Performance Evaluation of Chinese High-Speed Railway Bridges Under Seismic Loads

The multi-span simply supported (MSSS) box girder bridge is the most used structural form for the high-speed railway (HSR) in China. In structural design, it is required that the MSSS bridge system has high stiffness and low deflection under the operation loads. With the expansion of the HSR network to regions that are seismically active, the seismic performance of MSSS bridges in these regions is an issue of great concern. In this study, the performance-based earthquake engineering (PBEE) methodology originally developed to quantify the seismic performance of buildings and bridges has been adopted to quantify the seismic performance of the HSR MSSS bridges in China. Typically, a four-span MSSS bridge used in China's Sichuan-Yunnan HSR lines has been extensively assessed by the PBEE approach. This study is the first of its kind to systematically identify and quantify the damage states, repair actions, repair costs and travel delay losses for China's HSR MSSS bridge system. The results reveal that the financial loss from the MSSS bridge system is highly dependent on the anchorage capacity of the fixed bearings. Overall, the costs of travel delay outweigh those for structural repair. Most of the financial loss can be attributed to the functional loss of the track-slab components and bearings of the HSR MSSS bridge system.