Geomembrane interface friction

TLDR

Interface friction between an HDPE geomembrane and angular or rounded sand, gravel, and geotextile was investigated using a ring shear apparatus. Peak resistance occurs at small strain, while residual interface friction angles remain constant at large strain; the difference between peak and residual angles increases with substrate angularity, geotextile–geomembrane interfaces exhibit very low, indistinguishable peak and residual angles, and composite interfaces slide more readily on finer‑grained than on coarse‑grained geomembranes. Key words: geomembranes, geotextiles, interface friction, granular materials.

Abstract

Interface friction between an HDPE geomembrane and an angular as well as a rounded sand, a gravel, and a geotextile was investigated in a ring shear apparatus. The results indicate development of peak resistance at small strain and constant residual interface friction angles at large strain. The magnitude and difference between peak and residual friction angles increase with angularity. Interface friction angles between a geotextile and geomembrane were very low with no distinction between peak and residual. At composite interfaces, sliding occurred much more readily at a finer grained than a coarsegrained geomembrane interface. Key words: geomembranes, geotextiles, interface friction, granular materials.