Development of geosynthetic interface strength in landfill capping under seismic conditions.

The aim of this research is to carry out an analysis of the mobilisation of interface strength, in the geosynthetic liner system of a landfill capping, during seismic activity, since geosynthetics, widely-used for waterproofing, drainage and reinforcement, affect stability. Contact surfaces between geosynthetics and between geosynthetic and soil may become potential surfaces of slippage due to low available friction. The problem has been examined by means of a numerical Flac 2D model which, according to some simplifying hypotheses, could highlight the evolution of interface strength in the dynamic field. The analyses have shown that the seismic displacements may be large enough to mobilize dynamic friction at the level of the geosynthetic interface and thus that a dynamic characterisation of the interfaces is required in order to accurately predict stress in the liner and displacement of the capping.