Question

Hoop’s reinforcement is provided in cement concrete pressure pipes in order to counteract the _________

(a) water hammer pressure

(b) internal hammer pressure

(c) stresses caused by the external backfills

(d) both water hammer pressure and internal hammer pressure

I got this question in an international level competition.

This interesting question is from Pressure Conduites in division Pressure Conduits, Outlet Works through Dams and Rivers of Irrigation Engineering

Answer 1

Correct option is (d) both water hammer pressure and internal hammer pressure

For explanation: Hoop’s tension is the internal pressure exerted on the walls of the pipe by flowing water and the circumferential tensile stress (T1) is given by –

T1 = p1 d/2t where p1 is the internal static pressure, d is the diameter of the pipe and t is the thickness of the pipe shell.

Similarly, the circumferential tensile stress caused by water hammer pressure is given by –

T2 = p2 d/2t where p2 is the maximum water hammer pressure developed in pipelines.