DETERMINATION OF FABRICATED GEOMETRY AND PRE-ASSEMBLED GEOMETRY OF STEEL-BOX GIRDER IN CANTILEVER ERECTION PRACTICE OF LONG-SPAN BRIDGES

This paper presents a new method for determining the fabricated geometry and then the pre-assembled geometry of steel-box girders in cantilever erection practice of long-span bridges. Full considerations of global deformations and local deformations of girder segments are taken into accounts, which are obtained from two kinds of analysis, respectively, i.e. conventional construction process simulation via a beam element model and 3D FEA of the segments being lifted via a mixed element model. By fulfilling the design aims and in-situ assembling requirements, one can derive the fabricated slope angles at both ends of web plate of each girder segment. Given different elevation settlements of the first girder segment, the corresponding pre-assembled geometries of all the girder segments are then obtained. Finally, taking the cantilever erection practice of Guangzhou Huangpu cable-stayed bridge as an example, numerical results of the proposed method are presented.