中文摘要：

非饱和土渗流问题在大坝渗流、降雨入渗、垃圾填埋场内部污染物扩散等领域有着广泛的应用。对非饱和渗流Richards方程的数值求解,一直以来多是采用有限单元法计算基质吸力水头为自变量的方程进行的。但是,材料属性的高度非线性特征会导致数值解的质量守恒性质较差及非物理性震荡,同时可能引起迭代过程的不收敛。尝试着将光滑粒子法引入到基质吸力水头形式Richards方程的求解中,以便获得具有质量守恒特性的数值解,并通过数值算例验证其实用性和可靠性,从而为此类问题的求解提供一种新的思路。最后,采用基于光滑粒子法编写的程序模拟了蒸发条件下的一个复杂非饱和渗流问题,这对实际的工程应用有一定的借鉴价值。

英文摘要：

The unsaturated soil seepage occurs widely in the dam seepage,rainfall infiltration and pollutants diffusion in landfill etc. The numerical solution of unsaturated seepage equation of Richards based on the finite element algorithm has been derived with the matrix suction head as the independent variable. However,the strong nonlinear characteristics of the material properties leads to the poor mass conservation properties and non physical oscillation of the numerical solution,and may cause inconvergence of the iterative process at the same time. In order to obtain a numerical solution with mass conservation,smoothed particle method was introduced into the solution of the head-based form of Richards equation,and the practicability and reliability of the new algorithm was verified by a numerical example. Finally,a complex unsaturated seepage problem with the evaporation condition was simulated using a program which was written based on SPH algorithm.