Fatigue Assessment of Concrete Girder Bridges Based on Traffic Information

With the increasing of traffic volume and carrying capacity of vehicles, fatigue failure of concrete girder becomes the one of the most serious problem. A better way to evaluate the fatigue performance of concrete girder bridges is using existing information instead of taking field test. As the main load fatigue load of concrete girder bridges, vehicle load affects the fatigue life of concrete bridges significantly. Traffic information can be changed into fatigue load when bridge information is known. So a process is proposed to evaluate the fatigue performance of concrete girder bridges by using traffic information. An assessment method contains five parts including gathering vehicle load information, setting up fatigue load model, calculating stress spectrum, correcting the calculated stress spectrum and doing fatigue life calculation is proposed. To verify the effectiveness of the method, a small box girder bride is chosen as the case bridge. The weigh in motion system (WIM) and manual counting were used under the real traffic conditions. And in order to give the correction factor, dynamic strain monitoring data was taken to provide comparative results.