Based on the multi-phase flow & multi-field coupling theory, this paper adopted the finite element method to calculat e the t emperature distribut ion of Muyubao landslide as the atmospheric temperature changes. Further, it analyzed the influence of atmospheric temperature changes on the slope seepage according to the correlat ion between temperature and viscosity of w at er. The results of calculat ion showed that the effectof atmospheric temperature on temperature of the slope body is limited to the shallow surface; as the depth increases, the influence decreases and the hysteresis increases concurrent ly. The mobilit y of the water is affected by the change of the slope body's temperature and it can change the water permeability in the inner slope. The effectof atmospheric temperature on permeability coefficientof the slope has a nonlinear relationship with depth. The effectof atmospheric temperature on the permeabilit y coefficient declines as the depth increases. Generally, the permeability coefficientof the slope no longer change significantly when the depth is deeper t han The maximum depth of infiltration. The permeability coef-ficientof the slope shows seasonal variation with the atmospheric temperature. The permeability coefficient decreases with the increase of depth when the atmospheric t em perat ure is higher than The soil in summer. In cont rast, the permeabilit y coefficient increases w ith the increase of depth in w int er.

On the basis of the theory of two-phase ( water and air) flow, the law of water-air movement caused by rainfall infiltration in slope was revealed by means of finite element method. Daping landslide in Three Gorges Res-ervoir was taken as a case study. The simulation results show that the slope surface can be divided into the inflow area and the outflow area according to the inflow and outflow of water and air. Usually the upper part of slope is in-flow area, and the lower part is outflow area. The total infiltration rate of water and air in slope is relatively stable, slightly affected by rainfall characteristics, slope surface runoff and temperature changes. In the inflow area, when rainfall intensity is greater than infiltration rate, water in slope will run off, otherwise water or air will completely infiltrate. The saturation pressure of slope surface could transmit to groundwater surface through pore air, which in-creases the groundwater pressure head, unfavorable for slope stability.

通气条件是影响整个降雨入渗过程的重要因素之一.通过自主设计的降雨入渗试验模型、模拟降雨系统及数据自动采集系统,分别进行通气、封气条件下的人工降雨模拟试验,从而研究气相对降雨入渗的影响.对比通气和封气条件下的试验数据可知,封气条件下气体不能自由排出,对雨水下渗的阻滞作用明显,雨水入渗速率较小,坡体内饱和区变化缓慢;坡体内孔隙气压力随着降雨入渗的进行先增大后在10 cm水头上下波动.研究成果为原位试验的展开及数值模拟提供了数据支撑.