长大基坑平行上跨既有盾构隧道施工安全与变形控制技术研究

Research on construction safety and deformation control technology of existing shield tunnel with long and large-scale foundation pit parallel overpassing

随着地铁的迅猛发展,城市的有限土地资源使得新建地铁车站基坑上跨既有运营隧道的情况越来越常见,如何控制既有运营隧道的变形,确保既有隧道的运营安全,是目前亟待解决的难题。文章结合深圳地铁5号线西延线东门路站上跨既有运营2号线盾构隧道的工程实例,综合考虑变形控制技术、数值模拟验证和施工安全控制技术等方面,对长大基坑平行上跨既有运营盾构隧道施工安全与上浮变形控制技术进行研究,结果表明可较好控制基坑开挖卸载可能引起的既有盾构隧道上浮,对类似工程具有参考和借鉴意义。

With the rapid development of the metro,the limited land resources in the city make it more and more common for the foundation pit of the new metro station to overpassing the existing operating tunnel.However,how to control the deformation of the existing operating tunnel and ensure the operating safety of the existing tunnel is a difficult issue that needs to be urgently solved.In combination with the engineering example of Dongmen Road station of west extension line of Shenzhen metro line 5 overpassing the existing shield tunnel of line 2,the paper studies the construction safety and floating deformation control technology of long and large-scale foundation pits parallel overpassing the existing shield tunnel line by combining construction safety and deformation control technology,numerical simulation verification and on-site construction safety control technology,the research results can better control the floating risk of existing shield tunnel caused by excavation and unloading of foundation pit,and provide reference for similar projects.