Volume 29, Issue 2 (March 2006)
Shear Strength of Degraded Reconsitituted Municipal Solid Waste
Relative changes in Waste shear strength parameters as a function of strain level and stress path are investigated based on the results of 16 direct simple shear (DSS) tests, one direct shear (DS) test with four stages, and three triaxial tests. The magnitudes of shear strength parameters obtained from drained DSS tests and undrained DSS tests with pore water pressure measurement were comparable. This was the case even though the effective stress path in both approaches was different. Data indicated the dependency of the mobilized strength parameters on strain, or deformation level. Generally, stress-deformation response increased monotonically with no well defined peak or ultimate stress levels. The results of the DSS and DS tests show no dependency of the strength parameters on the stress level. Results from DSS and DS indicated a range of effective strength parameters of 9 to 14 kPa for cohesion and 23°–29° for friction angle. Data from the triaxial testing showed dependency of the shear strength parameters on the initial compression stress level. Given the number of potentially confounding issues associated with the measurement of shear strength, it is rather important to also report information on sample collection methods, sample age and chemical composition, sample processing, sample composition, the size of testing equipment and level of strain (instead of ultimate or peak) at which the strength parameters are evaluated.