Analysis Of Rational Construction State For Extradosed Cable-stayed Bridge

As a new type of bridge, extradosed cable-stayed bridge is favored by domestic and foreign designers for its firmness and flexibility, unique appearance and flexible structure, and is expected to become one of the mainstream bridges in the future. Extradosed cable-stayed bridge is an architecture composed of towers, beams and cable and its constructing technique is very complicated, which lead to the difficulty and complexity of the constructing practice. Therefore, the analysis on the rational constructing state of the extradossed cable-stayed bridge is of great practical significance.This paper takes an extradosed cable-stayed bridge located in Changshan, Zhejiang province as the engineering background, establishing the finite element model of Changshan Bridge by using the finite element analysis software MIDAS/CIVIL, and dividing the constructing stage in finite element model according to the actual constructing process. Based on the finite element model, this paper carries out an analysis on the reasonable constructing state of Changshan Bridge with the method for the reasonable constructing state of extradosed cable-stayed bridge existing at home and abroad. Firstly, it determinates the reasonable finished state of Changshan Bridge and raises a solution to the dead load moment feasible region in order to test the design finished bridge state, and determine the design finished bridge state as the target of construction status. Secondly, it determinates the rational constructing state of Changshan Bridge by using the forward iteration method with the finite element analysis software MIDAS/CIVIL, which includes initial cable force and formwork elevation. It verifies that the finished bridge state by the forward iteration method is coincided with the design finished bridge state. Finally, through the analysis of the force and deformation of structure in the constructing process, the security reserves of structure should be enough in the constructing process. It also points out the important constructing stage in the construction process and the consistence of the analysis of the experimental data and theoretical data, illustrating the reasonable constructing state by the forward iteration method is in accord with the actual engineering situation which has an engineering application value.