降雨条件下滚石斜坡失稳机理试验研究

Instability Mechanism of Rolling Slope under Rainfall Condition

为了探究滚石斜坡在降雨入渗条件下的失稳机理,通过模型试验分析不同降雨时长、不同坡度条件下,滚石斜坡的稳定性与含水率、孔隙水压力及土压力的映射关系,并结合模型试验推导滚石斜坡的稳定性计算方法。研究表明:随着降雨时长的增加,所有斜坡的含水率、孔隙水压力和土压力值均增加;55°斜坡比75°和35°斜坡更利于降雨入渗,其含水率、土压力和孔隙水压力均为最大,从而更易失稳滑动;降雨条件下,滚石斜坡的失稳破坏最先为岩土颗粒滚落,然后是局部滑动并不断扩大。结合模型试验,推导出适用于滚石斜坡降雨入渗条件的简布法稳定性计算公式。研究成果可用于西藏高原公路滚石斜坡的维修整治。

To explore the instability mechanism of the rolling stone slopes under the condition of rainfall infiltration,the mapping relationships between the stability of the rolling stone slopes and the water content,pore water pressure,and earth pressure was analyzed.the stability calculation method of the creeping rubble slopes was derived.show that with the increase of precipitation duration,the water content,pore water pressure and earth pressure of all slopes increase.55°is more beneficial to rainfall infiltration than 75°and 35°slopes,water content,earth pressure,and pore water pressure are all the largest,which unstable sliding.Under rainfall conditions,the unstable failure of the rolling stone slopes rolling down of rock and soil particles,and then local sliding and continuous expansion.Combined with the model test,Janbu method suitable for the rainfall infiltration conditions of the rolling stone slopes was derived.The research results can be used for the maintenance and repair of the rolling stone slopes on the Tibetan Plateau.