A study of shear strength properties of municipal solid waste in Chongqing landfill, China.

The aim of this study is to analyze the effect of biodegradation on the shear strength of municipal solid waste (MSW), leachate, and biogas production. The direct shear (DS) test shows that the shear strength of waste in the initial stages is mainly depended on its composition and inter-structure. After the waste has been in a landfill for 30 days, the waste's increased biodegradation exhibited a great influence on the waste's shear strength. The increase of moisture content in the waste mass might cause a decrease of its shear strength. Tri-axial tests under consolidation-drained (CD) condition show that the shear strength of the cohesion and friction angle for degraded samples increased when the defined axial strain increased from 5 to 20 %. The cohesion varied from 35.90 to 66.42 kPa and the drained friction angle ranged between 29° and 38°. The measurements of shear strength properties are utilized to assess the slope stability of landfills.