基于3维DDA的多块体滚石运动分析

发布时间：2018-04-10 07:52

本文选题：滚石　切入点：运动特征　出处：《工程科学与技术》2017年S1期

【摘要】：崩塌滚石是山区主要的地质灾害之一,分布范围及其广泛,突发性极强,预测困难,会造成建筑物损坏、交通运输线路堵塞、人员伤亡等严重后果。其防护结构的设计依据主要是边坡滚石的运动轨迹,目前,国内外对崩塌滚石的相关研究较为薄弱,从而导致滚石灾害治理上效果不佳。通过对国内外众多滚石灾害案例的研究,探索3维非连续变形分析方法(3-D DDA)在崩塌滚石中的应用。相比传统的2维模型,3维模型由于能够考虑3维地形效应,分析扩散角,近年来逐步成为主流的研究手段。实例分析中以某岩质边坡建立3-D DDA模型,采用恢复系数法描述滚石碰撞反弹的问题,通过数值模拟,分析多块体滚石事件的运动特征。结果表明:是否考虑滚石间相互碰撞所计算出的结果差异较大,虽然滚石间的相互碰撞通常会带来总能量的损失,但部分块体受到碰撞将接受动能,促进其远距离运动,滚石块体间的相互作用不能忽视。与现有方法相比,3-D DDA具有能直接在模拟块体间相互碰撞,更符合多块体滚石灾害事件的优点。进一步,基于运动特征分析成果验证了防护措施的效果。该方法可用于斜坡区多块体滚石运动特征的预测,并可为滚石灾害科学防治决策提供参考。
[Abstract]:Rock collapse is one of the main geological disasters in mountainous area. It is widely distributed, sudden and extremely difficult to predict, which will result in building damage, traffic congestion, casualties and other serious consequences.The design of its protective structure is mainly based on the trajectory of slope rolling stone. At present, the relative research on rock collapse is relatively weak at home and abroad, which leads to the poor effect on the treatment of rolling stone disaster.The application of 3-D DDAs to rock collapses is explored through the study of many cases of rock rolling disasters at home and abroad.Compared with the traditional 2D model, 3D model has become the mainstream research method in recent years because of its ability to consider the 3D terrain effect and analyze the diffusion angle.The 3-D DDA model of a rock slope is established in the case study, and the method of recovery coefficient is used to describe the problem of rolling rock collision and rebound. Through numerical simulation, the motion characteristics of multi-block rock rolling events are analyzed.The results show that there is a great difference between the calculated results whether or not the rolling stones collide with each other. Although the collision between the rolling stones usually results in the loss of total energy, some blocks will accept kinetic energy when they collide with each other, which will promote their long-distance motion.The interaction between rolling stones can not be ignored.Compared with the existing methods, the 3-D DDA can directly simulate the collision between blocks, which is more suitable for the multi-block rolling rock disaster event.Furthermore, the effectiveness of the protective measures is verified based on the results of motion feature analysis.This method can be used to predict the motion characteristics of multi-block rolling stones in slope area and can be used as a reference for the scientific prevention and control of rolling stone disasters.
【作者单位】：四川大学水力学与山区河流开发保护国家重点实验室水利水电学院;四川大学-香港理工大学灾后重建与管理学院;
【基金】：国家自然科学基金青年资助项目(51509173)
【分类号】：P642.21

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