Westhaven Phase 2B-LR170112Geotechnical2209 6Jfisconsin St. Tel: 972.620.8911
ALPHA fXTESTING Construction Alateritrls Suite 100 Fax: 972.620.1302
Envir•onatental Dallas, Texas 75229 ivtiviv.alphatesting.corn
T6PE Firer No. 813
WHERE IT ALL BEGINS
Gilco Contracting, Inc,
6331 Southwest Blvd..
Benbrook, TX 76132
Attention: Jamey Burchett
January 12, 2017
Re: Pavement Subgrade Stabilization
Westhaven Phase 2B
Coppell Texas
ALPHA Report No, 162128-1
Submitted herein are results of our analysis of the pavement subgrade stabilization for the streets at the above
referenced developmens. The exposed pavement subgrade was evaluated by obtaining a total of 7 discrete samples
from random locations along the alignment of the streets. Atterberg-limit tests were performed on 4 of the discrete
samples. Lime series tests by the Atterberg-limits (.ASTM C-977, Appendix XI) were performed on the soil sample
which exhibited the highest Atterberg-Limits. Results of the Atterberg-limit tests and the lime series are attached to
this report.
Based on visual observation of the exposed pavement subgrades and results of the above described lime series, it is
determined that the amount of lime required to reduce the subgrade soil's plasticity index to 15 percent or less is
about 2 percent of the subgrade soil dry unit weight of 120 pcf (about 11 lbs per 6 -inch thick subgrade for sq yard).
However, the City of Coppell requires street subgrades be mechanically lime stabilized using a minimum rate of 6
percent of subgrade soil's dry unit weight. As a result, ALPHA recommends the street's exposed subgrade soils at
the referenced development be mechanically lime stabilized with 6 percent lime. This percentage of lime equates to
32 lbs per sq yard per 6 -inch thick compacted depth based on a soil dry unit weight of about 120 pcf, This unit
weight is based on actual Proctor test (ASTM -D698) performed on soils obtained from the referenced site.
We appreciate the opportunity to be of service on this project. If we can be of further assistance, please call upon us.
Sincerely,
ALPHA TESTING, INC.
hill
Attef Abus kra, P. E.
Geoteche(Tony)
il EiEi,
52
Theodo. E.
Principal
Ap
.DYY�RD r•
f
10564
s �
�•�y,�D,Op4V...PA 1
1-(Z- 261-1
Elli
40
35
30
X
to
? 25
U
F— 20
CL
15
10
5
0 1
0%
1% 2%
SAMPLE NO.:
DESCRIPTION
LOCATION:
ATTERBERG-LIMITS LIME SERIES
3% 4% 5% 6% 7%
PERCENT HYDRATED LIME
4
BROWN CLAY WITH GRAVEL.
JOHNS AVENUE AT STATION 7+00
�tx
8% 9% 10%
CLIENT:
LABORATORY TEST:
Gilco Contracting, Inc.
LIME SERIES DATA
Benbrook, Texas
♦♦
IF
FIGURE - I
'I'BPE Finn No, 813
PROJECT NAME:
ALPHA PROJECT NO.:
DATE:
Westhaven Phase 2B
162128-,l
January 12,20J7
Coppell, Texas
2 of 4
LOCATION AND DESCRIPTION:
I LOCATION: WINDSOR DRIVE AT STATION 17+00
DISCRIPTION: DARK BROWN CLAY
2 LOCATION: SWEARING ROAD AT STATION 2+50
DISCRIPTION: DARK BROWN SANDY CLAY
3 LOCATION: WINGATE ROAD AT STATION 13+00
DISCRIPTION: BROWN SANDYCLAY
4 LOCATION: JOHNS AVENUE AT STATION 7+00
DISCRIPTION: BROWN CLAY WITH GRAVEL
CLIENT:
LABORATORY TEST:
Gilco Contracting, Inc.
LIME SERIES DATA
Benbrook, Texas
FIGURE - 2
TBPE Firm No. 813
PROJECT NAME:
ALPHA PROJECT NO.;
DATE:
Westhaven Phase 213
162128-1
January 12, 2017
Coppell, Texas
3 of 3