A finite-discrete element approach for modelling polyethylene pipes subjected to axial ground movement

Abstract

ABSTRACT The response of medium-density polyethylene (MDPE) pipes subjected to ground movement is often investigated using soil-pipe interaction models that were originally developed for steel pipes. In this study, the behaviour of MDPE pipes buried in dense sand under pull-out force is investigated using a coupled finite-discrete element framework. The pipe is modelled using finite elements whereas the granular soil is modelled using discrete elements. The model is validated using experimental data and then used to investigate the response of the pipe and the surrounding soil. The response of the MDPE pipe-soil system to axial loading is found to differ significantly from that of steel pipes due to the elongation and distortion that develop in the MDPE pipes, which affect the mobilized friction forces along the pipe. This study demonstrates that caution must be exercised when using current methods in the analysis of MDPE pipes.