Earthquake response of continuous girder bridge for high-speed railway: A shaking table test study

摘要

Continuous girder bridges for high-speed railway (HSR) are increasingly used to overcome undulating terrain and to provide a flat surface for high-speed travel. Only a few dynamic experiments have been applied to such bridges, none of them focusing on HSR continuous girder bridges. The aim of this paper is to use experimental results to investigate the earthquake response of bridges of this type constructed in China. To address this aim, a 1/12-scale typical Chinese HSR continuous girder bridge specimen was constructed and the experimental procedures were detailed. From the experimental results it was found that the first natural frequency of piers was obviously decreased after the specimen was subjected to the peak ground acceleration of 0.38 g earthquake excitation. The acceleration response observed at the top of piers increased with the increase of earthquake intensity, and the concrete at the bottom of piers was cracked when the peak ground acceleration exceeded 0.20 g. The results also showed that a fixed bearing installed on the HSR bridge was damaged under 0.32 g earthquake excitation, whereas no damage was found in a girder for all test scenarios (i.e., from 0.15 g to 0.38 g). In addition, compared to unidirectional earthquake excitation, the earthquake response increased under bidirectional earthquake excitation. The experimental procedures and findings can be used as benchmarks for practical applications or for further similar experiments.