Study On The Application Of Improved Long-span Composite Box Girder Bridge With Corrugated Steel Webs

The box girder bridge with corrugated steel webs is a new type of steel-concrete composite structure bridge.The type of bridge makes full use of performance advantages of concrete and steel respectively,meanwhile it brings good performance advantages.The type of bridge started from the application of small span bridges,and gradually develops to the direction of large span.However,traditional design of longspan box girder bridges with corrugated steel webs has some deficiencies.In this paper,the corresponding improvement measures are put forward,and a more comprehensive study is carried out basing on these improvement measures.The main work of this paper is four aspects.(1)Comparing between two practical projects,the structural characteristics of improved box girder bridge with corrugated steel webs are described in detail.The basic construction parameters of the improved structure are clarified,and the relationship between parameters and the main span of bridge is collected and summarized.(2)The reason,basis and significance of the horizontal arrangement on the facade of prestressed steel bundle in the bottom plate were analyzed in the improvement measures.In the analysis of the beam finite element,it calculates compressive stress and initial deflection in the midspan cross section.The results show that the longitudinal crack resistance and the performance of restraining the deflection are better than that the prestressed steel bundle in the bottom plate are Layout of curves on the fa(?)ade,when the prestressed steel bundle in the bottom plate are horizontal arrangement on the fa(?)ade.Through the solid finite element analysis,it calculates the transverse tensile stress values of the bottom plate.Results show that the horizontal arrangement on the fa(?)ade of the prestressed steel bundle in the bottom plate can effectively improve the lateral behavior of the bottom plate.(3)The bending,shear and torsion of the improved box girder bridge with corrugated steel webs are studied in detail by combining theoretical analysis and finite element analysis.The results show that the bending contribution of lining concrete,horizontal diaphragm and corrugated steel webs can be ignored in the calculation of bending effect.It`s necessary to consider the effect of variable cross section and the influence of bending moment and axial force when calculating the shear stress of corrugated steel webs.The structure of lining concrete and horizontal diaphragm can improve shear stability of corrugated steel webs and limit the normal stress and shear stress caused by torsion.It`s necessary to consider the eccentric load effect due to vehicle load in the calculation.(4)According to the conclusion of this paper,the practical design and calculation method of improved long-span box girder bridge with corrugated steel webs are given.