城市新鲜生活垃圾变形与强度的关联特性

为了研究新鲜生活垃圾压缩变形、抗剪强度的相关特性及其规律,参照杭州天子岭固体废弃物填埋场垃圾的主要成分,人工配制新鲜生活垃圾试样,采用大型压缩与直剪联合测定实验仪器,对新鲜生活垃圾试样进行压缩变形、强度联合测定试验,得到压缩量、孔隙比、时间与竖向压力的关系曲线.试样的初始孔隙比为2.1,试验竖向压力为25、50、100、200 kPa,每级竖向压力的作用时间分别为0、0.25、0.5、1、2、6、12、24 h.结果表明,新鲜生活垃圾的强度与垃圾压缩变形有关,随着竖向压力及压缩应变的增大而增大；城市新鲜生活垃圾的强度特性符合库仑强度理论；获得了垃圾的压缩性指标及抗剪强度参数.垃圾的压缩系数为1.4 MPa-1,压缩指数为0.372,内摩擦角在24°到31°之间,内聚力在9到23 kPa之间.

Correlation properties of the deformation and the shear strength of fresh municipal solid waste

To investigate the correlation properties of the compressibility and the shear strength of the fresh municipal solid waste (MSW), the combined tests of compression test and direct shear test were carried out by a large-scale laboratory testing equipment. Referring to the major compositions of MSW from the Tianziling landfill in Hangzhou, China, the fresh municipal solid waste testing samples were prepared in geo-environmental laboratory. The initial void ratios of the samples were 2.1. Four different vertical pressures, which were 25, 50, 100, 200 kPa were selected, and the compression times for every vertical pressure were 0, 0.25, 0.5, 1, 2, 6, 12, and 24 hours, respectively. Basing on the testing results, the relationship between the deformation and the shear strength was studied, and the curve of the settlement-void ratio-compression time-vertical pressure was obtained. The testing results show that the shear strength of the MSW has some connection with the compression strain of the MSW, and the shear strength increase with the increasement of the vertical pressure and the compression strain. Besides, the relationship between the shear strength and the vertical pressure applied on the test sample is conformity with the law of Coulomb. Furthermore, some parameters of the compressibility and the shear strength of the MSW are obtained, those are the compression coefficient is 1.4 MPa-1, the compression index is 0.372, the internal friction angle varies from 24 to 31 degree, and the cohesion force varies from 9 to 23 kPa．