ST8807-SY 881130 CONSTRUCTION MATERIALS TESTING
FIELD INSPECTION
INC.
"Excelk, nce b~ Experience" ..-
C~=ne! i Development.` inc.
P.O. Box 54-1057
Dal I -=,~.==. Te~as -' ~/ ~'i: -_'3- -- ~- i 057~
~*'~' ,,: . Jim Gaspar:
Re: U'Liiity Trench Design
Water, Sanitary 5~ Storm Sewer
Main : oc. ation
Royal Lane Ex ten'_=i on
Coppell, Texas
88-160
Dear Mr. Gaspar:
In accordance ~ith yo~r reques'-t, on November ~' 1988 we drilled
four (4) s,-~il core borings along the proposed centertines o¥ T'he
above referenced underground utitiles. Undisturbed samples were
procured and returned t~ our- laboratory for testing. The Summary
of tests, along with the Borin,~ Logs are attached.
Th=~ purpoae ~+~,c 'this investigation was to study the sub-surface soil
stratigrapny alon.= _,.e proposed utility lines in order to properly
de-s~gn an open trench to be used in utility construction.
Boring B-i: Line "B" -Sra. 1'0+00; 15 '~eet deep
Boring B-2: Line "B" -Sra. 5+00; 14 feet deep. "
Boring B-5: Line j'A" -Sra.. .B+O0;'. 14 '~eet deep..
~eet of s~f. ~ very st~f~ dark bro~n.-~o-'kan an'e;--broW ~-'~ . ' .......
No .groundwater was encountered in any of the borings after dril-
ling. We do not expect significant ground water intrusion during
constructi on.
In order to determine a safe open trench conf~_guration, we re-
fer'red to a bulletin on "Excavating and Trenching Operations",
published by the U.S. Department of Labor Occupational Safety &
Health Administration, July 1975, revised 1987. The angles of
repose from our enclosed typical trench cross-section were taken
from "Fi.~ure 1",Page 4, Titled "Approximate Angle of Repose ~or
Sloping ~f Sides o~ Excavations".
The project comprises approximately 2850 ~eet of twelve (12")
inch PVC water main, approximately 2050 ~eet o~ eight (8") inch
sanitary sewer main and approximately 1100 feet o~ 54 inch rein-
forced concrete pipe progressing up to two six (6) feet by four
(4) feet reinforced concrete box culver.t future storm sewer main.
A great majority of the trench excavation will require cuts bet-
ween ten (io~ and enurteen ~14) ~eet belo~ existing grade.
For purposes of continuity, we recommend that the trench walls be
cut vertically ~rom bottom a maximum hei,~ht of ~iv~ (~) feet. At
the top of the vertical cut, where necessary, the trench should~e
sloped back on a one-to-one (1:1) con~iquration up to the existing
ground surface, as shown on the typical trench cross-section sheet.
On ail vertical excavations adjacent to roadways, the contractor
may elect to utilize a qlidino trench box in all cuts deeper than
five (5) ~e~9 in order to prevent caving or sloughing of the
trench walls. This method is acceptable by the Code.
The foregoing recommendations are based on the analyses which pre-
sume the condition of soil properties between the borings to have a
normally t~niform variation of conditions revealed by the borings.
Sho~ld any unusual conditions be encountered during construction,
this office should be contacted immediately so that further investi-
gation and supplemental recommendations can be given.
Furt~'~er, since we are not actively engaged in any phase of trench
excavation, Geo-Technique~ Inc., or any of its employees accept~ no
responsibil-ity for the safety of these operations.
I trust this is the information you desire; and if we can.be
further service~ please ca~l on us. ~"].'
Respectfully submitted ~t~- ' '~-'
U3d SAAOq8
NOI.LyMI3N3d
0
m aunssaua o o o o o o o
L~ 9NINI'~NO::)
C,J H.LON 3 t=lJ.g c,') ,-~ ~' C) co t~ r'~
NOIS$3 ~d~lO::) n-) r~ ~0 ~O cr (Y) ~0
~0 o o c~ o o
LOG OF BORING
PROJECT: Utility Trench Design, Coppell, Texas BORINGNO.: B-1
CLIENT: Connell Development, Inc., Dallas, Texas LOCATION: Line "B"
Sta. 10+00
Le~m~d:
_~ · Sample X Penetration ~ Wat~
O~ ~/ De~ription of Strstum S~l Cl~
Stiff to Very Stiff Dark Brown &
- 5 ~ Gray Clay ~ CH
~ Very Stiff Tan&Gray Clay CH
Very Stiff Tan Clay w/ Thin
- lO- Sand Lenses~ CH
- 15- Bottom ~ 13 feet
No Groundwater Encountered
~ 20-
- 25-
-
- 35-
- 50-
LOG OF BORING
PROJECT: Uti 1 ity Trench Design, Coppel 1, Texas mORmN~ NO.:
CLIENT: Connell Development, [nc., Dallas, Texas LOCATION= Line "B"
Sta. 3+00
Dete: 11-22-88 Ty.~:Core Ground Elevatlo.:
i Legend:
-- ~ · Sample X Penetration ' · Wrater
Description of Stratum Soil Clm
Very Stiff Dark Brown & Gray Clay CH
- 5-~.:~ Very Stiff Gray & Tan Sandy Clay CE
i:' ! Very Stiff Tan Sandy Clay ~, CL
Very Stiff Tan & Gray Sandy Clay CL
- 15- Bottom @ 14 feet
No Groundwater Encountered
- 20-
- 25-
- 30-
- 35-
LOG OF BORING
PROJECT: Util'~ty Trench Design, Coppe11, Texas BORINGNOo: B-3
CLIENT: Conne11 Development, In~:,,~ Dallas, Texas L~T~ON= L~ne "A"
D.~: 11-22-88 T~:Core Gr~ s~,~= Sta. 8+00
I L~nd:
-- ~ · Sample X Penetration ~ W~t~
Descri~tion of S~tum Soil Cl~
I
~t~ff ~o Very ~t~ff Dark B~o~n & ~ffay S~lty Clay CL
- 5-~ Very Stiff Gray & ~an Clay CH
- ~0- Stiff to Very Stiff Tan & Gray
Sandy Clay CL
- 15- Bottom ~ 14 feet
No Groundwater Encountered
- 25-
- 30-
- 35-
- 40-
45- '
LOG OF BORING
PROJECT: Utility Trench Design. CoDpell. Texas BORINGNO.: B-4
CLIENT: Connell Development. [n.c. ,?al la$, Texas LOCATION= Line "A"
Da~e: ]1-22-88 Type.' Core (~rou,dla~v,tk~= Sta. 1+00
.= ~ _ · Sample X Penetration ~ Water
o/ Description of Stratum Soil Class
- 5- Very Stiff Tan & Brown Silty Clay CL
-- Very Stiff Tan Sandy Clay CL
- 15- Bottom (a 13 feet
No Groundwater Encountered
- 20-
- 25-
- 25-
- 40~
Existing Grade
4' min,i
varies
TYPICAL TRENCHCROSSSECTI~
KEY TO SOIL SYHBOLS AND DESCRIPTIONS
USED ON LO~S OF BORINGS
Gravel Silt ------' Rock ~ Limey
;;.'.:'.',~ Sand Clay , Shale
:: '.:*.. --
..:::.,
....._
COLOR
In color description of soil, the predominating color
stated first.
CONSISTENCY OF COHESIVE SOILS
. .Classifi~cation Compr~essive Strensth, psf
Very Soft Less than ~ 500
Soft 500- 1000
Plastic 1000 - 2000
Stiff 2000 - &000
Very Stiff 4000 - 8000
Hard Hore than - 8000
CONSISTENCY OF COHESIONLESS SOILS
Classification Standard Penetration? _b_pi
Loose Less than 10
Fir~ 10 - 30
Dense Hore than 30
Jointed - Cut by old shrinkage planes
FracCured - Containing old cracks~ frequently filled
sand, silt or clay of differing color
Inte~bedded - C~posed of alternace"layers o~
soil types
L~mey - Conta~n~ deposits of calci~
.