Experimental Investigation On The Static Behavior And Fatigue Of Cable-Girder Anchorage Structure Of Anqing Yangtze River Bridge

With the development of long-span cable-stayed bridge, the span becoming longer and longer, so the cable-girder anchorage structure of the bridge is put forward a higher request. The cable-stayed bridge with streamlined steel box girder is the trend of long-span cable-stayed bridge. The Cable-girder anchorage structure of this type cable-stayed bridge bear giant cable forces and have complicated structure, are keys to structure design. It is very important to know the strength and fatigue property of the Cable-girder anchorage structure.The Anqing Yangtze River Bridge applies the anchorage-box. In designing and constructing, such issues as the stress distribution, transfer paths of forces under the condition of dead load and the fatigue strength, reliability of fillet welding seam when it was subjected to pulsatile load shall be made thoroughly clear. Taking the experimental investigation on the static and fatigue of cable-girder anchorage structure of Anqing Yangtze River Bridge as an instantce, the issues mentioned above are studied in this thesis.First of all, the mechanic behavior, stress distribution and stress concentration under the condition of dead load of cable-girder anchorage structure were studied, and some beneficial results were obtained. The rationality and safety of structure were verified by checking static strength of structure.Secondly, The models of static test and fatigue test are analyzed with finite element method, then the analysis results and the tests results are compared and the tests results were verified.At last, the fatigue crack in the experiment and the main influential factor of fatigue strength of fillet welding seam was studied. Then the fillet welding seam of cable-girder anchorage structure was calculated by linear elastic fracture mechanics, an S-N curve was get for describing the fatigue properties and the fatigue of the fillet welding seam was studied. Some theories related to stress intensity factor, crack growth rate and fatigue damage cumulative rule were discussed.