Stress Analysis And Life Prediction Of Suspenders In Tied Arch Bridges

ABSTRACT:The tied arch bridge is a kind of bridge without horizontal forces. The level thrust generated by the arch is undertaken by tied bars. The the tied arch bridge is a outside statically determinate structure and a inside high-order indeterminate structure. Any stress change in a suspender would have effect on the whole structure. In recent years, there have been many project precedents of tied arch bridge damage and replacement. Therefore, it is necessary to study tied arch bridge in-depth. In recent years, there have been many project precedents of suspenders in tied arch bridge damage and replacement, therefore, it is necessary to study suspenders of tied arch bridge in-depth.In this paper, a finite element analysis model is established for the superstructure of the Hengtang Bridge in Zhenjiang. Emphasis is focused on the stress change in suspenders under dead loading, truck loading, temperature and concrete creep. The results showed that under the conditions of dead load, vehicle load and creep load, the stress increments in short suspenders are large, and the short suspenders are prone to damage. Regarding temperature effect, the stresses in suspenders are distributed evenly, and the stress increments are small.Corrosion and fatigue are the main reasons for damage of suspenders in tied arch bridges. The corrosion rate model of suspenders are derived and established, and the predicted life under corrosion of suspenders in the Hengtang bridge is about 18 years. Regarding fatigue influence, based on linear cumulative damage theory, calculated the fatigue life of short suspenders is calculated as 29 years, by using the relevant load spectrum and the S-N curve. Meanwhile, the fatigue life coupled with corrosion for short suspenders is about 21 years. It can be found, in tied arch bridges, corrosion has much effect on the life of suspenders than that of fatigue.