考虑损伤及非饱和效应的炭质泥岩路堤稳定性分析

Stability analysis of carbonaceous mudstone embankment considering damage and unsaturation effect

为了分析降雨条件下炭质泥岩路堤的稳定性,基于考虑岩土体损伤的Hoek-Brown准则,结合非饱和抗剪强度理论,提出一种考虑损伤及非饱和效应的路堤稳定性分析方法,并利用该方法对算例炭质泥岩路堤的降雨入渗过程及稳定性进行研究。研究结果表明:提出的路堤稳定性分析方法具有较强的针对性和实用性,能够同时考虑损伤及非饱和效应对路堤稳定性的影响;在降雨条件下,边坡表层孔隙水压力变化幅度、暂态饱和区形成范围均与降雨强度、降雨时间呈正比;在降雨过程中,边坡表层孔隙水压力逐渐增大,暂态饱和区自坡面向路堤内部不断延伸,路堤表层及内部塑性区沿坡面及路堤内部不断向坡顶延伸,路堤安全系数逐渐降低;降雨停止后,边坡表层孔隙水压力持续降低,暂态饱和区自上往下逐渐消散,路堤表层及内部塑性区均先增加后减小,路堤安全系数先小幅度降低,后持续增大。

In order to analyze the stability of carbonaceous mudstone embankment in the condition of rainfall, a stability analysis method of embankment that can consider the damage and unsaturation effect by combing the unsaturated shear strength theory was proposed based on Hoek-Brown criterion which considers the damage of soil, and the rainfall infiltration process and stability of carbonaceous mudstone embankment example were studied. The results show that the stability analysis method of embankment is strongly relevant and practical, which simultaneously considers the impact of damage and unsaturation effect on the embankment stability. Under the condition of rainfall, the change amplitude of pore water pressure of slope surface and the formed scope of transient saturated zone are directly proportional to the rainfall intensity and rainfall time. In the process of rainfall, the pore water pressure of slope surface increases gradually; the transient saturated zone extends constantly from the slope surface to the embankment internal; the plastic zone of slope surface and embankment internal extends constantly from the slope surface and embankment internal to the slope top; the safety factor of embankment decreases gradually. When the rain stops, the pore water pressure of slope surface decreases consistently, the transient saturated zone dissipates gradually from top to bottom, the plastic zone of slope surface and embankment internal decreases first and increases later, the safety factor of carbonaceous mudstone embankment reduces slightly first, then continues to increase.