基于离散元的公路边坡变形破坏过程分析

Based on the Discrete Element Highway Slope Instability Simulation

以雅安市大兴新区黄葛路边坡为研究对象,充分考虑该边坡工程地质条件,结合离散元颗粒流PFC^(2D)软件建立1∶1数值模拟分析模型,研究了该斜坡破坏力学机制模式以及变形破坏演化过程.结合现场调研对数值模拟各时间步的位移、应力与颗粒速度进行分析,结果表明:该滑坡初始阶段破坏模式表现为滑移-拉裂,随后表现为蠕变破坏;由软弱层面引起的滑坡其滑动面未必沿软弱层面,除了受软弱层的影响外,微地貌也是决定此类滑坡滑动面的影响因素之一;PFC^(2D)离散元颗粒流数值分析方法适用于黄葛路滑坡这类含软弱夹层的类土质滑坡,模拟结果与实际滑坡特征吻合较好,可为此类滑坡风险评估和防灾减灾提供理论参考.

In this paper,the slope of Huangge Road,Daxing New District,Ya'an city is taken as the research object,the engineering geological conditions of the slope are fully considered,the discrete element particle flow PFC^(2D)software is combined to establish a 1∶1 numerical simulation analysis model,and the mechanical mechanism mode and deformation and failure evolution process of the slope are studied.Combined with field investigation,the displacement,stress and particle velocity of each time step of numerical simulation were analyzed,and the results showed that:the failure mode of the landslide at the initial stage is slippage-tensile crack,followed by creep failure.The sliding surface of a landslide caused by the weak layer may not be along the weak layer.In addition to the influence of the weak layer,micro geomorphology is also one of the factors that determine the sliding surface of such a landslide.PFC^(2D)discrete element particle flow numerical analysis method is suitable for the landslide-like landslide with soft interlayer,such as Huangge Road landslide.The simulation results are in good agreement with the actual landslide characteristics,providing theoretical reference for the risk assessment and disaster prevention and mitigation of this kind of landslide.