Dynamic testing of railway truss-bridge

The investigation results of the historic narrow-gage railway steel truss bridge built in the previous century, still in use, are presented in this paper. The bridge was blasted during the World War II, later restored. This bridge is unique and original design documentation was lost, nevertheless the aim of this study is to investigate behavior and the structural condition of riveted steel truss bridge using full-scale dynamic experiments. Field load tests were performed with the aim to develop an analytical model to evaluate the capacity of the bridge. Dynamic testing of the bridge was conducted with original locomotive. Other dynamic tests with impulse excitation were also performed. Responses (dynamic displacements, accelerations, mode shapes, corresponding resonant frequencies and modal damping values) of the bridge structure were determined. Studies have shown that the bridge meets the safety requirements and has enough reserve for operation.