Analysis of Textured Geomembrane–Soil Interface Strength to Mining Applications

Abstract

In mining, due to the high environmental responsibility and the high load supported, the geomembrane-soil interface must guarantee parameters (such as friction angle and adhesion) that contribute to the stability of the barrier system. The use of a textured High-Density Polyethene (HDPE) geomembrane, known as a structured geomembrane, guarantees uniformity in asperity height due to the manufacturing process (flat-die). The present work presents the results of direct shear tests of the geomembrane-soil interface carried out for the liner project of a mining company, where the processing of bauxite, the primary natural source of aluminum, is carried out. The tests were performed with a textured geomembrane with different asperity heights, and two soil types representative of the site (in saturated and dry conditions). The results showed similar values for peak resistance and residual resistance. No influence of the asperity height on the interface parameters was observed, which suggests the need to evaluate other texture characteristics. The need to perform geomembrane-soil interface tests for any liner project, especially for mining, stands out.