Safety Study Of Self-anchored Suspension Bridges Subjected To The Breakage Of Corroded Hangers

The main cable of the self-anchored suspension bridge is anchored at the end of the main beam,which not only saves space and economic cost,but also provides pre-stress for the concrete main beam.Although the structural design is more reasonable,the cable exposed for a long time can not avoid the corrosion problem.With the increase of service time,the bearing capacity of the corroded hanger decreases,the structure vibrates violently and the internal force of the structure redistributes after the hanger breaks.At this moment,the breakage of corroded hangers is likely to develop into progressive breakage of hangers or damage of main beams,or even progressive collapse of bridges,which seriously threatens the overall safety of the structure.In this paper,Zhuanghe jianshe bridge with a span of 70 m + 200 m + 70 m is taken as the project background.By using ABAQUS finite element analysis software and nonlinear static and dynamic analysis method,the elastic-plastic solid element finite element model is established,and the bridge is divided into four areas:(1)1/2 side span;(2)bridge towers;(3)1/4 middle span and(4)1/2 middle span,and the research on the dynamic response of the structure after the breakage of intact or corroded hangers in different areas.To get the mechanical properties of the corroded hangers accurately,an improved series parallel model of hangers is proposed.The results show that the stress of the adjacent hangers and the internal force,displacement,stress and strain of the main beam at the broken hangers vary greatly after the breakage of the hanger,and the results of dynamic analysis are far from that of static analysis.When most of the hangers are seriously corroded,the continuous breakages of the three hangers will lead to the progressive breakage of the adjacent hangers,while the internal force and stress of the main beam change little.Finally,the stress of the adjacent hangers after the breakages of corroded hangers under different service time is analyzed to analyze the influence of the corrosion degree on the structural safety.