降雨非稳态入渗中堆积体坡包气带气-液耦合过程

基于堆积体的现场调查、室内试验，运用非饱和土力学等理论、采用数值方法对堆积体的降雨入渗的固-水-气耦合以及气体压缩效应进行研究。基于典型非饱和堆积体渗透试验、堆积体降雨的物理模拟等，对降雨作用下非饱和堆积体非稳态流的气-液耦合效应及其与滑坡的内在规律进行研究。在了解典型非饱和堆积体水、气渗透特征的基础上，分析堆积体的二相流特征，探索降雨过程中非稳态渗流的边界变化特征。开展不同应力状态下非饱和堆积体降雨试验。基于模型试验结果，建立降雨作用下非饱和堆积体固-水-气耦合模型，采用数值方法对该模型方程求解，侧重揭示气-液耦合效应以及气体压缩对堆积体非稳态孔隙水压力分布的影响规律，进而研究堆积体中二相流与滑坡的内在联系。结合工程，将研究成果应用于堆积体地区的降雨型滑坡以及松散堆积体坡的渗流评价。该研究将有助于推动我国环境地质灾害学的发展，也对堆积体地区的降雨型滑坡及渗流评价具有理论意义。

Based on in-situ investigation and laboratory tests of the deposits, unsaturated soil theory, and numerical methods, the coupled solid, water and atmosphere, and the effect of air compression on unsteady unsaturated infiltration are researched. Rainfall experiment and physical simulation on typical unsaturated deposits will be executed. Meanwhile, air-liquid coupling law of unsteady unsaturated infiltration associated with landslides is analyzed. On the basis of understanding basic characteristics of two-phase flow characteristics of the unsaturated deposits, boundaries variation of the unsteady seepage caused by rainfall is investigated. Rainfall modeling tests of unsaturated deposits have been carried out under different stress states. According to model test results, the model of solid-liquid-air coupling of the deposits will be established. The model equations will be solved using numerical methods. Then the influence of air-liquid coupling and air compression on the deposits’ unsteady infiltration will be discussed. We will study the intrinsic link between two-phase flow and the landslide in the region of deposits. Associated with engineering, the research results will be applied to seepage evaluation in areas of rainfall-induced landslides and loose deposits. The study will help promote environmental geological hazards in China. And it also has an important theoretical implication for stability analysis of rainfall-induced landslides made of deposits.