Four Lines Of Railway Load Three Partial Load Performance Study Of A Typical Long-span Bridges

On the study of three bridges of Wuhan-Guangzhou passenger line, which are ChenCun channel Bridge, TianXingZhou Bridge as well as DongPing steel truss arch bridge, this paper gives an analysis and calculation of long-span bridges performance under four-lane railway offset loads. Offset load coefficient of four-lane bridges has been presented. The main results of this paper are presented as follows:(1) On the study of three bridges, the model of these large-span bridges has been established respectively, such finite element model as large-span continuous beam grid, three-truss cable-stayed bridge as well as three-truss steel truss arch. Considering the various combinations of lane loading conditions, several of important data has been calculated, such as the max value of support bearings force, the max bending moment, shear force, deflection in each web plate. Meanwhile, the paper presents the corresponding lane layout which each bearing and web plate has max effects. Under the comparison with results of plane four-lane train load, offset-loads coefficients has been calculated, presenting variation pattern of offset-loads along longitudinal direction under various loads as well as uneven distribution of loads on each web.(2) Under the comparison of the offset-loads coefficient regularity among three bridges, loading lateral distribution of these three different bridge has been analyzed under the four-lane railway loads, including large-span four web prestressed concrete box-girder bridge, the three-truss cable-stayed bridge, the three-truss steel truss arch bridge. The main factors which affect lateral load distribution have been discussed.(3) The different distribution cable-force of three-truss cable-stayed bridge and axis-force of three-truss steel truss arch has been discussed by using simplified models. The effect on lateral distribution by cables and suspenders tensile stiffness as well as beam bending-resistance rigidity has been analyzed. The load distribution range of three-truss structure has been calculated.(4) The calculated results of this paper could provide regularity for the design of long-span multi-lanes railway bridges.