隧道玻璃纤维锚杆全断面预加固机理与应用

Mechanism and Application of Tunnel Full-face Pre-reinforcement Technology with Glass Fiber Anchor Bolts

  • 摘要: 在隧道开挖过程中,围岩应力重分布是一个三维过程,掌子面前方的“待挖核心体”的形变响应与洞室的收敛存在密切联系,“待挖核心体”的岩性决定了开挖后的围岩能否自然成拱。因此,对于不能自然成拱的破碎、软弱围岩常采用玻璃纤维锚杆对隧道掌子面进行全断面预加固。文章通过对不同工况下的玻璃纤维锚杆全断面预加固进行模拟分析,得到了隧道开挖过程中掌子面位移变形随开挖进程的变化规律,以及衡量玻璃纤维锚杆全断面预加固效果的位移指标。基于典型软弱围岩条件下的铁路隧道工程实例,结合多种工况条件,给出了玻璃纤维锚杆的优化设计参数和施工方案 ,可为同类工程提供借鉴。

     

    Abstract: Stress redistribution of surrounding rocks is a 3D process during tunnel excavation, the deformation re? sponse of the“advance core”in front of working face is closely related to cavern convergence, and the possibility of natural arching of surrounding rock after excavation is very much dependent on the lithology of“advance core”. So as the full-face pre-reinforcement measure, the glass fiber anchor bolts are commonly installed at tunnel working face for the fractured and soft rock mass in which natural arching is impossible. Through simulation analysis of fullface pre-reinforcement by glass fiber anchor bolts in different cases, the deformation law of working face varying with excavation process and the displacement index showing the effect of full-face pre-reinforcement were obtained. Based on the railway tunnel project in typical soft surrounding rocks and various kinds of cases, the optimized design parameters and construction schemes were proposed.

     

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