新建基坑对近临地铁区间结构的安全影响分析

Analysis on the Safety Influence of the New Foundation Pit on the Near Metro Section Structure

随着城市高层建筑的施工,基坑开挖必然引起周围土层的移动,从而引起周边既有结构的不均匀沉降,对既有结构的正常使用造成严重影响。现以某城市商业大厦基坑开挖对近临地铁区间结构影响为工程背景,结合大型ANSYS有限元数值分析模拟,主要内容包括:(1)不考虑土钉、考虑土钉两种工况下土体位移及衬砌位移分析;(2)不考虑或考虑土钉两种工况下土体应力、衬砌应力分析及地铁区间结构安全性分析。结果表明:在最不利情况(不考虑土钉支护)下,基坑开挖后,原有地铁区间结构安全性满足要求。

With the construction of urban high-rise buildings, foundation pit excavation inevitably led to the movement of surrounding soil, which caused the uneven settlement of existing structure of surrounding, and then caused serious impact on the normal use of the existing structure. The ANSYS finite element is used to analyze the numerical simulation in the paper, with a project as the background, mainly including :(1)the analysis of soil displacement and lining displacement;(2)the analysis of the soil stress, lining stress and the security of railway section structure, and both of the concept is considered with soil nailing and without soil nailing. Result shows that the safety of the original metro section structure meets the requirements when the foundation pit is starting to be excavated in the worst case(without soil nailing).