隐式中墙连拱隧道对称中隔壁工法设计与分析

摘要

In view of current research and developing trend on construction method for the double-arch tunnel, the symmetrical temporary middle wall method, a new construction method for the double-arch tunnel with concealed center wall, needing no temporary support of middle wall, can greatly im-prove construction efficiency achieve fast construction, cut down influencing time on the environment and reduce the cost. The symmetrical middle wall method is designed in detail and numerously analyzed. The results show that the symmetrical temporary middle wall method can ensures construction safety of the double-arch tunnel with concealed center wall, that the upper step excavation and support removing are key processes of vertical deformation control,and that the junction of left hole arch waist and middle wall, and the junction of left hole invert and middle wall are the safety control points of preliminary lining.%针对连拱隧道工法研究现状和趋势，结合新型连拱隧道结构型式-隐式中墙复合式连拱隧道[1]，提出了一种新的连拱隧道施工方法-对称中隔壁法，无需中墙临时支护，大幅提高连拱隧道的施工效率，实现了连拱隧道的快捷施工，减少了对环境的影响时间，降低了工程造价。对对称中隔壁法进行了详细设计，并进行了数值分析，结果表明：对称中隔壁法可保证隐式中墙复合式连拱隧道施工安全，各上台阶步序开挖和拆撑为控制竖向变形的关键工序，左洞拱腰与中墙连接处和左洞仰拱与中墙连接处是初期支护的安全控制点。