隧道水平旋喷加固效果及不同工法对稳定性影响分析

针对软弱破碎围岩隧道施工极易失稳的问题,采用FLAC2D软件建模对软弱破碎围岩隧道的施工过程进行数值仿真模拟,分析了水平旋喷预加固的效果;探讨了CRD(center cross diagram)法和三台阶法对隧道施工稳定性的影响。研究结果表明:水平旋喷预加固有利于控制沉降和衬砌内力;CRD法最大沉降值、衬砌内力均比三台阶法小,应优先选用;CRD法的中台阶左侧开挖为关键环节,应及时施作衬砌。在此基础上提出了一系列施工优化方案,在厦门公路隧道中实施应用,取得良好的效果,对同类隧道施工具有重要参考意义。

Reinforcement effect and stability analysis of tunnel horizontal jet grouting of different construction methods

In order to solve the stability problem of soft and broken surrounding rock in tunnel construction, the FLAC2D was employed to conduct numerical simulation to a section soft and broken surrounding rock tunnel. The effect of horizontal jet grouting pre-reinforcement was studied, the influence of CRD (center cross diagram) method and three steps method on tunnel construction stability was discussed. According to the analysis results, the jet grouting pre-reinforcement was helpful to control the settlement and lining internal force, the CRD method was recommended for the surrounding rock settlement and lining internal force of CRD is lower, and the excavation of left side of middle bench was the key link, and the lining should be done in time. Based on the analysis, a set of optimization methods of construction technology were put forward and applied in Xiamen highway tunnel, which could provide basis for the smooth construction, and could provide significant reference to similar tunnel construction.