Analysis And Optimization Of Double Thin–wall Pier Design Specifications Of Frame–continuous Combination Bridge

Frame-continuous combines bridge,is widely used at home and broad, which benefits from the T rigid frame and the continuous beam bridge and it also reflects its own characteristics. This kind of bridges have the features of long-link and large-span which will not only reduce the number of bridge expansion devices, increase the comfort of the driving but also avoid the usage of large tonnage support, reduce the difficulty of bridge maintenance.However, the rigid-continuous beam bridge is very sensitive to the factors of temperature,creep and shrinkage of concrete and so on, so all the design parameters of piers mentioned above must be analyzed and optimized in order to avoid these influences on the bridge.The double thin-wall pier is the most common form for frame-continuous combines bridge. The thickness of the single wall in the double thin-wall pier is the main reason for its anti-pushing rigidity; the double-wall space is the main reason for its bending rigidity.Therefore, these two are the most important parameters in the double thin-wall pier design.This paper does some researches based on the Yellow River bridge. These researches are as follows:(1)It researches the two parameters of the thickness of the single wall in the double thin-wall pier and the double-wall space which will affect the internal stress, the deformation and the stability. The internal stress and the deformation of the bridge will change with the thickness of the single wall and the double-wall space, which is obtained through the analysis and the calculation of the bridge using the finite element model; the relationships among the pier stability, the thickness of the single wall and the double-wall space under construction are given, which will provide reference for the design of the same bridge.(2)It does the numerical modeling to the wind load of different directions through the method of the CFD. The relationship between the height and the breadth of the rectangular section and the drag coefficient is studied and also the influence of the change of thickness of the single wall in the double thin-wall pier and the double-wall space in different wind attack angles on the aerostatic coefficient.(3)According to the stress situation of the double thin-wall pier, the top of the pier and the single wall in the double thin-wall pier under stress are connected together supposing that the rigidity of the piers of the main beam is infinity and the deformations of the two walls are completely consistent, and the optimized mathematic model of the double thin-wall pier and the double-wall space are established based on the ANSYS. The design parameters of the double thin-wall pier are optimized through optimized blocks of the ANSYS.