Modeling the stress–strain behavior of municipal solid waste samples under varying temperatures

It is a fact that the temperature inside the waste mass is higher than the ambient outside the landfill. However, only a few experimental works have tried to address the effect of such elevated temperatures on the mechanical behavior of waste. Accordingly, developing a constitutive model based on experimental achievement is still incipient. In this paper, results from experimental literature and the results of a complementary testing campaign aided in better understanding and modeling the waste thermo-mechanical behavior. An existing model framework by the authors is extended to incorporate thermal effects on the waste bulk and fibrous reinforcement particles. The model predicted fairly the mechanical behavior of waste in terms of deviatoric stress, pore water pressure, and volumetric strains in drained and undrained triaxial tests performed on samples at different temperatures and with different plastic contents. Values of deviatoric stress predicted by the model for two specific axial strains are compared with experimental results, considering all the tested samples, proving the model’s capabilities in reproducing the waste’s overall behavior. Considering an axial strain of 20%, the probabilities of the model error occurrence in the range of $\pm 25\text{\%}$ are 55% and 67% for CIU and CID tests, respectively.