地震作用下松散堆积体崩塌的颗粒流数值模拟

Particle Flow Numerical Simulation of Landslip of Loose Slope under Seismic Loading

应用基于离散单元法理论的二维颗粒流数值模拟程序，探讨了松散堆积体在地震诱发作用下的崩塌过程与规律．通过改变堆积体底部边界的角度模拟不同地震烈度对松散堆积体崩塌规律的影响，并将数值模拟结果与离心模型试验结果进行了比较．结果表明：在地震诱发作用下，松散堆积体的崩塌量占崩塌总量的比重，5度地震烈度时约为5％，偏离临界休止角不到1．0°；6度和7度地震烈度时为18％左右，偏离临界休止角1．0°～2．0°；而8度地震烈度时约为45％，已远远偏离临界休止角近10°．研究结果可供山区道路边坡抗震设防及崩塌体对道路、河流的阻塞评价参考．

The landslip process and law of loose slopes under seismic loading were investigated by using PFC2D （particle flow code in two dimensions） based on the discrete element method. In the numerical simulation, the effect of seismic intensity on the landslip of loose slopes was analyzed by changing the angle of underside due to pseudo-static method, and the numerical simulation results were compared with the exsiting centrifugal test ones. The research results show that the landslip law of loose slopes can be analyzed effectively by a particle flow code model. Under seismic intensities of 5, 6 to 7 or 8 degree, landslip scale is respectively about 5%, 18% and 45%, and departure from the critical slope is less than 1.0°, 1.0° to 2.0° and about 10°, respectively. The numerical simulation results are consistent with the exsiting centrifuge experimental ones. The research provides a reference for the aseismatic design of loose slopes and the evaluation of river and road barrage.