2019-135 Park 7 Environmental AssessmentDate: June 28, 2019 Report No. 2019-135
INFORMAL STAFF REPORT
TO MAYOR AND CITY COUNCIL
SUBJECT: Provide information about the proposed Park 7 development and concerns raised by residents and neighbors.
EXECUTIVE SUMMARY: Staff have researched the concerns raised by residents in the Scripture and Normal Street area
about the Park 7 development. Council Member Armintor also expressed concerns and requested
an update on the environmental and engineering aspects of the project, including an evaluation of
the risks of building in an area with groundwater. Site development has commenced with an
anticipated completion within the next eighteen to twenty-four months.
The concerns are related to the construction of an apartment complex and the presumed impacts
from this construction. Concerns shared with staff include the construction of a multi-story below-
grade parking garage; confirmation of the existence of aquifers in the area; impacts to the aquifers
and existing water wells located near the construction site; potential contamination of groundwater
with asbestos; and impacts to old gas lines during the construction of the below-grade parking
garage.
Staff found that these concerns can be addressed by providing information about the layout and
design of the parking garage, the geological characteristics of the aquifers in Denton, the findings
of the project’s geotechnical report and measures taken during the removal of building material
containing asbestos. The Texas Water Development Board (TWDB), the North Texas
Groundwater Conservation District, and a hydrogeologist were consulted in the preparation of this
report.
BACKGROUND:
Aquifers and water wells in Denton
In general, an aquifer is a rock layer that contains water and releases it in appreciable amounts.
The rock contains water-filled pore spaces, and when the spaces are connected, the water is able
to flow through the matrix of the rock. An aquifer may also be called a water-bearing stratum, lens,
or zone. Aquifers are further classified as confined or unconfined aquifers. The Trinity Aquifer, a
major aquifer, extends across much of central and northeastern parts of Texas. It is composed of
several smaller (minor) aquifers contained within the Trinity Group. Although referred to
differently across the state, they include the Antlers, Glen Rose, Paluxy, Twin Mountains, Travis
Peak, Hensell, and Hosston aquifers. These aquifers consist of limestones, sands, clays, gravels,
and conglomerates. Their combined freshwater saturated thickness averages about 600 feet in
North Texas and about 1,900 feet in Central Texas (US Geological Survey).
Date: June 28, 2019 Report No. 2019-135
The Paluxy, Antlers, Twin Mountains, and Woodbine aquifers run through Denton Country at
different elevations (Attachment 1). The Washita Group formation lays on top of the Paluxy
aquifer, serving as a cap or barrier along the top of the aquifer, making the two formations
hydrologically disconnected from each other (Attachment 2). In other words, any water percolating
through the Washita Group formation would not enter into the Paluxy aquifer. Water enters an
aquifer in an area known as the recharge zone. The recharge zones for the Antler, Paluxy, and the
Twin Mountain aquifers are located in Wise County (Bridgeport –Decatur area) (Attachment 3).
Many of the water wells drilled in Denton tap into the Paluxy aquifer.
In contrast with surface water, landowners own the groundwater beneath the land, pursuant to Tex.
Water Code §36.002(a). The Texas Water Development Board and regional groundwater
conservation districts (GCDs) oversee the use and management of groundwater in the state.
Denton is part of the North Texas GCD.
Parking garage layout and design
As proposed, the Park 7 site will be developed with a multi-story structure and parking garage with
two levels of subsurface parking in accordance with the Denton Development Code. According to
the September 14, 2018 Geotechnical Report (Attachment 4), construction requires excavating
from two to 24 feet across the footprint of the main building pad and the parking garage. The site
is currently at an elevation of 706 feet above sea level and the lowest point of the excavation would
reach approximately elevation 672 feet. The Paluxy Aquifer upper boundary is located at an
elevation of 500 feet. Therefore, there is an approximately 172 foot separation between the lowest
excavation point and the upper boundary of the Paluxy Aquifer. It is also important to note that
the excavation will take place in the Washita Group, a geological formation located above the
Paluxy Aquifer that is hydrologically disconnected from the aquifer underneath. Any water
percolating through the ground at the site would not enter into the Paluxy Aquifer, nor would the
excavation change the flow patterns within the Paluxy Aquifer formation or affect any existing
water wells.
Groundwater contamination by asbestos
Even though the human digestive system can be exposed to asbestos fibers from drinking water
and mucous cleared from the lungs, breathing asbestos-containing air into the lungs is the most
concerning type of asbestos exposure. In Texas, the Department of State Health Services requires
performing a survey to determine the presence of asbestos before conducting a building renovation
or demolition. If confirmed, abatement of asbestos must be conducted by a licensed asbestos
contractor. As a part of the City building permit process, the City requires certification that these
procedures have been followed. Demolition permits for 1401 and 1519 Scripture indicated that
asbestos was found in the adhesive of floor tiles and joint compound used on dry walls. The
applicant provided a copy of the asbestos abatement report from a licensed asbestos contractor.
The report documented the process of removing the construction materials containing asbestos and
Date: June 28, 2019 Report No. 2019-135
adherence to the proper protocol. Based on this information, there is no evidence of potential
groundwater contamination with asbestos associated with demolition work and subsequent
construction of the Park 7 apartments.
Impacts to gas lines
The replat for the Park 7 apartments was approved in August 2017. The plat shows no existing gas
easements on the property (Attachment 5). Staff has notified Atmos about the proposed
development and have requested information concerning any gas lines on the site. Atmos has also
stated that they will examine their infrastructure in the area.
CONCLUSION: Staff finds no evidence that the excavation for the below-grade parking garage would negatively
impact the Paluxy Aquifer. The depth information provided in the Geotechnical Report combined
with the isolation provided by the Washita Group indicates that the proposed activity does not pose
a risk to the underlying aquifer. Denton staff discussed the issue with staff at the North Texas
Groundwater Conservation District, which is the regulatory entity for groundwater protection in
this area, and staff at the District agreed with this finding. Proper procedures were followed during
the abatement of asbestos prior to building demolition on the site. Site information did not indicate
any gas line easements on the property, and Atmos staff has been informed of the development
and will assess infrastructure in the area.
ATTACHMENT(S): 1. Geologic Cross Section of the Trinity Aquifer for Wise, Denton, and Collin Counties 2. Geologic Cross Section of the Paluxy Aquifer for Decatur – Denton Corridor 3. Paluxy Recharge and Aquifer Zones Map
4. September 14, 2018 Geotechnical Report 5. Park 7 Final Replat
STAFF CONTACT: Deborah Viera Assistant Director of Environmental Services 940.349.7162 Deborah.Viera@cityofdenton.com
REQUESTOR: Council Member Armintor
PARTICIPTAING DEPARTMENTS: Environmental Services, Utilities Administration, Development Service, City Attorney’s Office, and City Manager’s Office
STAFF TIME TO COMPLETE REPORT: 40 Hours
ATTACHMENT 1
Geologic Cross Section of the Trinity Aquifer for Wise, Denton, and Collin Counties
ATTACHMENT 2
Geologic Cross Section of the Paluxy Aquifer for Decatur – Denton Corridor
Denton Decatur
ATTACHMENT 3
Paluxy Aquifer
Recharge Aquifer Zone
Geotechnical Engineering Report
Park Place
Denton, Texas
September 14, 2018
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TABLE OF CONTENTS
1.0 PROJECT DESCRIPTION ................................................................................................... 1
2.0 PURPOSE AND SCOPE ..................................................................................................... 2
3.0 FIELD AND LABORATORY INVESTIGATION .................................................................... 3
3.1 General .......................................................................................................................... 3
3.2 Laboratory Testing ......................................................................................................... 4
3.2.1 Unconfined Compression Tests ............................................................................ 5
3.2.2 Overburden Swell Tests ........................................................................................ 5
3.2.3 Direct Shear .......................................................................................................... 5
4.0 SITE CONDITIONS .............................................................................................................. 5
4.1 Stratigraphy .................................................................................................................... 5
4.2 Groundwater .................................................................................................................. 7
5.0 ENGINEERING ANALYSIS ................................................................................................. 8
5.1 Estimated Potential Vertical Movement (PVM) .............................................................. 8
6.0 FOUNDATION RECOMMENDATIONS ............................................................................... 8
6.1 Straight-sided Drilled Shafts ........................................................................................... 8
6.1.1 Lateral Load Parameters ..................................................................................... 10
6.1.2 Drilled Shaft Construction Considerations ........................................................... 11
6.1.3 Pier-Supported Grade Beams ............................................................................. 12
6.2 Soil-Supported Floor Slab ............................................................................................ 13
6.3 Floor Slab Sub-Drain System ....................................................................................... 13
7.0 EARTHWORK RECOMMENDATIONS ............................................................................. 13
7.1 Soil Preparation for Grade-supported Floor Slabs ....................................................... 14
7.2 Additional Considerations ............................................................................................ 15
8.0 BASEMENT RECOMMENDATIONS ................................................................................. 15
8.1 Below Grade Walls ....................................................................................................... 15
8.2 Wall Drainage ............................................................................................................... 17
8.3 Wall Backfill .................................................................................................................. 17
9.0 PAVEMENT RECOMMENDATIONS ................................................................................. 18
9.1 General ........................................................................................................................ 18
9.2 Behavior Characteristics of Expansive Soils Beneath Pavement ................................ 18
9.3 Subgrade Strength Characteristics .............................................................................. 18
9.4 Pavement Subgrade Preparation Recommendations .................................................. 19
9.4.1 Aggregate Base .................................................................................................. 20
9.5 Rigid Pavement ............................................................................................................ 21
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9.6 Pavement Joints and Cutting ....................................................................................... 21
9.7 Pavement Reinforcing Steel ......................................................................................... 22
OTHER CONSTRUCTION ................................................................................................. 22
10.1 Utility and Service Lines ............................................................................................. 22
10.2 Exterior Flatwork ........................................................................................................ 22
10.3 Surface Drainage ....................................................................................................... 23
10.4 Landscaping ............................................................................................................... 23
10.5 Site Grading ............................................................................................................... 24
10.6 Excavations ................................................................................................................ 24
SEISMIC CONSIDERATION ............................................................................................. 25
LIMITATIONS ..................................................................................................................... 25
APPENDIX A – BORING LOGS AND SUPPORTING DATA
APPENDIX B – GENERAL DESCRIPTION OF PROCEDURES
1
GEOTECHNICAL INVESTIGATION
PARK PLACE DENTON
DENTON, TEXAS
1.0 PROJECT DESCRIPTION
This report presents the results of the geotechnical investigation for the proposed Park
Place Denton, a student housing facility. The new facility will be located on the southeast
corner of the intersection of Scripture Street and Normal Street in Denton, Texas. The new
development will be a podium style structure with the residential units partially wrapping
around a new parking garage. The north portion of the site will be developed with one
below grade parking garage level, and 5 stories of apartments above it. A courtyard will
be constructed on the ground floor level above the parking garage with the residential
units wrapping around it. The south portion of the site will be developed with a six-story
parking garage, including two below-grade levels, an outdoor pool area on the upper level,
and four stories of apartments on the west side of the parking garage. The overall
development will have a footprint of about 77,000 square feet.
The site is currently developed with several commercial and residential structures and
associated pavements. The structures were not razed prior to the geotechnical
investigation. Based on the NCTCOG dfwmaps.com and available structural site and
layout plan, Park7 Group, dated March 9, 2018, the overall site slopes from the northeast
corner down to the southwest corner, with an overall topographic relief on the order of 10
feet. The overall site requires cuts on the order of 2 to 24 feet to accommodate below
grade stories, and fills on the order of 2 to 6 feet to reach final finished floor elevations at
other portions of the site. Photographs showing the recent site condition are presented
below.
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2.0 PURPOSE AND SCOPE
The purpose of this investigation was to:
Identify the subsurface stratigraphy present at the site.
Evaluate the physical and engineering properties of the subsurface soil and
bedrock strata for use in the geotechnical analyses.
Provide geotechnical recommendations for use in the design of foundations,
pavements and below grade walls for the new facility.
The scope of this investigation consisted of:
Drilling and sampling a total of nine (9) borings, advanced within the building
footprint to depths of 50 to 70 feet.
Laboratory testing of selected soil and bedrock samples obtained during the field
investigation.
Preparation of a Geotechnical Report that includes the following:
o Evaluation of Potential Vertical Movement (PVM)
o Recommendations for the design of foundations
o Recommendations for earthwork
o Recommendations for pavement design
o Recommendations for below grade walls
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3.0 FIELD AND LABORATORY INVESTIGATION
3.1 General
The borings were advanced utilizing a truck-mounted drilling equipment outfitted with
hollow stem flight augers. Undisturbed samples of cohesive soils and weathered
bedrock strata were obtained using 3-inch diameter tube samplers, which were
advanced into the soils in 1-foot increments by the continuous thrust of a hydraulic
ram located on the drilling equipment. After sample extrusion, a hand penetrometer
measurement was performed on each cohesive soil sample to provide an estimate of
soil stiffness.
Soil and bedrock materials were also intermittently tested in-situ using cone
penetration tests in order to determine their resistance to penetration. For this test, a
3-inch diameter steel cone is driven by the energy equivalent of a 170-pound hammer
falling freely from a height of 24 inches and striking an anvil located at the top of the
drill string. Depending on the resistance of the soil and bedrock materials, either the
number of blows of the hammer required to provide 12 inches of penetration is
recorded (as two increments of 6 inches each), or the inches of penetration of the
cone resulting from 100 blows of the hammer are recorded (as two increments of 50
blows each).
Soils and bedrock materials were sampled in general accordance with the Standard
Penetration Test (ASTM D1586). During this test, a disturbed sample of subsurface
material is recovered using a nominal 2-inch O.D. split-barrel sampler. The sampler
is driven into the soil strata utilizing the energy equivalent of a 140-pound hammer
falling freely from a height of 30 inches and striking an anvil located at the top of the
drill string. The number of blows required to advance the sampler in three consecutive
6-inch increments is recorded, and the number of blows required for the final 12
inches is noted as the “N”-value. The test is terminated at the first occurrence of either
of the following: 1) when sampler has advanced a total of 18 inches; 2) When the
sampler has advanced less than one complete 6-inch increment after 50 blows of the
hammer; 3) when the total number of blows reaches 100; or 4) if there is no
advancement of the sampler in any 10-blow interval.
Bedrock strata in four of the structure borings were near-continuously cored using a
double-tube core barrel fitted with a tungsten-carbide, saw-tooth bit. The length of
core recovered (REC), expressed as a percentage of the coring interval, along with
the Rock Quality Designation (RQD), is tabulated at the appropriate depths on the
Log of Boring illustrations. The RQD is the sum of all core pieces longer than four
inches divided by the total length of the cored interval. Core pieces shorter than four
inches which were determined to be broken by drilling or by handling were fitted
together and considered as one piece.
All samples obtained were extruded in the field, placed in plastic bags to minimize
changes in the natural moisture condition, labeled according to the appropriate boring
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number and depth, and placed in protective cardboard boxes for transportation to the
laboratory. The approximate locations of the borings performed at the site are shown
on the boring location map that is included in Appendix A. Existing ground elevation
of boreholes are included in the boring logs using available topographic maps in
dfwmaps.com. The specific depths, thicknesses and descriptions of the strata
encountered are presented on the individual Boring Log illustrations, which are also
included in Appendix A. Strata boundaries shown on the boring logs are approximate.
3.2 Laboratory Testing
Laboratory tests were performed to identify the relevant engineering characteristics
of the subsurface materials encountered and to provide data for developing
engineering design parameters. The subsurface materials recovered during the field
exploration were initially logged by the drill crew and were later described by a
Geotechnical Engineer in the laboratory. These descriptions were later refined by a
Geotechnical Engineer based on results of the laboratory tests performed. All
recovered soil samples were classified and described in part using the Unified Soil
Classification System (USCS) and other accepted procedures. Bedrock strata were
described using standard geologic nomenclature.
In order to determine soil characteristics and to aid in classifying the soils, index
property and classification testing were performed on selected soil samples as
requested by the Geotechnical Engineer. These index property and classification
tests were performed in general accordance with the following ASTM testing
standards:
Moisture Content ASTM D2216
Atterberg Limits ASTM D4318
Percentage of Particles Finer than No. 200 Sieve ASTM D1140
Additional tests were performed to aid in evaluating strength and volume change
which consisted of the following:
Unconfined Compressive Strength of Soil ASTM D2166
Unconfined Compressive Strength of Rock Cores ASTM D7012
Direct Shear ASTM D3080
Overburden Swell Testing
The results of index property, strength, and swell tests are presented at the
corresponding sample depths on the appropriate Boring Log illustrations. The index
property and classification testing procedures are described in more detail in
Appendix B.
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3.2.1 Unconfined Compression Tests
Unconfined compressive strength testing was performed on selected soil
samples and sections of intact bedrock cores. These tests were performed in
general accordance with ASTM D2166 Method for soil samples and ASTM
D7012 Method C for selected bedrock core samples. During each test, a
cylindrical specimen is subjected to an axial load that is applied at a constant
rate of strain until either failure or a large strain (i.e., greater than 15 percent)
occurs. Once the test is completed, the unit weight of the sample is determined
based on the moisture content.
3.2.2 Overburden Swell Tests
Selected samples of the near-surface soil were subjected to overburden swell
testing. For this test, a sample is placed in a consolidometer and subjected to
the estimated overburden pressure. The sample is then inundated with water
and is allowed to swell. The moisture content of the sample is determined both
before and after completion of the test. Test results are recorded, including the
percent swell and the initial and final moisture contents.
3.2.3 Direct Shear
Direct shear tests were performed on selected soil samples. Those tests
were performed in general accordance with ASTM D3080. The test
consists of placing a sample of relatively undisturbed soil and subjecting it
to full saturation and consolidation. A shear force is then applied on the
sample at a rate appropriate to maintain drained soil conditions. Test
results are recorded and plotted in a shear stress vs. horizontal
deformation graph, from where peak stress is calculated. A graph of shear
stress vs. normal stress allows computation of cohesion and friction angle
values.
4.0 SITE CONDITIONS
4.1 Stratigraphy
Based upon a review of the recovered samples, as well as the Geologic Atlas of
Texas, Sherman Sheet, this site is characterized by soil and bedrock strata
associated with both the Woodbine Formation, and the undivided Grayson Marl and
Main Street Limestone Formation.
At the surface within Borings B1 through B5 and B9, 4 to 8 inches thick asphalt
pavements sections were observed.
Beneath the asphalt layer within Borings B3 and B5 and at the ground surface within
Borings B6 and B7, clay fill soils are present. The fill soils are stiff to very stiff in
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consistency, are various shades of brown and gray in color, and contain variable
amounts of aggregate fragments and sand.
Below the fill soils within Borings B3, B5, B6, and B7, beneath the asphalt sections
within Borings B1, B2, and B4, and at the ground surface within Borings B8 and B9,
clay, sand and silt soils mixed at variable composition were encountered. The
cohesive clay and silt soils are stiff to very stiff in consistency, are various shades of
brown and gray, and red in color, and contain variable amounts of calcareous
nodules, iron oxide stains, and iron oxide nodules. The granular (sand) soils are
medium dense to very dense in condition, are various shades of brown and gray in
color and contain variable amounts of iron oxide stains. The overburden soils extend
to depths of about 13 to 20 feet.
Below the overburden soils within Borings B1 through B5, sandstone bedrock strata
are present, which extend to depths of about 20 to 34 feet. The sandstone bedrock
strata are very weakly cemented, are very soft to soft in rock hardness, are various
shades of brown and gray in color and contain variable amounts of very thin shale
seams.
The overburden soils within Borings B6 through B9, and the sandstone bedrock strata
within Borings B3 through B5, are underlain by weathered shale bedrock strata. The
weathered shale are very soft to medium hard in rock hardness, are various shades
of brown and gray in color and possess fissile structure. The weathered shale strata
extend to depths of about 23 to 36 feet.
Below the sandstone strata within Borings B1 and B2, and beneath the weathered
shale strata within Borings B3 through B9, fresh shale bedrock strata are present.
The fresh shale are soft to medium hard in rock hardness, are gray and dark gray in
color, contain variable amounts of very thin limestone seams and possess fissile
structure. The fresh shale extends to depths of about 40 to 60 feet within Borings B2,
B3, and B5 through B8 and to the maximum depth explored of about 50 to 60 feet
within Borings B1, B4 and B9.
The fresh shale strata are underlain by fresh limestone bedrock strata within Borings
B2, B3, and B5 through B8 and extend to the maximum depths explored of about 60
to 70 feet. The limestone bedrock strata are moderately hard to hard in rock hardness,
are gray and dark gray in color and contain variable amounts of very thin to thin shale
seams.
Subsurface stratigraphy of the borings is provided in Table 1. Table 2 lists the
approximate boring elevations for existing and final grades with estimated cut depths
near the adjacent boreholes for below grade stories by borehole location.
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Table 1. Subsurface Stratigraphy (Building Borings B1 through B9)
Boring No.
Approximate
Top of
Sandstone
Elevations
(MSL)
Approximate Top
of Fresh Gray
Shale Elevations
(MSL)
Approximate Top
of Fresh Gray
Limestone
Elevations (MSL)
Depth of
Boring
(ft.)
B1 EL 691 EL 672 NE 50
B2 EL 689 EL 679 EL 659 60
B3 EL 687 EL 679 EL 642 70
B4 EL 688 EL 678 EL 669 60
B5 EL 687 EL 679 EL 657 70
B6 NE EL 670 EL 661 60
B7 NE EL 664 EL 645 60
B8 NE EL 661 EL 651 70
B9 NE EL 669 NE 60
* NE = Not Encountered
Table 2. Estimated Existing and Final Grade
Boring ID Estimated Existing
Grade Elevation (MSL)
Estimated Final Grade
Elevation (MSL)
Approx. Cut
Depth (ft.)
B1 706 704 2
B2 702 690 12
B3 702 690 12
B4 702 690 12
B5 702 690 12
B6 701 690 11
B7 700 690 10
B8 696 672 24
B9 698 675 21
4.2 Groundwater
Groundwater seepage was observed during drilling operations within Borings B1, B2,
B4, B5, B8 and B9 at depths of about 14 to 26 feet. Upon completion of drilling
operations, groundwater was observed within Boring B9 at a depth of about 14 feet.
Borings B3 and B6 was observed to be dry prior to the introduction of drilling fluids at
20 feet. However, groundwater is often contained within the joints, fractures and other
rock mass defects present in bedrock strata. When intercepted, these defects can
produce appreciable amounts of water for a period of time, especially if those defects
are extensive and well inter-connected.
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5.0 ENGINEERING ANALYSIS
5.1 Estimated Potential Vertical Movement (PVM)
Potential Vertical Movement (PVM) was evaluated utilizing different methods for
predicting movement, as described in Appendix B, and based on our experience and
professional opinion.
At the time of our field investigation, the overburden soils were generally found to be
dry in moisture condition. Based upon the results of our analysis, the surficial soils of
the site to depths of about 13 to 20 feet are estimated to possess a PVM on the order
of 1-inch at the soil moisture conditions existing at the time of the field investigation.
However, where cuts extend to or encroach on weathered shale materials, PVM
values can approach 2 inches at the soil moisture conditions existing at the time of
the field investigation. Dry, average and wet are relative terms based on moisture
content and plasticity.
In the areas of anticipated fill, PVM will be limited to 1-inch or less when the earthwork
recommendations presented herein are adhered to.
Settlements for structural elements supported on subgrade soils prepared as outlined
in this report should be less than ½-inch.
6.0 FOUNDATION RECOMMENDATIONS
The near-surface soils present at the site have a low potential for post-construction vertical
movement with changes in soil moisture content. Considering the extent of cuts and fills
across the site, the types of structures, estimated loading intensities, and the anticipated
subsurface soil conditions, we recommend that the building be supported on a drilled shaft
foundation system using a soil supported floor slab system. If potential movements noted
herein cannot be tolerated, consideration should be given to a structurally supported floor
slab.
Please note that due to the proximity of bedrock after proposed site grading, portions of
certain structural elements will require some measure of rock excavation to install those
elements.
6.1 Straight-sided Drilled Shafts
We recommend that structural loads for the new building and other movement-
sensitive structures be supported on auger-excavated, straight-sided, reinforced
concrete drilled shafts. Depending on loading requirements, these shafts should be
founded in bedrock strata suitable to the required loading. We recommend that
straight-sided drilled piers for structural loads be a minimum of 18 inches in diameter
and should be proportioned as outlined in Table 3.
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Straight-sided drilled shafts may be designed to transfer imposed loads into the
bearing stratum using a combination of end-bearing and skin friction. Drilled shafts
should be designed for an allowable end bearing and side friction as outlined in Table
3 below for the new facility. Due to strain incompatibility, for shafts penetrating
sandstone materials and terminating into shale strata, the lower skin friction value for
shale should be used for both the sandstone and shale. Also due to strain
incompatibility, where shafts penetrate and terminate into limestone strata, the
allowable skin friction in any overlying sandstone or shale strata should be reduced
to 1,500 psf for design purposes.
The allowable side frictions noted in Table 3 may be taken from the top of the bedrock
or from the bottom of any temporary casing used, whichever is deeper, to resist both
axial loading and uplift.
Table 3. Drilled Shaft Allowable Bearing Parameters
Bearing Material Approx. Elevation
Range
Allowable Skin
Friction (psf)
Allowable End
Bearing (psf)
Sandstone 687 to 691 4,500 40,000
Fresh Shale 661 to 679 3,000 25,000
Fresh Limestone 642 to 661 6,500 60,000
The shafts should be provided with sufficient steel reinforcement throughout their
length to resist potential uplift pressures that will be exerted. For the near-surface
soils at their current moisture condition, these pressures are estimated to be
approximately 750 psf over an average depth of 10 feet where fills are less than 3
feet. Where fills exceed 3 feet and are placed in accordance with the
recommendations contained herein, these pressures reduce to 500 psf for the fill. In
areas of deep cuts, these pressures reduce to 100 psf when cuts extend to within 2-
feet of or into bedrock strata. Typically, one-half (½) of a percent of steel by cross-
sectional area is sufficient for this purpose (ACI 318). However, the final amount of
reinforcement required should be determined based on the information provided
herein and should be the greater of that determination, or ACI 318. Uplift forces acting
on individual shafts will be resisted by the dead weight of the structure, plus the
bearing stratum-to-concrete adhesion acting on that portion of the shaft that is in
contact with the limestone strata.
There is no reduction in allowable capacities for shafts in proximity to each other.
However, for a two-shaft system, there is an 18 percent reduction in the available
perimeter area for side friction capacity for shafts in contact (tangent). The area
reduction can be extrapolated linearly to zero at one shaft diameter clear spacing.
Please contact this office if other close proximity geometries need to be considered.
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We anticipate that a straight-sided drilled pier foundation system designed and
constructed in accordance with the information provided in this report will have a
factor of safety in excess of 2.5 against shear failure and may experience settlements
of small fractions of an inch.
6.1.1 Lateral Load Parameters
The subsurface stratigraphy across the site is variable. Because of this
topographic variation and the resultant cuts and fills, a single “representative
stratigraphy” is not provided. Instead of a range strata thicknesses based on
anticipated top of shaft elevations are provided in the tables below, together
with appropriate LPILE™ material parameters for each type of material. These
parameters were selected to conservatively approximate the subsurface
conditions across the site.
Table 4. Subsurface Material – LPILE™ Designations
Stratum Thickness
(ft)
Software Material
Designation
Unit Weight
(pcf)
CLAY, various shades of brown
(native and grade-raise fill) 4 - 20 Stiff Clay w/o Free
Water 115
SAND, various shades of brown 3.5 - 15 Sand 110
SANDSTONE, very weakly
cemented, gray 20 - 34 Weak Rock 125
SHALE, weathered, various
shades of brown and gray 3 – 22 Weak Rock 120
SHALE, fresh, gray, dark gray 9 – 40+ Weak Rock 125
LIMESTONE, fresh, gray 10 – 25+ Strong Rock 135
Table 5. Recommended Geotechnical Lateral Load Parameters
Depth Range (ft.) Software Material
Designation
Friction Angle
(degrees)
Soil Modulus
(pci)
2 - 5 Sand 27 120
5 – 10+ Sand 33 110
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Table 6. Recommended Geotechnical Lateral Load Parameters
Software
Material
Designation
Undrained
Cohesion
(psf)
Unconfined
Compressive
Strength – Rock (psi)
Modulus
(psi) RQD
Strain
Factor
ε50
Stiff Clay w/o
Free Water 1,000 NA NA NA 0.015
Weak Rock NA 150 10,000 90 0.003
Strong Rock NA 750 NA NA NA
6.1.2 Drilled Shaft Construction Considerations
Groundwater seepage was encountered within Borings B1, B2, B4, B5, B8 and
B9 during drilling operations or at the completion of drilling. However,
groundwater may be encountered when rock mass defects are intercepted
during excavations. The amount of water present in rock mass defects may
fluctuate over time. Temporary casing will likely be necessary at many shaft
locations, and should be locally available on site in the event that excessive
groundwater seepage is encountered that cannot be controlled with
conventional pumps, sumps, or other means, or in the event that excessive
sidewall sloughing occurs.
A licensed Engineer should be present on the first day of drilled shaft
installations to verify compliance with design assumptions including 1)
verticality of the shaft excavation, 2) identification of the bearing stratum, 3)
minimum pier diameter and depth, 4) correct amount of reinforcement, 5)
proper removal of loose material, and 6) that groundwater seepage, if present,
is properly controlled. Subsequent installations of all other drilled shafts should
be observed by experienced technical personnel under the direction of a
licensed geotechnical engineer to verify compliance of the same. D&S would
be pleased to provide these services.
During construction of the drilled shafts, care should be taken to avoid creating
an oversized cap ("mushroom") near the ground surface that is larger than the
shaft diameter. These “mushrooms” provide a resistance surface that near-
surface soils can heave against. If near-surface soils are prone to sloughing,
(a condition which can result in “mushrooming”), the tops of the shafts should
be formed in the sloughing soils using cardboard or other circular forms equal
to the diameter of the shaft.
Concrete used for the shafts should have a slump of 8 inches ± 1 inch.
Individual shafts should be excavated in a continuous operation and concrete
should be placed as soon after completion of the drilling as is practical. All pier
holes should be filled with concrete within 8 hours after completion of drilling.
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In the event of equipment breakdown, any uncompleted open shaft should be
backfilled with soil to be redrilled at a later date. This office should be contacted
when shafts have reached the target depth but cannot be completed.
6.1.3 Pier-Supported Grade Beams
In fill areas, or areas constructed near existing grades, structural cardboard
carton forms (void boxes) should be used to provide a minimum 4-inch void
beneath the grade beams; however, trapezoidal void boxes should not be
used. Where grade beams extend into bedrock, void boxes and side retainers
should not be required. Care should be taken to assure that the void boxes are
not allowed to become wet or crushed prior to or during concrete placement
and finishing operations. We recommend that masonite or other protective
material be placed on top of the carton forms per carton form manufacturer
recommendations to reduce the risk of crushing the cardboard forms during
concrete placement and finishing operations. We recommend using side
retainers along grade beams constructed in clay materials to prevent soil from
infiltrating the void space after the carton forms deteriorate. The bottoms of all
grade beam excavations should be essentially free of any loose or soft material
prior to the placement of concrete.
Due to the depth of bedrock, the proposed Finished Floor Elevations and site
grading planned at the new facility, large segments of grade beams for that
structure are likely to require some depth of shale or sandstone bedrock
excavation to achieve design grades. Grade beams in these areas, if utilized,
may bear directly on the bedrock or on a thin (less than 3-inch thick) bed of
leveling material. In either case a bond breaker such as poly sheeting or other
suitable material should be placed between the bearing surface and the grade
beam.
Grade beams in soil materials should be formed. Grade beams in the bedrock
may be neat cut and placed without forming. The exterior side of the grade
beams around the structure should be carefully backfilled with on-site clayey
soils. The backfill soils should be compacted to at least 95 percent of the
maximum dry density, as determined by ASTM D698 (standard Proctor), and
should be placed at a moisture content that is either at or above the optimum
moisture, as determined by the same test. This fill should extend the full depth
of the grade beam plus void space and should extend a minimum distance of
2 feet away from the exterior grade beam perimeter. All grade beams and floor
slabs should be adequately reinforced to minimize cracking as normal
movements occur in the foundation soils.
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6.2 Soil-Supported Floor Slab
A soil-supported floor system that is placed directly on the subgrade will be subjected
to potential vertical movement where elements are constructed near existing grades.
The majority of such movement is expected to occur in the perimeter 10 feet of the
building. We recommend that the subgrade be prepared according to the Earthwork
Recommendations section of this report in order to reduce the potential for post-
construction movement. The floor slab should be doweled to the beams at the
locations of the doors in order to prevent vertical steps from forming at these high-
traffic areas. We also recommend placing a moisture barrier, such as plastic sheeting,
under the soil supported floor slab to mitigate the infiltration of moisture through the
concrete slab.
We anticipate for soil supported floor slab, reinforcement and concrete likely cannot
be placed the same day final excavation grades are achieved, the base of the
excavation may be deepened slightly and covered by a thin seal slab of lean concrete
or flowable fill to protect the integrity of the bearing material. The bottom of all
excavations should be free of any loose or soft material prior to the placement of
concrete. We recommend that an experienced technical personnel under the
direction of a licensed geotechnical engineer observe all excavations prior to placing
concrete to verify the excavation depth, cleanliness, and integrity of the mat bearing
surface. D&S would be pleased to provide these services.
6.3 Floor Slab Sub-Drain System
We recommend that below grade lowest level floor slabs may be designed for
drainage to resist hydrostatic uplift pressures and with a sub-drain system to release
hydrostatic uplift pressures by removing the water below the floor. The need to design
the floor to resist hydrostatic pressures depends on the effectiveness of the floor
drain. The floor sub-drains should be imbedded in permeable material with a minimum
12-inch thickness. Collector pipes should drain the collected water to a sump from
which the water would be pumped to a suitable discharge facility. Consideration
should be given to the installation of a backup pump to promote continuity of service
in the event the primary pump breaks down.
7.0 EARTHWORK RECOMMENDATIONS
Based on plans provided by Park7 Group (dated March 9, 2018), fills on the order of 6
feet are expected near the west portion of the main building pad in order to reach a finished
pad elevation of about EL 704 feet. The amount of fill required decreases to the east. As
shown, the new facility will also require cuts ranging from about 2 to 24 feet across the
footprint of the main building pad and the parking garage. Soil and sandstone or limestone
bedrock excavated during grading may be used as grade-raise fill within the new building
footprint, provided that those bedrock materials are reduced to a maximum particle size
of 6-inches (no shale bedrock materials). However, these materials should not be placed
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within 3-feet of final grade elevation where sidewalks or pavements are planned unless
they are reduced in size to 1-inch or less.
Earthwork recommendations for subgrade preparation for possible parking lots and grade-
supported floor slabs are presented below.
7.1 Soil Preparation for Grade-supported Floor Slabs
Strip the site of all vegetation, demolition debris, pavement materials and
remove any remaining organic or deleterious material including root balls, and
matted roots. Typically, 6 inches is sufficient for this purpose.
After stripping, perform any necessary cuts and fills. Prior to the placement of
any grade-raise fill, scarify the exposed soils to a depth of 12-inch and
recompact to at least 95% of the maximum dry density as determined by ASTM
D698, and to a moisture content that is at or above the optimum moisture
content as determined by that same test.
Where the excavations extend into weathered shale materials scarify, rework,
and recompact the exposed stripped subgrade to a depth of 12 inches. The
scarified and reworked soils should be compacted to between 92 to 96 percent
of the maximum dry density, as determined by ASTM D698 (standard Proctor),
and placed at a moisture content that is at least three (3) percent above the
optimum moisture content, as determined by the same test.
Grade-raise fill may consist of on-site or imported soils having a liquid limit less
than 40 and a plasticity index less than 25.
Place grade-raise fill to the bottom of floor slab elevation. Grade-raise fill should
be placed in maximum 8-inch thick compacted lifts and should be compacted to
a minimum of 95 percent of the maximum dry density as determined by ASTM
D698 (standard Proctor) and be placed at a moisture content that is at least one
(1) percent above the optimum moisture content, as determined by that same
test.
Water should not be allowed to pond on any prepared subgrade either during
fill placement, or after reaching final subgrade elevation. To that end, the
subgrade surfaces should be shaped to shed water to the edges of the
respective pads.
Place a minimum 15-mil thick vapor barrier beneath all grade-supported floor
slabs.
Each lift of fill should be tested for moisture content and degree of compaction
by a testing laboratory at a minimum rate of one test per 5,000 square feet per
lift for the building. D&S would be pleased to provide these services in support
of this project.
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7.2 Additional Considerations
The following are considered to be best practices to minimize the potential for post-
construction vertical movement.
Where possible, trees or shrubbery with a mature height greater than 6 feet
and/or that require excessive amounts of water should not be planted near
structures or flatwork.
We anticipate that local code may require tree plantings that may encroach on
pavements. To the extent possible, trees should not be planted closer than the
mature tree’s height from structures or flatwork.
Water should not be allowed to pond next to structure foundations, pavements
or other flatwork. Rainfall roof runoff should be collected and conveyed to
downspouts. Downspouts should be directed to discharge at least 5 feet away
from the foundations.
The moisture content of subgrade soils that are in proximity to the structures
should be maintained as close as possible to a consistent level throughout the
year. We strongly recommend that excessive watering near foundations be
avoided.
8.0 BASEMENT RECOMMENDATIONS
8.1 Below Grade Walls
Current plans provide for below grade walls for the basement parking garages. We
anticipate that the height of the below-grade walls will range from about 12 to 24 feet.
If open excavations are advanced to depths greater than 5 feet below grade, the
excavations should conform to applicable OSHA excavation safety requirements
using shoring or benching.
The temporary support of excavations and basement wall backfill requirements will
influence below grade wall design. Below grade walls should be designed as
restrained walls. The walls must be designed to resist both lateral earth pressures
and any additional lateral loads caused by live load. As the walls are below grade, at-
rest pressures will develop under long-term lateral loading. For temporary excavation
support, active, braced loading lateral pressure may be used. If practical, temporary
excavation support may be incorporated in the final basement wall design. Lateral
pressure on the walls must also consider hydrostatic forces, or a drainage system
should be provided. Lateral pressure calculations should assume a level backfill. A
minimum surcharge area load of 250 psf should be used for traffic loading adjacent
to the restrained walls.
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The design lateral earth pressures recommended herein assume at-rest conditions,
do not include a Factor of Safety, and do not provide for dynamic pressures on the
walls. Because of the hydraulic properties of non-free draining materials, the
“Drained” pressures provided below should only be used if there is no possibility of
water entering into the subgrade soils from whatever means. If that possibility cannot
be ruled out, then the “undrained” values should be used, at least for some height of
the backfill. Lateral loads due to surcharge should be calculated as shown in Table 7.
These loads need to be considered where appropriate.
Figure 1: Lateral Earth Pressure
Table 7. Earth Pressure Recommendations
Earth
Pressure
Conditions
Coefficient for
Backfill Type
Drained
Equivalent
Fluid Density
(pcf)
Undrained
Equivalent
Fluid Density
(pcf)
Surcharge
Pressure
(psf)
Earth
Pressure
(psf)
At-Rest (Ko)
Free Draining
Aggregate -
0.44
55 NA (0.44)S (EFD)H
Select Fill Soil –
0.58 72 99 (0.58)S (EFD)H
Common Fill/
On-site Soil –
0.69
86 106 (0.69)S (EFD)H
Applicable conditions to Table 7 above include:
Uniform surcharge, where S is surcharge pressure
EFD is Equivalent Fluid Density (drained or undrained as appropriate)
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Wall height (H) should be taken from the base of any unbalanced soil.
Soil backfill total unit weight with a maximum of 125 pounds per cubic foot (pcf)
Horizontal backfill, compacted a minimum of 95 percent of Standard Proctor
maximum dry density, or to a minimum of 70 percent relative density
Positive drainage is provided behind all below-grade walls to preclude
development of hydrostatic pressures in free draining backfill.
No loading contribution from compaction equipment
8.2 Wall Drainage
Positive drainage should be provided behind below grade walls to preclude
development of hydrostatic pressure behind the walls, and to prevent saturation of
backfill and foundation materials. We recommend using a vertical wall drainage layer
immediately behind the wall to control groundwater when fine-grained soils are used
as backfill. If free-draining sand or gravel is utilized as backfill behind the wall, a
vertical drainage layer is not required. Free-draining backfill should meet the
requirements of ASTM C-33, size numbers 57, 6, 67, 7, 8, 89 or 9. Filter fabric should
be placed between free-draining backfill and on-site retained or backfill soils.
We recommend that a perimeter drain, such as a perforated pipe drain, be installed
along the base of the fill behind the walls to rapidly remove water from behind the
wall. The perimeter drain should discharge collected water to a sump. Design of
perimeter drainage systems placed in areas where weathered shale materials are
present should consider the potential for movement due to expansive nature of these
materials.
8.3 Wall Backfill
Free-draining backfill materials should be placed in maximum 2-foot thick loose layers
and be consolidated by use of vibrating plates or sleds, light hand operated
compactors, or other appropriate methods to adequately consolidate the backfill.
Heavy compactors and grading equipment should not be allowed to operate within 5
feet of the walls during backfilling to avoid developing excessive temporary or long-
term lateral soil pressures. Select fill or on-site soil backfill materials should be placed
in six (6) inch thick compacted layers and be compacted to between 92 and 95
percent of the maximum dry density as determined from the Standard Proctor test
(ASTM D698).
For the granular earth pressure values to be valid, the granular backfill must extend
out from a point 2 feet from the back of the wall, then up at an angle of at least 0.6H:
1V or flatter.
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A qualified geotechnical engineer or geotechnical representative should be present
to monitor all foundation excavations and fill placement. D&S would be pleased to
provide these services in support of this project.
9.0 PAVEMENT RECOMMENDATIONS
9.1 General
The pavement design recommendations provided herein are derived from the
subgrade information that was obtained from our geotechnical investigation, design
assumptions based on project information, our experience with similar projects in this
area, and on the guidelines and recommendations of the American Concrete
Pavement Association (ACPA). It is ultimately the responsibility of the Civil Engineer
of Record and/or other design professionals who are responsible for pavement design
to provide the final pavement design and associated specifications for this project.
9.2 Behavior Characteristics of Expansive Soils Beneath Pavement
Near-surface soils at this site are considered to generally have low potential for
volume change with changes in soil moisture content. The moisture content can be
stabilized to some degree in these soils by covering them with an impermeable
surface, such as pavement. However, if moisture is introduced as a result of surface
water percolation or poor drainage, the soils can heave and/or soften, causing
distress to pavements in contact with the soil in the form of cracks.
The edges of pavement are particularly prone to moisture variations, and so,
therefore, these areas often experience the most distress. When cracks appear on
the surface of the pavement, these openings can allow moisture to enter the
pavement subgrade, which can lead to further weakening of the pavement section as
well as the accelerated failure of the pavement surface.
In order to minimize the potential impacts of expansive soil on paved areas
constructed near current grades and to improve the long-term performance of the
pavement, we have the following recommendations:
Subgrade treatments should be extended at least 18 inches beyond the back of
curbs or edges of pavements constructed at the surface near current grades.
Avoid long areas of low-sloping roadway and adjust adjacent slopes to provide
maximum drainage away from pavement edges.
9.3 Subgrade Strength Characteristics
We recommend for the native soils that a California Bearing Ratio (CBR) value of 3
be used in the design with a corresponding resilient modulus of 4,500 psi. For either
lime treated subgrade or compacted aggregate base, we recommend using a resilient
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modulus of 30,000 psi. We recommend using a Modulus of Subgrade Reaction (k) of
195 pci for the completed subgrade prepared in accordance with the
recommendations in this report.
9.4 Pavement Subgrade Preparation Recommendations
The anticipated subgrade soils will generally be clay soils in the proposed paving
areas which can become weak and pump with appreciable increases in moisture
content. A commonly used method for clay soils to reduce the potential for pumping,
improve the strength properties of the subgrade soils, and provide a working platform
which will provide a uniform subgrade for the aggregate base. Due to the relatively
small areas of at grade pavements planned at the site, we recommend using
aggregate base beneath the pavements. To that end, we have the following
recommendations:
Remove all pavements, surface vegetation, including tree root balls and root
mats, construction debris and similar unsuitable materials from within the
limits of the project. We anticipate a typical stripping depth of about 6 to 12
inches.
Perform any cut operations as-needed.
We anticipate that excavation of overburden soils can be accomplished with
conventional earthwork equipment and methods.
In areas to receive fill, the fill may be derived from on-site or may be
imported. The fill should be placed in maximum 8-inch compacted lifts,
compacted to at least 95 percent of the maximum dry density, as determined
by ASTM D698 (standard Proctor), and placed at a moisture content that is
at or above the optimum moisture content, as determined by the same test.
Prior to compaction, each lift of fill should first be processed throughout its
thickness to break up and reduce clod sizes and blended to achieve a
material of uniform density and moisture content. Once blended,
compaction should be performed with a heavy tamping foot roller. Once
compacted, if the surface of the embankment is too smooth, it may not bond
properly with the succeeding layer. If this occurs, the surface of the
compacted lift should be roughened and loosened by dicing before the
succeeding layer is placed.
Water required to bring the fill material to the proper moisture content should
be applied evenly through each layer. Any layers that become significantly
altered by weather conditions should be reprocessed in order to meet the
recommended requirements. On hot or windy days, the use of water
spraying methods may be required in order to keep each lift moist prior to
placement of the subsequent lift. Furthermore, the subsurface soils should
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be kept moist prior to placing the pavement by water sprinkling or spraying
methods.
Fill materials should be placed on a properly prepared subgrade as outlined
above. The combined excavation, placement, and spreading operation
should be performed in such a manner as to obtain blending of the material,
and to assure that, once compacted, the materials, will have the most
practicable degree of compaction and stability. Materials obtained from on-
site should be mixed and not segregated.
Soil imported from off-site sources should be tested for compliance with the
recommendations herein and approved by the project geotechnical
engineer prior to being used as fill. Imported materials should consist of lean
clays (maximum Plasticity Index of 25) that are essentially free of organic
materials and particles larger than 4 inches in their maximum dimension.
Field density and moisture content testing should be performed at the rate
of one test per 10,000 square feet in pavement areas.
9.4.1 Aggregate Base
Based upon current grading plans provided by Park7 Group (dated March 9,
2018), the cut and fill operations for pavement subgrade across the site are
variable. We anticipate that cut materials will be used as grade-raise fill at other
parts of the project. However, excavated shale bedrock materials should not
be used as grade-raise fill. A six (6) inch thick layer of aggregate base should
be placed beneath pavements with clay subgrades. If used, aggregate base
should be placed in accordance with the following recommendations.
After proof rolling, and prior to the placement of aggregate base, the
exposed subgrade beneath pavement areas should be scarified and
reworked to a depth of 12 inches, moisture added or removed as
required, and the subgrade soils recompacted to a minimum of 95
percent of the maximum dry density of the materials obtained in
accordance with ASTM D698 (standard Proctor test) and that is at or
above the material’s optimum moisture content, as determined by the
same test. The rework and aggregate base should extend to at least
18-inches beyond the outside edges of curbs for pavements placed
at the ground surface.
Aggregate base, should be TxDOT Type A or D and meet the
gradation, durability and plasticity requirements of TxDOT Item 247
Grade 1-2 or better (2014). Aggregate base material should be
uniformly compacted in maximum 6-inch compacted lifts to a
minimum of 95% of the maximum standard Proctor dry density (ASTM
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D698) and be placed at a moisture content that is sufficient to achieve
density.
Field density and moisture content testing should be performed at the
rate of one test per 10,000 square feet in pavement areas.
9.5 Rigid Pavement
We recommend that Portland Cement Concrete Pavement for this site have a
minimum thickness of 5 inches for light-duty automobile parking over 6-inches of
aggregate base). Concrete thickness should be increased to 6 inches for fire lanes,
and to 7-inches for dumpster pads and heavy-duty traffic areas. Actual traffic loading,
frequency, and intensity may require an increase in these minimum
recommendations.
Recommended minimum design compressive strength: 3,500 psi with nominal
aggregate size no greater than 1 inch.
15 to 20 percent fly ash may be used with the approval of the Civil Engineer of
record.
Curing compound should be applied within one hour of finishing operations.
9.6 Pavement Joints and Cutting
The performance of concrete pavement depends to a large degree on the design,
construction, and long-term maintenance of concrete joints. The following
recommendations and observations are offered for consideration by the Civil
Engineer and/or pavement Designer-of-Record.
The concrete pavements should have adequately-spaced contraction joints to control
shrinkage cracking. Experience indicates that reinforced concrete pavements with
sealed contraction joints on a 12 to 15-foot spacing, cut to a depth of one-quarter to
one-third of the pavement thickness, have generally exhibited less uncontrolled post-
construction cracking than pavements with wider spacing. The contraction joint
pattern should divide the pavement into panels that are approximately square where
the panel length should not exceed 25 percent more than the panel width. Saw cut,
post placement formed contraction joints should be saw cut as soon as the concrete
can support the saw cutting equipment and personnel and before shrinkage cracks
appear, on the order of 4 to 6 hours after concrete placement.
Isolation joints should be used wherever the pavement will abut a structural element
subject to a different magnitude of movement, e.g., light poles, retaining walls,
existing pavement, stairways, entryway piers, building walls, or manholes.
In order to minimize the potential differential movement across the pavement areas,
all joints including contraction, isolation and construction joints should be sealed to
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minimize the potential for infiltration of surface water. Rubberized asphalt, silicone or
another suitable flexible sealant may be used to seal the joints. Maintenance should
include periodic inspection of these joints and the joints resealed as necessary.
9.7 Pavement Reinforcing Steel
We recommend that a minimum of 0.1 percent of steel be used for all concrete
pavements. For a 6-inch thick concrete pavement section, this reinforcement ratio is
approximately equivalent to No. 3 bars spaced at 18-inches on center each way.
Reinforcement requirements may increase depending on specific traffic loading and
design life parameters.
OTHER CONSTRUCTION
10.1 Utility and Service Lines
Backfill for utility lines should consist of on-site material so that they will be stable. If
the backfill is too dense or too dry, swelling may form a mound along the ditch line. If
the backfill is too loose or too wet, settlement may result along the ditch line. It is not
uncommon to realize some settlement along the trench backfill. The on-site fill soil
should be placed in maximum 6-inch compacted lifts, compacted to a minimum of 95
percent of the maximum dry density, as determined by ASTM D698 (standard
Proctor), and placed at a moisture content that is at least the optimum moisture
content, as determined by that same test. It is also recommended that the utility
ditches be visually inspected during the excavation process to ensure that
undesirable fill that was not detected by the test borings does not exist at the site.
This office should be notified immediately if any such fill is detected.
Utility lines connected to the structure may experience differential movement in
response to changing moisture conditions in expansive soil. These movements may
result in damage to the lines, especially at connections to the rigid building structure.
Flexible connections or oversized sleeves may be considered are recommended to
account for potential differential movement between the building and utilities.
Utility excavations should be sloped so that water within excavations will flow to a low
point away from the buildings where it can be removed before backfilling. Compaction
of bedding material should not be water-jetted. Compacted backfill above the utilities
should be on-site clays to limit the percolation of surface water. Utility trenches
extending under structures should include fat clay or concrete cut-off collars at the
perimeter/edge to prevent the transmission of water along trench lines.
10.2 Exterior Flatwork
Concrete flatwork should include high tensile steel reinforcement to reduce the
formation and size of cracks. Flatwork should also include frequent and regularly
spaced expansion/control joints and dowels to limit vertical offsets between
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neighboring flatwork slabs. Structure entrances should either be part of the structure
or designed to tolerate vertical movement without inhibiting access. The moisture
content of the subgrade should be maintained up to the time of concrete placement.
If subgrade soils are allowed to dry below the levels recommended herein, additional
moisture conditioning of the soils may be required. These recommendations are
intended to reduce possible distress to exterior flatwork but will not prevent movement
and/or vertical offsets between slabs.
10.3 Surface Drainage
Proper drainage is critical to the performance and condition of the building foundation,
pavements, and flatwork. Positive surface drainage should be provided that directs
surface water away from the building, pavements, and flatwork. We recommend that
the exterior grades slope away from foundations at the rate of five (5) percent in the
first ten (10) feet away in accordance with IBC Chapter 18 requirements. The slopes
should direct water away from structures and flatwork, and these grades should be
maintained throughout construction and the life of the structure.
The location of gutter downspouts and other features should be designed such that
these items will not create moisture concentrations at or beneath the structure or
flatwork. Downspouts should discharge well away from the structure and should not
be allowed to erode surface soil.
The potential for moisture-induced distress in structures with grade-supported
foundations and/or floor slabs can be positively addressed by constructing continuous
exterior flatwork that extends to the building line. Where this occurs, the joints created
at the interface of the flatwork and building line should be sealed with a flexible joint
sealer to prevent the infiltration of water. Open cracks that may develop in the flatwork
should also be sealed. The joint and any cracks that develop should be resealed as
they become apparent and should be part of a periodic inspection and maintenance
program.
However, we understand that sidewalks are not always practical or desired around
the full perimeters of some facilities. Where landscaping will be present adjacent to
building perimeters, diligent post-construction maintenance should be employed to
prevent excessive wetting or drying of those adjacent soils.
10.4 Landscaping
Landscaping against and around the exterior of the structure can adversely affect
subgrade moisture resulting in localized differential movements if not properly
maintained. If used, landscaping should be kept as far away from the foundation as
possible, and positive drainage away from the structure should be designed,
constructed, and maintained. Landscaping elements (such as edging) should not
prohibit or slow the drainage of water that could result in water ponding next to
foundations or edges of flatwork. When feasible, irrigation lines and heads should not
D&S ENGINEERING LABS, LLC Park Place Denton
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G18-2196
24
be placed in close proximity to the foundation to prevent the collection of water near
the foundation or flatwork, particularly in the event of leaking lines or sprinkler heads.
Trees (if planned) should not be placed in proximity to the structure or movement
sensitive flatwork, as trees are known to cause in localized soil shrinkage due to
desiccation of the soil by the root system, possibly leading to differential movements
of the structure. The desiccation zone varies by a tree, but trees should not be planted
closer to structures than the mature tree height, and in no case, should the drip-line
of the mature tree extend closer than 10-feet of rooflines. To the extent practical, it is
recommended that trees scheduled for removal (where required) in the vicinity of the
proposed structure and pavements be removed as far in advance of slab construction
as possible, ideally by several months or longer. This will tend to restore a more
favorable soil moisture equilibrium which will, in turn, tend to minimize the potential
for greater than anticipated post-construction ground movements. A moist but not
overly wet soil condition should be maintained at all times in all landscaped areas
near the building after construction to minimize soil volume changes caused by
changing soil moisture conditions.
10.5 Site Grading
Expansive clay cut, and fill slopes should be gentle and preferably should not exceed
4 horizontal to 1 vertical (4H: 1V).
Excess water ponding on and beside roadways, sidewalks, and ground-supported
slabs can cause unacceptable heave of these structures. To reduce this potential
heave, good surface drainage should be established. In addition, final grades in the
vicinity of structures, pavements, and flatwork should provide for positive drainage
away from these elements.
10.6 Excavations
Excavations greater than 5 feet in height/depth should be in accordance with OSHA
29CFR 1926, Subpart P. Temporary construction slopes should incorporate
excavation protection systems or should be sloped back. Where the excavation does
not extend close to building lines, these areas may be laid back. Where space allows,
temporary slopes should be sloped at 1.5 horizontal to 1 vertical (1.5H: 1V) or flatter.
Where excavation slopes greater than five (5) feet in height cannot be laid back, these
areas will require the installation of a temporary retention system or shoring to protect
the existing construction, restrain the subsurface soils and maintain the integrity of
the excavation. We recommend that monitoring points be established around the
retention system and that these locations be monitored during and after the
excavation activities to confirm the integrity of the retention system.
The slopes and temporary retention system should be designed and verified by the
contractor's engineer and should not be surcharged by traffic, construction
D&S ENGINEERING LABS, LLC Park Place Denton
Denton, Texas
G18-2196
25
equipment, or permanent structures. The slopes and temporary retention system
should be adequately maintained and periodically inspected to ensure the safety of
the excavation and surrounding property.
SEISMIC CONSIDERATION
North Central Texas is generally regarded as an area of low seismic activity. The 2012
International Building Code (IBC) requires certain geotechnical seismic design criteria to
aid the Structural Engineer in their analysis to develop an appropriate structure design to
accommodate earthquake loading. The Spectral Acceleration values were determined
using publicly available information from the United States Geological Survey (USGS).
Seismic Site Class was determined using ASCE 7-10 Table 20.3-1 based on the average
blow counts and unconfined compressive strength in the top 100 feet.
Based on experience, the boring log data, and general geologic information gathered, we
recommend that Soil Site Class “C” be used at this site, even though the shear wave
velocity of the near-surface limestone strata is estimated to be in excess of 2,000 feet per
second. The criteria pertaining to this classification are shown in Table 8 below. The other
information shown was determined using USGS US Seismic Design Maps based on
2012/2015 IBC.
Table 8. Seismic Design Parameters
Design Parameters Values
Site Class C
Spectral Acceleration for 0.2 sec Period, Ss (g) 0.111
Spectral Acceleration for 1.0 sec Period, S1 (g) 0.054
Site Coefficient for 0.2 sec Period, Fa 1.2
Site Coefficient for 1.0 sec Period, Fv 1.7
LIMITATIONS
The professional geotechnical engineering services performed for this project, the findings
obtained, and the recommendations prepared were accomplished in accordance with
currently accepted geotechnical engineering principles and practices.
Variations in the subsurface conditions are noted at the specific boring locations for this
study. As such, all users of this report should be aware that differences in depths and
thicknesses of strata encountered can vary between the boring locations. Statements in
the report regarding subsurface conditions across the site are extrapolated from the data
obtained at the specific boring locations. The number and spacing of the exploration
borings were chosen to obtain geotechnical information for the design and construction of
moderately to heavily loaded multi-storied residential structure foundations. If there are
any conditions differing significantly from those described herein, D&S should be notified
to re-evaluate the recommendations contained in this report.
D&S ENGINEERING LABS, LLC Park Place Denton
Denton, Texas
G18-2196
26
Recommendations contained herein are not considered applicable for an indefinite period
of time. Our office must be contacted to re-evaluate the contents of this report if
construction does not begin within a one-year period after completion of this report.
The scope of services provided herein does not include an environmental assessment of
the site or investigation for the presence or absence of hazardous materials in the soil,
surface water, or groundwater.
All contractors referring to this geotechnical report should draw their own conclusions
regarding excavations, construction, etc. for bidding purposes. D&S is not responsible for
conclusions, opinions or recommendations made by others based on these data. The
report is intended to guide the preparation of project specifications and should not be used
as a substitute for the project specifications.
Recommendations provided in this report are based on our understanding of the
information provided by the Client to us regarding the scope of work for this project. If the
Client notes any differences, our office should be contacted immediately since this may
materially alter the recommendations.
APPENDIX A - BORING LOGS AND SUPPORTING DATA
**BORING LOCATIONS ARE INTENDED FOR GRAPHICAL REFERENCE ONLY**
N.T.S.
DENTON TEXAS
SHEET NO.
DATE DRILLED
G1
August 9 to 15, 2018
PLAN OF BORINGS
PARK PLACE
B8
B2
B1
B3
B4B6
B7
B5
B9
**BORING LOCATIONS ARE INTENDED FOR GRAPHICAL REFERENCE ONLY**
N.T.S.
DENTON TEXAS
SHEET NO.
DATE DRILLED
G2
August 9 to 15, 2018
PLAN OF BORINGS
PARK PLACE
B8
B2
B1
B3
B4B6
B7
B5
B9
KEY TO SYMBOLS AND TERMS
CONSISTENCY: FINE GRAINED SOILS
CONDITION OF SOILS
SECONDARY COMPONENTS
WEATHERING OF ROCK MASS
TCP (#blows/ft)
< 8
8 - 20
20 - 60
60 - 100
> 100
Relative Density (%)
0 - 15
15 - 35
35 - 65
65 - 85
85 - 100
SPT (# blows/ft)
0 - 2
3 - 4
5 - 8
9 - 15
16 - 30
> 30
UCS (tsf)
< 0.25
0.25 - 0.5
0.5 - 1.0
1.0 - 2.0
2.0 - 4.0
> 4.0
CONSISTENCY OF SOILSLITHOLOGIC SYMBOLS
CONDITION: COARSE GRAINED SOILS
QUANTITY DESCRIPTORS
RELATIVE HARDNESS OF ROCK MASS
SPT (# blows/ft)
0 - 4
5 - 10
11 - 30
31 - 50
> 50
Description
No visible sign of weathering
Penetrative weathering on open discontinuity surfaces,
but only slight weathering of rock material
Weathering extends throughout rock mass, but the rock
material is not friable
Weathering extends throughout rock mass, and the rock
material is partly friable
Rock is wholly decomposed and in a friable condition but
the rock texture and structure are preserved
A soil material with the original texture, structure, and
mineralogy of the rock completely destroyed
Designation
Fresh
Slightly weathered
Moderately weathered
Highly weathered
Completely weathered
Residual Soil
Description
Can be carved with a knife. Can be excavated readily with
point of pick. Pieces 1" or more in thickness can be broken
by finger pressure. Readily scratched with fingernail.
Can be gouged or grooved readily with knife or pick point.
Can be excavated in chips to pieces several inches in size
by moderate blows with the pick point. Small, thin pieces
can be broken by finger pressure.
Can be grooved or gouged 1/4" deep by firm pressure on
knife or pick point. Can be excavated in small chips to
pieces about 1" maximum size by hard blows with the point
of a pick.
Can be scratched with knife or pick. Gouges or grooves 1/4"
deep can be excavated by hard blow of the point of a pick.
Hand specimens can be detached by a moderate blow.
Can be scratched with knife or pick only with difficulty.
Hard blow of hammer required to detach a hand specimen.
Cannot be scratched with knife or sharp pick. Breaking of hand
specimens requires several hard blows from a hammer or pick.
Trace
Few
Little
Some
With
Designation
Very Soft
Soft
Medium Hard
Moderately Hard
Hard
Very Hard
< 5% of sample
5% to 10%
10% to 25%
25% to 35%
> 35%
Condition
Very Loose
Loose
Medium Dense
Dense
Very Dense
Consistency
Very Soft
Soft
Medium Stiff
Stiff
Very Stiff
HardARTIFICIALAsphalt
Aggregate Base
Concrete
Fill
SOILROCKLimestone
Mudstone
Shale
Sandstone
Weathered Limestone
Weathered Shale
Weathered Sandstone
CH: High Plasticity Clay
CL: Low Plasticity Clay
GP: Poorly-graded Gravel
GW: Well-graded Gravel
SC: Clayey Sand
SP: Poorly-graded Sand
SW: Well-graded Sand
!
"
!
#$%&'()$%*++$,-)
,-)'.$/'',01/' %2
,-)'.$/'',01/' %2
3
"
!
#$%&'%-%2/(%4)++$,-)
56/-7#$%&'%-%2/(%4)++$,-)
8%2#$%&'()$%*++$,-)
,-)'.$/'',01/' %2
,-)'.$/'',01/' %2
!
" 9
9
" 9
9
0.233
21
14
16
19
5
1.0
4.5+
4.5+
4.5+
4.5+
3.0
1.5
28
20
58
705.7 ft
702.0 ft
691.0 ft
672.0 ft
99.217.4
12.7
15.1
19.2
20.2
0.3 ft
4.0 ft
15.0 ft
34.0 ft
CONCRETE; 4 inches
LEAN CLAY (CL); medium stiff tovery stiff; brown, light brown; trace to
few sand-estimated cut depth 2 feet
SILTY CLAYEY SAND (SC-SM);medium dense to very dense; brown,yellow brown, gray
SANDSTONE; very weakly to weaklycemented; very soft to soft; yellowish
brown, gray; trace to few very thinshale seams
AU
S
S
T
S
T
S
T
S
S
T
S
T
NR
T
B
T
B
T
B
2,6
17,22
50=5.75"
47
25,40
50=6.0",46
50=1.5"50=0.5"
50=3.0"50=0.75"
50=5.5"
50=0.25"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
0
5
10
15
20
25
30
35
Atterberg Limits
Clay(%)
B1
PAGE 1 OF 2
MC(%)
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REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Charles Ray Stephens (D&S)
START DATE: 8/14/2018 DRILL METHOD: Hollow Stem Flight Auger
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/14/2018
GROUND ELEVATION: Approx. 706 feet
GPS COORDINATES: N33.218569, W97.147888
PROJECT NUMBER: G18-2196
655.7 ft
50.3 ft
SHALE; fresh; soft to medium hard;dark gray
End of boring at 50.3'
Notes:-seepage at 23 feet during drilling
T
B
T
B
T
B
T
50=0.5"50=0.25"
50=2.75"
50=1.75"
50=2.5"50=1.5"
50=2.75"
50=0.5"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
35
40
45
50
55
60
65
70
Atterberg Limits
Clay(%)
B1
PAGE 2 OF 2
MC(%)
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REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Charles Ray Stephens (D&S)
START DATE: 8/14/2018 DRILL METHOD: Hollow Stem Flight Auger
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/14/2018
GROUND ELEVATION: Approx. 706 feet
GPS COORDINATES: N33.218569, W97.147888
PROJECT NUMBER: G18-2196
0.3NP NP NP
4.5+
3.0 30
58
61
701.5 ft
698.0 ft
689.0 ft
679.0 ft
117.55.7
7.1
7.9
14.8
0.5 ft
4.0 ft
13.0 ft
23.0 ft
ASPHALT; 6 inches
SILTY SAND (SM); medium dense tovery dense; brown, yellowish brown
SANDY LEAN CLAY (CL); very stiff;brown, reddish brown
-estimated cut depth 12 feet
SANDSTONE; very weakly
cemented; very soft to soft; yellowishbrown, gray; few very thin shaleseams
SHALE; fresh; soft to medium hard;dark gray; few very thin limestone
seams
AU
S
S
T
B
T
B
T
B
N
T
N
T
N
T
N
T
N
T
B
50=3.5"
50=2.0"
34,46
50=4.25"50=4.25"
8,18,18
20,31
18,34,48
22,50=5.25"
18,20,38
50=2.75"
50=1.0"
28,50=4.0"
50=3.75"
50=1.0"
22,50=5.25"
50=4.75"50=0.0"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
0
5
10
15
20
25
30
35
Atterberg Limits
Clay(%)
B2
PAGE 1 OF 2
MC(%)
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REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Daniel Earl (D&S)
START DATE: 8/16/2018 DRILL METHOD: Hollow Stem Flight Auger
LOGGED BY: Sandip Adhikari (D&S)
FINISH DATE: 8/16/2018
GROUND ELEVATION: Approx. 702 feet
GPS COORDINATES: N33.218016, W97.147931
PROJECT NUMBER: G18-2196
659.0 ft
641.7 ft
43.0 ft
60.3 ft
SHALE; fresh; soft to medium hard;dark gray; few very thin limestone
seams
LIMESTONE; fresh; moderately hard
to hard; gray; few thin shale seams
End of boring at 60.3'
Notes:-seepage at 26 feet during drilling
T
B
T
B
T
B
T
B
T
B
T
50=3.75"50=0.0"
50=5.0"50=2.25"
50=2.0"
50=0.0"
50=5.0"50=1.0"
50=2.0"50=0.5"
50=1.0"50=1.75"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
35
40
45
50
55
60
65
70
Atterberg Limits
Clay(%)
B2
PAGE 2 OF 2
MC(%)
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REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Daniel Earl (D&S)
START DATE: 8/16/2018 DRILL METHOD: Hollow Stem Flight Auger
LOGGED BY: Sandip Adhikari (D&S)
FINISH DATE: 8/16/2018
GROUND ELEVATION: Approx. 702 feet
GPS COORDINATES: N33.218016, W97.147931
PROJECT NUMBER: G18-2196
0.7
0.0
30
40
22
23
16
17
14
17
14
23
8
6
2.75
3.0
3.5
4.5+
3.25
4.5+
4.5+
4.5+
61
48
701.7 ft
701.0 ft
692.0 ft
687.0 ft
682.0 ft
679.0 ft
120.1
109.2
138.4 26.7
7.7
17.1
10.0
12.9
14.1
13.2
6.7
0.3 ft 1.0 ft
10.0 ft
15.0 ft
20.0 ft
23.0 ft
ASPHALT; 4 inches
FILL: LEAN CLAY (CL); stiff; brown,gray; few aggregate fragments and
sand
SANDY LEAN CLAY (CL); stiff tovery stiff; brown, trace calcareous
nodules and iron oxide stains
CLAYEY SAND (SC); very dense;
brown, gray; trace iron oxide stains
-estimated cut depth 12 feet
SANDSTONE; very weaklycemented; very soft to soft; yellowish
brown, gray; trace very thin shaleseams
SHALE; moderately weathered; soft;yellow brown, gray; fissile
SHALE; fresh; soft to medium hard;gray, dark gray; fissile; calcareous
89
89
9595
9292
AU
S
S
T
S
T
S
T
S
S
T
S
T
S
T
C
T
C
T
C
5,4
19,20
19,20
50=5.75"50=3.5"
50=3.5"
50=0.5"
50=1.75"50=0.75"
18,20
50=2.5"
50=0.125"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
0
5
10
15
20
25
30
35
Atterberg Limits
Clay(%)
B3
PAGE 1 OF 3
MC(%)
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REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Kevin Kavadas (D&S)
START DATE: 8/16/2018 DRILL METHOD: HSA/Core
LOGGED BY: Sandip Adhikari (D&S)
FINISH DATE: 8/16/2018
GROUND ELEVATION: Approx. 702 feet
GPS COORDINATES: N33.218329, W97.148248
PROJECT NUMBER: G18-2196
642.0 ft
120.1
125.2
133.3
127.0
136.6
14.6
27.8
26.1
23.7
52.0
14.0
12.9
9.4
11.6
6.7
60.0 ft
SHALE; fresh; soft to medium hard;gray, dark gray; fissile; calcareous
LIMESTONE; fresh; moderately hardto hard; gray; few very thin shaleseams
80
80
100100
8787
100
100
100100
9090
100100
T
C
T
C
C
C
C
C
C
50=1.0"50=0.0"
50=1.25"50=0.0"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
35
40
45
50
55
60
65
70
Atterberg Limits
Clay(%)
B3
PAGE 2 OF 3
MC(%)
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REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Kevin Kavadas (D&S)
START DATE: 8/16/2018 DRILL METHOD: HSA/Core
LOGGED BY: Sandip Adhikari (D&S)
FINISH DATE: 8/16/2018
GROUND ELEVATION: Approx. 702 feet
GPS COORDINATES: N33.218329, W97.148248
PROJECT NUMBER: G18-2196
631.9 ft 70.1 ftEnd of boring at 70.1'
Notes:-dry prior to introduction of water at 20
feet for coring purposes
T 50=0.75"50=0.0"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
70
75
80
85
90
95
100
105
Atterberg Limits
Clay(%)
B3
PAGE 3 OF 3
MC(%)
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REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Kevin Kavadas (D&S)
START DATE: 8/16/2018 DRILL METHOD: HSA/Core
LOGGED BY: Sandip Adhikari (D&S)
FINISH DATE: 8/16/2018
GROUND ELEVATION: Approx. 702 feet
GPS COORDINATES: N33.218329, W97.148248
PROJECT NUMBER: G18-2196
0.8
60
28
25
28
22
16
16
13
38
12
9
15
2.5
2.75
3.75
4.0
2.5
65
57
48
702.7 ft
700.0 ft
693.0 ft
689.0 ft
683.0 ft
680.0 ft
670.0 ft
107.6
27.0
25.7
14.7
12.7
13.9
19.0
17.5
0.3 ft
3.0 ft
10.0 ft
14.0 ft
20.0 ft
23.0 ft
33.0 ft
ASPHALT; 4 inches
FAT CLAY (CH); stiff; brown, olivebrown, yellow; little iron oxide
concretions and ferrous nodules
SANDY LEAN CLAY (CL); stiff tovery stiff; brown, light brown, gray;little iron oxide nodules
CLAYEY SAND (SC); loose to
dense; brown, gray; trace iron oxidenodules; fine grained sand
-estimated cut depth 12 feet
SANDSTONE; very weakly
cemented; very soft to soft; gray; tracevery thin shale seams
SHALE; highly to completelyweathered; very soft; yellow brown,
gray; slightly fissile
SHALE; moderately weathered; soft;gray, dark gray
SHALE; fresh; soft to medium hard;
gray, dark gray
AU
S
S
T
S
T
S
T
S
N
T
T
N
B
T
B
T
B
T
B
8,13
34,24
11,50=5.5"
13,17,24
7,12
50=5.75"
50=1.25"
50=6.0"
28,14
50=1.0"50=0.75"
50=2.25"50=1.25"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
0
5
10
15
20
25
30
35
Atterberg Limits
Clay(%)
B4
PAGE 1 OF 2
MC(%)
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REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Charles Ray Stephens (D&S)
START DATE: 8/10/2018 DRILL METHOD: Hollow Stem Flight Auger
LOGGED BY: Sandip Adhikari (D&S)
FINISH DATE: 8/10/2018
GROUND ELEVATION: Approx. 703 feet
GPS COORDINATES: N33.218577, W97.148558
PROJECT NUMBER: G18-2196
647.9 ft
55.1 ft
SHALE; fresh; soft to medium hard;gray, dark gray
End of boring at 55.1'
Notes:-seepage at 15 feet during drilling
T
B
T
B
T
B
T
B
T
50=2.75"50=3.5"
50=4.0"50=3.25"
50=1.25"
50=0.5"
50=1.0"
50=0.75"
50=0.75"50=0.5"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
35
40
45
50
55
60
65
70
Atterberg Limits
Clay(%)
B4
PAGE 2 OF 2
MC(%)
Legend: S-Shelby Tube N-Standard Penetration T-Texas Cone Penetration C-Core B-Bag Sample - Water Encountered
REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Charles Ray Stephens (D&S)
START DATE: 8/10/2018 DRILL METHOD: Hollow Stem Flight Auger
LOGGED BY: Sandip Adhikari (D&S)
FINISH DATE: 8/10/2018
GROUND ELEVATION: Approx. 703 feet
GPS COORDINATES: N33.218577, W97.148558
PROJECT NUMBER: G18-2196
0.1
26
32
15
12
11
20
2.0
2.5
4.5
4.5+
4.5+
4.5+
1.0
3.0
69
63
701.3 ft
701.0 ft
687.0 ft
682.0 ft
679.0 ft
107.9
121.4 12.1
17.4
15.5
14.7
17.2
13.5
34.9
13.9
0.7 ft
1.0 ft
15.0 ft
20.0 ft
23.0 ft
ASPHALT; 8 inches
FILL: CLAYEY SAND (SC); loose;yellowish brown, gray
SANDY LEAN CLAY (CL); stiff tovery stiff; yellowish brown, red, gray;
trace calcareous nodules and ironoxide stains
-estimated cut depth 12 feet
SANDSTONE; very weaklycemented; very soft to soft; yellowish
brown, gray; trace very thin shaleseams
SHALE; moderately weathered; soft;gray, dark gray
SHALE; fresh; medium hard; gray,dark gray; fissile; calcareous
8282
8484
AU
S
S
T
S
T
S
T
S
S
T
S
T
S
T
T
C
C
3,5
12,16
17,18
15,10
50=6.0"50=6.0"
50=6.0"50=2.0"
50=1.0"50=0.0"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
0
5
10
15
20
25
30
35
Atterberg Limits
Clay(%)
B5
PAGE 1 OF 3
MC(%)
Legend: S-Shelby Tube N-Standard Penetration T-Texas Cone Penetration C-Core B-Bag Sample - Water Encountered
REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Kevin Kavadas (D&S)
START DATE: 8/17/2018 DRILL METHOD: HSA/Core
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/17/2018
GROUND ELEVATION: Approx. 702 feet
GPS COORDINATES: N33.217927, W97.148377
PROJECT NUMBER: G18-2196
657.0 ft
133.5
127.0
143.3
18.5
26.5
70.6
10.4
12.0
5.9
45.0 ft
SHALE; fresh; medium hard; gray,dark gray; fissile; calcareous
LIMESTONE; fresh; moderately hard
to hard; gray, dark gray; few to somevery thin shale seams
7878
9696
100100
94
94
100100
100100
100100
C
C
C
C
C
C
C
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
35
40
45
50
55
60
65
70
Atterberg Limits
Clay(%)
B5
PAGE 2 OF 3
MC(%)
Legend: S-Shelby Tube N-Standard Penetration T-Texas Cone Penetration C-Core B-Bag Sample - Water Encountered
REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Kevin Kavadas (D&S)
START DATE: 8/17/2018 DRILL METHOD: HSA/Core
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/17/2018
GROUND ELEVATION: Approx. 702 feet
GPS COORDINATES: N33.217927, W97.148377
PROJECT NUMBER: G18-2196
631.9 ft 70.1 ftEnd of boring at 70.1'
Notes:-seepage at 14 feet during drilling
-introduction of water at 25 feet forcoring purposes
T 50=0.75"50=0.125"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
70
75
80
85
90
95
100
105
Atterberg Limits
Clay(%)
B5
PAGE 3 OF 3
MC(%)
Legend: S-Shelby Tube N-Standard Penetration T-Texas Cone Penetration C-Core B-Bag Sample - Water Encountered
REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Kevin Kavadas (D&S)
START DATE: 8/17/2018 DRILL METHOD: HSA/Core
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/17/2018
GROUND ELEVATION: Approx. 702 feet
GPS COORDINATES: N33.217927, W97.148377
PROJECT NUMBER: G18-2196
0.0
0.0
33
29
44
16
16
16
17
13
28
2.0
4.5+
4.5+
4.5+
4.5
4.0
4.5+
4.5+
53
60
700.0 ft
681.0 ft
670.0 ft
105.6
118.0
105.1
121.2
115.7
4.8
5.5
14.5
22.5
16.6
15.1
14.2
13.4
13.3
12.8
15.2
1.0 ft
20.0 ft
31.0 ft
FILL: LEAN CLAY (CL); stiff; brown,gray; few aggregate fragments; trace
sand
SANDY LEAN CLAY (CL); very stiff;brown, trace calcareous nodules andiron oxide stains
-estimated cut depth 12 feet
SHALE; moderately to highlyweathered; very soft; yellow brown,
gray; slightly fissile
SHALE; fresh; medium hard; gray,
dark gray; fissile; calcereous
9393
5858
8080
S
S
S
T
S
T
S
T
S
S
T
S
T
B
T
C
T
C
T
C
6,7
9,9
11,6
12,14
10,11
50=3.0"
50=0.5"
36,40
15,18
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
0
5
10
15
20
25
30
35
Atterberg Limits
Clay(%)
B6
PAGE 1 OF 2
MC(%)
Legend: S-Shelby Tube N-Standard Penetration T-Texas Cone Penetration C-Core B-Bag Sample - Water Encountered
REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Kevin Kavadas (D&S)
START DATE: 8/10/2018 DRILL METHOD: HSA/Core
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/10/2018
GROUND ELEVATION: Approx. 701 feet
GPS COORDINATES: N33.218573, W97.148965
PROJECT NUMBER: G18-2196
661.0 ft
641.0 ft
131.3
136.1
54.2
67.1
10.4
8.1
40.0 ft
60.0 ft
SHALE; fresh; medium hard; gray,dark gray; fissile; calcereous
LIMESTONE; fresh; moderately hardto hard; gray
End of boring at 60.0'
Notes:
-dry prior to introduction of water at 20feet for coring purposes
7878
100
100
8787
9292
100100
T
C
T
C
T
C
T
C
T
C
T
50=2.0"50=1.5"
50=0.13"50=0.0"
50=1.0"
50=0.0"
50=0.5"
50=0.0"
50=3.25"
50=0.0"
50=0.0"50=0.0"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
35
40
45
50
55
60
65
70
Atterberg Limits
Clay(%)
B6
PAGE 2 OF 2
MC(%)
Legend: S-Shelby Tube N-Standard Penetration T-Texas Cone Penetration C-Core B-Bag Sample - Water Encountered
REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Kevin Kavadas (D&S)
START DATE: 8/10/2018 DRILL METHOD: HSA/Core
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/10/2018
GROUND ELEVATION: Approx. 701 feet
GPS COORDINATES: N33.218573, W97.148965
PROJECT NUMBER: G18-2196
0.0
0.9
29
29
44
17
15
20
12
14
24
4.5+
2.5
2.0
2.5
4.5
2.5
4.5+
4.5+
699.7 ft
698.0 ft
680.0 ft
667.0 ft
121.9
116.8
17.4
14.6
18.8
15.5
13.3
11.7
0.3 ft
2.0 ft
20.0 ft
33.0 ft
ASPHALT 4 inches
FILL: LEAN CLAY WITH SAND (CL);stiff to very stiff; dark brown; trace to
little aggegate fragments
LEAN CLAY (CL); stiff to very stiff;brown, reddish brown, gray; trace to
little ferrous nodules
-estimated cut depth 12 feet
SHALE; highly to completelyweathered; very soft; yellowish brown,
light gray
SHALE; slightly to moderately
weathered; very soft; olive green,yellowish brown; fissile
S
S
S
T
S
T
S
T
S
T
S
T
S
T
B
T
T
B
4,4
5,5
7,6
7,11
10,6
30,50=2.75"
30,50=3.75"
20,25
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
0
5
10
15
20
25
30
35
Atterberg Limits
Clay(%)
B7
PAGE 1 OF 2
MC(%)
Legend: S-Shelby Tube N-Standard Penetration T-Texas Cone Penetration C-Core B-Bag Sample - Water Encountered
REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Charles Ray Stephens (D&S)
START DATE: 8/20/2018 DRILL METHOD: Hollow Stem Flight Auger
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/20/2018
GROUND ELEVATION: Approx. 700 feet
GPS COORDINATES: N33.218227, W97.148968
PROJECT NUMBER: G18-2196
664.0 ft
645.0 ft
639.8 ft
36.0 ft
55.0 ft
60.2 ft
SHALE; fresh; soft to medium hard;dark gray, gray; with frequent very thinlimestone seams
LIMESSTONE; fresh; moderatelyhard; gray, dark gray; with frequent
very thin shale seams
End of boring at 60.2'
Notes:
-dry during drilling-dry upon completion
T
B
T
B
T
B
T
B
T
B
T
40,41
50=4.0"50=1.5"
50=4.0"
50=1.5"
50=3.25"
50=0.5"
50=3.0"50=1.0"
50=1.25"50=1.0"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
35
40
45
50
55
60
65
70
Atterberg Limits
Clay(%)
B7
PAGE 2 OF 2
MC(%)
Legend: S-Shelby Tube N-Standard Penetration T-Texas Cone Penetration C-Core B-Bag Sample - Water Encountered
REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Charles Ray Stephens (D&S)
START DATE: 8/20/2018 DRILL METHOD: Hollow Stem Flight Auger
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/20/2018
GROUND ELEVATION: Approx. 700 feet
GPS COORDINATES: N33.218227, W97.148968
PROJECT NUMBER: G18-2196
1.2
0.3
30
62
62
13
27
28
17
35
34
2.0
3.5
4.5+
4.5+
4.5+
4.0
4.0
4.5+
52
13
689.0 ft
683.0 ft
676.0 ft
671.0 ft
112.0
109.3
113.0
104.2
6.5
1.1
15.4
13.9
9.3
8.9
13.2
18.9
20.1
19.1
5.3
7.0 ft
13.0 ft
20.0 ft
25.0 ft
SANDY LEAN CLAY (CL); stiff tovery stiff; brown, yellowish brown, light
gray
CLAYEY SAND (SC); medium denseto dense; gray, yellowish brown
SHALE; highly to completely
weathered; very soft; gray, yellowishbrown
SHALE; moderately to highlyweathered; very soft to medium hard;
gray, yellowish brown; tracecalcareous nodules
-estimated cut depth 24 feet
SHALE; slightly weathered; very softto soft; gray, dark gray
9696
9898
S
S
S
T
S
T
S
T
S
S
T
B
T
S
T
C
C
18,24
22,25
23,30
37,42
17,40
50=4.0"50=3.0"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
0
5
10
15
20
25
30
35
Atterberg Limits
Clay(%)
B8
PAGE 1 OF 3
MC(%)
Legend: S-Shelby Tube N-Standard Penetration T-Texas Cone Penetration C-Core B-Bag Sample - Water Encountered
REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Kevin Kavadas (D&S)
START DATE: 8/20/2018 DRILL METHOD: HSA/Core
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/20/2018
GROUND ELEVATION: Approx. 696 feet
GPS COORDINATES: N33.217783, W97.149044
PROJECT NUMBER: G18-2196
661.0 ft
651.0 ft
117.4
129.2
135.6
18.9
15.4
37.6
18.1
15.8
10.7
10.0
35.0 ft
45.0 ft
SHALE; fresh; gray, dark gray;calcareous; fossileferrous; fissile
LIMESTONE; fresh; hard; gray, dark
gray; few very thin shale seams
9898
100100
100100
100
100
100100
100100
100100
C
C
C
C
C
C
C
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
35
40
45
50
55
60
65
70
Atterberg Limits
Clay(%)
B8
PAGE 2 OF 3
MC(%)
Legend: S-Shelby Tube N-Standard Penetration T-Texas Cone Penetration C-Core B-Bag Sample - Water Encountered
REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Kevin Kavadas (D&S)
START DATE: 8/20/2018 DRILL METHOD: HSA/Core
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/20/2018
GROUND ELEVATION: Approx. 696 feet
GPS COORDINATES: N33.217783, W97.149044
PROJECT NUMBER: G18-2196
626.0 ft 70.0 ftEnd of boring at 70.1'
Notes:-seepage at 14 feet during drilling
-introduction of water at 25 feet forcoring purposes
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
70
75
80
85
90
95
100
105
Atterberg Limits
Clay(%)
B8
PAGE 3 OF 3
MC(%)
Legend: S-Shelby Tube N-Standard Penetration T-Texas Cone Penetration C-Core B-Bag Sample - Water Encountered
REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Kevin Kavadas (D&S)
START DATE: 8/20/2018 DRILL METHOD: HSA/Core
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/20/2018
GROUND ELEVATION: Approx. 696 feet
GPS COORDINATES: N33.217783, W97.149044
PROJECT NUMBER: G18-2196
2.0
5.3
31
26
48
13
16
16
18
10
32
4.5+
4.5+
4.5+
4.5+
4.5+
2.0
4.5+
4.5+
47
41
28
72
684.0 ft
678.0 ft
674.0 ft
669.0 ft
118.9
124.0 8.5
5.6
10.5
7.9
7.0
7.3
11.6
12.8
14.0 ft
20.0 ft
24.0 ft
29.0 ft
CLAYEY SAND (SC); dense to verydense; yellowish brown, gray; trace
iron oxide nodules
LEAN CLAY WITH SAND (CL); very
stiff; brown, gray, red; trace to fewcalcareous nodules; iron oxide stainsand charcoal fragments
SHALE; moderately to highlyweathered; soft; yellow brown, gray;
slightly fissile
-estimated cut depth 21 feet
SHALE; slightly weathered; mediumhard; gray, dark gray; fissile
SHALE; fresh; medium hard; dark
gray; with frequent very thin limestoneseams
S
S
S
T
S
T
S
T
S
S
T
T
N
S
T
B
T
T
B
35,41
49,50=5.0"
50=5.0"
50=4.0"
50=6.0"50=2.5"
34,42
18,17,15
50=4.75"36
50=2.0"
50=0.5"
50=3.5"
50=2.0"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
0
5
10
15
20
25
30
35
Atterberg Limits
Clay(%)
B9
PAGE 1 OF 2
MC(%)
Legend: S-Shelby Tube N-Standard Penetration T-Texas Cone Penetration C-Core B-Bag Sample - Water Encountered
REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Kevin Kavadas (D&S)
START DATE: 8/21/2018 DRILL METHOD: Hollow Stem Flight Auger
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/21/2018
GROUND ELEVATION: Approx. 698 feet
GPS COORDINATES: N33.217791, W97.148687
PROJECT NUMBER: G18-2196
637.8 ft
60.2 ft
SHALE; fresh; medium hard; darkgray; with frequent very thin limestone
seams
End of boring at 60.2'
Notes:
-seepage at 14 feet during drilling-water at 14 feet upon completion
T
B
T
B
T
B
T
B
T
B
T
50=4.0"50=2.0"
50=3.25"50=2.25"
50=1.25"50=0.5"
50=1.0"
50=0.5"
50=1.0"50=0.25"
50=1.0"50=1.0"
Swell(%)LL(%)PL(%)PI
TotalSuction(pF)
Hand
Pen. (tsf)orSPT
orTCP
Passing
#200Sieve
(%)
BORING LOG
GraphicLog DUW(pcf)
Unconf.Compr.Str (ksf)
Depth(ft)
35
40
45
50
55
60
65
70
Atterberg Limits
Clay(%)
B9
PAGE 2 OF 2
MC(%)
Legend: S-Shelby Tube N-Standard Penetration T-Texas Cone Penetration C-Core B-Bag Sample - Water Encountered
REC
(%)RQD
(%)
SampleType
Hand
Pen. (tsf)orSPT
orTCP
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Kevin Kavadas (D&S)
START DATE: 8/21/2018 DRILL METHOD: Hollow Stem Flight Auger
LOGGED BY: Mohammad Faysal (D&S)
FINISH DATE: 8/21/2018
GROUND ELEVATION: Approx. 698 feet
GPS COORDINATES: N33.217791, W97.148687
PROJECT NUMBER: G18-2196
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0.0010.010.1110
fine
SAND SILT OR CLAY
ASTM D1140
3 6 14 30 50 602
D30 %Clay
LL PI Cc
3
medium
GRAIN SIZE DISTRIBUTION
PL
10 40
coarse fine
GRAVEL
coarse
8.0 1.4 39.0 59.6
D100 D10BOREHOLE DEPTH
B2
%Gravel %Sand %Silt
Cu
9.51
1 3/4
Description
3/81.5 1/2 4 8
U.S. SIEVE OPENING IN INCHES 16 20 100 140 200
U.S. SIEVE NUMBERS HYDROMETER
PERCENT FINER BY WEIGHTGRAIN SIZE IN MILLIMETERS
D50
CLAYEY SAND (SC);
CLIENT: Park7 Group
LOCATION: Denton, TexasPROJECT: Park Place
DRILLED BY: Daniel Earl (D&S)
START DATE: 8/16/2018 DRILL METHOD: Hollow Stem Flight Auger
LOGGED BY: Sandip Adhikari (D&S)
FINISH DATE: 8/16/2018
GROUND ELEVATION: Approx. 702 feet
GPS COORDINATES: N33.218016, W97.147931
PROJECT NUMBER: G18-2196
B1 1-2 17.4 23.2 132 0.2
B2 2-3 5.7 20.4 261 0.3
B3 13-14 14.1 18.9 263 0.7
B3 19-20 13.2 19.1 263 0.0
B4 6-7 12.7 19.4 652 0.8
B5 14-15 17.2 19.8 395 0.1
B6 2-3 16.6 20.0 132 0.0
B6 9-10 13.4 14.9 1053 0.0
B7 14-15 13.3 14.7 265 0.0
B7 19-20 11.7 17.6 1042 0.9
B8 20-21 18.9 20.7 393 1.2
B8 25-26 20.1 22.3 912 0.3
B9 4-5 7.9 16.0 520 2.0
B9 19-20 12.8 17.2 263 5.3
Boring
Number Depth
feet Vertical Swell, %Final Moisture
Content, %
Initial Moisture
Content, %
Applied Pressure,psf
SWELL TEST RESULTS
CLIENT: Park7 GroupPROJECT: Park Place
PROJECT NUMBER: G18-2196 LOCATION: Denton, Texas
0
20
40
60
80
100
120
0 1 2 3 4
117.3
Axial Strain %Shear Stress (psi) 49.5 psi confinement
18.1
UNCONSOLIDATED-UNDRAINED TRIAXIAL TEST
ASTM D2850
Borehole Depth
MC%
Description
Major Principal Stress (psi)Minor Principal Stress (psi)
68.3
Deviator Stress (psi)
117.7
SHALE; fresh; gray, dark gray36.0B8
49.5
PROJECT: Park Place
LOCATION: Denton, TexasCLIENT: Park7 Group
PROJECT NUMBER: G18-2196
0
10
20
30
40
50
60
0 20 40 60 80 100 120
C u
,deg
34.1 psi
0
Major Principal Stress (psi)Total Normal Stress (psi)
Client:D&S Engineering Labs
Project Name:Park Place
Project Location: Denton, TX
GTX #:
Test Date:
Tested By:md
Checked By:njh
Boring ID:
Sample ID:
Depth, ft:
Visual Description:
Test No.:
Initial Diameter, in:
Initial Height, in:
Initial Mass, grams:
Initial Dry Density, pcf:
Initial Moisture Content, %:
Initial Bulk Density, pcf:
Initial Degree of Saturation:
Initial Void Ratio:
Final Dry Density, pcf:
Final Moisture Content, %:
Final Bulk Density, pcf:
Normal Stress, psf:
Maximum Shear Stress, psf:
Shear Rate, in/min:
Sample Type:
Estimated Specific Gravity:
Liquid Limit:
Plastic Limit:
Plasticity Index:
% Passing #200 sieve:
Soil Classification:
Group Symbol:
Notes:
Moisture content obtained before shear from sample trimmings
Moisture Content determined by ASTM D2216
"---" indicates testing required to determine these values was not requested.
Extruded from tube, cut, trimmed and placed into apparatus at the as-received density and moisture content
08/28/18
B8
---
6-7
Sandy Lean Clay (CL); brown, yellowish brown, light gray
1.0
115.4
Direct Shear Test of Soils Under Consolidated Drained Conditions
by ASTM D3080
intact
1.0
0.0004 0.0004
720 1440
308690
---
DS-5 DS-6
2.5
158 165
109.1
12.3 11.2
122.5
2.5
128.3
110.0 118.7
142.5
20.1
65.760.8
0.54 0.46
---
22.9
Values for cohesion and friction angle determined from best-fit straight line to the data for the specific test
conditions. Actual strength parameters may vary and should be determined by an engineer for site-specific
conditions.
---
---
---
---
2.70
1070
135.1
663
0
1000
2000
3000
4000
5000
0 1000 2000 3000 4000 5000 6000Shear Stress, psfNormal Stress, psf
0
1000
2000
3000
4000
5000
0.0 0.1 0.2 0.3 0.4 0.5Shear Stress, psfHorizontal Deformation, in
720 1440 #DIV/0!
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.0 0.1 0.2 0.3 0.4 0.5Vertical Deformation, inHorizontal Deformation, in
720 1440 #DIV/0!
Cohesion = 526 psf
Friction Angle = 29.5o
Client:D&S Engineering Labs
Project Name:Park Place
Project Location: Denton, TX
GTX #:
Test Date:
Tested By:md
Checked By:njh
Boring ID:
Sample ID:
Depth, ft:
Visual Description:
Test No.:
Initial Diameter, in:
Initial Height, in:
Initial Mass, grams:
Initial Dry Density, pcf:
Initial Moisture Content, %:
Initial Bulk Density, pcf:
Initial Degree of Saturation:
Initial Void Ratio:
Final Dry Density, pcf:
Final Moisture Content, %:
Final Bulk Density, pcf:
Normal Stress, psf:
Maximum Shear Stress, psf:
Shear Rate, in/min:
Sample Type:
Estimated Specific Gravity:
Liquid Limit:
Plastic Limit:
Plasticity Index:
% Passing #200 sieve:
Soil Classification:
Group Symbol:
Notes:
Moisture content obtained before shear from sample trimmings
Moisture Content determined by ASTM D2216
"---" indicates testing required to determine these values was not requested.
---
34.0
Values for cohesion and friction angle determined from best-fit straight line to the data for the specific test
conditions. Actual strength parameters may vary and should be determined by an engineer for site-specific
conditions.
---
---
---
---
2.70
1190 2100
121.2
1080
4560
114.2 118.0
90.4 89.2
122.5
100.0
37.4 29.8
90.8 81.891.2
0.87 0.94 0.76
129.8
308690
---
DS-1 DS-2 DS-3
2.5
150 147 152
90.4 96.0
29.2 31.8
116.8
2.5
Extruded from tube, cut, trimmed and placed into apparatus at the as-received density and moisture content
22.9
08/28/18
B8
---
19-20
Shale; gray, yellowish brown
2.5
1.0 1.0
86.7
Direct Shear Test of Soils Under Consolidated Drained Conditions
by ASTM D3080
intact
1.0
0.0003 0.0003 0.0003
1440 2280
0
1000
2000
3000
4000
5000
0 1000 2000 3000 4000 5000 6000Shear Stress, psfNormal Stress, psf
0
1000
2000
3000
4000
5000
0.0 0.1 0.2 0.3 0.4 0.5Shear Stress, psfHorizontal Deformation, in
1440 2280 4560
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
0.040
0.045
0.0 0.1 0.2 0.3 0.4 0.5Vertical Deformation, inHorizontal Deformation, in
1440 2280 4560
Cohesion = 513 psf
Friction Angle = 18.9o
APPENDIX B - GENERAL DESCRIPTION OF PROCEDURES
D&S ENGINEERING LABS, LLC Park Place Denton
Denton, Texas
G18-2196
ANALYTICAL METHODS TO PREDICT MOVEMENT
INDEX PROPERTY AND CLASSIFICATION TESTS
Index property and classification testing is perhaps the most basic, yet fundamental tool available
for predicting potential movements of clay soils. Index property testing typically consists of
moisture content, Atterberg Limits, and Grain-size distribution determinations. From these results,
a general assessment of a soil’s propensity for volume change with changes in soil moisture
content can be made.
Moisture Content
By studying the moisture content of the soils at varying depths and comparing them with the
results of Atterberg Limits, one can estimate a rough order of magnitude of potential soil
movement at various moisture contents, as well as movements with moisture changes. These
tests are typically performed in accordance with ASTM D2216.
Atterberg Limits
Atterberg limits determine the liquid limit (LL), plastic limit (PL), and plasticity index (PI) of a soil.
The liquid limit is the moisture content at which a soil begins to behave as a viscous fluid. The
plastic limit is the moisture content at which a soil becomes workable like putty, and at which a
clay soil begins to crumble when rolled into a thin thread (1/8” diameter). The PI is the numerical
difference between the moisture constants at the liquid limit and the plastic limit. This test is
typically performed in accordance with ASTM D4318.
Clay mineralogy and the particle size influence the Atterberg Limits values, with certain minerals
(e.g., montmorillonite) and smaller particle sizes having higher PI values, and therefore higher
movement potential.
A soil with a PI below about 15 to 18 is considered to be generally stable and should not
experience significant movement with changes in moisture content. Soils with a PI above about
30 to 35 are considered to be highly active and may exhibit considerable movement with changes
in moisture content.
Fat clays with very high liquid limits weakly cemented sandy clays, or silty clays are examples of
soils in which it can be difficult to predict movement from index property testing alone.
Grain-size Distribution
The simplest grain-size distribution test involves washing a soil specimen over the No. 200 mesh
sieve with an opening size of 0.075 mm (ASTM D1140). This particle size has been defined by
the engineering community as the demarcation between coarse-grained and fine-grained soils.
Particles smaller than this size can be further distinguished between silt-size and clay-size
particles by use of a Hydrometer test (ASTM D422). A more complete grain-size distribution test
that uses sieves to the relative number of particles according is the Sieve Gradation Analysis of
Soils (ASTM D6913). Once the characteristics of the soil are determined through classification
testing, a number of movement prediction techniques are available to predict the potential
movement of the soils. Some of these are discussed in general below.
D&S ENGINEERING LABS, LLC Park Place Denton
Denton, Texas
G18-2196
POTENTIAL VERTICAL MOVEMENT
A general index for movement is known as the Potential Vertical Rise (PVR). The actual term
PVR refers to the TxDOT Method 124-E mentioned above. For the purpose of this report, the
term Potential Vertical Movement (PVM) will be used since PVM estimates are derived using
multiple analytical techniques, not just TxDOT methods.
It should be noted that all slabs and foundations constructed on clay or clayey soils have at least
some risk of potential vertical movement due to changes in soil moisture contents. To eliminate
that risk, slabs and foundation elements (e.g., grade beams) should be designed as structural
elements physically separated by some distance from the subgrade soils (usually 6 to 12 inches).
Since the new building will be constructed with drilled shaft supported grade beams and
structurally supported floor slabs, the risk of post-construction PVM should be minimal.
SPECIAL COMMENTARY ON CONCRETE AND EARTHWORK
RESTRAINT TO SHRINKAGE CRACKS
One of the characteristics of concrete is that during the curing process shrinkage occurs and if
there are any restraints to prevent the concrete from shrinking, cracks can form. In a typical slab
on grade or structurally suspended foundation, there will be cracks due to interior beams and
piers that restrict shrinkage. Similar restraint can occur when pavements are cast directly against
rigid bedrock materials. This restriction is called Restraint to Shrinkage (RTS). These RTS cracks
do not normally adversely affect the overall performance of foundations or pavements. It should
be noted that for exposed floors, especially those that will be painted, stained or stamped, these
cracks may be aesthetically unacceptable. Any tile which is applied directly to concrete or over a
mortar bed over concrete has a high probability of minor cracks occurring in the tile due to RTS.
It is recommended if the tile is used to install expansion joints in appropriate locations to minimize
these cracks.
UTILITY TRENCH EXCAVATION
Trench excavation for utilities should be sloped or braced in the interest of safety. Attention is
drawn to OSHA Safety and Health Standards (29 CFR 1926/1910), Subpart P, regarding trench
excavations greater than 5 feet in depth.
FIELD SUPERVISION AND DENSITY TESTING
Field density and moisture content determinations should be made on each lift of fill with a
minimum of one (1) test performed per lift in the building pad area for every 7,500 square feet,
one (1) test per lift per 3,000 square feet in other fill areas, one test per lift in parking areas for
every 10,000 square feet, one (1) test lift per 300 linear feet of roadways and drives, and one (1)
test lift per 100 linear feet of utility trench backfill. Supervision by the field technician and the
project engineer is required. Some adjustments in the test frequencies may be required based
upon the general fill types and soil conditions at the time of fill placement.
D&S ENGINEERING LABS, LLC Park Place Denton
Denton, Texas
G18-2196
It is recommended that all site and subgrade preparation, proof rolling, and pavement construction
be monitored by a qualified engineering firm. Density tests should be performed to verify proper
compaction and moisture content of any earthwork. The inspection should be performed prior to
and during concrete placement operations. D&S would be pleased to perform these services in
support of this project.
14805 Trinity Boulevard, Fort Worth, Texas 76155
Geotechnical 817.529.8464 Corporate 940.735.3733
www.dsenglabs.com
Texas Engineering Firm Registration # F‐12796
Oklahoma Engineering Firm Certificate of Authorization CA 7181