The Static Performance Analysis On Hybrid Girder Cable-stayed Bridge In Long-span

Hybrid girder cable-stayed bridge consist of concrete girder in edge span and steel girder or steel-concrete composite girder in main span, which integrates the adventages of two materials and have become a competitive bridge form. By contras t of usual cable-stayed bridge, hybrid girder cable-stayed bridge has great superiority and flexibility in span capacity of main span, side to middle span ratio, construction safety, quality assurance and adaptability to terrain. As a result, it has unique competitiveness in long span bridge design.By relying on an actual project of hybrid and composite girder cable-stayed bridge of 360 meters main span, this paper mainly analyze the reasonable str uctural system, the finite element calculation method of shear-lag effect and the influence of concrete shrinkage and creep, which provide reference for the design optimization of similar composite cable-stayed bridge.Generally speaking, the main contents and conclusions are as follows:(1) By collecting literatures at home and abroad, this paper make a comprehensive elaboration on the development history, the mechanical characteristics and the advantages and disadvantages of hybrid girder cable-stayed bridge.(2)This thesis introduces the basic theory of reasonable finished state of the bridge, reasonable ratio of side to middle span and reasonable tower height, which be used to structure system analysis of Wujiang bridge. Based on the whole bridge finite element reference model, the influ ences of design parameters, such as bending stiffness of edge span and main span, tower height, side to middle span ratio, on structural stress of the hybrid girder cable-stayed bridge are performed.(3)Based on the research situation of shear-lag effect in composite cable-stayed bridge at home and abroad, a combination method consisting of three ty pes of finite element models is proposed in this paper. By establishing local rod system model, whole bridge rod system model can convert into local solid model accurately, which make computation result s more precise and efficient.(4)This paper discuss the influences on mechanical properties of the structure and stress redistribution in composite beams of concrete shrinkage and creep, and make a comparison analysis of progress on three years and ten yea rs. Finally, by considering the influ ences of different loading age, the rationaliy of concrete slab loading age was proved.