盾构隧道近距离下穿既有隧道安全性分析

为了充分掌握地铁盾构隧道近距离下穿既有隧道时管片、岩土体的变形,以深圳地铁9号线梅村站-上梅林站区间下穿既有4号线莲花北站-上梅林站区间工程为背景,运用Midas GTS有限元软件对下穿施工过程进行数值模拟,分析下穿时岩土体与既有线隧道管片的变形,对两条线设计竖向距离的安全性进行了验证,得出两隧道竖向最小距离在2.0~2.5 m范围是安全的。同时提出一些技术措施,如对既有隧道进行自动化监测,从既有隧道内注浆,信息化施工等。

Safety Analysis on Shield Tunnel Crossing Existing Tunnel Underneath at Short Distance

To fully master the deformation of segment and rock-soil due to the shield tunnel crossing existing tunnel underneath at short distance, taking the project of Meicun Station-Shangmeilin Station crossing Lianhua North Station-Shangmeilin Station underneath of existing Metro Line 4 as background, the Midas GTS finite element software is adopted to perform numerical simulation of crossing construction process, analyze the deformation of rock mass and existing line tunnel tube segment and verify the safety of vertical distance of two lines. The minimum vertical distance of two tunnels is safe in 2.0~2.5 m. Meanwhile, some technical measures are put forward, such as automatic monitoring on existing tunnel, grouting in existing tunnel and information construction and so on.