laboratory shear strength measurements of municipal solid waste at room and simulated in situ landfill temperature, barmshoor landfill, iran

This study was aimed to determine the influence of temperature within the landfill on the shear strength of the msw samples through the shearing procedure. different waste samples, i.e., the fresh (c1), 2 years old (c1-2y) and lab oratory prepared (c2) msw samples, were heated up, prepared, and placed in the shearing box with the designated temperatures of about 25, 45, and 65 °c (i.e., the range of an anaerobic landfill). the mohr–coulomb strength parameters for the warmed-up and room-temperature specimens were separately calculated and compared. the temperature decreases the friction angle from 21 to 17° for t > 45 °c. the cohesion was also decreased by temperature from 19.9 to 13.1 kpa. in addition, two nonlinear envelopes were developed for the specimens tested at room and simulated temperature within the landfill. the test results show a reduction of about 20% for friction angle and shear strength at the temperatures between 45 and 65 °c. although the warmed-up specimens of fresh msw were denser under certain normal stress, heating the msw specimens to temperatures of 45 and 65 °c resulted in loss of the shear strength. results further indicated that the temperature of the wastes plays an important role when the shear stress is conducted on the msw specimens. it can be then concluded that temperature of the landfill should be considered as a factor influencing the shear strength of msw. considering temperature for site investigation of the shear strength and the correlation of the results with the laboratory tests is important, too.