Park West CC(18)-CS 97041705/30/97 FRI 14:34 FAX 972 235 9544 Pacheco Koch Consult Eng ~003
April 17, 1997
Project No. 3486
Insignia Commercial Group, Inc.
7557 Rnmbler Road, Suite 1300
Dallas, Texas 75231-4167
ATTN: Mr. Kirk Tames
GEOTI~CHNICAL INVESTIGATION
PARKW~ST C~~ 1, BI.rIX,DING ri
A.I~L~N~ DRIV~ AT BELTLIN'~ ROAD
COPPELL, TEXAS
Transmitted herewith are copies of the referenced report. Should you have any
questions concerning our findings or if you desire additional information, please do not
hesitate to call.
Sincerely,
REED E~GINEER]2~G GROUP, ]2~C.
Ronald F. Reed, P.E.
~-p/RFR/apr
copies submitted: (2) Insignia Commercial Group, Inc./Mr. Kirk Tames
(2) Hardy-McCullah/MLM Architects, Inc./Mr. Harry Matthies --
(1) TenEyck Merritt Barnett & Pitt/Mr. Frank Merritt
05/30/97 FRI 14:34 FAX 972 235 9544 Pacheco Koch Consult Eng ~004
adjacent to the foundation, or extension of paving to the perimeter of the building. The barrier
should consist ora minimum six-inch wide, four-foot deep lean concrete wall. Trees and shrubs
should be planted outside the barrier. A moisture barrier (polyethylene) is recommended below
sections of the floor covered with carpeting, paint, or tile.
?avement
The specific pavement section will be dependent upon:
1. traffic loads and frequency;.
2. pavement type and strength;
3. desired pavement life and ending condition; and
4. strength and condition of the subgrnde.
~fformation regarding the specific traffic loads and frequency is not available. Therefore,
analysis was performed for a range of traffic conditions, and design thickness versus traffic load
diagrams were developed.
The pavement type. has been identified as concrete. Analysis was performed for both 3,000
---pounds per square inch (psi) and 4,000 psi compressive strength concrete. Based on
correlations between compressive strength and flexural strength, an allowable working stress of
370 and 425 psi was used for the 3,000- and 4,000-psi concrete, respectively. Control of the
water cement ratio at the design value during placement and use of quality construction will be
necessary to achieve the required flexural strength.
Project No. 3486 - 11 - April 15, 1997
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A 20-year life was used for the analysis. Total pavement life was based on a six-day week.
Analysis was performed in accordance with procedures developed by the American Association
of State Highway Offidals (AASHO).
Thc upper surface soils consist of CH clays. When these soils are moist, they are relatively soft.
For purposes of pavement analysis, the subgrade was assumed to be recompacted in accordance
with tho density and moisture recommendations in the Earthwork section and in a moist
condition. An effective modulus of subgrade reaction, k, of 100 pci was used for the analysis.
The effective k value ofthe subgrade can be increased to 270 pci by stabilization of the upper 6
inches with a minimum of six percent hydrated lime. Lime should be placed and compacted in
accordance with Item 260 of the current edition of TxDOT "Standard Specifications for
Construction of Highways, Street and Bridges". The lime stabilized subgrade should be
compacted to a minimum of 100 percent of ASTM D-698 density (Standard Proctor) unless
otherwise specified.
Generally, it is more cost-effective to increase the pavement thickness and construct over a non-
lime stabilized subgrade. Stabilization does howe, y. gr provide an all-weather working platform
for th~ contractor, and this may be beneficial fi.om a construction perspective. Stabilization is
also generally recommended if'the traffic speed exceeds 30' miles per hour (mph).
Project No. 3486 - I2- April 15, 1997
05/30/97 FRI 14:38 FAX 972 235 9544 Pacheco Koch Consult Eng ~006
Considering the above discussion, analysis was made for both unlimited repetitions of cars and
light trucks and for multiple repetitions of loaded tractor trailers. Analysis indicates a pavement
thickness of 4.5 inches of 3,000-psi concrete will be adequate for car and light truck tra~c. A
minimum five-inch section is recommended.
Pavements subject to multiple repetitions of tractor trailer traffic were analyzed using both
3,000- and 4,000-psi concrete. Trailers were assumed to be loaded to the maximum allowable
weight, 80 kips, consisting of two sets of tandem axles loaded to 32 kips, and one 16-kip axle.
Recommended sections for various frequency of truck traffic, based on number of repetitions
per day for a six-day week, are provided in the following tables.
TABLE 1 (K=100 PCl)
NUMBER OF TRUCK REPETITIONS VS. PAVEMENT THICKNESS
3,000-PSi COMPRESSIVE STRENGTH
Pavement Thickness No. of Repetitions
(inches) (oer dav]
6 11
7 27
8 ~, 58
9 125
Project No. 3486 - 13 - April 15, 1997
05/30/97 FRI 14:39 FAX 972 235 9544 Pacheco Koch Consult Eng ~007
TABLE 2 (K=100 PCI)
NUMBER OF TRUCK REPETITIONS VS. PAVEMENT THICKNESS
4,000..PSI COMPRESSIVE STRENGTH
Pavement Thickness No. of Repetitions
(inches) ~oer day)
6 18
7 47
8 101
9 224
Analysis of Tables 1 and 2 indicates an approximate 50 to 80 percent increase in the number of
truck repetitions can be obtained by increasing the concrete strength from 3,000 psi to 4,000 psi.
An increase of 100 to 150 percent is realized by increasing the thickness of the pavement by one
inch.
Although not provided herein, 'analysis of the allowable repetitions was also performed
considering a stabilized subgrade. For any given pavement thickness and strength of concrete,
an increase in the number of repetitions equal to 120 to 33 percent of the non-stabilized
repetitions is realized. Considering the relative costs associated with stabilizing the subgra-c~e, a
greater increase in repetitions (i.e., pavement life) is realized by increasing the pavement
thickness or strength versus stabilization of the subgrade.
Pavements should be lightly reinforced if shrinkage crack control is desired. Reinforcing for 5-
and 6-inch pavements should consist of the equivalent of#3 bars at 18 inches on-center.
Project No. 3486 - 14- April 15, 1997
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Pavement sections should be saw cut at an approximate spacing in feet of 2.5 to 3 times the
pavement thickness expressed in inches. (For example, a 5-inch pavement should be saw ~ut in
approximate 12.5 to 15-foot squares.) The actual jo'mt pattern should be carefully designed to
avoid irregular shapes. Recommended jointing techniques are discussed in detail in "~Ioint
Design for Concrete Highway and Street Pavements", published by the Portland Cement
Association (PCA).
Earthwork
All vegetation and topsoil containing organic material should be cleared and grubbed at the
beginning of earthwork construction. 5oils exposed at the surface, or which will underlie fill,
should be scarified to a depth of 6 inches and r~compacted to a minimum of 92 percent and a
maximum of 98 percent of the max/mum density as determined by ASTM D-698, "Standard
Proctor". The moisture content should range from +1 to +6 percentage points above optimum.
Site-excavated soils, where used as/ill, should be placed in maximum eight-inch loose lilts and
compacted to the moisture and density requirements outlined above.
Proper bacldilling around the building perimeter will reduce the potential for water seepage
_beneath the structure. FiU against the perimeter of the structure should consist of site-excavated
clays, or equal, and should be' placed and compacted in accordance with the recommendations
outlined above.
Project No. 3486 - 15- April 15, 1997
05/30/97 FRI 14:42 FAX 972 235 9544 Pacheco Koch Consult Eng ~009
IL.DING I BUlL.DING II BUlL. DING III
~ ~ ~B-9 B-10~ TRUCK ~
~ ~ ~T C~
m
r. ~ NOTE: Borings B-3 & B-4 drilled in February .1996
as part of preliminary investig, ation.
(Reed Engineering Group report ~2753)
t I I
100' 200' 400'
J
05/30/97 FRI 14:43 FAX 972 235 9544 Pacheco Koch Consult Eng ~]010
GEOTECHNICAL INVESTIGATION
PARKWEST CENTER 1, BUILDING II
AIRUNE DRIVE AT BELTLINE ROAD
COPPELL, TEXAS
Summary of Cl~,ssiflcation and Index Property Tests
Percent
Moisture Liquid Plastic Plasticity Passing
Boring Depth Content Limit Limi~ Index No. 200
No.- ~ ~ _(.?A)_ (%) .... (PI) Sieve
B-7 0.0 -1.5 34.4 ....
1.5 -3.0 32.6 ....
3.0 -4.5 32.9 .....
4.5 -6.0 28.3 ....
9.0 -10.0 27.5 - - - 86
14.0 -15.0 19.3 51 19 32 -
B-9 0.0 -1.5 35.2 ....
1.5 -3.0 34.4 ....
3.0 -4.5 32.9 .....
4.5 -6.0 30.9 .....
9.0 -10.0 32.0 ....
14.0 -15.0 26.6 ......
19.0 - 20.0 28.8 59 27 32 --
24.0 - 25.0 37.1 .......
B-11 0.0 1.5 34.6 ......
1.5 3.0 31.6 .....
3.0 4.5 30.2 .....
4.5 - 6.0 28.1 ....
9.0 - 10.0' 27.7 69 25 44 -
14.0 - 15.0 35.9 .....
19.0 - 20.0 30.8 ......
24.0 - 25.0 23.4 58 32 26 -
B-12 0.0 -1.5 35.7 .....
1.5 3.0 34.6 ......
3.0 4.5 31.6 ....
4.5 6.0 30.5 .....
9.0 -10.0 28.2 .....
14.0 -15.0 32.8 79 31 48 ......
19.0 - 20.0 30.6 .....
24.0 - 25.0 26.2 .......
SUMMARY OF LABORATORY TEST RESULTS PLATE 12
Pacheco Koch '
May 29,1997
PK No. 1628-97.068
Mr. Michael A. Martin, P.E.
CITY OF COPPELL
255 E. Parkway Boulevard
P.O. Box 478
Coppell, Texas 75019-4409
Re: PARK WEST CENTER, PHASE II
Block 2, Lot IR & 2R
Coppell, Texas
Dear Mr. Martin:
This letter shall request a variance to the Subdivision Ordinance for deletion of lime
stabilization in the subgrade. The pavement analysis and recommendations of the
Geotechnical Report offers several options to increase the effective modulus of subgrade
reaction (k) value. The Geotechnical Report was prepared by REED ENGINEERING
GROUP, INC., in April of this year. A copy of the "Pavement" Section on Pages 11-15
of that report has been provided for your reference and records.
The Geotechnical Report recommends a minimum five (5) inch section of 3,000-psi
concrete on a six (6) inches of line stabilized subgrade. The Report also allows
increasing the pavement thickness or strength versus stabilization of the subgrade. The
sections proposed for this project are five (5) inch and six (6) inch 4,000-psi concrete
reinforced with No. 3 bars on eighteen (18) inches on centers.
Your favorable consideration and approval of this variance for deletion of lime
stabilization in the subgrade is requested. Please advise should you have any questions
concerning this request.
Sincerely,
John R. Powell, P.E.
JRP/jaj
1628-62
eno.
cc: Mr. Norman Coates - Hardy McCullah/MLM Architects
Mr. Brian Grant - Insignia Group