超大跨度公路隧道超前支护措施研究

Advanced Support Measures for Super Large Span Highway Tunnels

为研究超前支护措施在超大跨度公路隧道中的应用及其对围岩的加固效果,以乐疃隧道为依托,通过现场监控量测手段,对3种超前支护措施在不同围岩条件下的应用及支护效果进行了分析。结果表明,超前大管棚支护措施能有效控制超大跨度隧道浅埋洞口段围岩变形,双排超前小导管支护能显著改善隧道V级围岩段围岩条件,单排超前小导管支护能有效确保隧道IV级围岩段围岩的稳定性。

In order to study the application of advanced support measures in super large span highway tunnel and its reinforcement effect on surrounding rock,this paper analyzes the application and support effect of three kinds of advanced support measures under different surrounding rock conditions by means of on-site monitoring and measurement based on Letuan Tunnel.The results show that the advanced large pipe shed support measures can effectively control the deformation of the surrounding rock of the shallow tunnel portal section;The double row advanced small pipe support can significantly improve the surrounding rock conditions of the V-class surrounding rock section of the tunnel;The single row advanced small pipe support can effectively ensure the stability of the surrounding rock of the IV-class surrounding rock section of the tunnel.