Page 282 - Buried Pipe Design

Rigid Pipe Products 253

Case I:
Hydrostatic: P class SF SF 4.0

earth load (transition)
Crush load: W SF SF 2.5
bedding factor
Case II:
Hydrostatic: P class SF SF 2.5
earth load live load impact
Crush load: W SF SF 2.5
bedding factor
In both case I and case II use combined loading.

P p
w W
P
Figure 5.1 Outline of design procedure for asbestos-cement class pressure pipe
(6 to 16 in).

Hydrostatic design:
P (operating pressure surge pressure) SF SF 2.0

Crush design:
earth load (transition) live load (H-20)
W SF SF 1.5
bedding factor

P p
w W
P
Figure 5.2 Outline of asbestos-cement transmission pipe design pro-
cedure (18 to 36 in).
1. Determine the earth load.

H 5.0
1.67 (from Fig. 2.2, C d 1.3)
B d 3.0
K 0.165 sand
2
W d 1.3 (120) (3.0) 1404 lb/ft
2. Determine load at the transition width. *

* 13.74 is the outer diameter (OD) which can be obtained from manufacturers’ specifi-
cations.