Avaliação dos parâmetros de resistência na interface solo-geomembrana através do equipamento de cisalhamento direto

Abstract

The environmental regulations are increasingly strict, raising the problematic around the environmental contamination. The final storage of urban solid waste on landfills creates an area with a high contaminant potential of the subsurface, due to the leachate, product of urban solid waste. In order to avoid the spread of the contaminating material into the subsoil, the landfill project must predict waterproofing systems on the foundation soil and slopes. These systems are usually composed of combinations between foundation material (soil) and geosynthetics. One of the combinations frequently applied is a geomembrane over the compressed clayish soil. The interaction parameters between soil and geomembrane are still not well known, what may result in a mistaken geotechnical analysis of the structure as a whole. This research seeks to avail the resistance parameters on the soil-geomembrane interface for three different horizons of a saprolytic soil, collected in the city of São Leopoldo – RS, with two geomembranes with different textures. For that, it was done geotechnical characterization of the soils and direct and interface shear tests under the flooded condition with different combinations between the materials. It was noted that the system composed by soil-geomembrane presents lower resistance of shear strength when compared to the resistance of soil. It was also possible to verify that the geomembrane with rough texture presents better geotechnical performance of the one with smooth texture.