Page 289 - Buried Pipe Design

260 Chapter Five

TABLE 5.6 Required Strength for Various Bedding Classes
Bedding class LF Three-edge, lb/ft Required strength, lb/ft
B 1.9 2046 Extra strength (2900)
C 1.5 2592 Extra strength (2900)
D 1.1 3535 This strength is not available

K 0.165 sand

2
2
W d C d B d 2.4 (120) (3.0) 2592 lb/ft
2. Determine the live load.
W L 150 lb/ft (from Fig. 2.19)

Note: 150 2592 (live load may be neglected).
3. Select the bedding and the load factor from Table 5.6.

Class D LF 1.1
Class C LF 1.5
Class B LF 1.9
4. Select the pipe strength (safety factor 1.5).

W d (SF) 2592 (1.5)
Three-edge strength
LF LF

Concrete Pipe

Concrete pipe products are made by several processes. Included are
nonreinforced products in sizes ranging from 4- to 36-in diameter and
various reinforced products in sizes 12- through 144-in diameter (see
Tables 5.7, 5.8, and 5.9).
The nonpressure types are described in ASTM C 14 for nonreinforced
and in ASTM C 76 for the reinforced type, and in CSA A257 for both types.
Concrete pressure pipe includes various types of wall construction.
Some are designed and manufactured for specific service applications,
and other types are constructed to be suitable for a broad range of
applications.

Prestressed concrete cylinder pipe
Prestressed concrete cylinder pipe has two types of construction: embed-
ded cylinder and lined cylinder (Figs. 5.5 and 5.6). In both types, manu-
facturing begins with a welded steel cylinder to which joint rings are
attached at each end. This steel cylinder is then hydrostatically tested.