Experimental and numerical modeling of thermally-induced ratcheting displacement of geomembranes on slopes

Exposed geomembranes are subjected to thermal cycles of relatively high amplitude. In the present study, the behavior of exposed geomembranes on inclined planes subjected to thermal cycles was investigated using experimental and numerical methods. Experimental results corroborated the emergence of thermally-driven displacement accumulation, or ratcheting, which was inversely proportional to the static factor of safety. The complementary numerical study considered the thermo-elastic membrane properties, constant temperature change amplitude, and an elastic-perfectly plastic constitutive model with a critical elastic threshold displacement for the membrane–soil interface. Results show that thermally-induced ratcheting displacements increased as the static factor of safety decreased, in agreement with experimental observations, and as the ratio between the unconstrained thermal elongation of the geomembrane and the critical elastic interface displacement increased.