WA9601B-CS 980921 SHIMEK, JACOBS & FINKLEA, L.L.P. q O{
CONSULTING ENGINEERS
8333 Douglas Avenue,//820 Dallas, Texas 75225-5816 Fax (214) 361-0204 Phone (214) 361-7900
ROSS L. JACOBS, PE.
RONALD V. CONWAY, PE.
JOHN W BIRKHOFF, PE.
JoE R. CARTER, P.E September 21, 1998
GARY C HENDRICKS, P.E
1. C F|NKLEA, P.E
Mr. Kenneth M. Griffin, P.E.
City Engineer/Assistant City Manager
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.
cc: Mr. Larry Davis
J\CLERICAL\COPPELL\96-149\LETTERS\CONST\city2 doc
_~~1HENLEY
JOHNSTON
& ASSOCIATES, INC,
r~tlSKtlc'~.',dn9 ,qeosc[encC CO~
16 Se ~tember 1998
Landn ark
1665 Flarmon Road
Fort V~orth, Texas 76177
Attenti,m: Mr. Joe Swinnea
Re: Density Tests
Water Line Backfill
Sandy Lake Road
Coppoll, Texas
HJA 6949
Dear ~ r. Swinnea:
In acccrdance 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 ne and about 6-foot depth in bore pits. Samples were taken at about 1-foot
interva s. At two locations, Station 77+87 and Station 92+90, bulk samples were
obtaine :i by augering to about 3-foot depth.
All She by Tube samples obtained from the borings were extruded from the sampler in
the fiek and encased in polyethylene plastic to prevent changes in moisture content and
to pres~.~rve in situ physical properties. The samples were labeled as to 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
Classifi,mtion 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 Plat~;s 1 and 2. Standard Proctor Compaction tests (ASTM D 698) were performed
on ead~ bulk sample. The results of these tests are presented on Plate 2. Each Shelby
Tube s;.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 Plahis 1 and 2.
~elcphone 214} 941-3808 J~z (214) 943-7645 235 Morgczrt Ave.. Dallas. Texas 75203-1088
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This rr athod 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
moisture and density measurements by nuclear methods. Small inclusions in the
physic ~1 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
frogroe nt in the sample may provide a "high" density and a "low" moisture content; A
void, c inclusion of organic matter, may provide a "low" density and "high" moisture
canton Pushing a sample tube into the soil and extracting the sample f~om the tube
will dis urb the soil, even though the sample is considered "undisturbed" for geotechnical
testing purposes.
Some ' ariations 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
two feet, the density drops off' considerably. We would expect that in the natural state
the upFler materials may have relatively high densities partially because of the relatively
dry car 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 water line. W._.9..e
w~uld ~infini,n~t~_ that, in normal moisture conditions, no. rural soils near the surface will
ty_picall:/have den. sities .r~ear 85 to 90 percent of the maximum dr,/.de. nsity determined
by a Standard Proctor Compaction tes..t.
The 0 ~timum Moisture Content for both Proctor samples is about 13.5 percent. In
Baring Nos. 1 and 2 below about 3 to 4-foot depth, the moisture contents are very low,
ranginc~ from about 3.5 to 7 percentage points below Optimum Moisture Content. The
upper to 3 feet of soil in Boring Nos. 3 and 4 also is very dry with moisture contents
about z to 7.5 percentage points below Optimum and the upper I foot of Boring No. 9
is very low in moisture content. Two high moisture content areas were noted - about 1
to 3 fee in Boring No. 2 and about I to 3 feet in Boring No. 5.
We do ~ot 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.
engln~¢~ ~e~C[~C~ consutt~qts
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Land ark Page 3
Mr. Jo a Swinnea
16 Se ~tember 1998
We trt st that this provides the information you need at this time. Please call us if you
have any questions or when we can be of further assistance to you.
Sincerely,
John W. Johnston, P.E.
Executive Vice President
Henley-Johnston & Associates, Inc.
JWJ
I=ncls.
HENLEY
JOHNSTON
ASSOCIATES, INC.
c. ttg~ne~'t~nJ~ geoscience
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WATER LINE IN SANDY LAKE ROAD
COPPELL, TEXAS
SUMMARY OF LABORATORY TESTS
BOR ~G STATION DEPTH MC DUW PROCTOR % MAXIMUM
NUME ER NUMBER (if) (%) (pc0 DRY DENSITY
~ B-1 82+79 0.0-1.0 10.3 111.5 001 97,0
B-1 1.0-2.0 15.4 114.4 001 99.5
~,p~. B-1 2.0-3.0 15.5 115,5 001 100+
~/Z/f/l~ E~-I 3.0-4.0 13.0 1138 001 98.9
8-1 4,0-5.0 6.5 101.5 002 ' 89.0
8-1 5.0-6.0 7.3 119.8 002 1 O0 +
IB-2 83+35 0.0-1.0 16.9 106.7 002 93.6
B -2 1.0 -2.0 21.0 109.1 002 95.7
~'f7jr' B-2 2.0-3.0 21.0 104.7 002 91.8
B-2 4.0-5.0 7.9 109.3 002 95.9
~" B-2 5.0-6.0 7.9 104.1 002 91.3
__.B-3 85+86 0.0-1.0 6.2 (~
/--j~, ~ B-3 1 .Q-2.O 7.0 101.0 002
8-3 2.0-3. O 14.7 109,6 002 96.1
B-4 87 + 89 0.0-1.0 8.5 115.4 002 100 +
B-4 1.0-2.0 9,3 101.1 002
~l~r, B-4 3.04.0 11.8 107.7 002 '94.5
lB-4 4.0-5.0 10.9 103.9 001 90.3
B-4 5.0-6.0 11,4 113.8 001 99.0
B-5 89 + 43 0,0-1.0 17.4 104.2 002 91.4
B -5 1.0-2.0 22,7 98.6 002
B-~ 3.04.0 17.1 104.0 002 91
B-5 4.0-5.0 1 ~.7 108.4 002 95.1
B-5 5.0-6.0 18.8 107.1 002 93.9
HENLEY
JOHNSTON
& ASSOCIATES~ INC.
~ . en~inetdn9 9eosc~e~ce c~suttan~s
P~TE
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WATER LINE IN SANDY LAKE ROAD
COPPELL, TEXAS
SUMMARY OF LABORATORY TESTS
BORI ,~G STATION DEPTH MC DUW PROCTOR % MAXIMUM
NUM ER NUMBER (~) (%) (pcf) DRY DENSITY
i!~ 94+68 O.O-1.0 13,5 119,6 002 100+
2,0-3,0 15.8 107.6 002 94.4
B-6 3,0-4,0 15,3 106.8 002 93.7
B-6 4.0-5,0 14.6 108,4 002 95.1
8-6 ~] .0-6.0 16.0 110.0 002 96.5
B-7 95+46 0.0-1,0 12.3 115.6 002 100+
8-7 1.0-2.0 12,0 111.1 002 97.5
B-7 2.0-3.0 11.6 103.9 002 91.1
B-7 3.0-4.0 13.2 105.0 002 92.1
B-7 4.0-5.0 11.3 102.7 002 90.1
B-7 5.0-6.0 17.0 105,6 002 92.6
1.0-2.0 15.8 114,3 002 100+
2.0-3.0 17.6 106.1 002 93.1
B-9 77+87 0.0-1.0 8.,5 120.9 001 100+
B-9 1.0-2.0 13.6 112.1 001 97.5
B-9 2.0-3,0 '1] .1 102.9 001 89.5
SUMMA I.Y. OF STANDARD PROCTOR DENSITY TESTS
01 Brawn and reddish brown sandy clay with some gravel
Optimum Moisture Content: 13.7 %
Maximum Dry Density: 115.0 pcf
Brown clay with some weathered limestone fragments
Optimum Moisture Content: 13,5 %
Maximum Dry Density: 114.0 pcf
* Unable to trim sample.
HENLEY
JOHNSTON
& ASSOCIATES, INC.
en,q(tlct'r~n.q 9eo.~c(etlcf2 consulb',nCS
PLATE 2
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