Structural Design of GRP Jacking Pipes

Abstract

Glass Reinforced Plastics (GRP) jacking pipes are now very commonly installed throughout Australia and New Zealand. These pipes are supplied with a very large range of stiffness classes, but design methods are not well established or well understood. This paper examines how the stiffness class should be selected based on both temporary and permanent design loads. Specifically, the paper considers how permanent loads should be designed for and whether the GRP jacking pipe should be considered as a flexible, rigid or even semi-rigid pipe. It also examines whether existing standards such as AS/NZS 2566.1 or even AS/NZS 3725 can be used for the design of such pipes and if so, what design criteria should be adopted and how design to these standards might compare with the German Standard DWA-A 161. The paper includes a design example. Many kilometres of such pipelines are constructed every year and it is very important to the industry and asset managers alike that pipes with appropriate stiffness classes are selected for both a cost-effective installation and that the installed asset continues to adequately perform for its intended design life.

Techniques