Research About Fatigue Property Of Steel Bridge Monolithic Joint

In the last few years, monolithic joint has been gradually adopted in the long span steel truss bridge. It is the highly important that we should know the fatigue property of monolithic joint with dense and various welded seam. Presently, there is only a little study about the fatigue property of steel bridge monolithic joint. In this thesis, the study method combining theory calculation with model test is adopted. Based on Chongqing Caiyuanba Yangtze Bridge, it is studied that various structure details impact on the fatigue property of steel bridge monolithic joint.First of all, some basic conceptions about fatigue failure of steel bridge are introduced, and some basic theories about fatigue strength are also introduced in this thesis. The main factors causing welded structure fatigue are analyzed. The fatigue strengths of some structure details of welded structure are compared. Secondly, the structure details contained in monolithic joint are analyzed, the research findings about these structure details are introduced, and the fatigue property of steel bridge monolithic joint is evaluated.At last, the fatigue strengths of structure details which are contained in the connection of monolithic joint and track cross beam of Chongqing Caiyuanba Yangtze double-deck Bridge are analyzed in this thesis. Based on these, test results and theory results are compared through model fatigue test and finite element analysis. Through analyzing and evaluating, it is proved that the connections of monolithic joint and track cross beam of Chongqing Caiyuanba Yangtze double-deck Bridge are reliable.