降雨型滑坡现场模拟试验研究

Research on On-site Simulation Test of Landslide by Artificial Rainfall

通过现场模拟人工降雨条件下诱发滑坡,在整个过程中,对坡面裂隙、土体深部位移、孔隙水压力、地表径流等进行实时监测,探求在降雨情况下的滑坡成灾特征及机理。试验得出了土体抗剪强度指标、滑动面形态特征等物理力学参数。降雨使土体吸水饱和,渗透性降低,抗剪强度降低,进而产生边坡失稳。通过数值模拟,得到降雨入渗过程中边坡稳定性、应力场和位移场的变化趋势。流-固耦合情况下边坡稳定系数比非耦合时降低5%,说明动水力对降雨型滑坡具有影响作用。

It has mainly studied the disaster properties and inducement mechanism of landslide on the condition of artificial rainfall or excavation by in - site analog experiment. During the while process, it has monitored the crannies at sloping surfaces, displacements in deep soil body, pore water pressure, and surface runoff which have been done to. The result shows some physical indexes, such as Anti -shear Strength Index and the shape properties of slope. After rainwater percolates into the fissures, the soil has been saturated,the penetrability and Anti - shear Strength is poor. In this case the slope would have been debacle. Based on numerical simulation, we have got the diversification tend of stability of slope and the change of the stress and displacement in the process of rainfall infiltration. The stability coefficient in fluid - solid coupling is lower than in non - fluid - solid coupling by 5 percent, which evidences that the seepage force is very important for landslide induced by rainfall.