考虑裂隙的膨胀土非饱和渗透特性及边坡降雨入渗数值模拟

项目名称： 考虑裂隙的膨胀土非饱和渗透特性及边坡降雨入渗数值模拟

项目编号： No.41302275

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 田东方

作者单位： 三峡大学

项目金额： 24万元

中文摘要： 强降雨是诱发膨胀土边坡失稳的重要因素之一。目前降雨入渗分析中，在借助连续介质理论分析膨胀土裂隙充分发育层的渗流问题时，未考虑裂隙对非饱和渗透特性及表征单元体体积的影响，且现有分析方法无法同时考虑气相和坡面径流对入渗的影响。本课题拟开展膨胀土非饱和渗透特性数值试验研究，建立边坡水气两相流与坡面径流联合求解模型，寻求一种切实可行的膨胀土边坡降雨入渗分析方法。基于完整膨胀土非饱和渗透特性、膨胀土失水开裂裂隙分布、单裂隙非饱和渗透特性，开展数值试验，建立考虑裂隙影响的膨胀土SWCC、水和气体相对渗透函数模型并确定表征单元体体积；基于水气两相流和运动波方程，结合有限元法，将运动波方程融入两相流方程坡面入渗边界，消去入渗率，建立边坡水气两相流与坡面径流联合求解模型,实现膨胀土边坡降雨入渗数值模拟，用膨胀土入渗强度试验加以验证。研究成果对于理解边坡失稳机制和边坡加固工程具有重要的理论和实际意义。

中文关键词： 降雨入渗；膨胀土裂隙；坡面径流；水气两相流；有限元

英文摘要： Intensive rainfall is one of the most important factors which induce the failure of expansive soil slope. At Present, the infiltration analysis is usually based on continuum theory, and it does not consider the effect of fracture induced by water loss on unsaturated permeability and REV volume of expensive soil. Furthermore, existing methods are incapable of considering the effect of pore gas and runoff simultaneously. So, deeper research is necessary. This proposal would make an attempt to establish a new feasible method for infiltration analysis for expansive soil slope numerical experiments and the integrated model for water-air two-phase flow and runoff. Based on the unsaturated permeability of intact expansive soil, the fracture distribution, and water and gas unsaturated permeability of single fracture, numerical experiments on SWCC, water and gas unsaturated permeability and REV of expansive soil would be done. Furthermore, the integrated model from the kinematic wave approximations of the Saint Venant equations and water-air two-phase flow equations would be established, and a finite element program for numercal simulation corresponding to the above model would be coded. Finally, introducing the unsaturated permeability of expansive soil and verified by the infiltration experiments, the program is used t

英文关键词： infiltration；fracture of expansive soil；runoff；water-air two phase flow；FEM