涨壳式预应力中空锚杆在机械化开挖大断面隧道中的施工应用研究

Research of Swelling Prestressed Bolts Using in Mechanized Excavation of Large Section Tunnel

为了解决软弱围岩隧道机械化开挖后快速支护的难题,采用三臂凿岩台车、风动扳手等配套机具施作涨壳式预应力中空锚杆对围岩进行快速支护。通过在郑万高铁高家坪隧道软弱围岩段大断面机械化施工条件下涨壳式预应力中空锚杆的应用研究,总结出涨壳式预应力中空锚杆工作原理、工艺流程,通过注浆试验对比分析,提出适合的隧道锚杆注浆比例,并结合锚杆轴力监测和地层位移监测结果,表明该锚杆具有快速约束围岩、形成应力拱、减少围岩松动圈、保证围岩稳定的优势,能够有效保障隧道机械化施工的安全,并提高隧道机械化施工效率。

In order to solve the problem of rapid support after mechanized excavation in soft surrounding rock tunnel, three arm rock drilling platform and pneumatic plate hand are used to carry out rapid support to the surrounding rock. The construction principle and process flow of the TB/T3356 are summed up through the application of the high shell prestressed hollow bolt under the mechanized construction condition of the large section of the weak surrounding rock section of the iron Gaojiaping Tunnel of Zhengzhou-Wanzhou High-speed Railway, and the proportion of the grouting for the tunnel bolt is put forward and the axial force of the bolt is combined with the grouting test. Monitoring and displacement monitoring fully verify the advantages of the bolt fast confining the surrounding rock, forming stress arch, reducing the surrounding rock loosening circle and ensuring the stability of the surrounding rock, ensuring the safety of the tunnel mechanization construction, improving the mechanized construction efficiency of the tunnel, and applying the large mechanized section to the weak surrounding rock section of the tunnel. It is of great significance to design and optimize the design of support.