径向基函数配点法求解边坡降雨瞬态渗流问题

Study on transient seepage of infinite slope using multiquadric RBFCM

根据土壤水分特征曲线Gardner模式推导线性化非饱和渗流Richard方程,应用无网格法中的多元二次径向基底函数配点法对空间域进行离散,利用龙格库塔法对时间域进行离散.通过离散点满足控制方程式与边界条件,建立求解非饱和渗流问题的数值模型.考虑土层组合以及降雨强度,计算分析非饱和无限边坡降雨入渗的瞬态渗流场的变化情况,得到边坡内不同时刻、不同深度的孔隙水压力.其数值计算结果与解析解相符,较有效地解决了传统数值方法在模拟非饱和土渗流产生的数值病态问题.

Based on the soil water characteristic curve Gardner model,the linearized unsaturated seepage Richard equation is derived.The space domain is discretized by the multiple two radial basis function collocation method in meshless method,and the Runge Kutta method is used to discretize the time domain.The control equation and boundary conditions are satisfied by discrete points,a numerical model for solving the problem of unsaturated seepage is established.Considering the distribution of different soil layers and the intensity of different rainfall,the transient seepage field of unsaturated infinite slope rainfall infiltration is calculated and analyzed,and the pore water pressure at different time and depth is obtained.The numerical results are consistent with the analytical solutions,the problem of numerical pathological problems in the simulation of unsaturated soil seepage is solved.