARKS
CU
CC
Sieve
3/8"
#4
#10
#20
#40
#60
#100
#200
99.35
96.06
91.16
85.74
80.37
75.1
70.3
70.25
99.04
94.73
81.79
62.67
47.56
38.14
31.21
27.09
27.09
1/2"
3/8"
#4
#10
#20
#40
#60
#100
#200
99.6
99.34
98.49
97.02
93.97
89.16
86.84
D60
D30
SILT OR CLAY
GRAVEL SAND
COBBLES
0.215
GRAIN SIZE
1.719
B 13
B 13
BULK
CL
SM
ML
86.8
27.1
70.3
12.8
54.7
25.8
17.2
3.3
SOIL DESCRIPTION
9 - 10.5
14 - 15
0 - 5
#4
#10
#20
#40
#60
#100
#200
BORING ID DEPTH % COBBLES % GRAVEL % SAND % SILT % FINES % CLAY USCS
Sieve % Finer Sieve % Finer
coarsemediumfine fine coarse
SILTY SAND with GRAVEL (SM)
SANDY SILTY CLAY (CL-ML)
D10 LEAN CLAY with SAND (CL)
% Finer
COEFFICIENTS
REMARKS
CU
CC
Sieve
#10
#20
#40
#60
#100
#200
99.75
98.4
93.18
84.11
73.92
71.34
91.58
89.75
87.19
78.34
70.04
63.31
57.58
52.76
52.68
1/2"
3/8"
#4
#10
#20
#40
#60
#100
#200
94.01
93.3
87.13
68.76
42.94
29.3
21.9
17.71
15.04
15.02
D60
D30
SILT OR CLAY
GRAVEL SAND
COBBLES
0.888
GRAIN SIZE
3.542 0.313
B 09
B 10
B 12
SM
CL-ML
CL
15.0
52.7
71.3
53.7
34.5
28.4
25.2
4.4
SOIL DESCRIPTION
9 - 10
2 - 3.5
4 - 5.5
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#100
#200
BORING ID DEPTH % COBBLES % GRAVEL % SAND % SILT % FINES % CLAY USCS
Sieve % Finer Sieve % Finer
coarsemediumfine fine coarse
SILTY SAND with GRAVEL (SM)
SANDY LEAN CLAY (CL)
D10 CLAYEY SAND with GRAVEL (SC)
% Finer
COEFFICIENTS
REMARKS
CU
CC
Sieve
1/2"
3/8"
#4
#10
#20
#40
#60
#100
#200
96.14
94.32
81.0
67.46
58.37
51.8
46.79
42.9
42.9
96.63
94.6
87.56
80.31
73.06
66.56
61.02
55.87
54.96
1/2"
3/8"
#4
#10
#20
#40
#60
#100
#200
96.56
95.28
87.79
76.09
57.0
40.26
32.56
29.45
26.8
26.19
D60
D30
SILT OR CLAY
GRAVEL SAND
COBBLES
0.275
GRAIN SIZE
2.291 0.226 0.991
B 07
B 08
B 08
SM
CL
SC
26.2
55.0
42.9
49.9
32.6
38.1
20.5
9.1
15.1
SOIL DESCRIPTION
14 - 15
2 - 3.5
9 - 10.5
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#100
#200
BORING ID DEPTH % COBBLES % GRAVEL % SAND % SILT % FINES % CLAY USCS
Sieve % Finer Sieve % Finer
coarsemediumfine fine coarse
SILTY, CLAYEY SAND with GRAVEL
(CLAYSTONE/SC-SM) SILTSTONE (CL)
D10 CLAYEY SAND with GRAVEL (SC)
% Finer
COEFFICIENTS
REMARKS
CU
CC
Sieve
1/2"
3/8"
#4
#10
#20
#40
#60
#100
#200
90.02
89.23
82.76
76.64
68.53
60.94
54.7
49.43
49.37
99.95
99.07
98.14
97.29
96.33
93.57
80.59
#4
#10
#20
#40
#60
#100
#200
91.19
89.75
79.94
65.98
53.67
41.08
31.09
26.06
26.03
D60
D30
SILT OR CLAY
GRAVEL SAND
COBBLES
0.224
GRAIN SIZE
1.32 0.392
B 06
B 06
B 07
SC-SM
CL
SC
26.0
80.6
49.4
53.9
19.4
33.4
11.2
7.3
SOIL DESCRIPTION
9 - 10
19 - 19.7
4 - 5
1/2"
3/8"
#4
#10
#20
#40
#60
#100
#200
BORING ID DEPTH % COBBLES % GRAVEL % SAND % SILT % FINES % CLAY USCS
Sieve % Finer Sieve % Finer
coarsemediumfine fine coarse
SILT with SAND (ML)
LEAN CLAY (CL)
D10 LEAN CLAY with SAND (CL)
% Finer
COEFFICIENTS
REMARKS
CU
CC
Sieve
3/8"
#4
#10
#20
#40
#60
#100
#200
99.72
98.05
93.71
88.49
82.64
76.89
71.76
71.54
99.85
99.54
98.35
96.62
93.45
89.88
#10
#20
#40
#60
#100
#200
100.0
98.66
98.66
98.11
96.56
94.0
90.69
85.74
80.13
79.25
D60
D30
0.0
SILT OR CLAY
GRAVEL SAND
COBBLES
GRAIN SIZE
B 04
B 05
B 06
ML
CL
CL
79.2
89.9
71.5
18.9
10.0
26.5
1.9
1.7
SOIL DESCRIPTION
2 - 3.5
4 - 5
2 - 3
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#100
#200
BORING ID DEPTH % COBBLES % GRAVEL % SAND % SILT % FINES % CLAY USCS
Sieve % Finer Sieve % Finer
coarsemediumfine fine coarse
SILTY SAND with GRAVEL (SM)
LEAN CLAY with SAND (CL)
D10 LEAN CLAY (CL)
% Finer
COEFFICIENTS
REMARKS
CU
CC
Sieve
#4
#10
#20
#40
#60
#100
#200
99.28
97.68
94.74
92.18
89.43
86.63
86.58
99.02
93.84
88.22
84.21
80.28
76.27
76.27
#4
#10
#20
#40
#60
#100
#200
92.17
89.3
81.99
58.93
36.15
23.03
17.7
14.91
14.91
D60
D30
SILT OR CLAY
GRAVEL SAND
COBBLES
0.614
GRAIN SIZE
2.082
B 02
B 03
B 03
SM
CL
CL
14.9
76.3
86.6
67.1
22.7
12.7
10.2
SOIL DESCRIPTION
9 - 10.5
2 - 3.5
4 - 5
1/2"
3/8"
#4
#10
#20
#40
#60
#100
#200
BORING ID DEPTH % COBBLES % GRAVEL % SAND % SILT % FINES % CLAY USCS
Sieve % Finer Sieve % Finer
coarsemediumfine fine coarse
SILTY, CLAYEY SAND with GRAVEL
(LEAN SC-SM) CLAY (CL)
D10 LEAN CLAY with SAND (CL)
% Finer
COEFFICIENTS
REMARKS
CU
CC
Sieve
#10
#20
#40
#60
#100
#200
99.68
97.37
93.5
89.07
84.14
80.33
99.36
98.75
98.07
96.7
94.57
91.8
91.72
#4
#10
#20
#40
#60
#100
#200
91.52
90.27
88.11
79.86
68.75
55.83
44.69
35.32
29.57
27.8
D60
D30
SILT OR CLAY
GRAVEL SAND
COBBLES
0.156
GRAIN SIZE
1.12
B 01
B 01
B 02
SC-SM
CL
CL
27.8
91.7
80.3
52.1
7.6
19.3
11.7
SOIL DESCRIPTION
4 - 5
9 - 10.5
2 - 3
3/4"
1/2"
3/8"
#4
#10
#20
#40
#60
#100
#200
BORING ID DEPTH % COBBLES % GRAVEL % SAND % SILT % FINES % CLAY USCS
Sieve % Finer Sieve % Finer
21
22
15
NP
22
23
26
21
18
16
21
23
NP
16
14
NP
16
16
22
NP
6
16
19
NP
15
16
13
12
8
6
10
12
NP
12
17
NP
7
16
9
NP
SC-SM
CL
CL
SM
CL
CL
ML
CL
CL
SC-SM
CL
SC
SM
CL
SC
SM
CL-ML
CL
CL
SM
SILTY, CLAYEY SAND with GRAVEL
LEAN CLAY
LEAN CLAY with SAND
SILTY SAND with GRAVEL
LEAN CLAY with SAND
LEAN CLAY
SILT with SAND
LEAN CLAY
LEAN CLAY with SAND
SILTY, CLAYEY SAND with GRAVEL
CLAYSTONE/SILTSTONE
CLAYEY SAND with GRAVEL
SILTY SAND with GRAVEL
SANDY LEAN CLAY
CLAYEY SAND with GRAVEL
SILTY SAND with GRAVEL
SANDY SILTY CLAY
LEAN CLAY with SAND
LEAN CLAY
SILTY SAND with GRAVEL
Boring ID Depth LL PL PI Fines USCS Description
B 01
B 01
B 02
B 02
B 03
B 03
B 04
B 05
B 06
B 06
B 06
B 07
B 07
B 08
B 08
B 09
B 10
B 12
B 13
B 13
4 - 5
9 - 10.5
2 - 3
9 - 10.5
2 - 3.5
4 - 5
2 - 3.5
4 - 5
2 - 3
9 - 10
19 - 19.7
4 - 5
14 - 15
2 - 3.5
9 - 10.5
9 - 10
2 - 3.5
4 - 5.5
9 - 10.5
14 - 15
28
92
80
15
76
87
79
90
72
26
81
49
26
55
43
15
53
71
87
27
CL-ML
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL-CONSOL
/LOAD
(%/psf)
LOCATION
Latitude: 40.5735° Longitude: -105.0963°
See Exploration Plan
GRAPHIC LOG
DEPTH
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Boring backfilled with bentonite chips after delayed water
levels were measured.
1901 Sharp Point Dr, Ste C
Fort Collins, CO
Notes:
Project No.: 20185115
Drill Rig: CME 55
BORING LOG NO. B 13
CLIENT: Blackbird Investments, LLC
Des Moines, IA
Driller: Drilling Engineers, Inc.
Boring Completed: 10-23-2018
PROJECT: Lombardy Student Housing
Elevations were interpolated from a topographic
site plan.
See Exploration and Testing Procedures for a
description of field and laboratory procedures
used and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
SITE:
Boring Started: 10-23-2018
13 feet while drilling
11.8 feet at completion of drilling
11.3 feet 2 days after drilling
WATER LEVEL OBSERVATIONS
ELEVATION (Ft.)
Surface Elev.: 5029 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
25
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL-CONSOL
/LOAD
(%/psf)
LOCATION
Latitude: 40.5735° Longitude: -105.0968°
See Exploration Plan
GRAPHIC LOG
DEPTH
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Boring backfilled with bentonite chips after delayed water
levels were measured.
1901 Sharp Point Dr, Ste C
Fort Collins, CO
Notes:
Project No.: 20185115
Drill Rig: CME 55
BORING LOG NO. B 12
CLIENT: Blackbird Investments, LLC
Des Moines, IA
Driller: Drilling Engineers, Inc.
Boring Completed: 10-23-2018
PROJECT: Lombardy Student Housing
Elevations were interpolated from a topographic
site plan.
See Exploration and Testing Procedures for a
description of field and laboratory procedures
used and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
SITE:
Boring Started: 10-23-2018
4 feet while drilling
10.6 feet at completion of drilling
9.8 feet 2 days after drilling
WATER LEVEL OBSERVATIONS
10
15
20
25
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL-CONSOL
/LOAD
(%/psf)
LOCATION
Latitude: 40.5739° Longitude: -105.0963°
See Exploration Plan
GRAPHIC LOG
DEPTH
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Boring backfilled with bentonite chips after delayed water
levels were measured.
1901 Sharp Point Dr, Ste C
Fort Collins, CO
Notes:
Project No.: 20185115
Drill Rig: CME 55
BORING LOG NO. B 11
CLIENT: Blackbird Investments, LLC
Des Moines, IA
Driller: Drilling Engineers, Inc.
Boring Completed: 10-22-2018
PROJECT: Lombardy Student Housing
Elevations were interpolated from a topographic
site plan.
See Exploration and Testing Procedures for a
description of field and laboratory procedures
used and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
SITE:
Boring Started: 10-22-2018
12 feet while drilling
9.6 feet at completion of drilling
9.5 feet 3 days after drilling
WATER LEVEL OBSERVATIONS
5
10
15
20
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL-CONSOL
/LOAD
(%/psf)
LOCATION
Latitude: 40.5739° Longitude: -105.0967°
See Exploration Plan
GRAPHIC LOG
DEPTH
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Boring backfilled with bentonite chips after delayed water
levels were measured.
1901 Sharp Point Dr, Ste C
Fort Collins, CO
Notes:
Project No.: 20185115
Drill Rig: CME 55
BORING LOG NO. B 10
CLIENT: Blackbird Investments, LLC
Des Moines, IA
Driller: Drilling Engineers, Inc.
Boring Completed: 10-23-2018
PROJECT: Lombardy Student Housing
Elevations were interpolated from a topographic
site plan.
See Exploration and Testing Procedures for a
description of field and laboratory procedures
used and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
SITE:
Boring Started: 10-23-2018
13 feet while drilling
9.3 feet at completion of drilling
9.4 feet 2 days after drilling
WATER LEVEL OBSERVATIONS
35
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL-CONSOL
/LOAD
(%/psf)
LOCATION
Latitude: 40.5739° Longitude: -105.0973°
See Exploration Plan
GRAPHIC LOG
DEPTH
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Boring backfilled with bentonite chips after delayed water
levels were measured.
1901 Sharp Point Dr, Ste C
Fort Collins, CO
Notes:
Project No.: 20185115
Drill Rig: CME 55
BORING LOG NO. B 09
CLIENT: Blackbird Investments, LLC
Des Moines, IA
Driller: Drilling Engineers, Inc.
Boring Completed: 10-22-2018
PROJECT: Lombardy Student Housing
Elevations were interpolated from a topographic
site plan.
See Exploration and Testing Procedures for a
description of field and laboratory procedures
used and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
SITE:
Boring Started: 10-22-2018
7 feet while drilling
4.6 feet at completion of drilling
4 feet 3 days after drilling
WATER LEVEL OBSERVATIONS
CONTENT (%)
DRY UNIT
WEIGHT (pcf)
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 5030 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
25
30
35
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL-CONSOL
/LOAD
(%/psf)
LOCATION
Latitude: 40.5736° Longitude: -105.0975°
See Exploration Plan
GRAPHIC LOG
DEPTH
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Boring backfilled with Auger Cuttings and/or Bentonite
Surface Capped with Asphalt
1901 Sharp Point Dr, Ste C
Fort Collins, CO
Notes:
Project No.: 20185115
Drill Rig: CME 55
BORING LOG NO. B 08
CLIENT: Blackbird Investments, LLC
Des Moines, IA
Driller: Drilling Engineers, Inc.
Boring Completed: 10-22-2018
PROJECT: Lombardy Student Housing
Elevations were interpolated from a topographic
site plan.
See Exploration and Testing Procedures for a
description of field and laboratory procedures
used and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
SITE:
Boring Started: 10-22-2018
9 feet while drilling
8.7 feet at completion of drilling
WATER LEVEL OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
25
30
35
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL-CONSOL
/LOAD
(%/psf)
LOCATION
Latitude: 40.5736° Longitude: -105.0981°
See Exploration Plan
GRAPHIC LOG
DEPTH
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Boring backfilled with Auger Cuttings and/or Bentonite
Surface Capped with Asphalt
1901 Sharp Point Dr, Ste C
Fort Collins, CO
Notes:
Project No.: 20185115
Drill Rig: CME 55
BORING LOG NO. B 07
CLIENT: Blackbird Investments, LLC
Des Moines, IA
Driller: Drilling Engineers, Inc.
Boring Completed: 10-23-2018
PROJECT: Lombardy Student Housing
Elevations were interpolated from a topographic
site plan.
See Exploration and Testing Procedures for a
description of field and laboratory procedures
used and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
SITE:
Boring Started: 10-23-2018
10 feet while drilling
5.9 feet at completion of drilling
WATER LEVEL OBSERVATIONS
ATTERBERG
LIMITS
LL-PL-PI
ELEVATION (Ft.)
Surface Elev.: 5026 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
25
30
35
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL-CONSOL
/LOAD
(%/psf)
LOCATION
Latitude: 40.5739° Longitude: -105.0981°
See Exploration Plan
GRAPHIC LOG
DEPTH
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Boring backfilled with Auger Cuttings and/or Bentonite
Surface Capped with Asphalt
1901 Sharp Point Dr, Ste C
Fort Collins, CO
Notes:
Project No.: 20185115
Drill Rig: CME 55
BORING LOG NO. B 06
CLIENT: Blackbird Investments, LLC
Des Moines, IA
Driller: Drilling Engineers, Inc.
Boring Completed: 10-22-2018
PROJECT: Lombardy Student Housing
Elevations were interpolated from a topographic
site plan.
See Exploration and Testing Procedures for a
description of field and laboratory procedures
used and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
SITE:
Boring Started: 10-22-2018
7 feet while drilling
4.6 feet at completion of drilling
WATER LEVEL OBSERVATIONS
15
20
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL-CONSOL
/LOAD
(%/psf)
LOCATION
Latitude: 40.574° Longitude: -105.0987°
See Exploration Plan
GRAPHIC LOG
DEPTH
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Boring backfilled with Auger Cuttings and/or Bentonite
Surface Capped with Asphalt
1901 Sharp Point Dr, Ste C
Fort Collins, CO
Notes:
Project No.: 20185115
Drill Rig: CME 55
BORING LOG NO. B 05
CLIENT: Blackbird Investments, LLC
Des Moines, IA
Driller: Drilling Engineers, Inc.
Boring Completed: 10-23-2018
PROJECT: Lombardy Student Housing
Elevations were interpolated from a topographic
site plan.
See Exploration and Testing Procedures for a
description of field and laboratory procedures
used and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
SITE:
Boring Started: 10-23-2018
10 feet while drilling
9.9 feet at completion of drilling
WATER LEVEL OBSERVATIONS
/LOAD
(%/psf)
LOCATION
Latitude: 40.5739° Longitude: -105.0992°
See Exploration Plan
GRAPHIC LOG
DEPTH
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Boring backfilled with bentonite chips after delayed water
levels were measured.
1901 Sharp Point Dr, Ste C
Fort Collins, CO
Notes:
Project No.: 20185115
Drill Rig: CME 55
BORING LOG NO. B 04
CLIENT: Blackbird Investments, LLC
Des Moines, IA
Driller: Drilling Engineers, Inc.
Boring Completed: 10-22-2018
PROJECT: Lombardy Student Housing
Elevations were interpolated from a topographic
site plan.
See Exploration and Testing Procedures for a
description of field and laboratory procedures
used and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
SITE:
Boring Started: 10-22-2018
10 feet while drilling
4.7 feet at completion of drilling
4.5 feet 3 days after drilling
WATER LEVEL OBSERVATIONS
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
25
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL-CONSOL
/LOAD
(%/psf)
LOCATION
Latitude: 40.5735° Longitude: -105.0991°
See Exploration Plan
GRAPHIC LOG
DEPTH
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Boring backfilled with bentonite chips after delayed water
levels were measured.
1901 Sharp Point Dr, Ste C
Fort Collins, CO
Notes:
Project No.: 20185115
Drill Rig: CME 55
BORING LOG NO. B 03
CLIENT: Blackbird Investments, LLC
Des Moines, IA
Driller: Drilling Engineers, Inc.
Boring Completed: 10-22-2018
PROJECT: Lombardy Student Housing
Elevations were interpolated from a topographic
site plan.
See Exploration and Testing Procedures for a
description of field and laboratory procedures
used and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
SITE:
Boring Started: 10-22-2018
9 feet while drilling
6.9 feet at completion of drilling
9.5 feet 3 days after drilling
WATER LEVEL OBSERVATIONS
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL-CONSOL
/LOAD
(%/psf)
LOCATION
Latitude: 40.5736° Longitude: -105.0997°
See Exploration Plan
GRAPHIC LOG
DEPTH
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Boring backfilled with bentonite chips after delayed water
levels were measured.
1901 Sharp Point Dr, Ste C
Fort Collins, CO
Notes:
Project No.: 20185115
Drill Rig: CME 55
BORING LOG NO. B 02
CLIENT: Blackbird Investments, LLC
Des Moines, IA
Driller: Drilling Engineers, Inc.
Boring Completed: 10-22-2018
PROJECT: Lombardy Student Housing
Elevations were interpolated from a topographic
site plan.
See Exploration and Testing Procedures for a
description of field and laboratory procedures
used and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
SITE:
Boring Started: 10-22-2018
7 feet while drilling
5.8 feet at completion of drilling
5.6 feet 3 days after drilling
WATER LEVEL OBSERVATIONS
ELEVATION (Ft.)
Surface Elev.: 5037 (Ft.)
WATER LEVEL
OBSERVATIONS
DEPTH (Ft.)
5
10
15
20
SAMPLE TYPE
FIELD TEST
RESULTS
SWELL-CONSOL
/LOAD
(%/psf)
LOCATION
Latitude: 40.5735° Longitude: -105.1003°
See Exploration Plan
GRAPHIC LOG
DEPTH
Page 1 of 1
Advancement Method:
4-inch solid-stem auger
Abandonment Method:
Boring backfilled with Auger Cuttings and/or Bentonite
Surface Capped with Asphalt
1901 Sharp Point Dr, Ste C
Fort Collins, CO
Notes:
Project No.: 20185115
Drill Rig: CME 55
BORING LOG NO. B 01
CLIENT: Blackbird Investments, LLC
Des Moines, IA
Driller: Drilling Engineers, Inc.
Boring Completed: 10-23-2018
PROJECT: Lombardy Student Housing
Elevations were interpolated from a topographic
site plan.
See Exploration and Testing Procedures for a
description of field and laboratory procedures
used and additional data (If any).
See Supporting Information for explanation of
symbols and abbreviations.
NW of Elizabeth St. and S. Shields St.
Fort Collins, CO
SITE:
Boring Started: 10-23-2018
13 feet while drilling
16.2 feet at completion of drilling
WATER LEVEL OBSERVATIONS
drilling, ft.
1 13 16.2 5020.8 Backfilled Backfilled
2 7 5.8 5026.2 5.6 5026.4
3 9 6.9 5025.1 9.5 5022.5
4 10 4.7 5024.3 4.5 5024.5
5 10 9.9 5017.1 Backfilled Backfilled
6 7 4.6 5021.4 Backfilled Backfilled
This section contains important information about the limitations of this geotechnical
engineering report.
1. If the reader is reviewing this report as a pdf, the topics (bold orange font) above can be used to access the
appropriate section of the report by simply clicking on the topic itself.
2. This summary is for convenience only. It should be used in conjunction with the entire report for design
purposes. It should be recognized that specific 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.
documents for the project.
■ Shallow groundwater is present on this site. Water depths were measured at depths
ranging from about 4.6 to 16.2 feet below existing site grades at the time of drilling.
Depending on the final design and depth of below-grade areas, groundwater may
impact construction as well as require management throughout the life of the project.