甘塔斯隧道膨胀性围岩支护技术研究

基于新奥法和新意法2种隧道修建理念,结合在国外实施的甘塔斯隧道工程实例,全面介绍隧道实施的支护类型,并特别强调新意法在不良地质情况下的特殊作用。在不良地质段的解决过程中,通过超前玻璃纤维锚杆的实施,起到稳固超前核心土的作用,从而实现通过控制超前核心土的挤出变形和预收敛来控制隧道支护变形的目的,使隧道掌子面具有可全断面开挖、一次闭合成环、减少围岩扰动的特点。在总结新意法支护类型实施过程的基础上,提出“杆超前、严注浆、大开挖、强支护、秒成环、勤量测”的实施精髓。

Research on Expansive Surrounding Rock Support Technology in Gantas Tunnel

Based on the New Austrian Tunneling Method(NATM)and the New Italian Tunneling Method(NITM),this paper comprehensively introduces the support types of tunnel construction,and especially emphasizes the special functions of NITM under unfavorable geological conditions according to the example of Gantas Tunnel works constructed abroad.During the treatment of unfavorable geological conditions,the implementation of advanced glass fiber anchor bolt plays a role in stabilizing the advanced core soil,which thus achieves the purpose of controlling the deformation of tunnel support by controlling the extrusion deformation and pre-convergence of the advanced core soil,making the tunnel face characterized with full-face excavation,one-time formation of closed ring and reduced disturbance of surrounding rock.On the basis of summarizing the implementation process of NITM support types,this paper puts forward the implementation essence of"advanced bolt,dense grouting,heavy excavation,strong support,ring formation in second and frequent measurement".