Analysis And Optimization Of The Hanging Cable Position Of Extradosed Cable-Stayed Bridge With Steel-Concrete Composite Beams

Nowadays, the structural dimensions are becoming thinner and thinner; while the intercombination among basic bridge types are becoming popular, which are the two main trends of the bridge structure development. Steel-concrete composite beams presents for the first thend, while extradosed cable-stayed bridge presents for the latter. Learning from their advantages, it can be presumed that the combination of Steel-concrete composite beams and extradosed cable-stayed bridge will lead to better optimization and higher efficiency. Thus in order to simulate the working condition of composite beam in the extradosed cable-stayed bridge, finite element method and modeling software are applied in this paper.First of all, by applying Midas / Civil (a finite element modeling and analysis software) and space grillage method, according to the sample of"Lanzhou Xiaoxihu Yellow River Bridge"and the girder of"Qingzhou Minjiang Bridge", the finite element model of extradosed cable-stayed bridge with steel-concrete composite beam in space is established.Secondly, influencial matrix with cable's strength is established, aiming at optimizing cable's strength, moment and displacement; also, Midas / Civil is applied to optimize and adjust the cable tension of extradosed cable-stayed bridge with steel-concrete composite beam by reducing the initial cable tension and girder negative moment. Finally, based on the Theorem of Translation of A Force, the changes of the hanging cable position within the available beam height range. In accordance with modulating principle, MATLAB Optimization Toolbox is applied to minimize the absolute value of negative moment, to discover the optimal point of hanging cable, and to establish the mathematical model. The optimization effect is remarkable,since the negative moment has been dropped 56.1%. That is to say, through adjusting the position of hanging cable, the internal force of composite beams can be optimized. As a result, strong bending resistance ability can be fully displayed, which is the ideal working status.This research can provide other researchers with useful reference of the combination of Extradosed cable-stayed bridge with Steel-concrete composite beams。...