Field Experience, Performance Testing and Design of Very Flexible Thermoplastic Pipe Systems

As pipe stiffness is reduced, prediction of deflection and deformation of buried pipes becomes less reliable. However, for thermoplastic pipe materials operating under predominantly constant strain conditions, the level of strain is not a critical failure parameter, and prediction of deformations and strains is likewise less relevant. Buckling and wall compression are the other mechanisms for system failure, but are unlikely to be critical factors except at very low or very high soil covers. Cost savings can therefore be achieved through the use of very low stiffness pipes, where the application and field conditions permit. Experimental work is described involving controlled loading tests on buried pipes, monitoring of field installations, and a large scale installation at the World Expo site in Brisbane using very low stiffness polyvinyl chloride (PVC) storm drains.