Vibration Suppression Analysis of a Long-Span Bridge Subjected to Combined Service and Extreme Loads

The long-span bridge structures are loaded by service loads including traffic and/or wind loads almost every day. The earthquake load may occur on the bridges simultaneously except for these two common service loads. The vibration response of long-span bridges under earthquake and service loads usually exceeds the expected values. Therefore, the suppressed system should be extensively studied to control the vibration of the bridges. In the work, a pounding tuned mass damper (PTMD) system was designed, which can be effectively used for the dissipation of impact energy. It is mainly made up of a tuned mass and an additional limit device. Based on the earthquake/wind/traffic/bridge coupled system, the numerical simulation of multiple PTMDs (MPTMDs) was carried out. Different parameters of MPTMDs were studied including different numbers, mass ratio, pounding stiffness, and the gap values. The simulations show that the MPTMDs are very effective in suppressing the displacements of the bridge caused by both the traffic flows/wind and traffic/earthquake, and the suppressing effectiveness for bridge vibration under traffic and earthquake is more than that under traffic and wind.