Page 307 - Buried Pipe Design

278 Chapter Five

Overfill (SW, ML, or CL)

H
D /6 (Min.) Excavation Line
O
D O D (Min.) as Required
O

Haunch (see Table 5.13)
D i
Lower Side
(see Table 5.13)

Bedding (see Table 5.13) Middle Bedding
D /3
O
Outer Bedding Loosely Placed
Material and Uncompacted Bedding
Foundation
Compaction Each Except for Type 4
Side, Same
Requirements
as Haunch
Figure 5.11 Standard trench installations.
The SIDD method may be applied by the use of hand calculations.
However, the method is much easier and more efficient if the SIDD
computer program and computer-aided calculations are used. A com-
plete discussion of SIDD is outside the scope of this book, but can be
found in Concrete Pipe Technology Handbook.

Design Strengths for Concrete Pipes
Design W 3-edge strengths for reinforced concrete pipe having various
standard diameters, wall thicknesses, concrete strengths, and rein-
forcement requirements for standard strength classes are given in
ASTM C 76, C 506, and C 507. Design requirements for reinforced pipe
with specified D load strength requirements and special reinforcement
designs are given in ASTM C 655. The pipe reinforcement designs
given in ASTM C 76 are based on strength factors of 1.5 to 1.25 over
the required service load D .01 , but this standard does not require that
quality control W 3-edge tests be taken to ultimate. The same applies to
ASTM C 506 and C 507.
In summary, under the indirect procedure, pipe designs for wall
thickness, reinforcement, and concrete strength to provide specific
required W 3-edge service and strength performance have been obtained