The Research Of Failure-safety Of Arch Bridge And The Suspenders

Bridge located in the key site of water and land transportation, belongs to the lifeline project, but the cable of cable structure bridges sudden broken lead to ruin the bridge sometimes occurring, and cause social influence greatly. The cost of replacement of cable and repair after bridge collapsed is higher than the cost of bridge construction, what's more, the cable still has the possibility of sudden broken in use after replacement; although bridge testing can detect the hidden danger of structure,replace and offer maintenance in time, still can not absolutely guarantee that they will not suddenly broken, because of the uncertainty of life on cable. Failure-safety cable apply the failure-safety theory which proposed in fracture mechanics to the bridge cable structure, hope to achieve:the sudden broken of single cable will not cause the entire bridge collapsed; the replacement of the cables need not interruption of traffic and special structural support, not depend on the detection. In this paper, we taken a through CFST arch bridge as the example, analyzed the influence of suspender sudden broken to bridge structure, and discussed the design of failure-safety parallel double suspender.Firstly, we analyzed the load behavior of the Arch Bridge, and impact of the suspender sudden broken to the bridge structure; and built the Ansys finite element analysis (FEA) model based on simplified mechanical model, to investigate the amplification coefficient of impact of the broken suspender; and researched the safety of ordinary double suspender.Secondly, we analyzed the breaking mechanism of the suspender, summarized the anti-fatigue design methods of suspender, and overviewed failure-safety design of the suspender based on the concept of failure-safety in the fracture mechanics.Thirdly, we used FEA software—Ansys to built the model of 3D finite element model of through CFST arch bridge, to analyzed the dynamic response of bridge under the conditions of different suspender sudden broken.Found the area of the bridge structure needed more attention where badly stressed when the suspender sudden broken.Finally, we discussed the failure-safety design of the parallel double suspender, and checked its safety factor under the different calculation condition, offered reference to the design of arch bridge's failure-safety suspender.