LARGE SCALE SHAKING TABLE TEST OF GANQIUCHI GRANITE ROCK AVALANCHE IN QINLIN MOUNTAINS

Huge hazards, which are often caused by earthquake-induced mountain avalanches, are a serious secondary, and the study of dynamic response characteristics and failure mechanism of the avalanches in certain geological condition is an important issue in engineering geology and geotechnical engineering. In this paper, a large-scale shaking table test was carried out to study the Ganqiuchi granite avalanche relic in Cuihua Mountain, which is typical in Qinling District. The testing results show that the amplification coefficient of the acceleration peak value inside of the model slope presents a significant three-stage trend with the increase of the excitation intensity. The horizontal acceleration response increases monotonously with the increase of elevation, while the vertical acceleration response first increases, then decreases and finally increases with the increase of elevation. The natural frequency curve of the model slope can be divided into three stages, showing a downward trend, indicating that the dynamic characteristics of the model have changed. The damaged model can be divided into two regions: the source area and the accumulation area. The failure sliding characteristics and evolution process of the model slope under seismic excitation are as follows: seismic wave excitation input→tension cracks formed on the trailing edge of the slope→the fracture extends downward and penetrates→unstable slope sliding→accumulating at the foot of the slope. Four stages of mountain failure are inversed: vibration-induced fracturing stage, high-speed start-up stage, impact and deceleration stage and accumulating stage. The experimental results are quite consist with field observation and can help to explain the failure mechanism of granite slope, and provide the basic data and scientific support for disaster reduction and the development and protection of Qinling Mountain landscapes and geological heritages.