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Abstract A series of triaxial shear tests on municipal solid waste(MSW) with the maximum vertical strain of approximately 50% were carried out by a modified triaxial apparatus. The test results show that MSW samples failed under large-strain condition and the failure strain decreases with the increasing of the landfill depth. The basic and reinforced phases of MSW were separated and triaxial consolidated drained(CD) shear tests were carried out on each phase. The results show that the stress-strain curves of both basic and reinforced phases have the strain-hardening characteristics. The structural formation and reinforcement effect of the organic fibers in basic phase were described through sieving and microscopic observation on granule groups. Then CD tests of several granule groups were carried out and the results demonstrate that every group has a strain-hardening stress-strain curve except the group with particle diameter smaller than 0.075 mm. The stress-strain curves of the basic phase before and after burned were compared，showing that the organic fibers will not play the reinforcement effect until a certain value of strain is reached. Fiber fracture and slipping along the interface seem to exist during shearing. Finally，based on the results of triaxial shear tests，methods for determining the shear strength parameters of triaxial consolidated undrained shear(CU) and CD tests were discussed respectively.
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Received: 26 March 2013
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2014, Vol. 33 
