Page 299 - Buried Pipe Design

270 Chapter Five

TABLE 5.10 Required Strength Based on SF 1.5 and Ultimate
Bedding Three-edge, D load,
class LF lb/ft (lb/ft)/ft Nonreinforced Reinforced
B 1.9 2046 1637 Choose class 1 Choose class III
(2600) (2000)
C 1.5 2592 2074 Choose class 2 Choose class IV
(2600) (3000)
D 1.1 4025 3220 Not available Choose class V
(3750)

Prestressed concrete pipe may be designed by the cubic parabola method,
as discussed in Chap. 4. Equation (4.14) is as follows:

3 P o p
W W o (4.14)
P o

For lined cylinder:

p 0.8P o (see AWWA C301)

For embedded cylinder:

(see AWWA C301)
p P o

From Example 5.3,
W d 2112 lb/ft

The required strength is
2112 2
W d
W 1111 lb/ft p 150 lb/in
LF 1.9

Therefore,
150 2
P o 187.5 lb/in for lined pipe
0.8

Total load W W d W L 2452 (see Example 5.3)

Lined-cylinder pipe
For lined-cylinder pipe,