Shear strength of geomembrane-cohesive soil interfaces

Department of Geotechnical Engineering, São Carlos School of Engineering (EESC), University of São Paulo (USP), São Carlos, São Paulo, Brazil

^* Corresponding author: eng.henriquelopes@usp.br

Abstract

Despite the increasing use of geosynthetics, the behavior of polymeric materials inserted in the soil is complex, and the wide availability of products on the market makes it difficult to standardize and predict the behavior of the interaction. Therefore, understanding the fundamental mechanisms that involve each type of geosynthetic and its use is a way of directing test conditions to obtain accurate parameters to investigate the behavior of interactions between soil-geosynthetic. In this article, tests were carried out to estimate the interface strength of the soil-smooth geomembrane and soil-textured geomembrane were conducted with cohesive lateritic soil in direct shear equipment with a shear box measuring 300 mm x 300 mm and a reduced area model. The objective of the study was to investigate the influence of soil particle size distribution, the type of geomembrane surface (smooth or textured), and the filling in the lower halfbox (with soil or rigid base) on the resistance of the soil-geosynthetic interface. The results demonstrated the efficiency of the interaction between cohesive soil and a textured geomembrane. For the interaction with a smooth geomembrane, cohesive soil did not exhibit significant mobilization of resistance.