Research On The Static Performance Of Concrete Self-anchored Suspension Bridge

Suspension bridge consists of cable, girder, tower, hanger, saddle, anchor and etc. The self-anchored suspension bridge develops rapidly in China for its advantages in asesthetics, adaptability and economics. Taking a real bridge as background, on the basis of previous research and design code of some countries, the thesis carried out comprehensive study on the self-anchored suspension bridge.Firstly, this thesis studied the analytical methods of the self-anchored suspension bridge, and analyzed the factors' effects on the nonlinearility of the suspension bridges. Those factors include the main cable's sag effects, large displacement effects, initial force effects, concrete shrinkage and creep as well as the loss of the prestress.Next, it studied the calculation method of the cable shape from the following aspects: unstressed length of the main cable, saddle offsetting, cable shape, the deviation of clamps and the length of hangers.Then, the finite element analysis software Midas/Civil is used to set up model to calculate a typical concrete self-anchored suspension bridge. The construction process of the bridge adopts the "backward-forward" iteration method. Since the cable's profile, girder's profile and the mechanical behavior of the whole bridge construction are affected by the tensioning sequence and tenisoning force, the comparison was made to determine the tensioning plan to choose the optimium one.Finally, further research was made on the mechanical behavior of concrete self-anchored suspension bridge through static and parametric analysis. Sensitive parameters include the span ratio, camber of the girder, bending stiffness and concrete shrinkage and creep. From the result, it can be found that increasing the span ratio and camber can promote structural stiffness and reduce internal forces under live load. In addition, the results showed that the concrete shrinkage and creep of the girder has a great effect on the structural deformation and internal forces. Therefore, the concrete shrinkage and creep effects should be taken account of when calculating the profile of the main cable when installed.