Thermo-Hydro-Mechanical Response of MSW in a Modified Large Oedometer Apparatus

Municipal solid waste (MSW) compressibility is normally a challenging task to study because it is affected by several parameters that are not easy to simulate in the laboratory. Here, a large-scale oedometer was developed to evaluate the compressibility of MSW, which can apply different levels of temperature to the specimens. In real MSW landfills, the anaerobic decomposition reactions act as a thermal source, raising MSW temperatures. Due to the nonstandard height-to-diameter ratio, the mobilized inner wall friction was investigated and stress distribution in the MSW specimen was corrected. Then, a series of compressibility tests on fresh MSW were performed at 25 degrees C, 45 degrees C, and 65 degrees C, and the horizontal and vertical permeabilities of MSW at each loading stage were measured. The results showed that MSW softened and the compression indices increased with increasing temperature. This softening in MSW and particles led to a decrease in MSW permeability.