Influence of expansion joint parameters on vehicle-induced dynamic response of long-span arch bridge

Abstract:

To study the influence of expansion joint parameters on vehicle-induced dynamic response of long-span concrete-filled steel tube (CFST) arch bridge, this paper proposes a vehicle-bridge coupling dynamic response analysis method (vehicle-gap-bridge coupling dynamic response analysis method) considering the influence of expansion joint parameters. Taking a long-span half-through CFST arch bridge as the research object, the influence of expansion joint height difference, support stiffness, and joint width on the vehicle-gap-bridge coupling dynamic response was investigated. Results show that under the design parameters of expansion joint, the vertical impact of vehicle on expansion joint first decreased and then increased with the increase in the vehicle speed, and the vehicle-induced impact on the expansion joint was more significant than that on the main beam. With the increase in the vehicle speed, the vehicle-induced impact coefficient of the main beam showed an increasing trend. Considering the influence of expansion joint parameters, the vertical impact of vehicle on the main beam was related to the spatial position, and the impact coefficient of the main beam measurement point close to the expansion joint position was greater. Under variable expansion joint parameters, the rise of the middle cross beam led to the increase in the impact of the vehicle on the expansion joint, and the rise or fall of the middle cross beam could both cause the increase in the impact of the vehicle on the beam end, resulting in the increase in the bearing reaction. When the support stiffness of the expansion joint decreased or the width of the joint increased, the impact of the vehicle on the middle cross beam of the expansion joint increased. The expansion joint parameters had little effect on the displacement response of the 1/4 cross-section and 1/2 cross-section of the main beam.