城市固体废弃物大直径三轴压缩试验研究

Large-Scale Triaxial Compression Test for Municipal Solid Waste

参照杭州天子岭填埋场城市固体废弃物(MSW)的主要成分,人工配制MSW试样,利用大型三轴剪力仪进行固结排水剪试验,研究MSW的剪切强度特性.由于MSW内部孔隙很大,导致固结过程中体变量非常大,固结时的体变与轴向应变基本成直线关系;当轴向应变达到15%时,剪切强度还在继续增长,MSW的应力应变关系表现为加工硬化型.破坏应变取值不同,MSW的强度参数c和φ差别很大.通过对比发现,现场静力触探试验得到的强度参数与室内大三轴试验破坏应变取为10%时得到的强度参数c和φ比较接近.

To investigate the shear strength characteristic of municipal solid waste （MSW）, the consolidated drained （CD） shear tests were conducted with large-scale triaxial compression apparatus on MSW samples simulating the compositions of MSW from the Hangzhou Tianziling Landfill. Because MSW is of macroporous matter, the consolidation volumetric strain is very large, which has high lin- earity with axial strain. The shear strength continuously increases with axial strain, without reaching a well defined peak value even when the axial strain is up to about 15 %. The cohesion c and friction angle φ of MSW largely vary with different failure strain values. A comparison of the test results of cone penetration tests （CPT） with those of large-scale triaxial compression tests shows that the shear strength parameters c and φ based on CPT tests are close to those of large-scale triaxial compression test when the failure strain is 10 %.