依托四川省汶川至九寨沟段高速公路第06标段（川主寺至九寨沟段）边坡工程，采用FLAC软件模拟，考虑降雨与地震作用，以水平位移、塑性区和滑移面为边坡失稳评价指标，研究了高海拔、高烈度地区碎石土边坡在降雨及降雨-地震共同作用这两种工况下支护前后的稳定性，提出了合理的支护方案。结果表明：强降雨导致的边坡浅层面溜滑主要发生在黏土与碎石土交界面处，滑动面为平面型，采用锚杆框架梁支护可保证边坡稳定；降雨-地震共同作用下边坡的破坏范围扩大，碎石土边坡沿土体内部约12 m深处出现圆弧型滑动面，主要发生在黏土与碎石土交界面处，采用复合抗滑桩和锚杆框架梁组合支护方式可以保证边坡稳定。
The project is rested on the Sichuan highway slope on No.6 tenders from Wenchuan to Jiuzhaigou (the Chuanzhusi to Jiuzhaigou section). Through computer simulation with FLAC software and using horizontal displacement, plastic zone and slip as the evaluation indexes of slope instability, the stability for gravel soil slope of high altitude and high intensity is studied under rains effect and rains and earthquakes combined effect, respectively. Then a reasonable support mode is put forward accordingly. The research shows that the slippery surface of the slope caused by heavy rainfall mainly occurs at the interface between clay and crushed stone, and sliding surface is flat; so anchor frame beam support can ensure the slope stability. Moreover, the damage range of the slope will expand under the combined action of rainfall and earthquake, and an arc sliding surface about 12 meters deep will appear inside the slope and in the interface of clay and gravel soil. Composite anti-slide pile and anchor frame beam combination support can ensure the slope stability.
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