Study On Structural Behavior Of Haimen Bridge And Fatigue Life Prediction Of Steel Bridge

Seeing the history of the bridge, a period of massive construction projects has been passed and most of bridge engineers have become to bridge maintenance engineers from designers. In order to ensure these bridges that have been built for many years use safely, economically and reliably, the repair, reinforcement and renovation of bridge have become hot questions in bridge engineering's research. Focusing on the questions of identifying the capacity of Haimen Bridge's lifting cross and assessment of the steel bridge's fatigue life, this paper carries out a systematic study. The main contents are shown as following:1. On the basis of deep learning about the composition of Haimen Bridge's lifting cross, the whole model is established using ANSYS software. Then finite element analysis is conducted on the model under four load combinations and seismic load, combined with analysis of the natural vibration;2. According to the loading test of Haimen Bridge in 2010, the general steps of using the loading test method to assess bridge's structural capacity are systematically described. Reference to the result of the loading test, combined with the loading tests of Haimen Bridge have been done since the opening in 1985, the capacity of the lifting cross is evaluated, and some feasible proposals to repair and reinforce the structure are made;3. Based on a lot of documents, comparative analysis of the evaluation methods to the steel bridge's fatigue life is processed, then some key problems in the method, such as fatigue load spectrum, rain flow method, the selection of fatigue resistance curve, and etc. are systematically studied. Through detailed analysis of the fatigue details'classification in the U.S. AASHTO specifications, the British BS5400 standard and the Chinese TB10002-2005 standard, some recommendations to classify the fatigue details in steel bridge criterion of our country are introduced;4. Using Fortran language, this paper gives the program to simulate the fatigue load spectrum and the program to load on the influence line based on the method of Monte-Carlo and equivalent damage. And finally, the fatigue life of some key bars in Haimen Bridge, which contain bottom chord bar, vertical bar and tilted belly pole, is predicted based on the nominal stress method.