Analysis Of Reasonable Construction State For Self-anchored Suspension Bridge

Recent decades, with the developing of long-span bridge structure in China, prestressed concrete self-anchored suspension bridge has been paid more attention owing to its advantages of nice appearance, adaptable structure and good economic performance. In terms of construction, there is a great deal of difference between self-anchored suspension bridge structure and the suspension bridge with ground anchors, in both construct method and construction simulation, for the characteristic of main cable that anchoring to stiffening girder. Structure analysis during the construction is necessary in order to ensure the internal force and displacement to reach requirement of reasonable finished state. The finished state is taken as the analysis target, on the basis of construction sequence of self-anchored suspension bridge; back-running method is used to carry out reasonable state of each construction stage.In this paper, the development actuality; structural and mechanics features; computation Theory including the theory of elasticity, reciprocal deflection, and finite displacement are introduced firstly. Geometric nonlinearity effect factor as well as relative theory and computational method are presented, and some of nonlinear equation solution method, such as the directive method, incremental method, and Newton-Raphson method. Convergence criterion is also given under the solution procedure. Secondly, initial state of equilibrium of self-anchored suspension bridge is analyzed by using the software of MIDAS/CIVIL to obtain the reasonable finished stage. Comparing with finished stage in design, the method in this paper is verified to be reliable. Thirdly, the procedure of construction, modeling, and simulating of each part of structure are represented. A sequence of the stretching suspenders is discussed though three plans and removing sequence of full framing through two plans. Then backward analysis is used to obtain the main cable displacement, and displacement, decrement, stress in the top and bottom edge of stiffening girder; decrement of main tower, and horizontal displacement of tower top. Finally, forward analysis model is established by the data of cable coordinates. Influence of construction for any part of bridge structure is analyzed. Influences of parametric variation, for instance, elastic modulus and density of main cable and concrete, on the construction are also discussed and studied.This paper deals with a detailed analysis for the self-anchored suspension bridge reasonable construction condition, meanwhile, initial equilibrium conditions analysis, backward analysis, forward analysis are also taken. Study of this paper could be taken as references for design and construction of such type of self-anchored suspension bridge in the future.