SS9402-CS 950619The City With A Beautiful Future
P.O. Box 478
Coppell, Texas 75019
214-462-0022
June 19, 1995
TNRCC
Mr. Sasha Earl
MC 148
P.O. Box 13087
Austin, TX 78711-3087
RE: SANITARY SEWER PROJECT GRAPEVINE III & IV BETHEL RD, SS94-02
Dear Mr. Earl:
The City of Coppell is submitting a set of plans, specifications and a design report for review
by TNRCC. This report was prepared by the city's consultant engineer, HDR. If you have any
questions or comments you may contact Larry Redden with HDR at (214) 960-4000 or myself
at (214) 304-3679.
Sincerely,
Michael A. Martin, E.I.T.
Graduate Engineer
June 14, 1995
I-DR
Mr. Kenneth M. Griffm, P.E.
Assistant City Manager/City Engineer
City of Coppell
255 Parkway Blvd.
Coppell, TX 75019
Re: TNRCC Plan Review
Dear Ken:
We are submitting to the City of Coppell a set of plans, specs and a design report for the City to
send for review to TNRCC.
The name and address to submit the package to is:
TNRCC
Attn: Sasha Earl
MC 148
P.O. Box 13087
Austin, TX 78711-3087
Assumptions were made for the geotechnical information which was required in the flexible pipe
design calculations. Please note the discussion about waiving the air test along a certain section
of Grapevine III. The TNRCC has indicated that they would require the television examination
to waive the air test.
Please contact me if you should have any questions.
Very truly yours,
HDR ENGINEERING, INC.
HDR Engineering, Inc.
Suite 125
12700 Hillcrest Road
Dallas, Texas
75230-2096
Telephone
214 960-4000
CITY OF COPPELL, TEXAS
PROJECT NO. SS94-02
ENGINEERING REPORT
WASTEWATER IMPROVEMENTS
GRAPEVINE III, IV AND BETHEL ROAD
CITY OF COPPELL, TEXAS
PROJ. NO. SS94-02
ENGINEERING REPORT
WASTEWATER IMPROVEMENTS
GRAPEVINE III, IV, AND BETHEL ROAD
The City of Coppell commissioned Rady & Associates in December, 1994, to provide
wastewater collection system analysis for ten-year (2004) and twenty-year (2014)
conditions. This analysis modeled future pipe improvements based upon assumed slopes.
This study is the City of Coppell's wastewater collection system master plan. Grapevine
III, IV and Bethel Road sewer lines were identified in that study as needing replacement.
The proposed wastewater improvements are required due to existing as well as
anticipated future capacity problems. In addition to capacity deficiencies in some
locations, the existing lines have been damaged and are out of alignment.
The design of these three lines has been carried out referencing the Coppell City
Ordinances, City of Coppell Standard Details and the North Central Texas Council of
Governments (NCTCOG) Specifications for public works construction.
The three projects are described in more detail as follows:
Grapevine III is approximately 4,200 feet in length and is 15" diameter SDR-35 pipe.
This construction replaces an existing 8" line. The area draining into this particular line
is generally commercial.
Boring is required due to a railroad crossing, road crossing, driveways and a culvert
crossing.
Manholes are spaced generally at 500 feet.
Due to the congested work area, the fact that the existing and proposed lines are at the
same elevations and the number of services, the City of Coppell would like to waive the
required air test between stations 27+46.67 and 41+98.17 only. In lieu of the air test,
close visual examination of each joint by the City Inspector will be performed in addition
to a television examination of the completed system.
Trench safety protection will be required due to the depth of this line along its entire
length.
Grapevine IV
Grapevine IV is approximately 2,100 feet in length and is 12" diameter SDR-35 pipe.
This line replaces an existing 8" line. The area draining into this line is primarily
residential.
The downstream end of this line is a siphon. The dual pipe siphon design was selected
due to the undesirable maintenance requirements by city crews of aerial crossings. The
siphon is 6" and 8" Class 50 ductile iron pipe with poly wrap. The siphon was designed
to take into account friction losses and to convey the flow coming into it which exceeds
the 2014 design flow. Restrictions are placed on the contractor to limit deflection at
joints to 5°.
Boring is required in some locations due to the presence of large trees.
Manholes are spaced at a maximum 500 foot interval.
Trench safety will be required due to depth of trench along this project's entire length.
Bethel Road is approximately 7500 feet in length. It is 12" and 10" diameter SDR-35
pipe. A short section of 12" SDR-26 is required due to close proximity to an existing 16"
water main. This system replaces existing 8" and 10" lines.
The downstream end of the project is a siphon. The dual pipe siphon design was chosen
due to the undesirable maintenance requirements by city crews of aerial crossings. The
siphon is 6" and 8" Class 50 ductile iron pipe with poly wrap. The siphon was designed
to take into account fi'ietion losses and convey the flow coming into it which exceeds the
2014 design flow. This particular siphon will require bends to be used due to creek
geometry.
The placement of the pipe generally in the middle of the eastbound lanes of Bethel Road
was selected due to the existing narrow right-of-way and utility locations. During
construction, the contractor will be allowed to close the eastbound lane of Bethel while
maintaining access to streets, businesses, and residences.
Trench safety will be required due to trench depth along the entire length of this project.
Sewer Capacities
New line segments are attached showing size, slope, and flow capacity. Segments are
identified in accordance with the sewer master plan.
Structural Design
A tabulation showing pertinent structural design information is attached. Since
geotechnical information is not available, values were assumed for E2 (soil modulus of
embedment material), E3 (soil modulus of native soil), unit weight of soil. Since the
prism load was used for pipe load, a deflection lag factor of 1.0 was used.
For the 8, 10, 12 and 15 inch diameters E3 of 400 was used in calculations, for the 24
inch diameter E3 of 600 was assumed.
GRAPrV~ III
Pipe Corm 0+00 to MH STA 1+01.87
102 LF 24" PVC ~ 0.50%
MH STA 1+01.87 to MH STA 4+50
348 LF 15" PVC ~ 0.69%
MH STA 4+50 to MH STA 8+00
350 LF 15" PVC ~ 0.20%
MH STA 8+00 to MH STA 11+79.27
390 LF 15" PVC ~ 0.20°/o
MH STA 11+79.27 to MH STA 12+96.58
117 LF 15" PVC ~ 0.20%
MH STA 12+96.58 to MH STA 13+83.07 (STA EQ)
87 LF 15" PVC ~ 0.20%
MH STA EQ 13+98.13 to MH STA 15+54
156 LF 15" PVC ~ 0.50%
MH STA 15+54 to MH STA 20+76.79
523 LF 15" PVC ~ 0.50%
MH STA 20+76.79 to MH STA 24+40.57
364 LF 15" PVC ~ 0.50%
MH STA 24+40.57 to MH STA 25+15.22
75 LF 15" PVC ~ 0.52%
MH STA 25+15.22 to MH STA 26+60.32
145 LF 15" PVC ~ 0.52%
MH STA 26+60.32 to EX MH STA 27+46.67
86 LF 15" PVC ~ 0.52%
EX MH STA 27+46.67 to MH STA 31+23.67
377 LF 15" PVC ~ 0.24%
MH STA 31+23.67 to MH STA 36+21.67
498 LF 15" PVC ~ 0.24%
MH STA 36+21.67 to MH STA 41+01.78
480 LF 15" PVC ~ 0.24%
MH STA 41+01.78 to EX MH STA 41+98.17 (End)
96 LF 15" PVC ~ 0.24%
3.46
1.87
1.87
1.87
1.87
2.95
2.95
2.95
3.01
3.01
3.01
2.04
2.04
2.04
2.04
Pipe Conn STA 0+00 to MH STA 0+38.07
38 LF 12" PVC ~ 1.81%
MH STA 0+38.07 to Siphon Box 2+53.07
215 LF 8" D.I. & 215 LF 6" D.I. (Siphon)
Box STA 2+65.40 to MH STA 7+00.91 (Equation)
436 LF 12" PVC ~ 0.30%
EQ MH STA 8+17.18 to MH 13+17.18
500 LF 12" PVC ~ 0.32%
MH STA 13+17.18 to MH STA 15+06.22
189 LF 12" PVC ~ 0.32%
MH STA 15+06.22 to MH STA 17+59.90
254 LF 12" PVC ~ 0.30%
MH STA 17+59.90 to MH STA 20+09.90
250 LF 12" PVC ~ 0.30%
MH STA 20+09.90 to MH STA 22+29.16
219 LF 12" PVC ~ 0.30%
MH STA 22+29.16 to MH STA 22+77.41
49 LF 12" PVC ~ 0.30%
MH STA 22+77.41 to MH STA 24+37.59
160 LF 12" PVC ~ 0.41%
MH STA 24+37.59 to MH STA 26+00.47
163 LF 12" PVC ~ 1.23%
MH STA 26+00.47 to MH STA 28+27.64
227 LF 12" PVC ~ 1.23%
MH STA 28+27.64 to MH STA 30+32.39
205 LF 12" PVC ~ 1.23%
MH STA 30+32.39 to EX MH STA 30+ 45.19 (End)
13 LF 12" PVC ~ 1.23%
3.09
1.20
1.26
1.30
1.30
1.26
1.26
1.26
1.26
1.47
2.55
2.55
2.55
2.55
BETHEL ROAD
Description
Ex MH STA -0+08 to MH STA 0+40
48 LF 12" PVC ~ 0.35%
MH STA 0+40 to Box STA 1+50
110 LF 8" D.I. & 110 LF 6" D.I. (Siphon)
Box STA 1+62.33 to MH STA 5.41.02
379 LF 12" PVC ~ 0.35%
MH STA 5+41.02 to 8+54.57 (Equation)
313 LF 12" PVC ~ 0.35%
MH EQ STA 8+54.53 to MH STA 12+10.00
355 LF 12" PVC ~ 0.20%
MH STA 12+10.00 to MH STA 16+36.00
426 LF 12" PVC ~ 0.20%
MH STA 16+36.00 to MH STA 20+56.00
420 LF 12" PVC ~ 0.20%
MH STA 20+56.00 to MH STA 25+47.35
491 LF 12" PVC ~ 0.20%
MH STA 25+47.35 to MH STA 30+46.68
499 LF 12" PVC ~ 0.20%
MH STA 30+46.68 to MH STA 33+47.78
301 LF 12" PVC ~ 0.20%
MI-I STA 33+47.78 to MH STA 35+40.41
193 LF 12" PVC ~ 0.20%
MH STA 35+40.41 to MH STA 40+35.00
495 LF 10" PVC ~ 0.26%
MH STA 40+35.00 to MH STA 42+52.27
217 LF 10" PVC ~ 0.30%
MH STA 42.52.27 to MH STA 47+27.00
475 LF 10" PVC ~ 0.30%
MH STA 47+27.00 to MH STA 52+22.00
495 LF 10" PVC ~ 0.30%
Mil STA 52+22.00 to MH STA 57+16.64
495 LF 10" PVC ~ 0.30%
MH STA 57+16.64 to MH STA 61+54.08
437 LF 10" PVC ~ 0.30%
MH STA 61+54.08 to MH STA 63+66.06
212 LF 10" PVC ~ 0.30%
MH STA 63+66.06 to MH STA 68+32.02
466 LF 10" PVC ~ 0.30%
1.36
1.30
1.36
1.36
1.03
1.03
1.03
1.03
1.03
1.03
1.03
0.72
0.77
0.77
0.77
0.77
0.77
0.77
0.77
BETHEL ROAD (CONT.)
'MH STA 68+32.02 to MH STA 72+86.01
454 LF 10" PVC ~ 0.30%
MH STA 72+86.01 to MH STA 74+72.04
186 LF 10" PVC ~ 0.25%
MH STA 74+72.04 to MH STA 75+02.71
30 LF 10" PVC ~ 0.30%
0.77
0.72
0.77
· # o
FLEXIBLE PiPE DESIGN DATE: 65-Jun-g5
HDR ENGINEERING, INC. PROJECT: COPPELL SEWERS
DEFLECTION
da=PIPE OD,IN= 8.40 10.50 12.50 15.30 24.50
da=PIPE DIAM,FT 0.70 0.88 1.04 1.28 2"07
b=TRENCH WlDTH,FT,MIN 2.70 2.88 3.04 3.28 4.07
(b/da - 1 ) = 2.86 2.29 1.92 1 .b'7 0.97
E2,PSI= 1,000 1,000 1,000 1,000 1,000
E3,PSI= 400 400 4430 400 600
E2/E3 = 2.50 2.50 2.50 2.50 1.67
DR=Do/t= 35 35 35 35 35
(DR-l) ^3 39,304 39,304 39,304 3~,204 39,304
t, in= 0.240 0.300 0.367 0.437 0.70~
D=MEAN PIPE DIAMETER, IN= 6.18 10.20 12.14 14.86 24.09
SOIL UNIT WT,LB/CF= 120 120 120 120 120
H =COVER ABOVE PIPE, FT= 20 20 20 20 30
PIPE STIFFNESS, PS= 46 46 46 46 45
2E/(3' (DR- 1) ^ 3) = 6.785 6.786 6.765 6.785 6.765
f= 1.179 1.054 0.9E7 0.848 0.611
zata= 0.79 0.71 0.67 0.62 0.72
K= 0.1 0.1 0.1 0.1 0.1
DI= 1 1 I 1 1
P,PSI= 16.7 16.7 10.7 16.7 25.0
~e 786 713 666 616 723
5 % DEFLECTION,IN= 0.42 0.525 0.62E 0.766 1~4015
DELTA y / D,%= 3.04 ;).31 3.62 3.74 4.01
BUCKLING
~ ~=,~ ~=,~ =,=,=,~aa~ m~=,~aB=,~~~~~~~~~~~e
Pcr. PSI=, 23.79 23.79 23.79 20.79 20.79
Pb,PSI= 167 lEO 146 139 151
P,actuaI,PSI- 16.7 16.7 16.7 18.7 25.0
SAFETY FACTOR=, 0.44 8.99 8.68 8.37 8.03
CRUSHING
Py,PSI= 16.7 16.7 16.7 16.7 25.0
A, IN2= 0.46 0.60 0.71 0.67 1
T,LBSflN = 1 35.0 170.0 2~Q.4 247.7 802.4
81GMAult, PSI=, 4,000 4,000 4,000 4,000 4,000
SIGMAactuaI,PSI= 283.3 283.3 283.3 283.3 425.0
SAFETY FACTOR-, 14.1 14,1 14.1 14.1 0.4
STRAIN
EPSILON h,IN/IN,,, 00.001 -0.001 -0.001 -0.001 -0.001
EPSILON f,5% DEFL.,II~IN- 0.006 0.006 0.006 0.006
EPSILON f, act~ DEI=I.,IN/IN - 0.00~ 0.003 0.003 0.00~ O.(X~