Monotonic and cyclic shear behaviour of geomembrane-sand interface

Abstract

Geomembranes have been widely applied in hydraulic systems and mineral and environmental engineering. For geomembrane-lined soil structures, such as dikes, dams, and landfills, the geomembrane-soil interface could be a potentially unstable plane under static and dynamic loading. In this study, a large-scale shear apparatus was employed to investigate the monotonic and cyclic shear behaviour of a geomembrane-sand interface under varying normal stress and shear-displacement amplitude. A nonlinear mathematical piecewise model was developed to simulate pre-peak stress-dependent stiffness and post-peak displacement-softening behaviour for the monotonic shear response of the geomembrane-sand interface. Furthermore, the study provided a modeling approach based on the Masing rule to represent the nonlinearity and hysteresis of the cyclic shear behaviour of the interface. The predictions made by the two proposed models were both in good agreement with the experimental monotonic and cyclic shear-test data.