基于Linear Cohesion模型的含水堆积体滑坡过程数值模拟

水通常是堆积体滑坡发生的触发因素,采用数值方法模拟堆积体滑坡时加入水的液桥力有助于提高计算结果的合理性。为了研究含水堆积体滑坡过程的各项运动特性,提出采用Linear Cohesion接触模型模拟含水湿润状态下松散堆积体滑坡的运动过程,利用离散元程序EDEM 2017建立了含水堆积体滑坡水槽数值模型,计算堆积体从失稳-滑动-堆积整个运动过程。结果表明:能量密度k是Linear Cohesion模型模拟含水堆积体滑坡的关键参数;当k<5000 J/m^3时,随着能量密度值逐渐增大,堆积体滑动过程的流动性越来越小,最大平均速度值和最大动能越大,当k≥5000 J/m^3时,含水堆积体的各项滑动特征变化不明显;较小能量密度的湿颗粒堆积体在滑动过程中结构体易发生破坏,形成的颗粒群流动性更强,滑动距离更远,扩大了滑坡灾害的影响范围。相关研究成果对今后类似的含水堆积体滑坡灾害的预测和评估有一定参考价值。

Numerical simulation of water-bearing deposition landslide process based on Linear Cohesion model

Water is the triggering factor of landslides usually,and using the numerical method to simulate landslides considering liquid bridge force will help to improve the rationality of the calculation results.In order to study the kinetic characteristics of water-bearing deposition landslide,the Linear Cohesion contact model was proposed to simulate the loose deposition landslides under wet condition.A numerical model of water-bearing deposition landslide flume was established by the discrete element program EDEM2017 to simulate the whole sliding process from instability to sliding to deposit.The results showed that energy density k was the key parameter of Linear Cohesion model in the simulation of water-bearing deposition landslide.When k<5000 J/m^3,with the increase of energy density,the fluidity of deposition sliding process became smaller,and the maximum average velocity and maximum kinetic energy increased.When k≥5000 J/m^3,the sliding characteristics of water-bearing deposition changed insignificantly.The structure of wet granular deposition with small energy density was easily to be destroyed during the sliding process,the fluidity of the granular groups formed in the process was stronger and the sliding distance was longer,which enlarged the impact scope of landslide disaster.These results are helpful for the prediction and evaluation of similar water-bearing deposition landslide disasters in the future.