Temperature Effects on Stability and Integrity of Geomembrane–Geotextile Interface in Municipal Solid Waste Landfill

Review of the limited experimental studies available in the published literature that investigate the effects of temperature on the shear strength of typical geomembrane (GM) and geotextile (GTX) interface is performed. These studies suggest that the shear strength of GM–GTX interfaces generally increase with an increase in temperature. However, there is no study that examined the combined effect of the temperatures along the bottom liner and the large displacement induced by the waste settlement on the short-term and long-term stability and integrity of the GM–GTX interface in a composite bottom liner system in municipal solid waste (MSW) landfills. This paper presents the application of a thermal model to predict the evolution and distribution of temperatures within the waste and along the bottom liner system of a typical landfill cell model, while simultaneously evaluating the influence of the predicted temperatures on the shear response of GM–GTX interfaces in the composite bottom liner system. The predicted temperatures along the liner interface of the simulated landfill cell varied between 4 and 32 °C, which are well within the reported temperatures in and around the bottom liners in MSW landfills. The results also suggest that beginning the placement of waste in summer is favorable than in winter, since the high temperatures at the GM–GTX during summer mobilize higher shear strengths resulting in lower shear displacements. Further, if stability analysis using limit equilibrium method is performed, then the shear strength of GM–GTX interface corresponding to the low temperature ranges expected at the site should be used for conservative and reliable estimates of the stability of the bottom liner system.