路堑顺层边坡稳定性分析及支挡防护数值模拟研究

Stability Analysis and Numerical Simulation Research on Retaining Protection of Layered Slope in Road Cutting

为研究含泥岩夹层顺层白云岩边坡的变形特征、稳定性及支挡防护,以某路堑边坡为例,基于midas GTS有限元软件进行了数值仿真计算,并结合现场观测分析边坡开挖及支挡防护后的坡体变形特征、应力状态、塑性区分布、抗滑桩受力特性,以及边坡加固后的稳定性状态。结果表明,研究边坡开挖至路基标高后,泥岩夹层出露,其破坏模式为平面滑动,稳定性系数为0.92,边坡不稳定,需做进一步支挡;边坡开挖后预应力锚索在坡体表面发生应力集中,且产生了良好的反向约束力,改善了坡体内部的应力分布;坡脚施加抗滑桩后与预应力锚索共同约束坡体,防止其沿泥岩夹层滑动,起到了良好的阻隔作用,且二者相结合后固脚强腰效果良好,确保了边坡整体稳定与局部稳定;经长期观测,边坡采用抗滑桩+框架锚索等多种结构综合治理具有良好的支护效果。

In order to study the deformation characteristics,stability,and support protection of a layered dolomite slope containing mudstone interlayers,numerical simulation calculations were conducted using midas GTS finite element software for a certain cutting slope.Combined with on-site observations,the deformation characteristics,stress state,plastic zone distribution,stress characteristics of anti slip piles,and stability status of the slope after excavation and support protection were analyzed.The results indicate that after the excavation of the research slope to the roadbed elevation,the mudstone interlayer is exposed,and its failure mode is plane sliding,with a stability coefficient of 0.92.The slope is unstable and further support is needed;After the excavation of the slope,the prestressed anchor cable experiences stress concentration on the surface of the slope and produces good reverse restraint,improving the stress distribution inside the slope;After applying anti slip piles at the bottom of the slope,they are combined with prestressed anchor cables to constrain the slope and prevent it from sliding along the mudstone interlayer,providing a good barrier effect.Moreover,the combination of the two has a good effect of strengthening the foot and waist,ensuring the overall and local stability of the slope;Through long-term observation,the comprehensive treatment of slopes using various structures such as anti slip piles and frame anchor cables has shown good support effects.The research results can provide reference for the stability analysis,deformation characteristics,and support protection design of similar construction sites.