Northlake WE P10C-CS 961220FUGRO-McCLELLAND (SOUTHWEST), INC.
December 20, 1996
Site Concrete
3328 Roy Orr Blvd.
Grand Prairie, Texas 75050-4207
2880 Virgo Lane
Dallas, Texas 75229
Tel: (214) 484-8301
Fax: (214) 620-7328
Attention: Mr. Mike Boney
Dear Mr. Boney:
Re:
Project No. 0761-2105
Pavement Subgrade Observation
Northlake Woodlands 10C
Coppell, Texas
As requested, the undersigned, Keyvan Ranjbaran, visited the site of the referenced
project on December 9, 1996. The purpose of this site visit was to visually observe the
nature of the subgrade materials exposed at the proposed streets after the completion
of the utility construction and to provide additional recommendations.
We had previously obtained two samples of the subgrade materials and based on the
results of the laboratory tests, we recommended the use of lime to stabilize the
subgrade soils.
At the time of our site visits, the subgrade of all the streets within the referenced site
were visually observed and samples of subgrade were obtained at several locations to
a depth of six inches. The results of the Atterberg Limits tests are presented below:
Sample Location::~ Matenai Description :;: :=...~,:::~: ~=:~::!:: ~.,~de:v ~! NO200
: : i~:i : : ; : .::i ; : :;: : :: : ~.: Sieve
1 Intersection of Light brown sandy
Willet Drive and clay with gravel 36 12 18 -
Hummingbird Drive
2 Bluejay Lane, at lot Light tan and brown
31 silty sandy clay with 23 10 13 -
gravel
3 Hummingbird Drive Tan fine sand
at lot 17 Non-Plastic 23
A member of the Fugro group of companies with offices throughout the world
Mr. Mike Boney
Project No. 0761-2105
December 20, 1996
Page 2
An Eades and Grim pH and a Lime Series test were performed on sample #1.
results are as follows:
percent Lime LiqUid i:: PlaStic PlaStiCity
pR:ii', iLl,it ::!' .Li~it :.: :Index::
0 8.18 36 12 18
2 11.90 - - -
4 12.24 25 15 10
6 12.33 - - -
8 12.34 - - -
The
The subgrade in the majority of the streets consist of intermixed clay and sandy clay
soils. In the majority of the locations the percentage of clayey type soils were greater
than the intermixed sandy soils. In these areas we recommend the use of lime to
stabilize the subgrade soils.
In some limited areas, the subgrade consist of either sandy soils or intermixed sandy
and clayey soils (with greater percentages being the sandy soils). In these areas, we
recommend the use of cement to stabilize the soils. The attached site plan identifies
the areas that require either lime or cement to stabilize the exposed subgrade.
The following table indicates the amount of lime or cement needed (in pounds per
square yard) to stabilize the top 6 inches of the subgrade soils:
24 pounds per square yard
28 pounds per square yard
The lime and the stabilization and compaction of the subgrade should be performed in
accordance with the applicable City specifications.
Mr. Mike Boney
Project No. 0761-2105
December 20, 1996
Page 3
We trust this information will be sufficient for your present needs. Please call if we can
be of further assistance.
Sincerely
FUGRO-McCLELLAND (SOUTHWEST}, INC.
SMH/br
Attachments
Distribution: Site Concrete - Mike Boney
Northlake Woodlands Development - Steve Parsons
~ USE CEMENT IN ZONE~TO MODIFY ~ USE LIME IN ZONE~TO MODIFY
SUBG~DE SANDY SOILS SUBGRADE C~YEY SOILS
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No~hlake Woodlands East
No. 10 C Coppell, Texas
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12-1~ GLP 0761-2~ 05 P LATE A