降雨模式对树坪滑坡稳定性影响分析

降雨是诱发滑坡失稳的重要因素,依据饱和-非饱和及斜坡稳定性分析理论,基于等量的降雨量和降雨时间,按照实际库水位调度和降雨集中时间分为三种工况:工况一,稳定水位145 m;工况二,175 m水位线经150 d降到145 m水位线;工况三,145 m水位线经60 d升到175 m水位线,采用Geo-studio软件模拟三峡库区树坪滑坡在不同工况中减弱型、增强型、集中型、平均型4种降雨模式下的降雨入渗过程和稳定性。探讨了树坪滑坡孔隙水压力随时间的变化规律,以及树坪滑坡稳定系数与时间的变化关系。结果表明:降雨模式对树坪滑坡降雨入渗和稳定性有明显的影响,除工况二下水位继续降低作用外,其他二种工况下减弱型降雨模式水位线变化早于其他三种模式,库水位的变动能改变降雨模式对滑坡水位线的影响;降雨模式和库水位变动的双重作用下降雨入渗也发生了明显的变化;滑坡的初始安全系数都在1.2以上,而在工况二下滑坡的安全系数都降到1.2以下,尤其是减弱型模式下滑坡安全系数降幅最大。

The rainfall patterns to the influence thestability of Shu ping Landslide

Rainfall is an important factor to induce landslide instability, based on the theory of saturated - unsaturated and slope stability analysis, based on the same amount of rainfall and rainfall time, the Geo - studio software simulation tree landslide under different water level and the three gorges reservoir in less type, enhanced type, concentration, average 4 kinds of the process of rainfall infiltration under rainfall patterns and stability, and probes into the landslide tree change law of pore water pressure with time, and the tree landslide stability coefficient and the change of time relationship. Results show that the rainfall patterns of tree has distinct effect on the stability of landslide and rainfall infiltration, except under the condition of two levels continue to reduce the effect of the other two type less rainfall patterns under the condition of water level changes before the other three models, the change of water level to the influence of changing rainfall patterns of water level; Rainfall patterns and water level changes of rainfall infiltration under the dual role of also obvious changes have taken place; Initial landslide safety coefficient is above 1.2, and the safety factor of the landslide under the condition of two dropped below 1.2, especially landslide safety coefficient under the model of weakening the largest decline.