IMPACT ENERGY CALCULATION FOR ROCK SLOPE AND QUANTITATIVE ASSESSMENT OF VULNERABILITY FOR ELEMENT AT RISK

In the processes of landslide mass sliding and impacting on element at risk,the internal collapse of landslide mass will dissipate part of kinetic energy.But in practice,this part of energy is not taken usually into account.The discrete element method(DEM) is adopted to get impact force-time curves;and the impact energy conversion equation is also deduced based on impulse law and energy conservation law.With the analysis of the energy dissipation principle in the sliding and impacting processes of a practical rock slope,a comparison is made between the calculation method which takes both internal and external energy dissipations into account and the method which only takes external energy dissipation into account.The result shows that there is a significant difference between the two methods;and the internal energy dissipation can not be ignored.Moreover,the influence factors of impact energy and vulnerability for element at risk are both analyzed.The analysis result shows that impact energy is most sensitive to internal friction angle of landslide debris;second sensitive to distance between element at risk and landslide mass,gap length between joint segments,density of landslide mass and width of impact surface;last sensitive to the cohesion of landslide mass.In addition,the impact direction of landslide debris can simulataneously effect both impact energy and anti-impact energy.