Laboratory and Field Testing of Large-Diameter Plastic Pipe

Abstract

Flexible plastic pipe is increasingly being used in the United Kingdom for drainage and ducting (conduit) purposes. This increase in use is leading to the introduction of larger-diameter pipes. The U.K. Department of Transport (DoT) uses a recently developed, theoretical method to specify installation conditions in place of traditional techniques (e.g., Spangler’s Iowa method). The DoT design method is outlined. The extensive program of laboratory and field testing carried out at Lough-borough University to determine the performance of plastic pipes under a range of loading conditions that may be expected in practice is then described. Laboratory test results compared well with the results obtained in the field once the different boundary conditions were accounted for, thereby validating the laboratory test methods by suggesting how allowance for field conditions can be made. Some reference is made to the shapes of deformation (determined from circumferential strain data) and the effect of installation conditions upon them. Pipe deformations were found to be well within acceptable, conservative limits under all load regimens, and near equilibrium of the pipe-soil system was established relatively quickly following application of a static or a dynamic load sequence to it.