区间隧道零距离下穿既有地铁车站施工方案研究

Adjacent Construction Option for a Running Tunnel Under an Existing Subway Station

针对新建区间隧道零距离下穿既有地铁车站的工程特点,为确定设计方案可行性、保证既有车站结构安全及运营正常,文章采用FLAC3D三维快速拉格朗日差分方法分析软件对不同开挖工法及周围地层不同加固范围等施工方案进行了数值模拟,分析了既有车站轨道沉降、结构应力及新建区间隧道周边变形、结构受力特点及规律。研究结果表明,在对区间隧道夹土层、掌子面地层和隧道左右侧3.0 m范围进行注浆加固的前提下,推荐采用CRD法施工方案。

In light of the engineering characteristics of a new running tunnel approaching an existing subway station and in order to verify the feasibility of the design scheme to ensure safe and normal operation of the existing station, different construction methods with various scopes of stratum reinforcement were sinmlated by the FLACSD Lagrange difference method, in which the rail settlement and structure stress of the existing station, as well as the law of surrounding rock deformation and the applied structural force of the new running tunnel, are analyzed. The analysis results show that the CRD method is recommended with the premise of grouting reinforcement in the interbed stratum, working face, and the left and right sides of the running tunnel within 3.0 m.