Theoretical study on degradation consolidation of municipal solid waste accelerated by horizontal sand blanket

To solve the problem of accelerating the degradation consolidation of municipal solid waste(MSW) by horizontal sand blanket, firstly, a one-dimensional degradation consolidation model was established for bilayer MSW at continuous drainage boundary, and the corresponding governing equations were obtained. Secondly, the numerical solution of the equation was obtained by the finite element software COMSOL Multiphysics, the nonlinear change conditions of compressibility and permeability in the consolidation were simplified, and the analytical solutions were derived. Finally, the influence of drainage boundary conditions on the consolidation behavior of MSW was discussed by changing the values of interface parameters α, and the optimal laying position of horizontal sand blanket was explored. The results show that with the increase of interface parameters α, the boundary drainage capacity increases, the pore water pressure dissipation rate is accelerated, and the process of principal strain development is accelerated. However, the final value of principal strain and secondary strain is not changed. The development rate of consolidation degree increases with the increase of interface parameters α, which is more obvious in the early and middle stage of consolidation. When the time is fixed, the boundary drainage capacity becomes stronger gradually, and the optimal laying position of horizontal sand blanket moves upward, that is, the position is more inclined to the boundary with weak drainage capacity. Compared with other laying positions, the horizontal sand blanket set in the optimal laying position can greatly improve the degradation consolidation efficiency of MSW. © 2023 Central South University of Technology. All rights reserved.