【作者】 张培文；

【导师】 宋玉普； 刘德富；

【作者基本信息】 大连理工大学 ， 结构工程， 2002， 博士

【摘要】 滑坡的稳定性由内在因素和外在因素所决定，内在因素是边坡本身所固有的，外界因素主要包括地震、降雨、开挖等。进年来，由于降雨导致的边坡的失稳越来越频繁。因此对于降雨条件下坡面水运动的研究无论在理论上还是在工程应用上，都具有十分重要的意义。 阐述了非饱和土中水流动的基本规律和土水特征曲线。由于土水特征曲线具有滞后的特点，提出了根据初始含水量来确定数值模拟初始时步非饱和土的渗透系数。 编制了基于Richards控制方程的饱和-非饱和渗流有限元分析程序，一些算例证明了本程序的正确性。改进了传统流量的计算方法，使得计算精度明显提高。 分析了降雨条件下地表水入渗的过程，提出了降雨条件下非饱和渗流的二维数学模型及边界条件。一些计算算例说明降雨条件下非饱和渗流的基本规律。 编制了基于Saint-venant控制方程的坡面径流的有限元分析程序，利用解析解和试验数据证明了程序的正确性。 根据非饱和土上水的转化机理，编制了降雨条件下地表水入渗和产流耦合的计算程序，并根据土-水特征曲线，提出了判断地表饱和的条件，根据此条件，加速了收敛速度，节省了CPU的时间。给出了降雨条件下水的入渗的实际过程。 利用降雨条件下地表水入渗和产流耦合的计算程序，分析了降雨强度、初始含水量、饱和渗透系数、孔隙率以及饱和渗透系数比对非饱和土入渗和产流过程的影响，进一步证明了传统理论的正确性。 利用降雨条件下地表水入渗和产流耦合的计算程序，模拟了小降雨强度和大雨强度对地下水位变化的影响，并用数值计算给出了地表排水沟对地下水变化的影响不是很显著的结论。更多还原

【Abstract】 The stability of the slope is determined by its internal and external factors. The internal factors of the slope are inherent, and the external factors mainly include earthquake, rainfall events, and human excavation. The slope failure occurred frequently because of rainfall events in recent years. As a result, a systemic study on shallow water flow over porous soil is of great importance both in theory and application to engineering.The rule about water flow in the unsaturated soil and the soil-water characteristic curve are described in this thesis In the first time step during the numerical simulation, the permeability coefficient is calculated according to the initial water content of the unsaturated soil, because of as shown in the soil-water characteristic curve has the hysteresis phenomenon.A saturated-unsaturated FEM seepage analysis program is developed based on the Richards equation. Some examples are given to show the validity of the program. A method to calculate the discharge is developed and more accurate than traditional method.The infiltration process of the water on the surface is analysized under rainfall conditions, the two-dimensional mathematical model and its boundary conditions are presented. Some examples are given to explain the rules of unsaturated soil infiltration.The slope runoff FEM analysis program is developed based on the Saint-venant equations. The numerical solutions are compared with the analytical solutions and the experiment data and the characteristic line method solutions, the result validate of the program.The coupling analysis program of surface flow and subsurface flow over porous media is developed based on the conversion principles of water on the surface under rainfall conditions. A new method to judge the saturation of the surface is proposed in this thesis, the convergence is speeded up and the CPU time is saved by using this method.Five parameters are studied .namely rainfall intensity, initial water content, vertical saturated hydraulic conductivities, porosity and the ratio of the vertical and the horizontal saturated hydraulic conductivities by using the coupling program, the______________________________________________Abstract_____________________________________________results show the validity of the traditional infiltration theory.The alteration procedure of the underground water level is simulated under drizzle and storm rainfall conditions respectively adopting the coupling FEM analysis program of surface flow and subsurface flow . The numerical simulation of the underground water level shows that the drain ditch installed over the slope does not have an notable effect on the underground water level.更多还原