Study on seismic performance of functionally integrated cylindrical steel damper bearing with energy dissipation and spacing

The bridge bearing serves as a crucial constituent that can exert a substantial influence on the seismic performance of the bridge structure. When subjected to seismic events, conventional fixed-type bearings transmit considerable seismic forces, leading to detrimental effects on the bridge piers. The damage incurred by the fixed-type bearings can result in significant relative displacement between the pier and girder, which can potentially contribute to the unseating. To effectively control the seismic damage to bridge piers and the relative displacements between the pier and girder, as well as to facilitate controllable design of bridge seismic behaviors, a novel functional integration approach was developed: the functionally integrated cylindrical steel damper bearing (FICSDB). The FICSDB incorporated certain functionalities, such as seismic isolation, energy dissipation, and displacement limitation. Specifically, following the constructional details and operational mechanisms of the FICSDB, the mechanical model was initially derived. Subsequently a series of cyclic shear tests were conducted on the FICSDB. Certain results were obtained as follows. (1) The bearing’s sliding performance remained relatively stable. (2) The cylindrical damper effectively achieved the desired objectives of energy dissipation and spacing, thereby exhibiting exceptional fatigue resistance. (3) The components demonstrated close cooperation, which ensured the overall stability and controllability of the FICSDB’s mechanical behavior. (4) The effectiveness of the FICSDB was validated through numerical calculations with the application of a continuous girder bridge as a case study. The results revealed that, in comparison to traditional fixed-type bearings, employing the FICSDB significantly reduced internal forces exerted on the bridge piers during rare seismic events. Additionally, when compared to conventional isolation bearings, the FICSDB realized the excellent minimization of the relative displacement between the pier and girder. Therefore, the FICSDB can enable the dual control of the pier damage and unseating, thereby facilitating the controlled design of bridge seismic behaviors.