地铁车站STS工法钢管混凝土横向连接正截面受弯数值模拟研究

Numerical Simulation Research on Transverse Anti-bending Characteristics of Concrete Filled Steel Tubes in STS Method for Subway Stations

韩国STS工法是一种用于下穿高速公路的隧道施工工法,该工法主要是采用管幕作为初期支护,具有沉降小、施工速度快的特点。沈阳某地铁车站施工将采用韩国STS与洞桩法施工技术结合的方法。然而焊接下翼缘板的改进,使得结构的抗弯刚度等一系列力学性能发生了较大的改变,迫切需要相关研究为施工与设计提供理论基础。使用ANSYS有限元分析软件,得到了STS结构竖向荷载作用下的应力分布与变形特点,结果表明焊接翼缘板在提升结构抗弯性能中起到了重要的作用。同时通过钢管的应力分布与变形特点,发现了翼缘板焊接后钢管壁出现了横向拉伸变形,该变形使得结构出现了应力集中的现象,同时也说明此时平截面假定不适用。

Korean STS （Steel Tube Slab） method is a new metro subsurface excavation method for tunnels beneath the highways .According to this method ,the pipes are used as the supporting materials while the tunnel is under construc-tion ,which only causes small settlement and saves time on construction A method that combines the STS method and the domestic Pile Beam Arch method （PBA） will be used for the construction of a subway station in Shenyang .However ,the improved welded flange slab in new method will cause great changes in the mechanical properties of the structure ,such as the bending stiffness .Therefore associated research is much needed to provide theoretical basis for the design and con-struction .The stress distribution and deformation of the simple supported STS structure under vertical load was acquired by using the the finite element software ANSYS .The result indicates that the welded flange slab plays an important role in improving the anti-bending property of the structure .The transverse tensile strain of steel pipe occurs after the welding of the flange slabs according to the stress distribution and the deformation of the structure ,which may cause the stress concentration ,and proves that the plane section assumption cannot be used for the STS structure .