ST9302-CS 990816ALPHA TESTING, INC.
2209 Wisconsin St., Suite 100
Dallas, Texas 75229
972/620-8911 - 972/263-4937 (Metro)
FAX: 972/406-8023
August 16, 1999
CITY OF COPPELL
255 Parkway Boulevard
Coppell, TX 750i9
Attention: Mr. Ken Griffin
Re: Pavement Subgrade
SANDY LAKE ROAD (WEST BOUND)
(Station 0+00 through 56+00)
Project No. ST-93-02
Coppell, Texas
ALPHA Report No. 98881-55
Submitted herein are the results of our analysis of the pavement
subgrade at the above referenced site. The subgrade was sampled
and ten (10) typical subgrade soil samples were obtained.
Atterberg-limit tests were performed on six representative
samples. Results of the Atterberg-limit tests are attached to
this report.
Project plans and information supplied by client's representative
establish the application rate of stabilization or modification
as 39 lbs per square yard (per 8 inch compacted depth) by dry
weight, however the decision on whether to apply lime or cement
to the subgrade is to be determined by laboratory tests. Based on
visual observation of pavement subgrade and results of Atterberg-
limit tests, it is recommended that the pavement subgrade be
modified with portland cement at the above referenced rate. While
the addition of either lime or cement at the above referenced
rate would reduce the plasticity index of the higher plastic
material to 15 or less, the addition of cement would better
improve the performance of the lower plastic materials.
Ail mechanical modification should be performed in general
compliance with the City of Coppell Standards and Specifications.
We appreciate the opportunity to be of service on this project.
If we can be of further assistance, please call upon us.
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(1) Client
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Geotechnical Engineering · ConslTuCfion Materials Testing · Environmental Engineering · Consulting
RESULTS OF LABORATORY TESTS
SAMPLE LIQUID LIMIT
PLASTICITY INDEX
I 27 13
2 43 23
3 53 9
6 45 23
7 35 18
8 40 20
LOCATION AND DESCRIPTION:
SANDY LAKE WEST BOUND ~ STATION 7+50
[LIGHT BROWN SANDY CLAY (CL)]
SANDY LAKE WEST BOUND @ STATION 12+50
[BROWN SANDY CLAY (CL)]
SANDY LAKE WEST BOUND ~ STATION 17+50
[LIGHT BROWN SANDY CLAY (CL)]
SANDY LAKE WEST BOUND ~ STATION 32+50
[BROWN CLAY (CL) WITH SOME LIMESTONE]
SANDY LAKE WEST BOUND ~ STATION a7" +50
[LIGHT BROWN CALCAREOUS CLAY (CL)]
SANDY LAKE WEST BOUND ~ STATION 42+50
[BROWN CLAY (CL) WITH LIMESTONE]
CITY OF COPPELL
COPPELL, TEXAS
SANDY LAKE ROAD
COPPELL~ TEXAS
LARORATORY TEST RESULTS
(FIGURE-I)
98881 -55 8/12/99