H = height of cover (ft) 120 lb/ft, Simulates 20 ton truck traffic + impact – Carlon External Load Calculation for Buried Conduit User Manual
Page 4
EXTERNAL LOAD CALCULATIONS FOR DIRECT BURIED CONDUIT
25701 Science Park Drive
Cleveland, Ohio 44122
216-464-3400
1-800-3CARLON (322-7566)
www.carlon.com
γγγγ = UNIT WEIGHT OF BACKFILL (lb/ft
3
)
H = HEIGHT OF COVER (ft)
120 lb/ft
3
IS A COMMONLY USED VALUE FOR THE UNIT WEIGHT OF
BACKFILL.
LIVE LOADS (LL) CAN BE CALCULATED BY USING THE BOUSSINESQ
FORMULA FOR A POINT LOAD AT THE SURFACE OF THE SEMI-INFINITE
ELASTIC SOIL OR BY USING THE PREDETERMINED VALUES IN THE
FOLLOWING TABLE:
LIVE LOADS ON PVC OR HDPE CONDUIT OR DUCT
(LIVE LOADS TRANSFERRED TO CONDUIT lbs/in
2
)
HEIGHT OF
COVER
HIGHWAY
RAILWAY AIRPORT
HEIGHT OF
COVER
HIGHWAY
RAILWAY AIRPORT
H (ft)
H20
1
E80
2
3
H (ft)
H20
1
E80
2
3
1
12.50
*
*
14
*
4.17
3.06
2
5.56
26.39
13.14
16
*
3.47
2.29
3
4.17
23.61
12.28
18
*
2.78
1.91
4
2.78
18.40
11.27
20
*
2.08
1.53
5
1.74
16.67
10.09
22
*
1.91
1.14
6
1.39
15.63
8.79
24
*
1.74
1.05
7
1.22
12.15
7.85
26
*
1.39
*
8
0.69
11.11
6.93
28
*
1.04
*
10
*
7.64
6.09
30
*
0.69
*
12
*
5.56
4.76
35
*
*
*
40
*
*
*
1
SIMULATES 20 TON TRUCK TRAFFIC + IMPACT
2
SIMULATES 80,000 lb/ft RAILWAY LOAD + IMPACT
Gross Automation (877) 268-3700 · www.carlonsales.com · [email protected]