SPH-DEM流固耦合方法模拟金沙江白格滑坡应用研究

Study on Application of SPH-DEM Fluid-structure Interaction to Simulating Baige Landslide in Jinsha River

从力学本质来讲,滑坡属于滑坡动力学和水动力学复杂流固耦合问题。采用离散元方法(DEM)模拟滑坡体大变形、不连续问题,以光滑粒子流方法(SPH)模拟水体的流体动力学特性,充分利用不同数值计算方法的特点,构建SPH-DEM流固耦合算法,并应用于2018年10月10日西藏白格滑坡堵江的灾害模拟中。结果显示计算模型能较为准确地捕捉滑坡碎屑体入江激起水砂射流的规模以及范围,再现主堆积区向次堆积区产生二次滑移的动力过程,完整刻画堆积体的厚度、几何形态和断面特征。仿真结果有助于进一步深化对高速高位滑坡产生堵江过程和机理的认识,为后续进行抢险施工组织设计,制定防灾减灾策略提供参考。

In terms of mechanical nature,landslide can be categorized as the complex fluid-structure interaction of landslide dynamics and hydrodynamics.The discrete element method(DEM)is used to simulate the large deformation and discontinuity of landslide,and the smooth particle flow method(SPH)is used to simulate the hydrodynamic characteristics of water body,the SPH-DEM fluid-structure interaction algorithm is formed by making full use of different numerical calculation methods.This algorithm is applied to simulating Baige landslide blocking Jinsha river,a catastrophic landslide occurred in Baige village of Tibet on October 10,2018.It shows that the computational model can accurately obtain the scale and range of the water-sand jet caused by the landslide debris falling into the river,recreating the dynamic process of the secondary landslide from the main accumulation area to the secondary accumulation area,displaying the thickness,geometric shape and cross-sectional characteristics of the accumulation body.The findings are helpful for further understanding of the process and cause of river blockage caused by high-speed high-locality landslide,and provide reference for future design of emergency construction and formation of disaster prevention and mitigation strategies.