Impact of Underliner on the Local Deformation of HDPE Geomembranes

A series of short-term puncture tests is conducted to investigate the deformation behavior of a 0.5-mm-thick high-density polyethylene (HDPE) geomembrane on particulate underliners subjected to high water pressures. The influence of some key factors (i.e., type of underliner material, particle size, applied pressure, and loading rate) are evaluated. The results indicate that the applied pressure contributing to the geomembrane damages gradually increases with decreasing particle size. It is observed that the wide void spaces between particles and high pressures are the main reasons for the geomembrane damages. An enhanced mathematical model is established to reveal the relationship between the particle size and peak applied pressure. The proposed model provides a useful tool for selecting the maximum particle size of underliner materials to prevent the geomembrane from being punctured.