Quantification of shear-induced wear development on textured geomembrane-geotextile interfaces

The development of wear on the textured geomembrane interface has a significant influence on the reduction of post-peak interface shear strength. This study aims to examine and quantify the development of shear-driven wear on geosynthetic interfaces. New interfacial parameters are introduced to systematically describe the changes in the surface morphology of a geomembrane during the shearing process by combining quantitative and qualitative digital imaging techniques. Based on the developed surface roughness geometric parameters, an
intensive quantitative and stereoscopic analysis of the wear development of the geomembrane surface morphology has been conducted during interfacial shear. The geometric parameters of the textured surface, namely asperity height, top angle, top radius, approach angle, and departure angle, can capture the changes in surface topography of the geomembrane in pre- and post-shearing. The top angle and radius, as well as the
approach and departure angles, change significantly during the early stages of shearing (5 mm–20 mm). In general, the changes in the adopted geometric parameters resulted from a shearing rise associated with the increase in normal pressure. Furthermore, they could be used to better define the evolution of wear through
complex stress histories that geomembranes frequently experience.