Tests on shear strength behavior and envelop of double lines of municipal solid waste

The triaxial and direct shear tests are the main methods to study strength behavior of municipal solid waste. By use of triaxial tests and direct shear tests on artificial solid waste, standard sand with textile and remolded municipal solid waste from field, the stress strain curves exhibit steady hardening and saw waving after certain strain is reached. Through the analysis of the existing test results in China, it is found that the dry density of solid waste is the key influence factor of strength and has good relation with the strength behavior. The results show that envelop of solid waste can be simulated by double lines, and that the cohesion and friction angle are dependent upon whether or not the solid waste is rolled. The shear strength of solid waste by direct shear tests is between that by CU triaxial tests and that by CD triaxial tests and is closer to that by CU triaxial tests. The direct shear tests are more accurate in simulating friction behavior between blocks of solid waste feasible to determine the strength parameters of solid waste. The failure shear strain in the triaxail tests and the displacement in the direct shear tests are suggested.