WA9601-LR 980921SHIMEK, JACOBS & FINKLEA, L.L.P.
CONSULTING ENGINEERS
8333 Douglas Avenue, #820 Dallas, Texas 75225-5816 Fax (214) 361-0204 Phone (214) 361-7900
ROSS L. JACOBS, P.E.
JOHN W. BIRKHOFF, P.E.
JOE R. CARTER, P.E. ~ · '~ e em e ,
GARY C. HENDRICKS, P.E.
I. C. FINKLEA, P.E.
Mr. Kenneth M. Griffin, P.E.
City of Coppell
Post Office Box 478
Coppell, Texas 75019
Re: Sandy Lake Road Water Line
Backfill Compaction Testing
Dear Mr. Griffin:
We are enclosing the backfill density test report prepared by Henley, Johnston and Associates, Inc for the
Sandy Lake Road water line project. From our review of the results it appears that the backfill densities
generally meet the requirements for backfill compaction of the North Central Council of Governments
specifications (NCTCOG Item 6.2.9b(2)).
Three locations are indicated to have densities less than 90%. However, all three are within the upper two
feet of the backfill. It is our opinion these isolated cases will not adversely affect the construction or
performance of the proposed brick screening wall adjacent to the water line project.
We are available to discuss this project further at your convenience.
Sincerely yours,
~ Mr. Larry Davis
J:\CLERICAL\COPPELL\96- | 49~LETTERS\CONST~city2. doc
HENLEY
JOHNSTON
& ASSOCIATES, INC.
16 September 1998
Landrr ark
1665 Harmon Road
Fort Worth, Texas 76177
Attention: Mr. Joe Swinnea
/
/
Re:
Density Tests
Water Line Backfill
Sandy Lake Road
Coppell, Texas
HJA 6949
Dear IV r. Swinnea:
In accordance with our recent discussions, we have completed post-construction density
testing of backfill along the Sandy Lake Road water line, from approximately Station
77+87 to Station 95+46, in Coppell, Texas. A truck-mounted geotechnical drilling rig
was used to push Shelby Tube samplers into the soil to about 3-foot depth over the
water I'ne and about 6-foot depth in bore pits. Samples were taken at about 1-foot
intervals. At two locations, Station 77+87 and Station 92+90, bulk samples were
obtained by augering to about 3-foot depth.
All She by Tube samples obtained from the borings were extruded from the sampler in
appropriate
boring lumber and depth, and placed in core boxes for transport to the laboratory,
All soil samples were classified in the laboratory in accordance with the Unified Soil
Classification System. Moisture Content and Unit Dry Weight were determined for each
Shelby Tube sample. The sample at 0 to 1-foot depth in Boring No. 3 (Station 85+86)
was so dry that it crumbled when unwrapped in the laboratory and only a moisture
content test could be performed for this sample. The above test data are summarized
on Plates I and 2. Standard Proctor Compaction tests (ASTM D 698) were performed
on eaci' bulk sample. The results of these tests are presented on Plate 2. Each Shelby
Tube sF..mple was matched to one of the compaction tests and dry density of the sample
compared to the maximum dry density determined by the appropriate compaction test.
These comparisons are tabulated for each sample as percent of maximum dry density
on Plates I and 2.
cel~phone (234] 941-3808
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8888-6£~-Ll8:33~ ·
235 Morgc~rt Ave..
Dallas. Texas 75203.1088
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This method of testing can vary from results provided by on-site field density check tests
during construction, but does provide a basis for determining if the material was placed
consis:ently and generally in accordance with specifications. The sample taken and
tested by this method is smaller than the volume of material typically included in the
moistu-e and density measurements by nuclear methods. Small inclusions in the
physical sample could cause variations that might be "averaged" in the larger sampling
volume of the nuclear gauge. For example, inclusion of a piece of gravel or rock
fragment in the sample may provide a "high" density and a "low" moisture content; A
void, or inclusion of organic matter, may provide a "low" density and "high" moisture
conten:, Pushing a sample tube into the soil and extracting the sample from the tube
will dis:urb the soil, even though the sample is considered "undisturbed" for geotechnical
testing purposes.
Some variations in density are noted in the samples obtained for this investigation. We
unders:and that the samples obtained in Boring No. 8 were in soil that had not been
excava:ed for the water line installation. It should be noted that the upper two feet of
material at this location had hig. h densities compared to the maximum dry density; below
two feet, the density drops off considerably. We would expect that in the natural state
the upper materials may have relatively high densities partially because of the relatively
dry cot ditions at the time of the sampling and partially because construction equipment
may h~ve run over this location many times during construction of the wster line. W,,_.9,,e
would enfinip~ that, in normal moisture conditions, natural soils nea_.r the_ surface will
typically have densities near 85 to 90 percent of the maximum dry d~nsity determined
by a Standard Proctor Compaction tes.t
The Optimum Moisture Content for both Proctor samples is about 13.5 percent. In
Boring Nos. 1 and 2 below about 3 to 4-foot depth, the moisture contents are very low,
ranging from about 3.5 to 7 percentage points below Optimum Moisture Content. The
upper 2 to 3 feet of soil in Boring Nos. 3 and 4 also is very dry with moisture contents
about 4 to 7.5 percentage points below Optimum and the upper I foot of Boring No. 9
is very ow in moisture content. Two high moisture content areas were noted - about 1
to 3 feet in Boring No. 2 and about 1 to 3 feet in Boring No. 5,
We do qot know what the specifications require for this project; the above comments
are get oral observations from the data obtained from this investigation.
HENLEY
JOHNSTON
& ASSOCIATES, INC.
en.qmecrin9 9e,,.,~dertce cons~t~nrs
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We trust that this provides the information you need
have aly questions or when we can be of furlher assistance to you.
Page 3
at this time. Please call us if you
Sincerely.
John W. Johnston, P.E.
Executive Vice President
Henley-Johnston & Associates. Inc.
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HENLEY
JOHNSTON
& ASSOCIATES, INC,
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WATER LINE IN SANDY LAKE ROAD
COPPELL, TEXAS
SUMMARY OF LABORATORY TESTS
RORI'qG
NUMEER
B-1
B-I
B'1
B-1
B-1
8-1
~rB.2
B-2
B-2
8-2
8-2
B-3
B-3
B-3
fB..4
B-4
B-4
B-4
B-4
B-5
5-5
B-S
B-S
B-5
B-5
gOO'd
STATION
NUMBER
82+79
83+35
85+86
87+89
89+43
DEPTH MC DUW
(~) (%) (pcr)
0,0-1.0 10.3 111.5
1.0-2.0 15.4 114.4
2.0-3.0 15,5 115,5
3.0-,4.0 13.0 113.9
4.0-5.0 6,5 101.5
5.0o6.0 7,3 119.8
PROCTOR
001
001
001
001
002
o02
% MAXIMUM
DRY DENSITY
97,0
g9.5
100+
99.9
"89.0
100+
0.0-1-0 16.9 106.7 002 93.6
1.0-2.0 21.0 109.1 002 95.7
2.0-3,0 21.0 104.7 002 91.8
3,0-4,0 9,8 112,4 002 98,6
4.0-5.0 7,9 109.3 002 95.9
5,0-6.0 7.9 104.1 002 91,3
0.0-1.0 6.2 *
1.0-2.0 7.0 101,0 002
2.0-3.0 14.7 109,6 002 96.1
0.0-1,0 8.5 115,4 002 100+
1.0-2.0 9,3 101.1 002 (~
2.0-3.0 10.5 110.0 002 96.5
3.0-4.0 11.8 107.7 002 '94.5
4,0-5,0 10,9 103.9 O01 90.3
5.0-6.0 11.4 113.8 001 99.0
0.0-1 .O 17.4 104,2 002 91.4
1,0-2,0 22.7 98,6 002 ~
2.0-3,0 19,9 108.2 002 94.9
3.0-4.0 17,1 104.0 002 91.2
4.0-5,0 15,7 108,4 O02 95,1
5.0-6.0 18,8 107,1 002 93,9
·
HENLEY
JOHNSTON
& ASSOCIATES, INC.
c'tlginestin99eosc~,,nce con~utc<mcs
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PI~ATE 1
(nH~) 86 ,L[- 'a3S
WATER LINE IN SANDY LAKE ROAD
COPPELL, TEXAS
SUMMARY OF LABORATORY TESTS
B-6
B-6
B-6
B-6
8-6
B-7
B-7
B-7
STATION
NUMBER
94+68
95+46
92+90
77+87
DEPTH MC DLRN PROCTOR % MAXIMUM
(~) (%) (pcf) DRY DENSITY
0.0-1.0 13.5 119.6 O02 100 +
1,0-2.0 12.1 111,1 O02 97.S
2.04.0 15.8 107.6 002 94.4
3.0--4.0 15.3 106.8 002 ." '93.7
4.0-5,0 14,6 108.4 002 95.1
5,0-6.0 16.0 110.0 002 96.5
0,0-1,0 12.3 115.6 002 100 +
1.0-2.0 12,0 111,1 002 97.5
2.0-3.0 11,6 103.9 002 91.1
3.0-4.0 13.2 105,0 002 92.1
4.0-5.0 11.3 102,7 002 90.1
5.0-6,0 17.0 105,6 002 92.6
0.0-1.0 11,9 120.6 002 100+
1.0-2.0 15.8 114.3 002 100+
2.0-3,0 17.6 106, 1 002 93,1
0,0-1 ,O 8.5 120,9 001 100+
1.0-2.0 13.6 112.1 O01 97,5
2,04,0 11.1 102.9 001 89,5
SUMMARY OF STANDARD PROCTOR DENSITY TESTS
C01
Brown and reddish brown sandy clay witl~ some gravel
Optimum Moisture Content: 13.7 %
M~cimum Dry Density: 115,0 pcf
002
Brown clay with some weathered limestone fragments
Optimum Moisture Content: 13.S %
Maximum Dry Density: 114.0 pcf
* Unable to trim sample,
900 'a
·
8888 -6.et~-L 18:131
HENLEY
JOHNSTON
& ASSOCIATES, INC,
enOlnet'nn.q 9eo,~clertc~' consuC~ancs
PLATE 2
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