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.