Static Reliability Analysis Of Girders Of Concrete Cable-Stayed Bridges

In the paper, at the first, the theory of reliability and several methods of computational reliability are introduced. Then the probabilistic models of the loads which are acted on the bridge structures are overviewed. At last, computational reliability of the key sections of the girder of the concrete cable-stayed bridges with the method of JC is given top priority to be discussed.Take one of the floating concrete cable-stayed bridges in Chongqing as an example, adopting simplified computational model, which is matched with the actual situation possibly. It is effective to analyse the static reliability of the girders of the cable-stayed bridges , which are middle-span, a rather large rigidity. And the results of linear analysis can meet the needs of the strength and the rigidity. According to the stress characters of the girders of the floating concrete cable-stayed bridges, the parameters of the limiting equation are composed of the moment of resistance of the section, the moment produced by the dead load, and the moment produced by the live load. The reliabilities of the key sections of the main span are calculated with the method of JC individually, and are compared with the results computed by the mean point method and improved method of First-Order Second-Moment.Finally, the reliabilities are calculated individually as the coefficient of variations are changed, then the degrees which are influenced by the parameters are analysed .As a result, the conclusions are obtained: the static reliability of girders is influenced severely by the moment of the resistance of the section; the influence of the live load is more difference than the dead load because of the uncertainty.In the end,it presents some good recommendations for the further study.