Comparative analysis on practical implications and evaluation of PVC geomembrane interfaces against particulate materials

Abstract

An experimental research study including a series of laboratory large displacement interface shear tests betweendifferent particulate materials (rounded, angular sands) and smooth PVC geomembranes, and additionally, a series ofShore D Hardness measurements were conducted. The aim of this study is to investigate an easy and quick means ofpredicting shear resistance/strength of sand-polymer interfaces indirectly from the hardness of the continuummaterial (i.e. PVC geomembrane) at the interface to establish a comparative analysis between direct test results andindirect practical evaluation through hardness property based on an important interface shear property; frictionangle, (δ) at peak and residual states measured directly from interface shear tests performed in the laboratory as wellas computed indirectly from empirical models developed in the study for the case of different normal loadingconditions (i.e. normal stress levels:25, 100, 400 kPa). The results and analysis will be presented throughout thepaper demonstrate that the mobilized shear response and the resulting frictional resistance of sand (rounded,angular) – PVC geomembrane interface systems are highly dependent on a combination of loading conditions,geomembrane physical material properties (i.e. hardness) and particulate shape (i.e. angularity/roundness). Fordirect and indirect assessment of the resultant [δPeak] and [δResidual] values, the comparative analysis showed that areasonable similarity between the laboratory test results and the indirect analytical assessment analysis is evidentfrom the analogicalness of the experimentally measured values at the predetermined normal stress levels (25, 100and 400 kPa) to the computed values from the proposed empirical correlation equations proposed in the paper.