关键词: 斜拉桥, 扁平空腹钢箱梁, 截面变形, 有限元模型

Abstract:

The Zhanjiang Bay bridge with a main span of 480 m is a two-pylon cable-stayed .bridge with spatial double-cable planes and hybrid girders. The steel girder of the bridge is flat hollow streamline steel box girder with truss-form diaphragms and intemal webs. As the loads on the segment being lifted differ from those on the segment supporting the crane , the two segment splices are of various section deformations during the cantilever erection. In order to reveal the relative deformation of box girder sections during the cantilever erection , the 3D finite element models of the segment being lifted and supporting the crane are established via the mixed element method. The in-fluences of several parameters including the truss stiffness on the deformation are then analyzed. The results indicate that the flat hollow steel box girder with truss-form diaphragms and intemal webs is feasible to long-span cable-stayed bridges , and that the relative deformation of the box girder is govemed by the transverse location of crane-acting
point and the global stiffness of the steel box girder.

Key words: cable-stayed bridge, flat hollow steel box girder, section deformation, finite element model