Strain Induced Changes in Geomembrane Surface Topography

Textured geomembranes are commonly used in field applications to increase the strength of geomembrane-soil and geomembrane-geosynthetic interfaces. Under normal operating conditions, geomembranes within landfill liner systems are subjected to both multiaxial and uniaxial strains induced by anchorage in trenches, differential settlements, and thermal changes. The existence of strain may alter the geomembrane surface, thereby affecting the strength of the interface. This paper presents the results of an investigation into changes in surface topography of geomembranes subjected to uniaxial strain. An integrated strain profilometer device was developed to permit quantification of geomembrane surfaces while they were subjected to strain. Geomembranes manufactured using various texturing processes were subjected to increasing uniaxial strain levels ranging from 1 to 25%. Results show that the effect of strain on the surface topography is dependent on the geomembrane manufacturing process. The implications of changes in surface topography are linked to potential changes in the interface strength.