ABSTRACT
ABSTRACT: Running heavy haul trains on the existing railway line can satisfy the rapid development of China’s railway transport, but it is bound to have an adverse effect on the safety and the fatigue life of existing railway bridges. The finite element model of a four-span continuous steel truss bridge was built with ANSYS software, the dynamic responses were analyzed under ordinary train loads and heavy haul train loads, respectively, and the stress time history of some typical members were obtained. Then, the rain flow method was used to count the stress amplitude number, and the cumulative damage degree was deduced by linear cumulative damage theory. On the base of the cumulative damage degree, the fatigue lives of some typical members were evaluated at last. The analysis results show that, the vertical deformation, transverse amplitude, and vertical acceleration of the steel truss all increase with the train’s axial load and speed. In general, the fatigue lives under C96 heavy haul train loads of the typical members in the steel truss bridge in this paper will be about 80% shorter than that of under the ordinary train loads.
