Design Research on Simply Supported Tied-Arch Bridge with Long-Span in High Speed Railway

The article,aiming at the design of 128-m simply supported tied-arch bridge in high speed railway,using BSAS program and MIDAS program for modeling calculation and analysis,analyzes and researches emphatically the rise-span ratio,rigidity ratio of beam arch,initial tension of suspender,buckling stability and the dynamic characteristics.The analysis results show that: when the rise-span ratio is 1/5,the structure designs for the arch rib and tie beam are easier to be dealt with,more secure and economic.It is the rigidity ratio between the arch rib and the tie beam that creates the greatest influence on the vertical rigidity of the structure.If the rigidity ratio is selected appropriately,then the arch rib's section size will be quickly determined and optimized.Structure instability is mainly because of the out-of-plane buckling of arch rib,so the transverse connection should be strengthened in design.The overall rigidity of the structure can be improved by means of increasing the suspender rigidity and enhancing the ability of cooperative work among the arch rib,tie beam and the suspender.