Analysis of the Cable and Tower of Long-Span Suspension Bridges
|School||Harbin Institute of Technology|
|Keywords||Long Span Suspension Bridges The main cable bending stiffness Geometric nonlinearity The ultimate bearing capacity of the bridge towers Elastic stability analysis Large displacement elastoplastic analysis|
With the development of large-span suspension bridge, the analysis of the main cable is more and more precise and rigorous, even considering the change of the tangent to the tangent point of the construction of the main cable saddle. However, the analysis is still assume that the main cable is not bending and compressive. There is no doubt the main cable before installing the boom all ropes tied to span a large and very soft overall, but it is definitely not completely bending stiffness. In order to figure out the main cable bending stiffness of the mechanical properties of the suspension bridge, this paper established a finite element model of a span suspension bridge - Jiangyin Yangtze River Bridge - the main cable model numerical comparison simulation analysis, results show that with the suspension bridge spans the increase main cable hanging cross ratio decreases, the analysis of the actual bending stiffness of the main cables of suspension bridges is influential. Analysis showed that the analysis of the construction monitoring node displacement difference of more than a dozen centimeters, which will give construction brought no small trouble; cross-section edge normal stress maximum possible difference of 15%, the force and deformation of the suspension bridge may have a negative impact, can be seen to be fully and correctly reflect the actual static performance of the main cable, ensure the long span suspension bridges accurate calculation of the safety analysis, the main cable should consider the bending stiffness of the impact. With increasing bridge span, the bridge towers constantly towering, the box girder thin as well as the application of high-strength materials, making the relatively small bridge design safety factor as another important component of the suspension bridge - the main tower, The calculation and analysis of the ultimate bearing capacity of the tower gradually become one of the main factors for the suspension bridge safety. Finally, the Jiangyin Yangtze River Bridge, the bridge towers as the research object, based on considering geometric and material nonlinearity using self programming MockCool respectively consider consider the main cables and other components of the impact of the main tower alone tower fiber unit and the entire bridge model elastic stability and large displacement elastoplastic analysis. The results show that, In this paper, two computational model, both elastic instability problem are the second class of extremal stability issues, but because of the different boundary conditions, not only elastic buckling modes and limit bearing capacity varies widely. The study concluded, after the same type of bridge design and want to be able to provide a reference.