某山岭隧道叠交上穿施工及运营对既有地铁区间隧道影响分析

Analysis on Influence of Overlapping and Overpassing Construction and Operation of a Mountain Tunnel on the Existing Metro Section Tunnel

以某山岭隧道叠交上穿既有地铁区间隧道施工为例,采用MIDAS/GTS有限元软件,模拟计算并分析了该工程施工期及运营期对既有地铁区间隧道位移特征的影响,并对该既有地铁区间隧道的安全性进行了研究。研究结果表明:施工及运营期间,既有隧道所受上方隧道开挖的位移影响以竖向位移为主并满足相关要求;相比于施工阶段,运营期各方向变形皆有减小;从新建隧道施工开挖到远离与既有隧道的叠交影响区域,施工均对既有隧道的竖向位移产生明显影响,此阶段需要加强监测,并及时反馈指导施工。

Taking the construction of a mountain tunnel overlapping and overpassing the existing metro section tunnel as an example,the simulated calculation and the analysis on the influence of the construction and operation period of the project on the displacement characteristics of the existing metro section tunnel are carried out by using MIDAS/GTS finite element software,and the safety of the existing metro section tunnel is studied.The research results show that:during the construction and operation period,the displacement of the existing tunnel affected by the excavation of the upper tunnel is mainly vertical displacement and meets the relevant requirements;compared with the construction stage,the deformation in all directions during the operation period is reduced;the construction has a significant impact on the vertical displacement of the existing tunnel from the beginning of new tunnel construction to the time when the new tunnel is far away from the overlapping influence area of the existing tunnel.At this stage,it is necessary to strengthen monitoring and timely give the feedback to guide the construction.