FATIGUE RELIABITY OF SLAB-ON-GIRDER BRIDGES CONSIDERING VEHICLE-INDUCED DYNAMIC RESPONSE

Fatigue problem is a serious issue for steel bridge components when various dynamic loads were exerted on the bridge. In the present study, limit state function (LSF) of bridge components are founded and the five random variables (RV) are used in the LSF by assuming certain types of distribution. A fully computerized approach to simulate the interaction of the coupled vehicle-bridge system including a 3-D suspension vehicle model and a 3-D dynamic bridge model was used to obtain the stress history and the number of cycles per truck passage. Based on the mean values and the coefficients of variance of the five random variables obtained from the literature and present study, Monte Carlo simulation technique was used to obtain the fatigue reliability index. The effects of the road surface condition and vehicle speed on the fatigue reliability was studied based on the results of numerical simulations.