The Static Analysis And The Cable Bent Tower Stability Research Of Bias Tower Self-anchored Suspension Bridge

The Bias Tower Self-anchored Suspension Bridge is a new bridge structure. Due to its good-looking shape, low requirement for the topography and strong adaptability, it is getting more and more appreciated. As a new structure, its mechanical performance is different from the regular Suspension Bridge. So, it is necessary to conduct research based on its own mechanical features. This paper takes the bridge at South Road, Yanyang Mountain of Chaoyang City as an example, and does some static analysis, the stability research of the cable tower and the optimizing design of the cable tower, providing reference for the design and research of the similar bridges. The main contents are as follows.(1) First of all, this paper elaborates the development of Suspension Bridge as well as Self-anchored Suspension Bridge. And then introduces the calculation methodology, the causes of geometrical nonlinear and several solutions to nonlinear problem of Self-anchored Suspension Bridge.(2) Second, this paper builds spatial model of the bridge using MIDAS CIVIL, deducts the cable line shape of the finished bridge using section line method and catenary theory, calculates the adjusted unstressed length of main cable and hanger taking the influence of cable clamps into consideration. This paper also compares force condition of the main parts under different loads to determine how loads affect structure.(3) Third, this paper introduces the theory background and analysis methodology of stability, conducts stability analysis of cable bent tower of bias tower self-anchored suspension bridge with ANSYS model. And then this paper compares the stability coefficient which covers elastic stability, geometric nonlinearity stability and material nonlinearity stability under different load cases through different element models. Results show that the stability index of the dual nonlinearity is58%smaller than the stability index of geometric nonlinearity. So, both geometric nonlinearity and material nonlinearity should be taken into consideration when analyzing the stability of the structure.(4) Forth, this paper briefly explains the structure and design of steel-pipe truss to identify the main design problem. This paper focuses on the factors which influence the stability of steel-pipe truss tower, including pipe-wall thickness, pipe diameter, brace layout and aspect ratio, in order to provide reference for the cable bent tower design. Results show that the45mm-thickness,1.6m-diameter steel tube can meet the stability requirement and the material stress reserves. To reach the same stability, Warren layout costs16.9%less material than Pratt layout. As width-height ratio increasing, the stability of the cable tower rises first and falls after. When width-height ratio is0.7, the stability index gets the peak value.