非饱和岩土介质渗流问题的光滑粒子法模拟.pdf

第 35 卷 第 X 期 岩石力学与工程学报 Vol.35 No.X 2016 年 X 月 Chinese Journal of Rock Mechanics and Engineering XXX，2016 非饱和岩土介质渗流问题的光滑粒子法模拟 陈佩佩，白 冰 (北京交通大学土木建筑工程学院，北京 100044) 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。 关键词：土力学；非饱和渗透；Richards 方程；非线性；SPH 算法；质量守恒 中图分类号：TU 411 文献标识码：A 文章编号：1000–6915(2016)00–0000–00 SPH simulation of seepage problem in unsaturated soil CHEN Peipei，BAI Bing (School of Civil Engineering，Beijing Jiaotong University，Beijing 100044，China) Abstract：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. But 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，so the new numerical procedures for solving this kind of problem are presented. Finally，a complex unsaturated seepage problem with the e