DYNAMIC RESPONSE CHARACTERISTICS OF CONTINUOUS GIRDER BRIDGE DURING TRAIN PASSAGE AND ITS SIMPLE EVALUATION METHOD

Abstract

 In the railway continuous girder, the knowledge about the dynamic response in the high-speed region has not been organized, and rational design by a practical evaluation method has been difficult. This study firstly organized and generalized the structural specifications of general railway continuous girders and, secondly, carried out comprehensive dynamic response analysis of continuous girders during train passage. The impact coefficient of the deflection of the continuous girder shows multiple maximum points at the resonance speed of each natural vibration mode. When the number of spans is odd, the 1^st and 3^rd modes are amplified at the resonance speed, and the number of spans is even, the 2^nd mode is amplified at the resonance speed. Dominant vibration modes become unclear with the increase in the number of spans and the span length, and the impact coefficient of deflection tends to decrease in the region where the train speed is less than 400 km/h. Based on the clarified dynamic response characteristics of continuous girder, a simple evaluation method of the impact coefficient with the applicable range up to 400 km/h has been proposed, and its validity has been demonstrated.