Analysis On Ultimate Carrying Capacity Of Steel Truss Beam And Flexible Arch Railway Bridge

Based on Jingkaiqu Bridge, a steel truss beam and flexible arch railway bridge, which is part of the Hefei-Fuzhou Railway and now under construction at South Ring Line in Hefei City, by using the large scale software ANSYS, the spatial finite element model is built up, the stability and ultimate carrying capacity are analyed, and some relevant conclusions are obtained in this thesis. The main works are as follows:(1) Through the analysis of the elastic stability on the steel truss beam and flexible arch railway bridge under different load cases, the main bucking modes and bucking coefficients are known.(2) Considering of different nonlinear factors, the internal force and deformation of the steel truss beam and flexible arch railway bridge are analyzed under the load case of dead load and4.69-fold dead load, then the influences of material nonlinearity and geometrical nonlinearity on the structural internal force and deformation are expounded.(3) Considering of material nonlinearity and geometrical nonlinearity, the ultimate carrying capacity of the steel truss beam and flexible arch railway bridge is analyzed, then the failure route and mechanism of the bridge are studied, and essence of the failure and relative weakness of the bridge are revealed.(4) Four parametric analyses are carried out in the thesis, such as nonlinear factors, live load layout, initial imperfection and across-wind load. Then the influence of the parameter on ultimate carrying capacity is studied, at last critical factors which affect the steel truss beam and flexible arch railway bridge are determined.