不同排水条件下城市固废一维降解固结解析解

目前关于城市固废的降解固结理论研究均沿用太沙基传统排水边界，但是这样不能完全描述垃圾填埋场中复杂的排水边界条件。因此，在已有的简化降解固结模型基础上引入连续排水边界条件，建立了新鲜面为连续排水边界的饱和城市固废一维降解固结模型。在此基础上，借助特征函数解偏微分方程得到了级数形式的解析解答，解的退化检验和收敛性判断初步验证了其合理性。解析解与已有解答的对比分析显示，引入连续排水边界条件后，超静孔压分布有显著的变化；且解析解可解决初始条件和边界条件的矛盾，能反映边界上孔压消散的时间效应。进一步的参数敏感性分析显示，通过调整界面参数可以模拟各种排水条件，获得从完全不排水到完全排水的连续解答。此外，从排水能力差异会改变降解固结发展速度出发，提出了一种保证填埋场稳定的可行策略。

Analytical solution for 1D degradation-consolidation of municipal solid waste under different drainage conditions

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.