近水平岩层状围岩公路特长隧道支护参数优化研究

Optimization Study of Support Parameters for Long Highway Tunnels in CloseProximity to Horizontal Layered Rock Masses on Highways

考虑近水平岩层拱顶及拱墙处的破坏特征存在明显的差异,对近水平岩层隧道的破坏特征进行研究;采用数值计算及监测反馈的方法,考虑爆破对围岩及结构面的劣化作用,分析隧道各个部位的位移、锚杆轴力等数值,提出近水平岩层优化方案。研究结果表明,近水平岩层深埋硬岩隧道,可取消拱墙部位的锚杆,仅在拱顶范围设置,可节省系统锚杆约40%的工程量,能够节约资金和保证安全,同时也缩短了工期。

Considering distinct differences exist in the failure characteristics at the arch crown and sidewall of such rock formations.Through the study of failure characteristics in tunnels with nearly horizontal rock strata,numerical calculations,monitoring feedback methods,and the consideration of the deteriorative effects of blasting on surrounding rock and structural planes were employed.This analysis evaluated various parameters,such as displacements and axial forces of anchor rods,to propose an optimized approach for tunnels in nearly horizon-tal rock strata.The research result indicates that for deeply buried hard rock tunnels with nearly horizontal strata,it is feasible to eliminate anchor rods in the sidewall area and only install them within the arch crown zone,resulting in approximately 40%reduction in anchor rod quantity,thereby saving costs and ensuring safety while also shortening the construction period.