Many ejection landslides in the 2008 Wenchuan earthquake exhibited unusually dramatic behaviour in which a huge sliding mass was launched into the air and supported for a long distance because of the aerodynamic effect. In this paper, the formation conditions and movement characteristics of ejection landslides are analysed. The flight behaviour of the centroid of the ejection mass is studied by numerical solution with and without the aerodynamic effect. The impact and movement processes of the sliding mass are simulated by incorporating an advanced discretisation approach into discontinuous deformation analysis (DDA). Simulation results of the Dayanke rock avalanche induced by the 2008 Wenchuan earthquake show that the aerodynamic effect significantly affects its flight behaviour before collision. Simultaneously, the colluvium on the slope surface remarkably reduces its traveling speed and runout. Moreover, the initial angle between the velocity of the detached ejection mass and the horizontal direction strongly affects the flight distance and final deposition pattern of the avalanche.

中文翻译：

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2008年汶川地震引发的喷发滑坡和基于空气动力学理论和人工崩解碰撞技术的运动模拟

在2008年汶川地震中，许多喷射滑坡表现出异常的戏剧性行为，由于空气动力效应，巨大的滑移质量块被发射到空中并被支撑了很长的距离。本文分析了喷射滑坡的形成条件和运动特征。通过数值解研究了有空气动力学效应和没有空气动力学效应的抛射质心的飞行行为。通过将先进的离散化方法结合到不连续变形分析（DDA）中，可以模拟滑动块的冲击和运动过程。2008年汶川地震引发的大雁科岩崩雪崩的模拟结果表明，空气动力效应显着影响其碰撞前的飞行行为。同时，坡面上的洞穴明显降低了其行进速度和跳动。此外，脱离的喷射物质的速度与水平方向之间的初始角度强烈影响雪崩的飞行距离和最终沉积模式。