岩石地层基坑开挖对下部地铁车站结构受力的影响分析

Analysis of the Influence of Rock Strata Pit Excavation on Structural Force of the Lower Metro Station

摘要: 地铁建设在改善城市交通的同时，可以带动沿线地块的开发。地铁车站往往吸引高大建筑物在其附近修建，因此在地铁车站周围会出现越来越多的近接、超近接的施工影响问题。为了研究岩石地层建筑物深基坑开挖对下部既有地铁车站的影响，以重庆城区常见的IV级围岩为例，采用有限元数值模拟方法，研究深基坑开挖深度对下部地铁车站初期支护和二次衬砌结构受力的影响。结果表明，基坑开挖对下部地铁车站初期支护结构的影响一般大于对二次衬砌结构的影响；基坑开挖深度的增大会导致地铁车站初期支护和二次衬砌的拱部及边墙区域产生局部受拉区，进而产生拉裂缝。

Abstract: Subway construction can bring development along the plot while improving urban traffic. The subway station often attracts high buildings in its vicinity, so there will be more and more close, super-close construction problems around the subway station. In order to study the influence of the deep pit excavation of rock formation buildings on the lower existing subway station, the common IV surrounding rock in Chongqing is used as an example. The finite element numerical simulation method was used to study the influence of the depth of deep pit on the initial support and secondary lining structure of the lower subway station. The results show that the impact of pit excavation on the initial support structure of the lower subway station is generally larger than the effects of secondary lining structure; the increase of the depth of excavation will lead to the formation of local tension zones in the arch and sidewall areas of the initial support and secondary lining of the subway station, and then the tensile cracks will occur.