Determining Of Reasonable Finite Element Model And Construction Controlling Of Cable-stayed Bridges With Composite Girder

The composite beam is composed of concrete plate, steel beam, and shear connection. Due to the strong spanning capacity, beautiful appearance, economical cost and other advantages composite girder cable-stayed bridge has been widely used in china. Composite girder cable-stayed bridge is a flexible system of hyperstatic and complex stress, so the construction controlling is very necessary.Based on hekou bridge as the engineering background, this paper studies the problem of composite girder cable-stayed bridge construction controlling, and determine the finite element model of construction control simulation analysis.the following is the main content and conclusion of this paper:① Based on the finit element method to study the theory foundation of composit girder cable-stayed bridge construction controlling. Summarizing method of composite girder cable-stayed bridge construction control simulation analysis, clearing the pupose and method of hekou bridge construction controlling.② Proposing the structural analysis thought which incloud the plate-beam finit element model(double beam finit element mode) and beam element model of hekou bridge.Analyzing and calculating the two models of the construction process by running the bridge structure analysis software the CSB program. In comparison of the two models through the theoretical value of the structure displacement and element axial force, there are large difference between the displacement of the two models, but the unit axial force is similar.③ According to the monitoring scheme detailed determines the linear measuring point position and testing time, the stress test point position, the cable test method and test process in the hekou bridge construction controlling. By comparing with the measured value of the elevation and cable force, we can get that the theoretical elevation of the plate-beam model and measured values is consistent. We should give priority to the plate-beam model in a composite girder cable-stayed bridge construction control simulation analysis, and through the conversion section model checking of the elevation and internal force.④ We get the feasibility of the “tower and beam synchronization” construction scheme by comparing with the finite element analysis calculation results of the “first towet”. Analyzing and determing the program of tension and adjustment the cable-stayed of hekou bridge, through the principle of equivalent elastic modulus, we derive the formulas for unstressed cable length. At the same time, we propose the influence of pre-camber.