Design of prestressed concrete pipes
The design of prestressed concrete pipes should cover the following five stages :
(a) Circumferential prestressing, winding with or without longitudinal prestressing,
(b) Handling stresses with or without longitudinal prestressing,
(c) Condition in which a pipe is supported by saddles at extreme points with full water load but zero hydrostatic pressure,
(d) Full working load conforming to the limit state of serviceability, and
(e) The first crack stage corresponding to the limit state of local damage.