地震作用下高路堑黄土边坡细观力学研究

Micro-mechanical Study on High Cutting Loess Slopes under Earthquake

为研究地震时高路堑黄土边坡破坏的细观力学过程,以黄土地区某高速公路边坡为例,在野外工程地质勘察和室内试验基础上,用强度折减法对开挖后的高路堑黄土边坡的初始状态进行分析,进而对该高路堑边坡采用PFC2D建立数值计算模型,模拟边坡地震响应全过程;通过分析地震响应过程中颗粒的位移、配位数、孔隙率、应力和应变率等关键要素,从细观层面揭示边坡的失稳过程。结果显示,通过该方法能够再现地震作用下滑坡的细观物理力学过程,涵盖了边坡的破坏模式和破坏过程,以及应力应变等时空演化规律。研究结果对于认识地震作用下高路堑黄土边坡的破坏机理具有重要意义。

To study the micro-mechanical failure process of high cutting loess slopes during earthquake,a highway slope in loess area was taken as an example in this paper.On the basis of field engineering geological investigation and indoor test,initial state of the high cutting loess slope after excavation was analyzed with the strength reduction method,and then a numerical calculation model of the cutting slope was established by using PFC2D,and seismic response of the slope was simulated.Through the analysis of some key elements of particle during the process of seismic response,e.g.displacement,coordination number,porosity,stress,and strain rate,instability process of the slope was revealed on meso-level.The results showed that the method proposed in this paper can reproduce the micro-physical and mechanical process of landslides under the action of earthquake,covering the failure mode and process of slope,as well as the temporal and spatial evolution law of stress and strain.The research results has a great significance for understanding the failure mechanism of high cutting loess slopes under seismic action.