暗挖拓建地铁车站对上穿既有结构的影响研究

Study on the Influence of Underground Extension and Construction of Subway Station Crossing over the Existing Station Structure

以北京地铁原6号线二里沟站拓建16号线新二里沟站工程为研究对象,采用三维有限元分析软件Midas/GTS建立地铁车站—既有车站的三维有限元模型,对上穿既有建筑的拓建部分进行施工工序模拟,计算分析拓建结构对既有结构的变形特征。研究结果表明:在拓建结构施工过程中,上穿既有车站结构部分对既有结构影响最大;在上穿既有结构部分暗挖施工过程中,中洞开挖引起既有结构上浮值为1.582 mm,占整体变形的31.51%;扣拱开挖对既有结构的上浮值为3.3 mm,影响最大,占累计变形的63.46%;因此,在中洞开挖与扣拱开挖施工过程中需要严加注意,必要时采取加固措施。

Taking the extension project of Erligou Station of Beijing Subway Line 6 to the new Erligou Station of Line 16 as the research object, the three-dimensional finite element analysis software Midas/GTS is used to establish the three-dimensional finite element model of the subway station to the existing station, simulate the construction process of the extension part passing through the existing building, and calculate and analyze the deformation characteristics of the extension structure to the existing structure. The research results show that: in the construction process of extension structure, the part of the existing station structure that crosses over has the greatest impact on the existing structure;during the underground excavation of the part crossing over the existing structure, the floating value of the existing structure caused by the excavation of the middle tunnel is 1.582 mm, accounting for 31.51% of the overall deformation;the uplift value of the existing structure caused by arch buckle excavation is 3.3 mm, which has the largest impact, accounting for 63.46% of the total deformation. Therefore, great attention should be paid to the excavation of middle tunnel and arch buckle, and reinforcement measures should be taken if necessary.