Theoritial And Experimental Study Of Fracture Caused By Differential Subsidence In Evapotran-spiration Landfill Cover

The waterproofing properties of cover system at landfill site would be significantly weakened by crack which was induced by the waste’s differential settlement, and the leachate would increase subsequently, which would lead to serious engineering accident, such as instability of waste body, pollutant dispersion and so on.Evapotranspiration cover system is a new type of closure cover system, in the principle of water storage-release to achieve seepage control effect. Evapotranspiration cover system is simple structure, low engineering cost, has become the research and application hotspot of cover nowadays. Fine soil layer is the core layer of Evapotranspiration cover system, once water storage capacity of fine soil layer Weakened or failure on account of other factors (Such as cracks), the anti-seepage performance of Evapotranspiration cover system will be affected. Therefore research on the Cracking and failure mode of Unsaturated fine grained soil Under the influence of differential settlement In Evapotranspiration cover system Has important engineering significance.Based on the analysis of plane Terzaghi soil arching effect model, shear plane is a vertical direction is assumed, Introduction of unsaturated soil shear strength criterion, based on the theory of rotation of principal stress axes of unit above Trapdoor, expression theoretical derivation of the Loose soil pressure has carried on considering the matrix suction.Analyzing the effect of rainfall on the matrix suction, through SEEP/W finite element software, and then analyzes the impact of rainfall on loose soil pressure, loose earth pressure of soil which has higher initial saturation before the rain will increased significantly, and that in less rainfall time achieve saturated state, and loose soil pressure of soil with lower initial saturation is significantly increased after some time of raining.Adopting qiantang river silt as the material for Fine soil layer in evapotranspiration cover system, carried on a centrifugal model test for powder soil cracking under the influence of differential settlement using the ZJU-400geotechnical centrifuge, revealing the failure mode and crack developing process of fine soil layer under the influence of differential settlement,...