三台阶六部短距法在铁路隧道施工中的应用研究

研究目的:新建贵(阳)广(州)铁路客运专线三都～五通间属于高原斜坡侵蚀、构造中、低山区,沿线地质构造复杂多变,隧道洞身地质中Ⅳ、Ⅴ级围岩等级所占比重大,施工安全风险高。针对开挖断面为138 m2～146 m2的特大开挖断面的软弱地质围岩铁路隧道,必须采取可靠的施工工法,才能确保隧道施工安全。研究结论:以贵广铁路大断面Ⅳ、Ⅴ级软弱围岩地质隧道施工为背景,在总结了传统三台阶施工工法的经验基础上,施工采用三台阶六部短距开挖工法,将隧道整个开挖断面分为三个台阶六个作业面,上、中、下各台阶施工同步推进,弥补了CRD法或双侧壁导坑法等方法工序多、工期长、对围岩扰动次数多的不足,便于现场施工组织管理,且机械化程度高,缩短了工期。根据现场工程实践,该工法既保障了隧道施工安全,又提高了施工进度。

Research on Application of Three - bench and Six Short - range Method in Construction of Railway Tunnel

Research purposes: The section between Sandu and Wutong of Guiyang-Guangzhou Passenger Dedicated Line passes through the plateau slope erosion,tectonic and low mountain areas with the complex and changeable geological structures.There area many surrounding rocks of IV grade and V grade in the area of the tunnel body,so there is high construction risk.For excavation of the 138-146 m2 section railway tunnel with weak surrounding rock,the reasonable construction method must be adopted for safe construction of the tunnel. Research conclusions:For construction of the large section IV and Ⅴgrades weak surrounding rock tunnel of the Guiyang-Guangzhou Railway,based on summing up the experience of the traditional three-bench construction method,the three-bench and six short-range method was used in construction to divide the excavation section into three benches and six working faces with synchro-construction on the upper,middle and low benches.With this method,the deficiencies of lots of procedures,long construction period,insufficient turbulence on the surrounding rock in using CRD method and twine sidewall method can be overcome and the construction period can be shortened by machinery construction.The construction practice shows using this method can guarantee the construction security and enhance the construction process.