Engineering Structures | 2021
Seismic assessment of tall pier bridges with double-column bents retrofitted with buckling restrained braces subjected to near-fault motions
Abstract
Abstract Previous researches on dynamic performance of tall pier bridges generally focus on those composed of single columns, and studies on those with double- or multi-column bents are limited. This paper investigates the seismic responses of typical tall pier bridges with double-column bents, as well as the efficiency of mitigating dynamic demands using buckling restrained braces (BRBs). Near-fault motions are specifically considered as input, which might be most devastating loadings for structures with long fundamental periods as tall pier bridges. Nonlinear time history and fragility analysis methods are employed assessing the performance in deterministic and probabilistic manners, respectively, to provide more comprehensive insights. The results show that the BRB could effectively reduce the seismic vulnerability and improve the performance of the prototype bridge, whether linear or nonlinear response is involved. Furthermore, while reducing local excessive seismic demands, the BRB device has little influence on the global responses. This phenomenon is of great significance that it helps engineers to make a quick decision about the location of BRBs, and thus facilitates the retrofitting procedures.