A Study on the Comparison of Dynamic Behaviour of High Speed Railway Bridges

초록

The dynamic behavior of two steel bridges crossed by the Korean High Speed Train (KTX) has been investigated experimentally and the results are compared with the specification requirement and other typical prestressed concrete box girder bridge's responses. The investigated bridges are a 2-girder steel bridge of 1@40m span length, 2@50m span length, and a PSC Box girder bridge of 2@40m span length. A set of experimental tests were performed during operation of KTX, and a number of accelerometers, LVDTs and ring-type displacement transducers were utilized for measurement of three kinds of dynamic responses (acceleration, deflection, and end-rotation angle). Measured responses show that the vertical deflections and end-rotation angles of the three bridges are all satisfying the spec. requirement with large margin, but it was also found acceleration responses which are very close or exceed the limit value. Most of the excessive acceleration responses were found when the passing speed of the train is close to the critical velocity which causes resonance. No noticeable differences of dynamic responses due to the different materials (steel or concrete) could be found within these experimental results.