基于离散单元法的滑坡堆积及其涌浪计算

采用离散单元法对水库库岸边坡的动态破坏过程进行了研究，给出了计算流程并开发了相应的软件。介绍了离散单元法的基本原理，分析了常用的计算滑坡速度方法的不足及用离散单元法的优势，基于离散单元法提供的块体运动信息并结合波动方程模拟了滑坡体滑入水库时所激起的涌浪。此外，采用离散单元法研究了滑坡的堆积形状。通过算例验证了方法的可行性与程序的正确性。算例结果表明：块体在坡面上运动时，用离散单元法计算得到的块体的速度和能量法与潘家铮法一致，且更方便、更高效；由于涌浪的叠加，多个块体所激起的涌浪高度比单个块体的涌浪高一些，这表明在进行涌浪分析时，考虑多块体的涌浪叠加效应是至关重要的，滑坡的堆积形状为滑坡的灾害评估提供了依据。通过自行开发的离散单元法软件模拟了块体的滑动和涌浪的产生及其传播过程，其模拟结果为研究边坡的滑动破坏的启动、破坏过程及滑坡的风险评价提供了新的思路。

Calculation of heap shape of landslide and its surge based on discrete element method

Discrete element method(DEM) is adopted to simulate the whole failure process of reservoir bank slope.The flow chart of this paper is carried out and its corresponding software is developed.The basic principles of DEM are introduced.The disadvantages of the existing methods of calculating landslide velocity and advantages of DEM are analyzed.The height and shape of the surge of the reservoir stirred up by the landslide is simulated by combining the block information provided by DEM and wave equation,the heap shape of the landslide is also carried out by DEM.The feasibility and accuracy of the method is verified by case studies.The results of the examples indicate that the block velocity on the slope calculated by DEM agrees well with that the energy conservation method and Pan Jiazheng method;the DEM is more convenience and has a higher efficiency.The height of surge stirred up by multi-blocks is greater than that of single-block due to the plus of surges,which indicates that it is important to consider the plus of surges when analyzing the height of surge.The heap shape of the blocks provides basic data for the disaster assessment of landslide.The sliding of the block and the generating and transmitting of surge are also carried out by a self-developed DEM software,which provides a new idea for the study of the start,the process and the risk assessment of slope failure.