公路隧道含煤层围岩加固措施及效果分析

Reinforcement Measures and Effects Analysis on Surrounding Rock with Coal Seam in Highway Tunnel

为了解决公路隧道在含煤层围岩区段施工塌方问题,以我国西南地区某穿越含煤地层隧道施工为例,采用现场监控量测、数值模拟的方法,分析隧道含煤层区段加固前后因开挖造成的围岩变形特征。结果表明,在含煤层围岩区段,隧道右侧拱肩处的沉降值较其他位置的沉降值大,周边收敛值偏高。据此,对煤层段围岩进行了超长大管棚加固、超前预注浆等综合加固处理。加固后现场围岩变形监控右拱肩累计最大沉降量为2.13 mm,表明综合加固方法对围岩的变形控制效果显著,有效解决了该隧道含煤层围岩段的加固技术问题。

In order to solve the construction collapse problem of highway tunnel in the surrounding rock section with coal seam,taking the construction of a tunnel passing through the coal bearing stratum in Southwest China as an example,this paper analyzes the deformation characteristics of surrounding rock caused by excavation before and after the reinforcement of the coal seam section of the tunnel by using the methods of on-site monitoring measurement and numerical simulation.The results show that in the surrounding rock section with coal seam,the settlement value at the right spandrel of the tunnel is larger than that at other positions,and the peripheral convergence value is higher.Based on this,the surrounding rock of coal seam section is reinforced by super-long-pipe shed and advanced pre-grouting.On site monitoring of surrounding rock deformation after reinforcement shows that the cumulative maximum settlement of the right spandrel is 2.13 mm,indicating that the comprehensive reinforcement method has a significant effect on the deformation control of surrounding rock,and effectively solves the technical problem of surrounding rock reinforcement of coal seam in the tunnel.