DEM study on the effect of landslide volume on the low friction of large landslides

• 1、School of Civil Engineering,Chongqing University,Chongqing 400045

Abstract：The investigation of landslide disaster found that for large high-speed long-distance landslide, the effective friction coefficient calculated according to the landslide process is much lower than the normal friction coefficient of the soil on the slip surface, and the larger the landslide volume is, the lower the effective friction coefficient is. This phenomenon is called the effect of landslide volume on the low friction of large landslide. In order to reveal the mechanism and influencing factors of the low friction of large landslide, the influence of landslide volume, landslide aspect ratio, slope angle of slip surface and base friction coefficient on sliding speed and moving distance have been studied by means of DEM, and furthermore, the effective friction coefficient was calculated according to the process of landslide. The results showed that although landslide volume, landslide aspect ratio and slope angle of slip surface all have influence on the sliding speed and moving distance, the effective friction coefficient does not decrease with the increase of landslide volume or sliding speed if the base friction coefficient remains unchanged. Only by changing the base friction coefficient on the slip surface can the effective friction coefficient change obviously, indicating that the low friction of large landslide is caused by the degradation of the mechanical properties of the sliding zone soil during the sliding process.

Keywords： geotechnical engineering large landslide effective friction coefficient low friction volumetric effect