Simulation of Landslide Movement Process by Discontinuous Deformation Analysis
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摘要: 坡是一个动态过程, 滑坡体的运动是一个集滑动、转动、拉张等运动方式的复杂运动过程.传统的极限平衡计算和有限元分析均无法描述滑坡的运动学特点和运动过程.非连续变形分析(DDA) 是最近发展起来的一种新的离散数值分析方法, 该方法基于块体的运动学理论及数值分析, 可以开展块体的静力和动力学计算.应用非连续变形分析方法对长江三峡库区新滩滑坡的运动全过程进行了数值模拟研究, 模拟方案充分依据该滑坡的地质、地形特征, 按不同岩土体和地质结构面类型进行块体单元的划分, 共划分成5 0 4个块体单元.模拟结果表明, 新滩滑坡是以斜坡中部姜家坡一带的局部破坏为其运动的开始阶段, 并进一步牵引上部滑体和推动下部滑体.代表性块体单元的位移变化曲线和滑动速度变化曲线反映了滑动过程中滑坡体块体系统的变形是非连续的, 各处块体的运动形态各异.从而很好地再现了新滩滑坡的整个动态过程, 揭示了滑坡的运动机制.Abstract: Landslide is a dynamic process. The movement of landslide body is a complex dynamic process composed of sliding, rotational, and tensile movements. Either the traditional limit equilibrium calculation or finite element analysis cannot be used to describe the characteristics and process of landslide movements. The discontinuous deformation analysis (DDA), a new discrete numerical simulation method, incorporates both the massive dynamic theory and the numerical analysis, so as to make a static and dynamic calculation of the massive body. In this paper, the discontinuous deformation analysis is applied to the numerical simulation of the dynamic movement process of Xintan landslide in the Three Gorges reservoir. This simulation classifies the landslide profile as 504 units in terms of geology, topography, soil and rock body types and geological structural surface types. The simulation results show that the Xintan landslide started with the partial failure of the Jiangjiapo belt in the middle of the landslide, and then the upper part of the landslide was further trailed upward and the lower part of the landslide was further pushed downward. Both the displacement variation curves and the sliding speed variation curves of the representative massive units show that the deformation of the massive body system of the sliding slope is discontinuous in the sliding process, and that the movements of different masses are quite different in shape, reflecting well the whole dynamic process of the landslide and revealing the dynamic mechanism of the landslide.
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Key words:
- landslide /
- simulation /
- discontinuous deformation analysis
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表 1 计算参数的取值
Table 1. Parameters for calculation
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