Abstract: Rainfall has a significant impact on the deformation and stability of slopes. This article uses MIDAS GTX NX finite element software to simulate the analysis of slope rainfall infiltration stability. By simulating two working conditions of different soil types and rainfall intensities, the deformation and stability of the slope during rainfall infiltration process are obtained. Analysis shows that with the increase of rainfall intensities and changes in soil types, the total vertical displacement of the slope gradually increases. And at the same time, the sliding area of the slope gradually forms a continuous slip zone. Under this working condition, due to the fast infiltration rate of rainfall, the pore water pressure increases significantly, and the vertical displacement is more significant, resulting in the phenomenon of soil sliding from the top to the foot of the slope. This will reduce the shear strength of unsaturated soil, cause local instability of the slope, and ultimately lead to a decrease in the safety factor; The slope has undergone plastic deformation during the process of rainfall infiltration, gradually spreading from the foot of the slope to the top, and forming an arc-shaped penetration surface inside the slope. During the rainfall process, the soil strength gradually decreases due to changes in matrix suction, and the stability coefficient of the slope gradually decreases, affecting the overall stability of the slope.

Key words: rainfall infiltration, MIDAS GTX NX, stability, pore water pressure

摘要： 降雨对边坡的变形及稳定性有着显著的影响。文中利用MIDAS GTX NX有限元软件对边坡降雨入渗稳定性进行分析,通过模拟不同土质类型和不同的降雨强度2种工况,得到在降雨入渗过程中边坡的变形及稳定性的变化规律。分析表明:随着降雨强度的增加和土质类型的改变,边坡竖向总位移逐渐增大,同时坡体滑动区域逐渐形成贯通状态。说明在此工况下由于降雨入渗速度较快,孔隙水压力上升明显,竖向位移较为显著,出现了坡顶的土体向坡脚滑动的现象,这会降低非饱和土的抗剪强度,坡体发生局部失稳,进而导致安全系数下降;边坡在降雨入渗过程中已经发生塑性变形,并逐渐由坡脚向坡顶蔓延,边坡内部形成圆弧形贯通面。降雨过程中,土体强度由于基质吸力的改变而逐渐减小,边坡的稳定系数逐渐变小,影响边坡的整体稳定性。

关键词: 降雨入渗, MIDAS GTX NX, 稳定性, 孔隙水压力