关键词: 地铁车站, 施工工法, 6导洞PBA工法, 8导洞PBA工法, 一次扣拱暗挖逆作法, 数值模拟, FLAC3D, 地表沉降, 拱顶沉降, 拱顶应力

Abstract:

In this paper, comparison and contrast is made among three constructions methods, i.e., 6pilot PBA method, 8pilot PBA method, and cast insitu arch and cutandcover topdown method, in terms of ground surface settlement above tunnel axial line, crown settlement and crown stress. The numerical simulation model of Jiefanglu Station of Changchun Metro is established, so as to analyze the optimization of construction method. The study results show that: 1) The ground surface settlement above the tunnel axial line, crown settlement and crown stress of the three construction methods are different； 2) The cast insitu arch and cutandcover topdown method is superior to 6pilot PBA method and 8pilot PBA method for this project, and the 6pilot PBA method is the worst. The results achieved can provide reference for construction of similar projects in the future.

Key words: Metro station, construction method, 6pilot PBA method, 8pilot PBA method, onetime castinsitu arch and cutandcover topdown method, numerical simulation, ground surface settlement, crown settlement, crown stress