Mechanism of post-peak strength reduction for textured geomembrane–nonwoven geotextile interfaces

This note is intended to provide insight into the cause of post-peak strength reductions for textured geomembrane–nonwoven geotextile interfaces. Direct shear tests were conducted with incremental displacements, where one of the two interface materials was replaced, and also with continuous displacement. The results indicate that post-peak shear strength reduction is primarily due to a small-scale wearing of the geomembrane texture, either co-extruded or laminated. This conclusion applies to normal stresses from 16 to 690 kPa.