高海拔超长铁路隧道TBM施工断面优化的探讨

TBM(Tunnel Boring Machine)施工的高海拔超长隧道面临开挖断面较大和TBM直径统一的问题,考虑采用刚性接触网、减小疏散通道宽度、缩小净空有效面积等措施对TBM施工隧道内轮廓和断面进行优化。通过建立TBM施工隧道衬砌和底部结构模型、高海拔隧道内接触网模型,对TBM施工隧道断面进行对比分析及优化。研究结果表明:160 km/h等级TBM施工隧道断面尺寸受控于接触网安装要求,采用刚性接触网时隧道开挖断面面积比采用柔性接触网时减小9.88 m^2;200 km/h等级TBM施工隧道断面尺寸受控于空气动力学要求,净空有效面积采用48.00 m^2时隧道开挖断面面积比设计规范要求减小4.64 m^2;TBM+刚性接触网可显著降低隧道工程造价、减少隧道弃渣量,有利于TBM同步衬砌技术实施,提高隧道防灾能力。

Discussion on the Cross Section Optimization of High-altitude Extra-long Railway Tunnel Driven Using TBM

The high-altitude and extra-long tunnel constructed by TBM(tunnel boring machine) is faced with the problems of large excavation section and uniform TBM diameter.The internal contour and cross section of the tunnel constructed by TBM are optimized by using rigid catenary,reducing the width of evacuation passage and reducing the effective area of clearance.The cross section of TBM construction tunnel was analyzed and optimized by establishing the TBM construction tunnel lining and bottom structure model,high-altitude tunnel internal contact network model.The research results show that the cross section size of 160 km/h TBM construction tunnel is controlled by the installation requirements of catenary,and the cross section area of tunnel excavation with rigid catenary is 9.88 m^2 smaller than that with flexible catenary.The cross section size of 200 km/h TBM construction tunnel is controlled by the aerodynamic requirements.When the effective area of clearance is 48.00 m^2,the cross section area of tunnel excavation is 4.64 m^2 less than the design specification.The method of TBM+rigid catenary can significantly reduce the cost of tunnel engineering,reduce the amount of waste slag in the tunnel,facilitate the implementation of TBM synchronous lining technology,and improve the disaster prevention capacity of the tunnel.