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.

gravel soil slope  /  rainfall infiltration  /  earthquake  /  stability  /  FLAC