Triaxial tests and analysis of shear strength of municipal solid waste at medium and high ages

In order to investigate the mechanical property of municipal solid waste(MSW) at medium and high ages, the artificial model MSW was made up by adding appropriate mass ratio of turf into the mixture of Quartz sand and kaolin clay, and then a series of consolidated drained and undrained triaxial tests were conducted. The tests results showed that the stress-strain of MSW at both high and medium age demonstrate continuous hardening characteristics during shear. The volumetric strain of medium age MSW in drained tests is little bigger than that of high age, the pore water pressure of high age MSW in undrained test is bigger than that of medium age. When the shear stress at 15% axial strain is adopted as the shear strength, the reduction coefficient of the pore water pressure and shear strength parameter were obtained by according to the Skempton's principle of effective stress. The reduction coefficient of the artificial model MSW is shown to increases with the age, the cohesion of the artificial model MSW decreases with the age, while the friction angle increse with the age.