Abstract: At present, all of the theoretical studies about degradation-consolidation of municipal solid waste (MSW) still use the traditional Terzaghi drainage boundary. However, it cannot fully describe the complex drainage boundary conditions in landfills. Accordingly, this paper introduces the continuous drainage boundary into the existing simplified degradation-consolidation model, and then builds a new model of 1D degradation-consolidation of saturated MSW with a fresh surface described by continuous drainage boundary. On this basis, the analytical solution is obtained by solving the characteristic function, and its rationality is preliminarily verified through degradation analysis and convergence judgment. A comparative analysis of the present solution and the existing solutions shows that the distribution of excess pore pressure changes significantly after introducing the continuous drainage boundary condition. Meanwhile, the present solution can solve the contradiction between initial condition and boundary condition, and reflect the time effect of the pore pressure dissipation on the boundary. Further parameter sensitivity analysis indicates that various drainage conditions can be simulated by adjusting the interface parameter, and continuous solutions from complete impervious condition to complete pervious condition are available under boundary conditions. As the interface parameter changes, pore pressure distribution, strain development and consolidation degree development show continuous regular changes. Finally, a feasible strategy of changing drainage conditions is proposed to ensure the stability of landfills based on the characteristics above.

Key words: municipal solid waste, consolidation, degradation, continuous drainage boundary