Modeling the WRC and volume change behavior of GCLs considering net stress and temperature

Abstract

Geosynthetic clay liners (GCLs) are used in cover and bottom lining systems to mitigate contamination from landfills. During their service period, they are often subjected to varying net mean stress levels, temperature fluctuation, and water content, which could affect their water retention and volume change behavior severely. These changes under thermo-hydro-mechanical conditions can be evaluated through experimental methods or mathematical models. In the present study, the combined effect of net mean stress and temperature on water retention and volume change behavior of GCL in the unsaturated regime were studied. A theoretical thermo-hydro-mechanical framework for GCLs over a wide suction range is proposed based on experimental observations. The proposed framework was implemented in a simple water retention model and volumetric constitutive model to capture the thermo-hydro-mechanical behavior of GCL through several sets of experimental data available in the literature. The predicted results from the proposed method were in good agreement with the experimental results. Also, the proposed method required minimal input parameters to predict water retention and volume change behavior over a wide suction range. The proposed framework is therefore quite useful for engineering applications of GCLs under the combined effect of suction, net mean stress, and temperature.