Seismic performance of double-column tall pier bents using fusing connections

Abstract

The dynamic responses of tall pier bridges with single column have been extensively investigated, while the research on double- or muti-column tall pier bent bridges is limited to date. This paper investigates the seismic performance of this type of tall pier bents and proposes a fusing connection between pier columns and link beams, to alleviate damage and improve seismic resilience. By setting strength hierarchies among various components, the proposed fusing connection is designed to yield prior to both column and link beam. Therefore, the nonlinear damage and energy dissipation during earthquakes are shifted to these connections, and the pier column and link beam are protected. To validate the efficiency of the proposed fusing connections, a typical double-column tall pier bent constructed at Southwest China is employed as a prototype. Through the nonlinear time history and fragility analysis procedures, the performance of the tall pier bent using fusing connection is evaluated and compared with the prototype in deterministic and probabilistic ways, respectively. The results show that the utilization of fusing connections effectively suppresses both the section curvature and shear force demands of pier columns. Thus, the seismic vulnerability of the prototype is reduced, and the seismic performance is improved, in both linear and nonlinear stage. Furthermore, the link beams are also protected by the connections and remain elastic during excitations, indicating lower probability of secondary damage, as well as reduced post-earthquake repair work and cost.