降雨类型对浅层深层滑坡渗流及稳定性的影响

为研究不同降雨类型对浅层及深层滑动面渗流特性及边坡稳定性的影响,采用有限元分析软件Geo-slope中的Seep/w和Slope/w模块,分析了相同降雨量不同降雨模式(平均型、前锋型、中锋型、后锋型)下浅层及深层体积含水率、孔压变化规律,得出了其安全系数随时间的变化曲线。结果表明,降雨期间边坡表面体积含水率增大至饱和,孔压趋向于0,停雨后边坡上部体积含水率及孔压逐渐减小,而坡脚处几乎不变,不同降雨模式影响了土体含水率及孔压的分布;下部浅层滑动面安全系数变幅大于上部浅层滑动面,深层滑动面安全系数变化滞后于降雨;平均型降雨对于深层滑动面安全系数影响最大,而后锋型降雨对于浅层滑动面安全系数影响最大。研究结果为边坡滑坡机理的认识及滑坡治理提供了参考。

Influence of Different Rainfall Patterns on Seepage and Stability of Shallow and Deep Landslides

In order to study the influence of different rainfall types on the seepage characteristics of shallow and deep sliding surfaces and the stability of slopes, the Seep/w and Slope/w modules in the finite element analysis software Geo-slope were used to analyze the volumetric water content and pore water pressure of the same rainfall in different rainfall patterns (average type, forward type, center type, front type), and the curves of safety factor versus time were obtained. The results show that: the surface water content of the slope increases to saturation and pore water pressure tends to 0 during the rainfall, the volume water content and pore water pressure at the top of the slope decrease gradually after the rainfall and the toe of slope is almost unchanged. Different rainfall patterns affect the soil water content and pore pressure distribution. The safety factor amplitude of the lower shallow sliding surface is larger than that of the upper shallow slip surface, and the change of safety factor of deep sliding surface lags behind rainfall. The average-type rainfall has the greatest impact on the safety factor of deep sliding surface while the front-type rainfall safety coefficient has impact on the shallow sliding surface. The research results provide a reference for understanding and treatment of the slope landslide mechanism.