Static Characteristics And Structural Optimization Analysis Of Girder And Arch Combination Bridge

With its beautiful style, reasonable force structure, diversity of construction methods, etc, girder and arch combination bridge has been applied more and more extensively. Although girder and arch combination bridge has been some studies currently,but the study to the optimization of the structure is very few. In this paper, taking the engineering of Gangou bridge as an example, introduces static characteristics and structural optimization analysis of girder and arch combination bridge. The main investigations are as follows.(1) taking the engineering of Gangou bridge as an example, introduces the design process of under deck, single-ribbed arch bridge,the effect of various load to the structure,and the local stress conditions of steel arch.Through these analysis,found that force structure meets to the specification requirements,when the arch top section use beam and shell element space to simulate, the results differ little, The force of Arch of roof,floor and web is uniform,beam's force is small.(2) Introduces bridge structure optimization design theory.Through design parameters analysis of girder and arch combination bridge,such as span ratio,arch and beam's stiffness ratio,pressure of end section, etc, summaries the influence of the structure when change these design parameters.(3)Through using optimization method based on minimum eccentricity's catenary arch axis and the method fixing reasonable arch axis by cubic spline interpolation function,optimize the arch axis of Gangou bridge.Then conduct comparative analysis of the structure under various load before and after optimization. Through these analysis,found that the optimal arch axis of the structure is a cubic spline under the dead load action,but spline curves is hard to calculate,also it can not improve the structure's internal force very well compared with parabola.So original design using parabolic arch axis is reasonable.