不同长度注浆锚杆支护效果及围岩变形曲线规律

Supporting effect of grouting anchors with different lengths and deformation curves of surrounding rock

为了探究注浆锚杆支护作用效果,以吉林甄峰岭隧道已出现大变形的软弱围岩区为例,分析了不同注浆范围条件下隧道循环进尺开挖后围岩变形规律.根据大变形区域实测位移进行反演分析,获取隧道围岩真实力学参数,分别对不同注浆锚杆施工支护方案进行循环进尺开挖计算,获得了各方案下隧道各位置位移变化曲线,并采用单元安全度方法对计算结果进行评价.结果表明,目标工程的注浆锚杆最佳应用长度为3 m,其作用效果主要体现在对急速变形阶段变形量的控制.

In order to explore the supporting effect of grouting anchors,a weak surrounding rock area with large deformation in Zhenfengling tunnel of Jilin province was taken as an example,and the deformation law of surrounding rock after cyclical tunnel footage excavation under different grouting conditions was analyzed.A back analysis was performed according to the measured displacement of large deformation area to obtain the real mechanical parameters for the grouting anchors.In addition,the calculation of cyclical tunnel footage excavation in different supporting schemes for the grouting anchors was carried out,the displacement change curves for each tunnel position under various schemes were obtained,and the calculation results were evaluated with a unit safety degree method.The results show that the optimal length of grouting anchors for target project application is 3 m,and its effect can be reflected mainly in the control of deformation amount at the rapid deformation stage.