Mechanical Performance Research On Slotted Steel Box-Girder Of Suspension Bridge

With the development of modern bridge, the span is bigger and bigger, and the bridge deck is broader and broader, but the request to the self-weight is lighter and lighter. In order to seek the main beam pattern being suitable to the developing trend, at the same time to improve the air dynamic performance and critical wind speed of flutter, the new main beam pattern of slotted box-girder (both stringpieces links up with a crossbeam) was appeared. The lotted steel box-girder as an important beam section is an innovation after closed box section. The thesis takes Jiang Dong bridge in Hangzhou city as the object to study the mechanical property of lotted steel box-girder of suspension bridge.According to the relevant documents, the research on dynamic performance of the lotted steel box-girder is more than on static's. The thesis takes this as the studying point to analyse the influence of different link stiffness and different stiffening girder analysis models on structure. The thesis has carried out the following job in several aspects mainly:The thesis introduced the structural characteristic of lotted steel box-girder firstly, the home and abroad application and the current studying situation on lotted steel box-girder in the following, then the theory of calculation on suspension bridge under load effects such as vertical, transverse loads and torsion be introduced.Build single girder model, double geometrical center girder model to analyse the effect on static performance of structure in different load conditions.Building pole beam models with software BNLAS to analyse the structure internal force and deformation in identical load conditions but with different link stiffness.The large-scale finite element software ANSYS was applied for building space finite element calculation model to study the structure deformation, internal force and stress etc. under various load conditions, then compared with the result of pole beam model to get the reasonable range of link stifmess between stringpiece and crossbeam.Through analysing the stress distribution on crosssection of lotted steel box beam by ANSYS model under various load conditions to know the stress distribution of the cable axis force in main beam crosssection of self-anchored suspension bridge, and shearing lag effect on main beam of Jiang Dong bridge in Hangzhou city.By reaching a few conclusion relevant to lotted steel box-girder mechanical characteristic performance of Jiang Dong bridge in Hangzhou city, hope to have certain reference value to the design of lotted steel box beam of self-anchored suspension bridge.