上跨地铁基坑施工对地铁隧道结构安全影响分析

摘要

This paper summarizes the research status about the effect on the tunnel structure caused by the pit excavation at home and abroad from theoretical research,numerical analysis and field measurement,and summed up the domestic cross-subway section of the foundation pit soil reinforcement method.Taking the metro tunnel in Guangzhou metro line 6 as the research object,this paper studies the influence of the tunnel structure safety caused by the pit construction above the tunnel through the finite element analysis.The following conclusions are reached:1) Due to the unloading effect of soil above the subway tunnel,the subway tunnel produces large bulge deformation and large internal force changes during the pit construction;2) Soil consolidation and optimization of excavation process can make the deformation and internal force changes of the metro tunnel in a reasonable range.%文中既从理论研究、数值分析、现场实测等方面,总结了国内外基坑开挖对既有隧道结构影响研究现状,又总结了国内上跨地铁区间基坑土体加固方法.以广州地铁六号线某地铁区间隧道为研究对象,通过有限元分析,研究其上部基坑施工对隧道结构安全的影响,得出如下结论:①上跨地铁区间的基坑施工过程中,由于地铁隧道上方土体卸载作用,地铁区间隧道产生较大的隆起变形和较大的内力变化;②采用土体加固和优化基坑开挖工序等方法可以将地铁隧道的变形和内力变化控制在合理的范围之内.