Creep behaviour of sand–geomembrane interfaces

Abstract

ABSTRACT: Creep behavior is among the critical properties of soil–geomembrane interfaces. However, there have been very limited studies in this area. In this study, one smooth and one textured high density polyethylene geomembrane were tested for their frictional characteristics with slightly dense Nevada sand. Normal pressures employed in the tests were 25, 50 and 75 kPa. The sustained loadings lasted 240 min, and under each constant normal stress, creep occurred at three levels of shear stress at room temperature. Two loading speeds, 1 and 5 mm/min, were employed in the direct shear tests before and after creep. The study found that the post-creep frictional resistance appeared to be approximately the same as that obtained from a direct shear test without creep. The shear creep behaviour of sand–geomembrane interfaces followed the typical pattern of material creep, and under relatively small normal pressures that did not result in considerable damage of geomembrane surfaces, textured geomembrane interface with sand might exhibit larger shear creep displacement than smooth ones.