Study On Structure Analysis And Parameters Optimization Of Cable-stayed Bridge With Double-arch Tower

Due to the unique structure of abnormal cable-stayed bridges, they have various stress situations. It is difficult to summarize them systematically. There is not much study about abnormal cable-stayed bridges at home and aboard. People usually carried out a research focused on a specific project. Cable-stayed steel bridge with double-arch tower whereas is a new kind of abnormal cable-stayed bridge, so the research of it is much less currently. In order to find out the reasonable cable force and the influence design parameters bring, this paper took a cable-stayed steel bridge with double-arch tower as an example to conduct the static analysis and geometry optimization of its kind. The main content is as follows:(1) According to the characteristics of the stress of the double arch tower cable-stayed bridge, this paper analyzed the loading characteristics of the double arch-tower cable-stayed bridge with Midas/Civil. It showed that the force of girder was similar to the design value. Under the condition of a new evaluation criterion of the reasonable completion state of cable-stayed bridges, considering the dead load and live load of the bridge, the bridge was analyzed from the aspects of the bending moment, displacement of the arch-tower. The force of girder and the structure of the bridge can be optimized by changing the force of girder.(2)Zero-displacement method was adopted in this article to adjust the force of girder in completed bridge stage. The bridge state we got by controlling the line shape of the girder had not much difference with original completed bridge state, and satisfied the engineering demands. So zero-displacement method can be used to optimize the force of girder when it comes to steel cable-stayed bridge.(3)The influence matrix method was adopted in this article to adjust the force of girder in completed bridge stage, based on minimum bending energy, proposed to combine mathematical programming software MATLAB with projects and it settled the problem in solution of cable force.(4)According to the mechanical balance principle and the structure geometry relationship, this paper provided a formula of the angle and force of girder, and then made dynamic research using finite element software about the angle and depth-span ratio. This paper gave a reasonable range of the angle 45°~50°and depth-span ratio 0.509~0.534 and offered a reference to the design of cable-stayed bridge with double arch-tower.