岩质贴坡路堤台阶型式研究

Research of the shape of excavation steps on rock slope foundation in embankments construction

台阶法作为加强贴坡路堤稳定性的方法被广泛应用,而台阶的适用条件和台阶型式是其设计中的重点,对此相关设计规范中对此并无详细描述.结合高速公路建设实践,采用数值计算软件FLAC对岩质贴坡路堤的台阶设置进行模拟,通过对不同工况的岩质贴坡路堤稳定性计算,归纳总结出台阶的适用条件和台阶型式,计算结果显示:岩质斜坡地基上台阶设置主要针对滑动破坏为整体滑动和折线型滑动,对于圆弧形滑动,即填方内部破坏则影响不明显;在不同斜坡坡度下,岩质斜坡地基上填方路堤极限承载力随台阶宽度的加大而增加,挖台阶与否对其极限承载力的影响较大;台阶的宽度大于1m时,台阶宽度对其极限承载力影响不明显.

The embankments that constructed on mountain foundation is applied usnally,excavation steps on slope foundation as a step to enhance the stability of embankment method is widely used.However,there are no detaile description in the shape of steps of the specification.According to practice experiences in the expressway construction on the mountain region,numerical simulation was used to study the shape of the steps.After studing a lot of models,some useful conclusions were obtained.Such as:the first,the bearing capacity of embankments was increased little under excavation steps in ciecle slip failure mechanism;the second,the bearing capacity of embankments were increased with the step width in broken line slip failure mechanism;the third,the bearing capacity of embankments were increased little when the step exceed 1m.