Dynamic Interface Shear Strength Properties of Geomembranes and Geotextiles

Abstract

Shaking‐table tests to measure the dynamic interface shear strength properties between geotextiles and geomembranes were performed and the results are reported. It was observed that there is a limited shear stress, hence a limited acceleration, that can be transmitted from one geosynthetic to another. Beyond this acceleration, relative displacement along the geosynthetic interface is initiated. Hence, the primary concern about the dynamic response of a geotechnical facility that incorporates geosynthetics should be the permanent relative displacement that may accumulate along the geosynthetics interfaces. The dynamic interface friction angles measured at the onset of relative displacement between the geosynthetics are not appreciably different from those obtained from static tests. It was also observed that the dynamic interface friction angle increased slightly as the table acceleration increased beyond the level causing initial sliding. This increase could not be attributed to the potential effect of the frequency of motion of the shaking table and normal stress. Finally, an innovative use of geosynthetics as base isolation for earthquake hazard mitigation is proposed and its applicability is demonstrated. Further exploration of this application of geosynthetics may lead to products that can provide varying degrees of base isolation, especially in geotechnical earthquake engineering.