路堑边坡施工顺序对边坡稳定性影响数值模拟分析

Numerical Simulation Analysis for the Influence of Construction Process of Deep Cut Slop on Its Stability

边坡的开挖、支挡施工顺序对边坡的稳定性有较大影响 ,本文采用有限元强度折减法对深挖路堑边坡的不同施工方案进行了有限元数值模拟分析。结果表明 ,开挖一级 ,锚固一级 ,可控制边坡的变形 ,有利于边坡的稳定 ,但是另一方面锚索的受力会随着往下逐级开挖而逐渐增大 ,有时甚至会超过其设计强度。边坡的稳定最好是依靠其自身就能基本自稳 ,加固处理仅作为安全储备 ,最好的办法是一方面既要确保边坡工程的稳定 ,同时也要允许边坡开挖后有一定的变形 ,释放一部分应力 ,充分发挥边坡的自稳定能力 ,以减少支护受力 ,即将所谓的“新澳法”

In this paper, the FEM numerical simulation and stability analysis on different excavation and support scheme of deep cut slope was carried out by strength reduction method. The results show that with excavation, the slope will be stable only in case of simultaneous installation of support (such as anchor cables and bolts etc.) and the support load will be increased with the step by step excavation. Sometimes, the load could exceed the strength of the anchor cable. In order to ensure the stability of the slope, it is reasonable to have self stability of the slope and at the same time a reasonable limited deformation is permitted to unload partly the slope after excavation. That is, the idea of NATM method used in tunnel support could be applied.