Villages of CC 4-CS 920918The City With A Beautiful Future
September 18, 1992
P.O. Box 478
Coppell, Texas 75019
214-462-0022
Mr. Dennis Freeman
The Nelson Corporation
5999 Summerside g202
Dallas, TX 75252
Re: Villages of Cottonwood Creek Section IV
Dear Mr. Freeman:
This letter is written in response to our phone conversation of September 18, 1992 in which we
discussed the soil report submitted for this project. The soils report was submitted in an attempt
to gain approval to eliminate the subgrade stabilization on this project. However, after reviewing
the soils report and plotting the location of the borings on a site plan, it is apparent that to
eliminate the requirement for stabilization will require additional information to be submitted.
There were fourteen borings taken on this site, however, only #1, #4, #10 and #13 are either
in or near where a proposed street will be. Of those four, two show sand as the material, one
has a PI of 16 and one has a PI of 8. Also, because material has been brought in on this site,
there are some drastic soil changes as you go from 2 to 4 feet deep in some of the areas. Based
on the test results, the borings that have soil changes from 2 to 4 feet include #1, g2, #3, #6,
#g,//9, #11, #12, #13, and #14. Most of these change from a clay type sand to just a sand,
however, boring #6 changes from a clay sand to a sandy clay that has a PI of 26. This is a
fairly drastic change in only 2 feet.
If you wish to pursue the elimination of subgrade stabilization for this project, the following
information would be helpful in obtaining a positive recommendation from engineering.
1)
Soil samples should be taken in street right-of-way locations and they should be
representative of the various types of soil existing on the site. A minimum of five
should be taken. Also, the soil samples should be obtained after the street right-
of-way has been rough cut to grade.
Letter to Mr. Dennis Freeman
September 18, 1992
Page 2
2)
A lime series test should then be performed on the soil samples to determine if
lime will be beneficial to the stabilization of the soil. In areas where the soil is
obviously sand, the City would expect some type of cement stabilization to obtain
a foundation for the street.
I hope this direction has been helpful and if you should need any additional information, please
feel free to contact me at your conveaience.
Sincerely,
Kenneth M. Griffin, P.E.
City Engineer
KMG/bd
cc: Garreth Campbell, Construction Inspector
cotto 1