RFB - Community Center Improvements - Structural & Drainage Addendum 3

GEOTECHNICAL STUDY
Superior Community Center
Superior, Colorado
Prepared for:
Mr. Jason Murray
J&T Consulting, Inc.
305 Denver Avenue, Suite D
Fort Lupton, CO 80621
Project No. 23.3055
December 8, 2023
Colorado Regional Office: 7108 South Alton Way, Building B * Centennial, CO 80112
Arizona * Colorado * Idaho * Texas * Utah
Phone 303-220-0300 * www.cesareinc.com

GEOTECHNICAL STUDY
Superior Community Center
Superior, Colorado
Prepared for:
Mr. Jason Murray
J&T Consulting, Inc.
305 Denver Avenue, Suite D
Fort Lupton, CO 80621
Project No. 23.3055
December 8, 2023
Prepared by:
12/8/23
Jonathan A. Crystal, P.E.
Project Engineer
23.3055 Superior Community Center Report 12.08.23 i

CMT TECHNICAL SERVICES - COLORADO
TABLE OF CONTENTS
1. PURPOSE ..................................................................................................................................... 1
1.1 GENERAL .................................................................................................................................... 1
1.2 SCOPE OF SERVICES ................................................................................................................... 1
2. SUMMARY OF FINDINGS AND CONCLUSIONS ............................................................................ 1
3. PROJECT DESCRIPTION .............................................................................................................. 1
4. FIELD EXPLORATION .................................................................................................................. 1
5. LABORATORY TESTING ............................................................................................................... 2
6. SITE CONDITIONS ...................................................................................................................... 2
7. GEOLOGIC CONDITIONS ............................................................................................................. 3
7.1 SURFICIAL DEPOSITS .................................................................................................................. 3
7.2 BEDROCK ................................................................................................................................... 3
7.3 GEOLOGIC HAZARDS ................................................................................................................... 3
7.4 SOIL SITE CLASS AND SEISMIC RESPONSE DATA .......................................................................... 3
8. SUBSURFACE CONDITIONS ........................................................................................................ 3
9. GEOTECHNICAL CONSIDERATIONS ............................................................................................ 4
9.1 SITE PREPARATION ..................................................................................................................... 4
10. FOUNDATION RECOMMENDATIONS ......................................................................................... 4
10.1 HELICAL PILES .......................................................................................................................... 4
12.5 MICROPILES ............................................................................................................................. 6
11. EXCAVATIONS ........................................................................................................................... 7
12. STRUCTURAL BACKFILL SOIL ................................................................................................... 8
12.1 IMPORT FILL ............................................................................................................................. 9
13. SUBSURFACE DRAINAGE .......................................................................................................... 9
14. SURFACE DRAINAGE ............................................................................................................... 10
15. GEOTECHNICAL RISK .............................................................................................................. 10
16. LIMITATIONS .......................................................................................................................... 11
TABLES
TABLE 5.1. Laboratory Testing Performed ...................................................................................... 2
TABLE 11.1. Allowable Slope Configuration for Onsite Material .................................................... 8
TABLE 12.1. Compaction Specifications .......................................................................................... 9
TABLE 12.2. Import Fill Specifications ............................................................................................ 9
FIGURES
VICINITY MAP ................................................................................................................... FIGURE 1
SITE PLAN AND BORING LOCATIONS ............................................................................... FIGURE 2
APPENDICES
FIELD EXPLORATION ................................................................................................... APPENDIX A
LABORATORY TESTING ................................................................................................ APPENDIX B
23.3055 Superior Community Center Report 12.08.23 ii

CMT TECHNICAL SERVICES - COLORADO
COMMON ABBREVIATIONS AND ACRONYMS
AASHTO ......... American Association of State Highway and Transportation Officials
ABC ................ aggregate base course
ACI ................ American Concrete Institute
ADA ............... Americans with Disabilities Act
ADSC ............. International Association of Foundation Drilling
AI .................. Asphalt Institute
APM .............. asphalt paving material
ASCE .............. American Society of Civil Engineers
ASTM ............. American Society for Testing and Materials
AWWA ........... American Water Works Association
bgs................. below ground surface
CAGE.............. Colorado Association of Geotechnical Engineers
CBR ................ California Bearing Ratio
CDOT ............. Colorado Department of Transportation
CFR ................ Code of Federal Regulations
CGS ................ Colorado Geological Survey
CKD ............... cement of kiln dust stabilized subgrade
CMU ............... concrete masonry unit
CTB ................ cement treated base course
deg ................ degree
EDLA .............. equivalent daily load application
e ................. edge moisture variation distance
m
EPS ................ expanded polystyrene
ESAL .............. equivalent single axle loads
f'c .................. specified compressive strength of concrete at the age of 28 days
F ................... seismic site coefficient
a
FHWA ............ Federal Highway Administration
FS .................. factor of safety
F ................... seismic site coefficient
V
GSA ................ global stability analysis
GVW .............. gross vehicle weight
IBC ................ International Building Code
ICC-ES ........... International Code Council Evaluation Services, Inc.
IRC ................ International Residential Code
kip ................. 1,000 pounds-force
km ................. kilometer
LTS ................ lime treated subgrade
MDD .............. maximum dry density
mg/L ............. milligrams per liter
MGPEC ........... Metropolitan Government Pavement Engineers Council
mm ................ millimeter
Mr .................. resilient modulus
MSE ............... mechanically stabilized earth
mV ................. millivolts
NAPA ............. National Asphalt Pavement Association
N ........... design gyrations
DESIGN
23.3055 Superior Community Center Report 12.08.23 iii

CMT TECHNICAL SERVICES - COLORADO
OMC ............... optimum moisture content
OSHA ............. Occupational Safety and Health Administration
OWTS ............ onsite wastewater treatment system
PCA ................ Portland Cement Association
PCC ................ portland cement concrete
pcf ................. pounds per cubic foot
pci .................. pounds per cubic inch
pH .................. power of hydrogen
psf ................. pounds per square foot
psi .................. pounds per square inch
PT .................. post-tension
RAP ................ recycled asphalt pavement
S ................... mapped spectral accelerations for short periods
s
UBC ............... Uniform Building Code
USGS ............. United States Geological Survey
23.3055 Superior Community Center Report 12.08.23 iv

Important Information about This
Geotechnical-Engineering Report
Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes.
While you cannot eliminate all such risks, you can manage them. The following information is provided to help.
The Geoprofessional Business Association (GBA) will not likely meet the needs of a civil-works constructor or even a
has prepared this advisory to help you - assumedly different civil engineer. Because each geotechnical-engineering study
a client representative - interpret and apply this is unique, each geotechnical-engineering report is unique, prepared
solely for the client.
geotechnical-engineering report as effectively as
possible. In that way, you can benefit from a lowered
Likewise, geotechnical-engineering services are performed for a specific
exposure to problems associated with subsurface
project and purpose. For example, it is unlikely that a geotechnical-
conditions at project sites and development of
engineering study for a refrigerated warehouse will be the same as
them that, for decades, have been a principal cause one prepared for a parking garage; and a few borings drilled during
of construction delays, cost overruns, claims, a preliminary study to evaluate site feasibility will not be adequate to
and disputes. If you have questions or want more develop geotechnical design recommendations for the project.
information about any of the issues discussed herein,
contact your GBA-member geotechnical engineer. Do not rely on this report if your geotechnical engineer prepared it:
Active engagement in GBA exposes geotechnical * for a different client;
* for a different project or purpose;
engineers to a wide array of risk-confrontation
* for a different site (that may or may not include all or a portion of
techniques that can be of genuine benefit for
the original site); or
everyone involved with a construction project.
* before important events occurred at the site or adjacent to it;
e.g., man-made events like construction or environmental
Understand the Geotechnical-Engineering Services remediation, or natural events like floods, droughts, earthquakes,
Provided for this Report or groundwater fluctuations.
Geotechnical-engineering services typically include the planning,
collection, interpretation, and analysis of exploratory data from Note, too, the reliability of a geotechnical-engineering report can
widely spaced borings and/or test pits. Field data are combined be affected by the passage of time, because of factors like changed
with results from laboratory tests of soil and rock samples obtained subsurface conditions; new or modified codes, standards, or
from field exploration (if applicable), observations made during site regulations; or new techniques or tools. If you are the least bit uncertain
reconnaissance, and historical information to form one or more models about the continued reliability of this report, contact your geotechnical
of the expected subsurface conditions beneath the site. Local geology engineer before applying the recommendations in it. A minor amount
and alterations of the site surface and subsurface by previous and of additional testing or analysis after the passage of time - if any is
proposed construction are also important considerations. Geotechnical required at all - could prevent major problems.
engineers apply their engineering training, experience, and judgment
to adapt the requirements of the prospective project to the subsurface Read this Report in Full
model(s). Estimates are made of the subsurface conditions that Costly problems have occurred because those relying on a geotechnical-
will likely be exposed during construction as well as the expected engineering report did not read the report in its entirety. Do not rely on
performance of foundations and other structures being planned and/or an executive summary. Do not read selective elements only. Read and
affected by construction activities. refer to the report in full.
The culmination of these geotechnical-engineering services is typically a You Need to Inform Your Geotechnical Engineer
geotechnical-engineering report providing the data obtained, a discussion
About Change
of the subsurface model(s), the engineering and geologic engineering
Your geotechnical engineer considered unique, project-specific factors
assessments and analyses made, and the recommendations developed
when developing the scope of study behind this report and developing
to satisfy the given requirements of the project. These reports may be
the confirmation-dependent recommendations the report conveys.
titled investigations, explorations, studies, assessments, or evaluations.
Typical changes that could erode the reliability of this report include
Regardless of the title used, the geotechnical-engineering report is an
those that affect:
engineering interpretation of the subsurface conditions within the context
* the site's size or shape;
of the project and does not represent a close examination, systematic
* the elevation, configuration, location, orientation,
inquiry, or thorough investigation of all site and subsurface conditions.
function or weight of the proposed structure and
the desired performance criteria;
Geotechnical-Engineering Services are Performed
* the composition of the design team; or
for Specific Purposes, Persons, and Projects,
* project ownership.
and At Specific Times
Geotechnical engineers structure their services to meet the specific As a general rule, always inform your geotechnical engineer of project
needs, goals, and risk management preferences of their clients. A or site changes - even minor ones - and request an assessment of their
geotechnical-engineering study conducted for a given civil engineer impact. The geotechnical engineer who prepared this report cannot accept

responsibility or liability for problems that arise because the geotechnical conspicuously that you've included the material for information purposes
engineer was not informed about developments the engineer otherwise only. To avoid misunderstanding, you may also want to note that
would have considered. "informational purposes" means constructors have no right to rely on
the interpretations, opinions, conclusions, or recommendations in the
Most of the "Findings" Related in This Report report. Be certain that constructors know they may learn about specific
Are Professional Opinions project requirements, including options selected from the report, only
Before construction begins, geotechnical engineers explore a site's from the design drawings and specifications. Remind constructors
subsurface using various sampling and testing procedures. Geotechnical that they may perform their own studies if they want to, and be sure to
engineers can observe actual subsurface conditions only at those specific allow enough time to permit them to do so. Only then might you be in
locations where sampling and testing is performed. The data derived from a position to give constructors the information available to you, while
that sampling and testing were reviewed by your geotechnical engineer, requiring them to at least share some of the financial responsibilities
who then applied professional judgement to form opinions about stemming from unanticipated conditions. Conducting prebid and
subsurface conditions throughout the site. Actual sitewide-subsurface preconstruction conferences can also be valuable in this respect.
conditions may differ - maybe significantly - from those indicated in
this report. Confront that risk by retaining your geotechnical engineer Read Responsibility Provisions Closely
to serve on the design team through project completion to obtain Some client representatives, design professionals, and constructors do
informed guidance quickly, whenever needed. not realize that geotechnical engineering is far less exact than other
engineering disciplines. This happens in part because soil and rock on
This Report's Recommendations Are project sites are typically heterogeneous and not manufactured materials
with well-defined engineering properties like steel and concrete. That
Confirmation-Dependent
lack of understanding has nurtured unrealistic expectations that have
The recommendations included in this report - including any options or
resulted in disappointments, delays, cost overruns, claims, and disputes.
alternatives - are confirmation-dependent. In other words, they are not
To confront that risk, geotechnical engineers commonly include
final, because the geotechnical engineer who developed them relied heavily
explanatory provisions in their reports. Sometimes labeled "limitations,"
on judgement and opinion to do so. Your geotechnical engineer can finalize
many of these provisions indicate where geotechnical engineers'
the recommendations only after observing actual subsurface conditions
responsibilities begin and end, to help others recognize their own
exposed during construction. If through observation your geotechnical
responsibilities and risks. Read these provisions closely. Ask questions.
engineer confirms that the conditions assumed to exist actually do exist,
Your geotechnical engineer should respond fully and frankly.
the recommendations can be relied upon, assuming no other changes have
occurred. The geotechnical engineer who prepared this report cannot assume
Geoenvironmental Concerns Are Not Covered
responsibility or liability for confirmation-dependent recommendations if you
fail to retain that engineer to perform construction observation. The personnel, equipment, and techniques used to perform an
environmental study - e.g., a "phase-one" or "phase-two" environmental
site assessment - differ significantly from those used to perform a
This Report Could Be Misinterpreted
geotechnical-engineering study. For that reason, a geotechnical-engineering
Other design professionals' misinterpretation of geotechnical-
report does not usually provide environmental findings, conclusions, or
engineering reports has resulted in costly problems. Confront that risk
recommendations; e.g., about the likelihood of encountering underground
by having your geotechnical engineer serve as a continuing member of
storage tanks or regulated contaminants. Unanticipated subsurface
the design team, to:
environmental problems have led to project failures. If you have not
* confer with other design-team members;
obtained your own environmental information about the project site,
* help develop specifications;
ask your geotechnical consultant for a recommendation on how to find
* review pertinent elements of other design professionals' plans and
environmental risk-management guidance.
specifications; and
* be available whenever geotechnical-engineering guidance is needed.
Obtain Professional Assistance to Deal with
You should also confront the risk of constructors misinterpreting this Moisture Infiltration and Mold
report. Do so by retaining your geotechnical engineer to participate in While your geotechnical engineer may have addressed groundwater,
prebid and preconstruction conferences and to perform construction- water infiltration, or similar issues in this report, the engineer's
phase observations. services were not designed, conducted, or intended to prevent
migration of moisture - including water vapor - from the soil
Give Constructors a Complete Report and Guidance through building slabs and walls and into the building interior, where
Some owners and design professionals mistakenly believe they can shift it can cause mold growth and material-performance deficiencies.
unanticipated-subsurface-conditions liability to constructors by limiting Accordingly, proper implementation of the geotechnical engineer's
the information they provide for bid preparation. To help prevent recommendations will not of itself be sufficient to prevent
the costly, contentious problems this practice has caused, include the moisture infiltration. Confront the risk of moisture infiltration by
complete geotechnical-engineering report, along with any attachments including building-envelope or mold specialists on the design team.
or appendices, with your contract documents, but be certain to note Geotechnical engineers are not building-envelope or mold specialists.
Telephone: 301/565-2733
e-mail: info@geoprofessional.org www.geoprofessional.org
Copyright 2019 by Geoprofessional Business Association (GBA). Duplication, reproduction, or copying of this document, in whole or in part, by any means whatsoever, is strictly
prohibited, except with GBA's specific written permission. Excerpting, quoting, or otherwise extracting wording from this document is permitted only with the express written permission of
GBA, and only for purposes of scholarly research or book review. Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind.
Any other firm, individual, or other entity that so uses this document without being a GBA member could be committing negligent or intentional (fraudulent) misrepresentation.

CMT TECHNICAL SERVICES - COLORADO
1. PURPOSE
1.1 GENERAL
CMT Technical Services - Colorado (CMT) performed a geotechnical study at the Superior Community
Center structure located near the intersection of Coalton Road and Rock Creek Parkway in Superior,
Colorado. The study was performed to characterize the subsurface conditions at the site to provide
design criteria for helical pile underpinning to remediate structural distress in the structure and
address other pertinent geotechnical issues. Information gathered during the field exploration and
laboratory testing is summarized in Figures 1 and 2 and Appendices A and B. CMT's opinions and
recommendations presented in this report are based on data generated during this field exploration,
laboratory testing, and its experience.
1.2 SCOPE OF SERVICES
The scope of services performed is detailed in Cesare, Inc.'s (now CMT) Master Agreement No.
F211202 executed on January 19, 2022. In addition, an email from J&T Consulting, Inc., dated
September 13, 2023, defined the specific scope.
2. SUMMARY OF FINDINGS AND CONCLUSIONS
This section is intended as a summary only and does not include design details. The report should
be read in its entirety and utilized for design.
CMT encountered about 6 to 7 inches of APM directly on 7 to 8 feet of clay fill. Claystone
bedrock was encountered directly below the fill, extending to the remaining depth
explored of about 39 feet.
Geologic hazards include expansive clay soil and claystone bedrock. The subsurface
stratigraphy classified as Seismic Site Class C.
Helical pile foundations were requested; however, the claystone encountered is very hard
and will likely refuse helical pile penetration.
Due to the very hard claystone bedrock, micropiles are provided as an alternative.
Good surface drainage should be established and positive drainage away from the
structures should be provided during construction and maintained throughout the life of
the structure.
3. PROJECT DESCRIPTION
Information regarding the existing structure was provided by J&T Consulting, Inc. and was not
observed or evaluated by CMT. CMT understands the structure is likely of metal frame. The
foundation system is not known; however, considering the depth of fill encountered in the borings,
the structure may bear on shallow spread type footings, likely at a depth of about 3 feet. Various
elements of the structure have undergone movement, likely heave, and exhibit distress. The
proposed remediation will consist of installing helical piles in the distressed area(s) to resist future
heave and reduce future movement.
4. FIELD EXPLORATION
Three borings were drilled on September 25, 2023 to depths of about 39 feet at the locations
indicated in Figure 2 to explore subsurface conditions. Graphical logs of the subsurface conditions
23.3055 Superior Community Center Report 12.08.23 1

CMT TECHNICAL SERVICES - COLORADO
observed, locations of sampling, and further explanation of the exploration are presented in the
boring logs presented in Appendix A.
5. LABORATORY TESTING
CMT personnel returned samples obtained during field exploration to its laboratory where
professional staff visually classified them and assigned testing to selected samples to evaluate
pertinent engineering properties. Laboratory tests performed are listed in Table 5.1. Further
discussion of laboratory testing and the laboratory test results are presented in Appendix B.
TABLE 5.1. Laboratory Testing Performed
Laboratory Test To Evaluate
Grain size analysis Grain size distribution for classification purposes.
Atterberg limits Soil plasticity for classification purposes.
Consolidation/swell Effect of wetting and loading on the soil.
Unconfined compressive strength Undrained shear strength.
6. SITE CONDITIONS
The community center is located near the southwestern quadrant of the Coalton Road and Rock
Creek Parkway intersection in Superior, Colorado as shown in a vicinity map on Figure 1. The overall
community center lot is bounded by Coalton Road on its north, commercial properties fronting Rock
Creek Parkway on its east, and residential properties on its south and west. The site is relatively flat
with a gentle slope downward to the northwest with an estimated maximum relief of about 13 feet
across its extent.
Little is known of the building's construction. The building is on the order of 30 years old and was
originally used for an auto dealership. Due to the showroom and repair facilities requiring cars to be
parked on the floors, the floors are likely concrete slab-on-grade. The foundation system is unknown;
however, considering the expansive clay soil and claystone bedrock and heave related structural
distress, foundations are possibly spread footings. Outside the building, the ground surface is largely
covered with concrete or APM.
Some vegetation is present around the building lot perimeter consisting of irrigated lawn type grasses
and coniferous and deciduous trees. An unnamed lake is located about 950 feet north, Autry
Reservoir is about 1,800 northeast, and Hodgson-Harris Reservoir is about 4,200 feet north-northeast
of the site at estimated elevations of about 35, 15, and 40 feet lower than the site, respectively. A
second unnamed lake is about 1,050 feet southwest and a third unnamed lake is about 1,400 feet
southwest, both at estimated elevations about 30 feet higher than the site. Numerous other small
unnamed ponds are located between about 3,000 and 5,000 feet northwest, northeast, and southeast
of the site. No bedrock outcrops were observed onsite.
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CMT TECHNICAL SERVICES - COLORADO
7. GEOLOGIC CONDITIONS
7.1 SURFICIAL DEPOSITS
The Louisville surficial geology map1 indicates the site may have been underlain by elements of
Holocene age Piney Creek alluvium. The Piney Creek alluvium is characterized as interbedded sand,
silt, and clay with gravel interbedded in the lower portion.
7.2 BEDROCK
The Louisville bedrock geology map2 indicates the site is underlain by the Laramie Formation of Upper
Cretaceous age. The upper 600 feet of the formation is characterized as claystone, shale, sandy shale
and lenticular beds of sandstone and lignite.
7.3 GEOLOGIC HAZARDS
The soil and bedrock swelling map3 indicates the presence of very high swelling clay and claystone
at the site.
7.4 SOIL SITE CLASS AND SEISMIC RESPONSE DATA
The soil, bedrock, and groundwater conditions present onsite are consistent with criteria for Site
Class C according to the 2021 IBC and ASCE 7, Chapter 20. Additional geophysical studies are
necessary to justify a different site classification.
8. SUBSURFACE CONDITIONS
CMT's borings encountered:
APM about 7 to 8 inches thick.
Clay fill below the APM extending to a depth of about 7 to 8 feet.
Claystone bedrock below the fill at a depth of about 7 to 8 feet extending to the remaining
depth explored of about 39 feet.
Groundwater at a depth of about 16 feet in Boring B-2 at the time of drilling and 16-1/2
feet two days after drilling.
The borings had not caved when measured two days after drilling.
A more complete description of the subsurface conditions encountered is contained in the
boring logs presented in Appendix A.
The subsurface conditions encountered in CMT's borings are not consistent with those described in
Section 7.1 SURFICIAL DEPOSITS, in that the soil encountered was fill, likely from reworked
claystone. The bedrock conditions were reasonably consistent with those described in Section 7.2
BEDROCK. These observations represent conditions at the time of field exploration and may not be
indicative of other times or other locations. Groundwater can be expected to fluctuate and can be
influenced by variations in seasons, weather, precipitation, drainage, vegetation, landscaping,
irrigation, leakage of water and/or wastewater systems, etc., both onsite and offsite. Discontinuous
1 Malde, G., Surficial Geologic Map of the Louisville Quadrangle, Colorado, Department of the Interior, United States Geological Survey,
1951.
2 Spencer, F.D., Geologic Map of the Louisville Quadrangle, Colorado, Bedrock Geology, Department of the Interior, United States
Geological Survey, 1961.
3 Hart, SS: Potentially Swelling Soil and Rock in the Front Range Urban Corridor, Colorado, Colorado Geological Survey, 1973-1974.
23.3055 Superior Community Center Report 12.08.23 3