SC-Coppell HS-SY221110
REPORT COVER PAGE
Geotechnical Engineering Report
__________________________________________________________________________
CHS Fine Arts Rehearsal Building
Coppell, Texas
November 10, 2023
Terracon Project No. 94235370
Prepared for:
Coppell ISD
Coppell, TX 75019
Prepared by:
Terracon Consultants, Inc.
Dallas, Texas
Terracon Consultants, Inc. 8901 John W Carpenter Freeway Dallas, Texas 75247 Registration No. F -3272
P (214) 630 -1010 F (214) 630 -7070 terracon.com
REPORT COVER LETTER TO SIGN
November 10, 2023
Coppell ISD
1303 Wrangler Circle
Coppell, TX 75019
Attn: Mr. Chris Trotter
P: (214) 496-6006
E: ctrotter@coppellisd.com
Re: Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building
185 W. Parkway Boulevard
Coppell, Texas
Terracon Project No. 94235370
Dear Mr. Trotter:
This report presents the findings of the subsurface exploration and provides geotechnical
recommendations concerning earthwork and the design and construction of foundations and floor
slabs for the proposed project. This study was performed in general accordance with Terracon
Proposal No. P94235370, Revision 1 dated September 1, 2023 and authorized on September 5,
2023.
We appreciate the opportunity to be of service to you on this project. If you have any questions
concerning this report or if we may be of further service, please contact us.
Sincerely,
Terracon Consultants, Inc.
Nafiz Ahmed, P.E. Saad M. Hineidi, P.E.
Senior Engineer Senior Principal
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REPORT TOPICS
REPORT SUMMARY ....................................................................................................... I
INTRODUCTION ............................................................................................................. 1
SITE CONDITIONS ......................................................................................................... 1
PROJECT DESCRIPTION .............................................................................................. 2
GEOTECHNICAL CHARACTERIZATION ...................................................................... 2
GEOTECHNICAL OVERVIEW ....................................................................................... 4
EARTHWORK ................................................................................................................ 5
DEEP FOUNDATIONS ................................................................................................. 10
FLOOR SLABS ............................................................................................................ 14
SEISMIC CONSIDERATIONS ...................................................................................... 17
CORROSIVITY ............................................................................................................. 17
GENERAL COMMENTS ............................................................................................... 18
Note: This report was originally delivered in a web-based format. For more interactive features, please view your project
online at client.terracon.com.
ATTACHMENTS
EXPLORATION AND TESTING PROCEDURES
SITE LOCATION AND EXPLORATION PLAN
EXPLORATION RESULTS
SUPPORTING INFORMATION
Note: Refer to each individual Attachment for a listing of contents.
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
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REPORT SUMMARY
Topic Overview Statement 1
Project
Description
The proposed project consists of construction of one-story building with a footprint
of about 41,500 sf. Site retaining walls are anticipated to be planned to adjust the
grade changes across the site.
Geotechnical
Characterization
Subsurface conditions generally consist of clayey sand and sand fill and fat and lean
clays overlying a shale bedrock. Groundwater was encountered at depths of 6 and
7 feet in borings B-2, B-4 and B-6 during drilling. It was measured at depths of 38
and 35 feet in borings B-1 and B-4, respectively, upon completion of drilling.
Earthwork On-site soils, free of vegetation, organic material, debris, any deleterious materials
and/or rocks greater than 4 inches in maximum dimension can be used for site grades.
Deep
Foundations
Straight drilled shafts founded in the dark gray shale can be used to support the
structural loads of the building and retaining walls. These shafts can be designed
using a combination of end bearing and skin friction. Casing and underwater
concrete placement will mostly be required to properly construct straight-sided drilled
shafts.
Floor Slabs Structurally suspended floor slab in conjunction with a drilled shaft foundation
system is recommended. The slab movement is expected to be less than 1 inch.
Seismic
Considerations
Based on the 2012/2015 International Building Code (IBC) and ASCE/SEI 7-10, the
seismic site classification for this site is C.
General
Comments
This section contains important information about the limitations of this geotechnical
engineering report.
1. This summary is for convenience only. It should be used in conjunction with the ent ire report for design
purposes.
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INTRODUCTION
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building
185 W. Parkway Boulevard
Coppell, Texas
Terracon Project No. 94235370
November 10, 2023
INTRODUCTION
This report presents the results of our subsurface exploration and geotechnical engineering
services for the proposed CHS Fine Arts Rehearsal Building to be located at 185 W. Parkway
Boulevard in Coppell, Texas. The purpose of these services is to provide information and
geotechnical engineering recommendations relative to:
■ Subsurface soil and rock conditions ■ Floor slab design and construction
■ Groundwater conditions ■ Seismic site classification per IBC
■ Site preparation and earthwork ■ Lateral earth pressures
■ Excavation considerations ■ Pavement design and construction
■ Foundation design and construction
The geotechnical engineering Scope of Services for this project included the advancement of 6
test borings to a depth of 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 samples are
included on the boring logs in the Exploration Results section.
SITE CONDITIONS
Item Description
Parcel Information
The project site is located at 185 West Parkway in Coppell, Texas.
Approximate GPS Coordinates: 32.974980 N; 96.955960 W
See Site Location
Existing Improvements Existing Coppell High School Campus, buildings, playground, drives and
parking lots
Current Ground Cover Native grass and sandy soils
Existing Topography Fairly flat
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
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PROJECT DESCRIPTION
Item Description
Project Description The proposed development consists of the construction of a one-story
building with a footprint of about 41,500 sf
Maximum Column Load
(provided by the client)
Anticipated Dead load: 175 kips
Anticipated Transient load: 50 kips
Non-load bearing wall: Dead Load 1 klf; Live Load 100 psf
Building Construction The structures are anticipated to be supported on deep foundations in
conjunction with a structurally suspended floor system
Finished Elevations
(assumed) ±2 feet of existing grade
Site Retaining Wall
Site retaining walls are anticipated to be planned to adjust the grade
changes across the site. We anticipate maximum wall heights of about
5 feet.
GEOTECHNICAL CHARACTERIZATION
Site Geology
The site is situated on the outcrop of Terrace Deposit near the Woodbine geologic formation. This
formation generally consists of sandy soils and clays over shale bedrock. The clays may exhibit
moderate to high shrink/swell potential with moisture variations.
Subsurface Characterization
We have developed a general characterization of the subsurface conditions based upon our
review of the subsurface exploration, laboratory data, geologic setting and our understanding of
the project. This characterization, termed GeoModel, forms the basis of our geotechnical
calculations and evaluation of site preparation and foundation options. Conditions encountered at
each exploration point are indicated on the individual logs. The individual logs and GeoModel can
be found in the Exploration Results section of this report.
As part of our analyses, we identified the following model layers within the subsurface profile. For
a more detailed view of the model layer depths at each boring location, refer to the GeoModel.
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
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Model Layer Layer Name General Description
1 Fill, Sandy soils Fill materials consisting of clayey sand (SC) and sand (SP),
brown, tan and orange
2 Clays Fat clay (CH) and lean clays (CL), shaley, brown, orange and
gray
3 Bedrock Shale, dark gray
The following table summarizes the depth to dark gray shale in the borings advanced for this
project:
Boring Number
Approximate Depth and Elevation of Top of
Dark Gray Shale, feet1 Boring Depth,
feet1 Depth Elevation
B-1 14 464 40
B-2 14 461 40
B-3 14 462 40
B-4 13 462 40
B-5 14 464 40
B-6 13 461 40
1. Depths are below existing grade
Groundwater Conditions
The borings were advanced using dry auger drilling techniques which allows short-term
groundwater observations to be made while drilling. Groundwater seepage observations are
presented in the table below.
Borings Groundwater Seepage, While
Drilling, feet 1
Groundwater Seepage,
After Drilling, feet 1
B-1 Not Observed 38
B-2 6 Not observed
B-4 7 35
B-6 7 Not observed
1. Depths are below existing grade
Groundwater was not observed in any of the other borings while drilling or for the short duration the
borings could remain open. However, this does not necessarily mean the borings terminated above
groundwater. Due to the low permeability of the soils encountered in the borings, a relatively long
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
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period may be necessary for a groundwater level to develop and stabilize in a borehole. Long term
observations in piezometers or observation wells sealed from the influence of surface water are often
required to define groundwater levels in materials of this type.
Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff
and other factors not evident at the time the borings were performed. Therefore, groundwater
levels during construction or at other times in the life of the structure 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 construction plans for the project.
GEOTECHNICAL OVERVIEW
The on-site soils consist of clayey sand and sand fill and clays. Loose fill was encountered up to
a depth of 8 feet in the borings across the site. The clay soils presents at the site are active and
can experience volume changes with changes in soil moisture content. The clay soils tend to
shrink with soil moisture losses and swell with soil moisture increases. These soil volume changes
can result in vertical movements of ground supported elements such as floor slabs, flatwork,
foundations, and utilities. The potential magnitude of post construction movements at this site is
dependent on several factors including the thickness of active clay soils and moisture levels of in-
situ soils. The magnitude of the moisture induced potential vertical movement (PVM) is estimated
to be on the order of 1.5 to 2 inches based on dry soil moisture conditions.
It should be noted that there is a risk that even ½ inch of movement can result in unsatisfactory
performance. Some of the risks that can affect performance include uneven floors, floor and wall
cracking, and sticking doors.
The near surface overburden soils could become unstable with typical earthwork and construction
traffic, especially after precipitation events. The effective drainage should be completed early in
the construction sequence and maintained after construction to avoid potential issues. If possible,
the grading should be performed during the warmer and drier time of the year. If grading is
performed during the winter months, an increased risk for possible undercutting and replacement
of unstable subgrade will persist. Additional site preparation recommendations including
subgrade improvement and fill placement are provided in Earthwork.
Straight drilled shafts extending into the dark gray shale (GeoModel layer 3) can be used to
support the foundation loads of the building and site retaining walls for this project. Casing and
possible underwater concrete placement will be required for installation of the piers. Vibration of
the casing may be required to extend the casing through sandy soil and shaley clay layers. Grade
beams and pier caps should be supported by the drilled shaft foundations with a void space
between the grade beams and the subsurface clay soils.
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CHS Fine Arts Rehearsal Building ■ Coppell, Texas
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Due to the presence of loose and very loose fill materials at the site, we recommend that a
structurally suspended floor system in conjunction with a drilled shaft foundation system be used
for the building. The differential slab movement is expected to be less than 1 inch for a structurally
suspended floor system.
The General Comments section provides an understanding of the report limitations.
EARTHWORK
The following sections provide recommendations for use in the preparation of specifications for
the work. Recommendations include critical quality criteria as necessary to render the site in the
state considered in our geotechnical engineering evaluation for foundations and floor slabs.
Existing Fill
Fill soils were encountered to depths of about 6 to 8 feet in the borings. The fill materials consisted
of clayey sand and sand. There is a possibility of deeper fills at this site and under compacted
zones of soil or debris within the fill materials. Under compacted zones and debris could lead to
unacceptable settlements of floor slab on grade. Removal of the fills and replacing them in a
controlled manner is the most positive method to reduce movement of ground supported elements
of the project. If some risk of settlement can be taken in the flatwork, proof rolling as described in
section Site Preparation can be considered in lieu of complete removal of the fill. Proof rolling is
intended to represent a reasonable approach for construction of flatwork; however, it will not
eliminate the risk of unexpected movements in some areas.
Site Preparation
The site should be stripped and grubbed to remove all vegetation, root balls, deleterious material
(such as, any visible waste products, hazardous chemicals, trashes, biodegradable materials, etc.),
and any debris. Over excavation required to remove the root balls and existing site improvements
should be backfilled with properly placed and compacted fill as discussed in Fill Placement and
Compaction Requirements. The exposed subgrade should then be proof rolled prior to placing
any fill. In cut areas, proof rolling should be performed after excavating to final grade. The proof
rolling should be performed with a fully loaded, tandem-axle dump truck or other equipment
providing an equivalent subgrade loading. A minimum gross weight of 20 tons is recommended
for the proof rolling equipment. Where practical, the proof rolling should consist of several
overlapping passes in mutually perpendicular directions over a given area. Any soft or pumping
areas should be modified using one of the methods discussed in this section.
Methods of remediating soft areas identified during the proof rolling include scarification and
compaction at the proper moisture content, lime/cement treatment, or removal of unstable
materials and replacement with granular fill (with or without a geogrid). The appropriate method
of improvement, if required, would be dependent on factors such as schedule, weather, the size
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
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of the area to be stabilized, and the nature of the instability. More detailed recommendations can
be provided during construction as the need for subgrade modification occurs. Performing site
grading operations during warm seasons and dry periods would help to reduce the amount of
subgrade stabilization required.
Fill Material Types
Fill materials should meet the following requirements.
Material Type Description Appropriate Use
On-Site Soils
Free of vegetation, organic material, debris, and
rocks greater than 4 inches in maximum
dimension. Shale from excavation areas should
not be used within the moisture conditioned fill.
■ General site grading
■ Flatwork subgrade
■ Utility trench backfill
■ Moisture conditioned soils
Imported Fill
Clay soil free of hazardous chemicals,
vegetation, organic material, debris, and rocks
greater than 4 inches in maximum dimension,
with a liquid limit (LL) of 50 or less
■ General site grading
■ Flatwork subgrade
■ Utility trench backfill
■ Moisture conditioned soils
Select Fill 1
Uniformly blended sandy clay to clayey sand with
a liquid limit (LL) of 35 or less, a plasticity index
(PI) in the range of 6 and 15, and in the range of
30 and 60 percent passing a #200 US sieve ■ Site retaining wall backfill,
if required for this project
Granular Wall
Backfill
Non-plastic material with less than 3% passing
no. 200 sieve and less than 30% passing #40
sieve. Maximum aggregate size of 2 inches.
1. The on-site sandy soils could meet the requirements for select fill material. Sandy materials that are
excavated during the site grading activities can be tested and stockpiled for use as select fill. The
material should be tested for use as select fill material prior to use wherever required.
Fill Placement and Compaction Requirements
We recommend that all fill be observed and 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 must be reworked and
retested as required until the specified moisture and compaction requirements are achieved.
Recommendations for compaction are presented in the following table. Fills should be placed at
a maximum loose lift thickness of 6 and 9 inches for hand-operated and heavy compaction
equipment, respectively.
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
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Item Compaction Moisture Content
On-site soils or imported fills
placed outside the moisture
conditioned zone
A minimum of 95% maximum
standard Proctor dry density
(ASTM D 698)
For PI < 20: At or above optimum
moisture content
For PI ≥ 20: At a minimum of
+2 percentage points of optimum
moisture content
Backfill against the face of
grade beams
In the range of 93% to 98%
maximum standard Proctor dry
density (ASTM D 698)
For PI < 20: At a minimum
+2 percentage points of optimum
moisture content
For PI ≥ 20: In the range of +4 to
+8 percentage points of optimum
moisture content
Select fill
A minimum of 95% maximum
standard Proctor dry density
(ASTM D 698)
In the range of -2 to +2 percentage
points of optimum moisture
content
Granular wall backfill At a minimum of 60% of relative
density (ASTM D4253)
At a moisture content that
facilitates compaction
Utility Trenches
Utility trenches are a common source of water infiltration and migration. All utility trenches that
penetrate beneath the structure should be backfilled to restrict water intrusion and flow through
the trenches that could migrate below the structure. We recommend const ructing a clay or
flowable fill “trench plug” that extends at least 2 feet out from the exterior perimeter of the building.
The clay fill/flowable fill should be placed to surround the entire utility line and it should fill the
utility trench in width and height, with the exception of topsoil at the surface. If a clay plug is used,
it should consist of a clay soil with a minimum plasticity index (PI) of 30 and should be compacted
in accordance with the applicable recommendations as described in Fill Placement and
Compaction Requirements. If flowable fill is used, it should meet the requirement of TxDOT
Item 401, excavatable or non-excavatable characteristics.
Loose and very loose sandy soils were encountered across the site. Therefore, proper shoring,
equipment and trenchers will be required during utility trench excavations extending through the
loose materials.
Utility lines will be placed in backfilled trenches surrounded by expansive clays capable of moving
several inches cyclically throughout the year. This level of movement can lead to bending,
cracking, or separation of utility lines and connections. Care should be taken that utility trenches
are not left open for extended periods and they are properly backfilled. Flexible joints and
connections should be designed by the Mechanical, Electrical and Plumbing (MEP) to
accommodate differential movements along the utility lines, particularly in areas where ground
supported utilities and structurally supported utilities converge. Where utilities penetrate grade
beams, wall panels, and below-grade walls, an opening should be provided in the grade beams,
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
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wall panels, and below-grade walls and the utility line should be centered in the opening. A clear
spacing equivalent to the potential vertical movement (PVM) of the on-site soil should be provided
between the outside surface of the utility line and the grade beam, wall panel, and below-grade
wall.
Earthwork Construction Considerations
It is anticipated that excavations in the on-site soils can be accomplished with conventional
earthmoving equipment.
The majority of the on-site sandy soils and clay soils exposed during construction are anticipated
to be relatively dense and stiff and therefore should be able to support lightly loaded construction
equipment when dry. Some areas have loose sandy soils which may create difficulty during
construction activities. Moreover, the stability of the subgrade will be affected by rainfall and
repetitive construction traffic. If unstable conditions develop, workability of the soils may be
improved by scarifying and drying.
Construction traffic over the completed subgrades should be avoided. The site should also be
graded to prevent ponding of surface water on the prepared subgrades or in excavations. Water
collecting over or adjacent to construction areas should be removed. If the subgrade freezes,
desiccates, saturates, or is disturbed, the affected material should be removed, or the materials
should be scarified, moisture conditioned, and recompacted prior to any grade-supported
elements, such as flatwork construction.
Groundwater could affect excavation efforts. A temporary dewatering system consisting of sumps
with pumps may be necessary to achieve the recommended depth of over excavation depending
on groundwater conditions at the time of construction.
As a minimum, excavations should be performed in accordance with OSHA 29 CFR, Part 1926,
Subpart P, “Excavations” and its appendices, and in accordance with any applicable local and/or
state regulations.
Construction site safety is the sole responsibility of the contractor who controls the means,
methods, and sequencing of construction operations. Under no circumstances shall the
information provided herein be interpreted to mean Terracon is assuming responsibility for
construction site safety or the contractor's activities; such responsibility shall neither be implied
nor inferred.
Excavations or other activities resulting in ground disturbance have the potential to affect
adjoining properties and structures. Our scope of services does not include review of available
final grading information or consider potential temporary grading performed by the contractor for
potential effects such as ground movement beyond the project limits. A preconstruction/
precondition survey should be conducted to document nearby property/infrastructure prior to any
site development activity. Excavation or ground disturbance activities adjacent or near property
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
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lines should be monitored or instrumented for potential ground movements that could negatively
affect adjoining property and/or structures.
Construction Observation and Testing
The earthwork efforts should be monitored under the direction of the Geotechnical Engineer.
Monitoring should include documentation of adequate removal of any existing vegetation, any
debris/ deleterious materials, trees, tree roots, and top soil, 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 the Geotechnical Engineer prior to placement of additional lifts as outlined in Fill Placement
and Compaction Requirements section and as recommended in the table below.
Subgrade Frequency of In-Place Moisture and Density Tests1
Flatwork subgrade At least one test per 5,000 square feet of area per 6 inches
lift with minimum 3 tests per lift
Trench backfill At least one test for every 50 linear feet of compacted trench
backfill
Daily reports documenting activities, test results and list on non-conforming tests should be
provided to the team. The imported fill and select fill should be sampled and tested on a regular
basis to confirm that it does meet the properties recommended in this report.
In addition to the documentation of the essential parameters necessary for construction, the
continuation of the Geotechnical Engineer into the construction phase of the project provides the
continuity to maintain the Geotechnical Engineer’s evaluation of subsurface conditions, including
assessing variations and associated design changes.
Site Grades and Drainage
All permanent slopes taller than 6 feet should be 4 Horizontal to 1 Vertical (4H:1V) or flatter. A
slope stability analysis should be performed if steeper slopes are considered.
Positive drainage away from the building must be provided during the construction and maintained
through the life of the building. Infiltration of water into excavations should be prevented during
construction. It is important that subgrade soils are not allowed to become excessively wet or dry.
Exposed (unpaved) ground should be sloped away from the building for at least 10 feet beyond
the perimeter of the building.
Roof runoff and surface drainage should be collected and discharged away from the building to
prevent wetting of the subgrade soils. Roof gutters should be installed and connected to
downspouts and pipes directing the roof runoff at least 10 feet away from the building or
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
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discharged on to positively sloped flatwork such as the aprons. Ideally, roof drains should
discharge by closed pipe into the storm drainage system.
After building construction and landscaping, final grades should be verified to document effective
drainage has been achieved. Grades around the structures should also be periodically inspected
and adjusted as necessary as part of the structure’s maintenance program. Where paving or
flatwork abuts the structures, a maintenance program should be established to effectively seal
and maintain joints and prevent surface water infiltration. Water permitted to pond next to the
structures can result in greater soil movements than those discussed in this report. Estimated
movements described in this report are based on effective drainage for the life of the structures
and cannot be relied upon if effective drainage is not maintained.
Landscaping Considerations
Sprinkler mains and spray heads should be located at least 5 feet away from the building such
that they cannot become a potential point source of water directly adjacent to the building.
Watering of vegetation should be performed in a timely and controlled manner and prolonged
watering or prolonged non-watering periods should be avoided. Special care should be taken
such that underground utilities do not develop leaks with time.
A general guideline would be to locate trees no closer than a distance equal to the mature tree
height for that tree species. Planters located adjacent to the building should preferably be self-
contained, or at least designed to drain away from the building.
DEEP FOUNDATIONS
Straight Drilled Shafts – Axial Capacity
Design parameters are provided in the following table for the design of straight drilled shaft
foundations based on subsurface conditions encountered in the borings. The values presented
for allowable end bearing and skin friction include a factor of safety (F.S.).
Design Parameter Recommendations
Bearing strata Dark gray shale
Approximate depth to the top of the
bearing stratum 13 to 14 feet below existing site grades
Minimum penetration into the bearing
strata to develop end bearing
3 feet
(Deeper penetrations may be required to support the
structural load and lateral resistance of the building)
Allowable end bearing pressure
(F.S.=2.5) 10,500 psf
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
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Design Parameter Recommendations
Allowable skin friction in compression
below top the bearing materials or
below bottom of temporary casing,
whichever is deeper (F.S.=2.5)
1,700 psf
Allowable skin friction in tension below
top the bearing materials or below the
bottom of temporary casing, whichever
is deeper (F.S.=3.0)
1,300 psf
Minimum center to center spacing to
develop full skin friction
2.5 times the diameter of the larger shaft. Closer spacing
may require some reductions in skin friction and/or changes
in installation sequences. Closely spaced shafts should be
examined on a case by case basis. As a general guide, the
design skin friction will vary linearly from the f ull value at a
spacing of 2.5 diameters to 50 percent of the design value
at 1.0 diameter.
Groups of 3 or more shafts spaced
closer than 2.5 shaft diameters
Should be evaluated on a case by case basis by this office.
Alternative installation sequences may be needed to allow
for a minimum of 48 hours concrete curing time, before
installation of adjacent shafts.
Total settlement Up to 1 inch
Drilled Shaft Construction Considerations
The construction of all drilled shafts should be observed by experienced geotechnical personnel
during construction to confirm: 1) the bearing stratum; 2) the minimum bearing depth; 3) that
groundwater seepage, if encountered, is correctly handled; and 4) that the shafts are within
acceptable vertical tolerance.
Recommendations for drilled shaft construction are presented in the following table.
Item Recommendation
Drilled shaft installation
specification
Current version of American Concrete Institute’s “Standard Specification for
the Construction of Drilled Piers” ACI 336.
Top of shaft completion Enlarged (mushroom-shaped) top in contact with the clays should not be
allowed.
Time to complete Drilled shaft construction should be completed within 8 hours in a
continuous manner to reduce side wall and base deterioration.
Installation methods
The concrete should be placed in a manner to avoid striking the reinforcing
steel during placement. Care should be taken to not disturb the sides and
bottom of the excavation during construction. The bottom of the shaft
excavation should be free of loose material before concrete placement.
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
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Item Recommendation
Concrete should be placed as soon as possible after the foundation
excavation is completed, to reduce potential disturbance of the bearing
surface.
Groundwater control
Seepage was observed in borings B-1, B-2, B-4 and B-6 at various depths
and will most likely be encountered during installation of the straight shafts.
Also, due to presence of loose and very loose sandy soils in the upper
layers, caving/sloughing soils will likely be encountered in drilled shaft
excavations. Seepage rates and caving/sloughing soils will require the use
of temporary casing for installation of the straight shafts . Vibratory methods
might be required to advance the casing through the sandy soil and shaley
clay layers. The casing should be seated in the bearing material with all
water and most of the loose material removed prior to beginning the design
penetration. Heavy duty cranes will most likely be required to place the
temporary casing. While withdrawing casing, care should be exercised to
maintain concrete inside the casing at a sufficient level to resist earth and
hydrostatic pressures acting on the casing exterior. Arching of the concrete,
loss of seal and other problems can occur during casing removal and result
in contamination of the drilled shaft. These conditions should be considered
during the design and construction phases. Placement of loose soil backf ill
should not be permitted around the casing prior to removal.
If groundwater is encountered in the bearing strata during construction
phase, this water usually cannot be controlled with casing. Special
underwater placement using a tremie or pumped concrete is often required.
Mineral solid or chemical polymer slurry may be required to stabilize the
shaft excavation. The properties and mixing of slurry and the installation of
the shaft should follow the requirements in ACI 336. Tremied or pumped-in
concrete for shafts should take place as continuously as possible until the
concrete placement is complete. The bottom of the discharge pipe should
always be kept below the surface of the concrete . Before tremied or
pumped-in concrete is used, care should be taken to ensure that the water
is at a stabilized level and muck is removed to as low level as possible,
which will provide for a thin water solution to be displaced during concrete
placement. The pipe or tremie is to be plugged when inserted into the shaft
and lowered until it is resting on the bottom of the hole . It should be filled
with concrete and then lifted off the bottom about 1 foot. The concrete should
then be placed in a continuous operation until all water is forced out of the
hole. The tremie or pipe must always have about 5 feet of pipe into the
concrete. Once the water is forced from the shaft, the remaining concreting
operation will be the same as for a cased hole.
The drilled shaft installation process should be performed under the direction of the Geotechnical
Engineer. The Geotechnical Engineer should document the shaft installation process including
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
Responsive ■ Resourceful ■ Reliable 13
soil/rock and groundwater conditions encountered, consistency with expected conditions, and
details of the installed shaft.
Straight Drilled Shafts – Soil Induced Uplift Loads
Drilled shafts will be subject to uplift as a result of heave in the overlying clay soils. The magnitude
of these loads varies with the shaft diameter, soil parameters, and particularly the in-situ moisture
levels at the time of construction. The shafts must contain sufficient continuous vertical reinforcing
and embedment depth to resist the net tensile load.
For the conditions encountered at this site, the uplift load can be approximated by assuming a
uniform uplift of 1,000 psf over the shaft perimeter for a depth of 10 feet The uplift loads can be
neglected in the portion of the shafts embedded in the sandy soils.
Drilled Shaft Lateral Loading
The drilled shafts will be subject to lateral loads. The upper 3 feet of soil below the existing grade
or finished grade, whichever deeper, should be neglected in passive resistance to allow for soil
shrinkage.
The following table lists input values for use in LPILE analyses. LPILE estimates values of soil
modulus (kh) and soil strain factor (E50) based on strength; however, non-default values of kh
should be used where provided, especially for sandy soil stratum. Since deflection or a service
limit criterion will most likely control lateral capacity design, no safety/resistance factor is included
with the parameters.
Soil or Rock Type Clay Soils1, 2 Sand and
Clayey Sand 1, 2
Dark Gray
shale
LPILE Material Type Stiff clay without free
water Sand (Reese) Weak Rock
Effective Soil Unit Weight AWT BWT AWT BWT 130 pcf 125 pcf 63 pcf 128 pcf 65 pcf
Undrained Cohesion, c AWT BWT Not Applicable
(N/A) N/A 1,500 psf 750 psf
Friction Angle, degree N/A N/A 30 N/A
Modulus (kh) for Sandy soils, pci N/A N/A AWT BWT N/A 90 60
Initial Modulus of Rock Mass, Er N/A N/A N/A 8,500 psi
Uniaxial Compressive Strength N/A N/A N/A 89 psi
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
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Soil or Rock Type Clay Soils1, 2 Sand and
Clayey Sand 1, 2
Dark Gray
shale
Estimated Rock Quality
Designation, RQD N/A N/A N/A 80%
Strain Factor for Rock, Krm N/A N/A N/A 0.0007
1. AWT – Above Water Table
2. BWT – Below Water Table (submerged)
Grade Beams. / Pier Caps
All grade beams or wall panels should be supported by the straight drilled shafts. A minimum void
space of 6 inches is recommended between the bottom of grade beams or pier cap extensions
and the subgrade. The void will serve to minimize distress resulting from swell pressures
generated by the clay soils. Structural cardboard forms are one acceptable means of providing
this void beneath cast in place elements. Soil retainers should be used to prevent infilling of the
void.
The grade beams should be formed rather than cast against earth trenches. Backfill against the
exterior face of grade beams, wall panels and pier caps should be on site materials placed and
compacted as described in Fill Placement and Compaction Requirements.
FLOOR SLABS
Lightly loaded floor slabs and flatwork placed on-grade will be subject to movement as a result of
moisture induced volume changes in the active soils that can occur following construction. The
soils expand (swell) with increases in moisture and contract (shrink) with decreases in moisture.
The movement typically occurs as post construction heave.
The potential magnitude of the moisture induced movement is rather indeterminate. It is
influenced by the soil properties, overburden pressures, and soil moisture levels at the time of
construction. Based on the soil types encountered in the borings, the maximum potential vertical
movement (PVM) in slabs placed on grade for dry soil moisture conditions that can exist prior to
construction is expected to be 1.5 to 2 inches as described in the Geotechnical Overview.
Due to the presence of loose and very loose fill materials at the site, we recommend that a
structurally suspended floor slab in conjunction with a drilled shaft foundation system be used for
a differential slab movement of less than 1 inch.
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
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Structural Floor Slabs
A minimum void space of 6 inches is recommended below a structurally suspended floor slab
system. The minimum void space can be provided by use of cardboard carton forms, or a deeper
crawl space. A ventilated and drained crawl space is preferred under the structures for several
reasons, including the following:
■ Ground movements will affect the project utilities, which can cause breaks in the lines and
distress to interior fixtures.
■ A crawl space permits utilities to be hung from the superstructure, which greatly reduces
the possibility of distress due to ground movements. It also can provide ready access in
the event repairs are necessary.
■ Ground movements could be uneven. A crawl space can be positively drained preventing
the ponding of water and reducing the possibility of distress due to unexpected ground
movements.
RETAINING WALLS AND BELOW GRADE WALLS
At the time of this report preparation, no wall information was available. Retaining walls or below
grade walls up to about 5 feet in height are expected to be constructed as part of site development
to achieve final grades. Based on the subsurface conditions encountered in the borings located
in this area, excavations will generally encounter sandy and clay soils. These soils can be
excavated and sloped back with standard earthwork equipment. Applicable OSHA standards
should be followed. Consideration should also be given to erosion protection on exposed slopes.
Retaining walls should be supported by straight drilled shafts as recommended in Deep
Foundations. A void space should be provided below drilled shaft supported walls, as described
in Grade Beams / Pier Caps.
Lateral Earth Pressure
Site retaining walls or below grade walls planned for this project will be subjected to lateral earth
pressures from earthen backfill. Lateral earth pressures acting on the walls will depend on the
type of backfill material, drainage conditions behind the walls, and the amount of wall movement
that will occur. For walls that are expected to be restrained from lateral movements, at-rest earth
pressures are recommended. Active earth pressures can be used where the top of the wall will
deflect on the order of 0.5 percent of the wall height.
Recommended lateral earth pressures, expressed as equivalent fluid pressure (EFP), and lateral
earth pressure coefficients are presented in the following table for walls with drained and
undrained conditions. The values assume horizontal ground surface behind of the wall. The
recommended design lateral earth pressures do not include a factor of safety.
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
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Backfill Type
Lateral Earth
Pressure Coefficient
EFP Without
Hydrostatic Pressures
(psf/ft)
(Drained Condition)
EFP With Hydrostatic
Pressures (psf/ft)
(Undrained Condition)
Active At-Rest Active At-Rest Active At-Rest
On site clay soils 0.5 0.7 65 90 95 105
Select fill or on-site
sandy soils meeting the
select fill criteria
0.4 0.6 55 80 90 100
Free draining granular
backfill 0.3 0.5 40 65 85 95
The limits of granular backfill should extend outward at least 3 feet from the base of the wall and
then upward on a 1H:1V slope.
The lateral earth pressure values do not include surcharge loads due to overburden, future
structures, traffic, equipment, etc. Surcharge loads should be considered if they apply at the
surface above the wall within an area defined by an angle of 45 degrees extending up from the
base of the wall. Care should be taken that backfill is not over compacted, which could increase
the lateral pressures on the walls.
Wall backfill materials should be placed and compacted as described in Fill Placement and
Compaction Requirements. Granular backfill should not be water jetted to achieve compaction
and should be placed at a moisture content to allow the desired density to be achieved. The top
of the backfill should be protected by flatwork/paving or a minimum thickness of 2 feet of clay fill
(PI>30) to reduce surface water infiltration.
Wall Drainage Considerations
Drainage must be provided behind the walls to prevent the development of hydrostatic pressures
for the wall designed for drained conditions. A vertical drain is recommended behind walls. This
drain may consist of a manufactured drainage panel or an aggregate drain.
The aggregate drain should meet the graduation requirements presented in Fill Material Types
for granular backfill. For walls associated with the structure, the vertical drain should be connected
to a permanent perimeter drainage system that is located. Drainage for free standing walls can
be provided by using a collector pipe or weep holes near the base of the wall.
The perimeter drain should be a perforated or slotted drain with a minimum pipe diameter of
6 inches. The pipe should be surrounded with at least 6 inches of drainage rock. The drainage
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
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rock should be wrapped with an effective geotextile for protection against infiltration. Accessible
clean-outs should be provided. Below grade walls in occupied space should be waterproofed.
Drainage must be provided behind the walls to prevent the development of hydrostatic pressures
for the wall designed for drained conditions. Aggregate drains can also be used. The aggregate
drains should meet the gradation requirements for granular backfill. Collector pipes or weep holes
near the base of the wall are also recommended. Drains or weep holes should be properly filtered
to reduce the potential for erosion through these drains and/or plugging of drain lines.
Wall Backfill Settlement
The backfill behind the walls settle with time, and settlement should be anticipated. Piping and
conduits through the fill should be designed for potential earth loading due to fill settlement.
Therefore, it is recommended that special consideration be given to the design of any foundation
elements, slabs, and pavements that may extend over this backfill to help minimize the effects of
such settlements. Backfill compacted to the density recommended above is anticipated to settle
on the order of one to two percent of the fill thickness.
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 and 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
C. 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.
CORROSIVITY
Selected soil samples were tested for pH, soluble sulfates, sulfides, chlorides, red-ox potential,
total salts, and electrical resistivity. The results of these test are provided in the following table.
The values may be used to estimate potential corrosive characteristics of the on-site soils with
respect to contact with the various underground materials that will be used for project
construction.
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
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Corrosivity Test Results Summary
Boring
Sample
Depth
(feet)
pH
Soluble
Sulfate
(ppm)
Sulfides
(ppm)
Chloride
(ppm)
Red-Ox
Potential
(mV)
Total
Salts
(ppm)
Electrical
Resistivity
(Ω-cm)
B-2 0 - 2 7.9 57 nil 131 +510 880 2,478
B-3 8 - 10 7.8 2,694 nil 106 +489 4,605 413
pH – ASTM G 51 Soluble Chloride – ASTM D 512 Soluble Sulfate – ASTM C 1580
Electrical Resistivity – ASTM G 187 Total Salts – ASTM D 1125-14
Red-Ox – ASTM D 1498 Sulfides – ASTM D 4658-15
GENERAL COMMENTS
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 this 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
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
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
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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.
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ATTACHMENTS
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES 1 of 2
EXPLORATION AND TESTING PROCEDURES
Field Exploration
Boring ID Boring Depth (feet) Location
B-1 through B-6 40 feet Building
Boring Layout and Elevations: Boring coordinates are obtained with a handheld GPS unit
(estimated horizontal accuracy of about ±20 feet) and approximate elevations are obtained by
interpolation from public data provided by the North Central Texas Council of Governments
(NCTCOG) topographic maps. If elevations and a more precise boring layout are desired, we
recommend borings be surveyed following completion of fieldwork.
Subsurface Exploration Procedures: Borings were drilled using a truck-mounted drill rig. Borings
were continuously sampled in the upper 10 feet of each boring and at intervals of 5 feet thereafter.
The borings were sampled using push tube samplers in clays. Standard Penetration Tests (SPT)
were conducted within sandy soils and clays where the soils were too hard to push tubes. The SPT
resistance values, also referred to as N-values, are indicated on the boring log at the test depths.
The load carrying capacity of bedrock was evaluated in the field using the Texas Department of
Transportation’s (TxDOT) Cone Penetration Test.
The sampling depths, penetration distances, and other sampling information are recorded on the
field boring logs. The samples are placed in appropriate containers and taken to our soil laboratory
for testing and classification by a geotechnical engineer. Final boring logs are prepared from the
field logs. The boring logs included with this report represent the engineer’s interpretation of the
field logs and include modifications based on visual evaluation of the samples and laboratory test
results.
The boring logs are presented in Exploration Results. The Unified Soil Classification System
(USCS) and description of rock properties are presented in Supporting Information.
Laboratory Testing
The laboratory tests were performed by geotechnical laboratory technicians under the supervision
of the engineer. Liquid and Plastic Limits tests, percent passing No. 200 sieve and moisture
content tests were performed to aid in classifying the soils in accordance with the USCS.
Absorption swell tests were performed on selected samples of the cohesive materials. These
tests were used to quantitatively evaluate volume change potential at in-situ moisture levels.
Strength of cohesive soils were evaluated by hand penetrometer tests. Our laboratory procedures
were based on applicable ASTM procedures.
Geotechnical Engineering Report
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES 2 of 2
The results of the absorption swell tests performed for this study are presented in the following
table.
Swell Test Results
Boring
No.
Depth
(feet)
Liquid
Limit
(%)
Plasticity
Index
(%)
Initial
Moisture
(%)
Final
Moisture
(%)
Surcharge
(psf)
Swell
(%)
B-1 6 – 8 35 23 15.5 21.9 875 1.1
B-3 8 – 10 57 36 15.0 22.1 1,125 1.4
Corrosion Testing
Two samples obtained from borings B-2 and B-3 within the building area from depths of 0 to 10
feet were tested to evaluate the corrosion properties of the soils.
The test results are provided in the Corrosivity section of the report.
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SITE LOCATION AND EXPLORATION PLAN
Contents:
Site Location
Exploration Plan
SITE LOCATION
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
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MAP 1 PORTRAIT
DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS
EXPLORATION PLAN
CHS Fine Arts Rehearsal Building ■ Coppell, Texas
November 10, 2023 ■ Terracon Project No. 94235370
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MAP 2 LANDSCAPE
DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS
EXPLORATION RESULTS
Contents:
Boring Logs (B-1 through B-6)
GeoModel
4.5+ (HP)
10-10-8
N=18
1-1-2
N=3
2.5 (HP)
4.5+ (HP)
TC=100/3.75"
TC=100/6"
TC=100/8"
TC=100/11.25"
TC=100/9.75"
TC=100/5.5"
7.6
3.4
14.1
15.5
26.6
26-13-13
35-12-23
FILL - CLAYEY SAND (SC), brown and
orange, loose to dense
LEAN CLAY (CL), shaley, gray, very stiff to
hard
SHALE, dark gray
Boring Terminated at 40 Feet
6.0
14.0
40.0
472+/-
464+/-
438+/-
Approximate latitude and longitude were obtained using
hand-held GPS unit. Approximate surface elevation was
obtained from NCTCOG topography map.
24
Stratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 94235370 CHS FINE ARTS REH.GPJ TERRACON_DATATEMPLATE.GDT 11/9/23DEPTH (Ft.)5
10
15
20
25
30
35
40 WATER LEVELOBSERVATIONSSTRENGTH TEST
FIELD TESTRESULTSWATERCONTENT (%)ATTERBERG
LIMITS
LL-PL-PI
LOCATION See Exploration Plan
Latitude: 32.9748° Longitude: -97.0024°GRAPHIC LOGMODEL LAYERDEPTH
Approximate Surface Elev.: 478 (Ft.) +/-
ELEVATION (Ft.)
Page 1 of 1
Advancement Method:
Dry Augered
Abandonment Method:
Boring backfilled with soil cuttings upon completion.
Notes:
Project No.: 94235370
Drill Rig: Truck-mounted
BORING LOG NO. B-1
Coppell ISDCLIENT:
Coppell, TX
Driller: StrataBore
Boring Completed: 10-09-2023
PROJECT: CHS Fine Arts Rehearsal Building
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.
185 W. Parkway Blvd.
Coppell, TX
SITE:
Boring Started: 10-09-2023
8901 John W Carpenter Fwy Ste 100
Dallas, TX
While drilling
Dry at completion
WATER LEVEL OBSERVATIONS DRY UNITWEIGHT (pcf)STRAIN (%)COMPRESSIVESTRENGTH(tsf)TEST TYPEPERCENT FINES1
2
3 SAMPLE TYPE
2.5 (HP)
2.0 (HP)
3-2-2
N=4
4-17-22
N=39
4.5+ (HP)
TC=100/3.5"
TC=100/4.25"
TC=100/7.25"
TC=100/10.25"
TC=100/12"
TC=100/6"
3.0
6.1
16.0
14.2 73-28-45
FILL - CLAYEY SAND (SC), brown and
orange, loose to medium dense
FAT CLAY (CH), shaley, gray, hard
SHALE, dark gray
Boring Terminated at 40 Feet
6.0
14.0
40.0
469+/-
461+/-
435+/-
Approximate latitude and longitude were obtained using
hand-held GPS unit. Approximate surface elevation was
obtained from NCTCOG topography map.
12
Stratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 94235370 CHS FINE ARTS REH.GPJ TERRACON_DATATEMPLATE.GDT 11/9/23DEPTH (Ft.)5
10
15
20
25
30
35
40 WATER LEVELOBSERVATIONSSTRENGTH TEST
FIELD TESTRESULTSWATERCONTENT (%)ATTERBERG
LIMITS
LL-PL-PI
LOCATION See Exploration Plan
Latitude: 32.9749° Longitude: -97.0019°GRAPHIC LOGMODEL LAYERDEPTH
Approximate Surface Elev.: 475 (Ft.) +/-
ELEVATION (Ft.)
Page 1 of 1
Advancement Method:
Dry Augered
Abandonment Method:
Boring backfilled with soil cuttings upon completion.
Notes:
Project No.: 94235370
Drill Rig: Truck-mounted
BORING LOG NO. B-2
Coppell ISDCLIENT:
Coppell, TX
Driller: StrataBore
Boring Completed: 10-09-2023
PROJECT: CHS Fine Arts Rehearsal Building
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.
185 W. Parkway Blvd.
Coppell, TX
SITE:
Boring Started: 10-09-2023
8901 John W Carpenter Fwy Ste 100
Dallas, TX
While drilling
Dry at completion
WATER LEVEL OBSERVATIONS DRY UNITWEIGHT (pcf)STRAIN (%)COMPRESSIVESTRENGTH(tsf)TEST TYPEPERCENT FINES1
2
3 SAMPLE TYPE
3.0 (HP)
3.5 (HP)
4-3-2
N=5
5-23-30
N=53
4.5 (HP)
TC=100/3.25"
TC=100/6.25"
TC=100/7.75"
TC=100/12"
TC=100/11.75"
TC=100/10"
4.8
6.2
6.0
21.9
15.0
26-11-15
57-21-36
FILL - CLAYEY SAND (SC), orange and
tan, loose to medium dense
SANDY LEAN CLAY (CL), orange, hard
FAT CLAY (CH), shaley, gray, hard
SHALE, dark gray
Boring Terminated at 40 Feet
6.0
8.0
14.0
40.0
470+/-
468+/-
462+/-
436+/-
Approximate latitude and longitude were obtained using
hand-held GPS unit. Approximate surface elevation was
obtained from NCTCOG topography map.
29
18
43
Stratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 94235370 CHS FINE ARTS REH.GPJ TERRACON_DATATEMPLATE.GDT 11/9/23DEPTH (Ft.)5
10
15
20
25
30
35
40 WATER LEVELOBSERVATIONSSTRENGTH TEST
FIELD TESTRESULTSWATERCONTENT (%)ATTERBERG
LIMITS
LL-PL-PI
LOCATION See Exploration Plan
Latitude: 32.9751° Longitude: -97.0021°GRAPHIC LOGMODEL LAYERDEPTH
Approximate Surface Elev.: 476 (Ft.) +/-
ELEVATION (Ft.)
Page 1 of 1
Advancement Method:
Dry Augered
Abandonment Method:
Boring backfilled with soil cuttings upon completion.
Notes:
Project No.: 94235370
Drill Rig: Truck-mounted
BORING LOG NO. B-3
Coppell ISDCLIENT:
Coppell, TX
Driller: StrataBore
Boring Completed: 10-09-2023
PROJECT: CHS Fine Arts Rehearsal Building
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.
185 W. Parkway Blvd.
Coppell, TX
SITE:
Boring Started: 10-09-2023
8901 John W Carpenter Fwy Ste 100
Dallas, TX
No seepage encountered
Dry at completion
WATER LEVEL OBSERVATIONS DRY UNITWEIGHT (pcf)STRAIN (%)COMPRESSIVESTRENGTH(tsf)TEST TYPEPERCENT FINES1
2
3 SAMPLE TYPE
4.5+ (HP)
8-7-5
N=12
1-1-2
N=3
1-1-0
N=1
9-28-40
N=68
TC=100/2.5"
TC=100/7"
TC=100/9.75"
TC=100/9.75"
TC=100/10"
TC=100/5.75"
3.9
2.9
7.6
13.5
NP
66-26-40
FILL - POORLY GRADED SAND (SP), tan,
dense
FILL - CLAYEY SAND (SC), brown and
orange, loose to medium dense
- very loose below 5 feet
FAT CLAY (CH), shaley, gray, hard
SHALE, dark gray
Boring Terminated at 40 Feet
2.0
8.0
13.0
40.0
473+/-
467+/-
462+/-
435+/-
Approximate latitude and longitude were obtained using
hand-held GPS unit. Approximate surface elevation was
obtained from NCTCOG topography map.
15
8
Stratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 94235370 CHS FINE ARTS REH.GPJ TERRACON_DATATEMPLATE.GDT 11/9/23DEPTH (Ft.)5
10
15
20
25
30
35
40 WATER LEVELOBSERVATIONSSTRENGTH TEST
FIELD TESTRESULTSWATERCONTENT (%)ATTERBERG
LIMITS
LL-PL-PI
LOCATION See Exploration Plan
Latitude: 32.9751° Longitude: -97.0017°GRAPHIC LOGMODEL LAYERDEPTH
Approximate Surface Elev.: 475 (Ft.) +/-
ELEVATION (Ft.)
Page 1 of 1
Advancement Method:
Dry Augered
Abandonment Method:
Boring backfilled with soil cuttings upon completion.
Notes:
Project No.: 94235370
Drill Rig: Truck-mounted
BORING LOG NO. B-4
Coppell ISDCLIENT:
Coppell, TX
Driller: StrataBore
Boring Completed: 10-09-2023
PROJECT: CHS Fine Arts Rehearsal Building
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.
185 W. Parkway Blvd.
Coppell, TX
SITE:
Boring Started: 10-09-2023
8901 John W Carpenter Fwy Ste 100
Dallas, TX
While drilling
At completion of drilling
WATER LEVEL OBSERVATIONS DRY UNITWEIGHT (pcf)STRAIN (%)COMPRESSIVESTRENGTH(tsf)TEST TYPEPERCENT FINES1
2
3 SAMPLE TYPE
3.5 (HP)
13-15-4
N=19
4-5-6
N=11
1-1-2
N=3
4.5+ (HP)
TC=100/3.5"
TC=100/4"
TC=100/3.75"
TC=100/9.25"
TC=100/8.25"
TC=100/5.5"
6.5
4.2
6.3
19.2
18.8
21-16-5
76-31-45
FILL - CLAYEY SAND (SC), brown and
orange, medium dense to dense
- loose below 6 feet
FAT CLAY (CH), shaley, gray, hard
SHALE, dark gray
Boring Terminated at 40 Feet
8.0
14.0
40.0
470+/-
464+/-
438+/-
Approximate latitude and longitude were obtained using
hand-held GPS unit. Approximate surface elevation was
obtained from NCTCOG topography map.
20
23
Stratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 94235370 CHS FINE ARTS REH.GPJ TERRACON_DATATEMPLATE.GDT 11/9/23DEPTH (Ft.)5
10
15
20
25
30
35
40 WATER LEVELOBSERVATIONSSTRENGTH TEST
FIELD TESTRESULTSWATERCONTENT (%)ATTERBERG
LIMITS
LL-PL-PI
LOCATION See Exploration Plan
Latitude: 32.9753° Longitude: -97.0024°GRAPHIC LOGMODEL LAYERDEPTH
Approximate Surface Elev.: 478 (Ft.) +/-
ELEVATION (Ft.)
Page 1 of 1
Advancement Method:
Dry Augered
Abandonment Method:
Boring backfilled with soil cuttings upon completion.
Notes:
Project No.: 94235370
Drill Rig: Truck-mounted
BORING LOG NO. B-5
Coppell ISDCLIENT:
Coppell, TX
Driller: StrataBore
Boring Completed: 10-09-2023
PROJECT: CHS Fine Arts Rehearsal Building
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.
185 W. Parkway Blvd.
Coppell, TX
SITE:
Boring Started: 10-09-2023
8901 John W Carpenter Fwy Ste 100
Dallas, TX
No seepage encountered
Dry at completion
WATER LEVEL OBSERVATIONS DRY UNITWEIGHT (pcf)STRAIN (%)COMPRESSIVESTRENGTH(tsf)TEST TYPEPERCENT FINES1
2
3 SAMPLE TYPE
3.0 (HP)
13-13-7
N=20
1-1-1
N=2
3-8-21
N=29
24-45-41
N=86
TC=100/3.25"
TC=100/3"
TC=100/4.25"
TC=100/11"
TC=100/2.75"
TC=100/7.5"
4.4
4.5
12.5
17.4
16.9
FILL - CLAYEY SAND (SC), brown and
orange, medium dense to dense
- very loose at 3 to 5 feet
FAT CLAY (CH), shaley, gray, hard
SHALE, dark gray
Boring Terminated at 40 Feet
8.0
13.0
40.0
466+/-
461+/-
434+/-
Approximate latitude and longitude were obtained using
hand-held GPS unit. Approximate surface elevation was
obtained from NCTCOG topography map.
17
30
Stratification lines are approximate. In-situ, the transition may be gradual.THIS BORING LOG IS NOT VALID IF SEPARATED FROM ORIGINAL REPORT. GEO SMART LOG-NO WELL 94235370 CHS FINE ARTS REH.GPJ TERRACON_DATATEMPLATE.GDT 11/9/23DEPTH (Ft.)5
10
15
20
25
30
35
40 WATER LEVELOBSERVATIONSSTRENGTH TEST
FIELD TESTRESULTSWATERCONTENT (%)ATTERBERG
LIMITS
LL-PL-PI
LOCATION See Exploration Plan
Latitude: 32.9754° Longitude: -97.0018°GRAPHIC LOGMODEL LAYERDEPTH
Approximate Surface Elev.: 474 (Ft.) +/-
ELEVATION (Ft.)
Page 1 of 1
Advancement Method:
Dry Augered
Abandonment Method:
Boring backfilled with soil cuttings upon completion.
Notes:
Project No.: 94235370
Drill Rig: Truck-mounted
BORING LOG NO. B-6
Coppell ISDCLIENT:
Coppell, TX
Driller: StrataBore
Boring Completed: 10-09-2023
PROJECT: CHS Fine Arts Rehearsal Building
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.
185 W. Parkway Blvd.
Coppell, TX
SITE:
Boring Started: 10-09-2023
8901 John W Carpenter Fwy Ste 100
Dallas, TX
While drilling
Dry at completion
WATER LEVEL OBSERVATIONS DRY UNITWEIGHT (pcf)STRAIN (%)COMPRESSIVESTRENGTH(tsf)TEST TYPEPERCENT FINES1
2
3 SAMPLE TYPE
430
435
440
445
450
455
460
465
470
475
480
ELEVATION (MSL) (feet)CHS Fine Arts Rehearsal Building Coppell, TX
Terracon Project No. 94235370
Layering shown on this figure has been developed by the geotechnical
engineer for purposes of modeling the subsurface conditions as
required for the subsequent geotechnical engineering for this project.
Numbers adjacent to soil column indicate depth below ground surface.
NOTES:
B-1
B-2 B-3 B-4
B-5
B-6
This is not a cross section. This is intended to display the Geotechnical Model only. See individual logs for more detailed conditions.
GEOMODEL
First Water Observation
Second Water Observation
The groundwater levels shown are representative of the date and time of our
exploration. Significant changes are possible over time.
Water levels shown are as measured during and/or after drilling. In some cases,
boring advancement methods mask the presence/absence of groundwater. See
individual logs for details.
3 Shale, dark gray
LEGEND
Clayey Sand
Lean Clay
Shale
Fat Clay
Sandy Lean Clay
Poorly-graded Sand
1
Model Layer Layer Name General Description
Fill materials consisting of clayey sand (SC) and sand (SP),
brown, tan and orange
Fat clays (CH) and lean clays (CL), brown, orange and gray,2 shaley
Bedrock
Fill Sandy soils
Clays
6
14
40
1
2
3
38
6
14
40
1
2
3
6 6
14
40
1
2
3
8
13
40
1
2
3
35
7
8
14
40
1
2
3
8
13
40
1
2
3
7
SUPPORTING INFORMATION
Contents:
General Notes
Unified Soil Classification System
CHS Fine Arts Rehearsal Building Coppell, TX
Terracon Project No. 94235370
0.25 to 0.50
> 4.00
2.00 to 4.00
1.00 to 2.00
0.50 to 1.00
less than 0.25
Unconfined Compressive Strength
Qu, (tsf)
Shelby
Tube Split Spoon
Texas Cone
Penetrometer
N
(HP)
(T)
(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
SAMPLING WATER LEVEL FIELD TESTS
GENERAL NOTES
DESCRIPTION OF SYMBOLS AND ABBREVIATIONS
Water levels indicated on the soil boring logs are
the levels measured in the borehole at the times
indicated. Groundwater level variations will occur
over time. In low permeability soils, accurate
determination of groundwater levels is not possible
with short term water level observations.
Water Initially
Encountered
Water Level After a
Specified Period of Time
Water Level After
a Specified Period of Time
Cave In
Encountered
Exploration point locations as shown on the Exploration Plan and as noted on the soil boring logs in the form of Latitude and
Longitude are approximate. See Exploration and Testing Procedures in the report for the methods used to locate the
exploration points for this project. 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.
LOCATION AND ELEVATION NOTES
Soil classification as noted on the soil boring logs is based Unified Soil Classification System. Where sufficient laboratory data
exist to classify the soils consistent with ASTM D2487 "Classification of Soils for Engineering Purposes" this procedure is used.
ASTM D2488 "Description and Identification of Soils (Visual-Manual Procedure)" is also used to classify the soils, particularly
where insufficient laboratory data exist to classify the soils in accordance with ASTM D2487. In addition to USCS classification,
coarse grained soils are classified on the basis of their in-place relative density, and fine-grained soils are classified on the basis
of their consistency. See "Strength Terms" table below for details. The ASTM standards noted above are for reference to
methodology in general. In some cases, variations to methods are applied as a result of local practice or professional judgment.
DESCRIPTIVE SOIL CLASSIFICATION
The soil boring logs contained within this document are intended for application to the project as described in this document.
Use of these soil boring logs for any other purpose may not be appropriate.
RELEVANCE OF SOIL BORING LOG
STRENGTH TERMS
Standard Penetration or
N-Value
Blows/Ft.
Descriptive Term
(Density)
Hard
15 - 30Very Stiff> 50Very Dense
8 - 15Stiff30 - 50Dense
4 - 8Medium Stiff10 - 29Medium Dense
2 - 4Soft4 - 9Loose
0 - 1Very Soft0 - 3Very Loose
(50% or more passing the No. 200 sieve.)
Consistency determined by laboratory shear strength testing, field visual-manual
procedures or standard penetration resistance
> 30
Descriptive Term
(Consistency)
Standard Penetration or
N-Value
Blows/Ft.
(More than 50% retained on No. 200 sieve.)
Density determined by Standard Penetration Resistance
CONSISTENCY OF FINE-GRAINED SOILSRELATIVE DENSITY OF COARSE-GRAINED SOILS
UNIFIED SOIL CLASSIFICATION SYSTEM
UNIFIED SOIL CLASSIFICATION 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 [Cc<1 or Cc>3.0] 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 [Cc<1 or Cc>3.0] E SP Poorly graded sand I
Sands with Fines:
More than 12% fines D
Fines classify as ML or MH SM Silty sand G, H, I
Fines classify as CL or CH SC Clayey sand G, H, I
Fine-Grained Soils:
50% or more passes the
No. 200 sieve
Silts and Clays:
Liquid limit less than 50
Inorganic: PI 7 and plots on or above “A”
line J
CL Lean clay K, L, M
PI 4 or plots below “A” line J ML Silt K, L, M
Organic: Liquid limit - oven dried 0.75 OL Organic clay K, L, M, N
Liquid limit - not dried Organic silt K, L, M, O
Silts and Clays:
Liquid limit 50 or more
Inorganic: PI plots on or above “A” line CH Fat clay K, L, M
PI plots below “A” line MH Elastic Silt K, L, M
Organic: Liquid limit - oven dried 0.75 OH Organic clay K, L, M, P
Liquid limit - not dried Organic silt K, L, M, Q
Highly organic soils: Primarily organic matter, dark in color, and organic odor PT Peat
A Based on the material passing the 3-inch (75-mm) sieve.
B If field sample contained cobbles or boulders, or both, add “with cobbles
or boulders, or both” to group name.
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 =
6010
2
30
DxD
)(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.