研究期間：10108~10207;The isolation systems have been extensively adopted in bridges to mitigate the induced seismic force. However, the deck displacements of isolated bridges may become excessively large under extreme ground motions. Although the installation of supplemental damping devices can mitigate the seismic responses of isolated bridges, the columns may subject to extra forces induced by the supplemental dampers so that the displacements of columns and bearings may increase under strong earthquakes if the bearings and the supplemental dampers are not properly designed. Furthermore, the seismic responses of isolated bridges with columns of irregular heights are very complicate due to the irregular distribution of column stiffness. For effectively mitigating the seismic responses of the bridges with columns of irregular height, the bearings and supplemental dampers should be designed simultaneously. Consequently, the objective of this research is to develop an optimal design methodology for designing appropriate damping coefficients and locations for viscous dampers and stiffness for bearings simultaneously for isolated bridges. The isolated bridges with columns of irregular heights will be focused in this study. During the analysis, the deck is considered to be rigid, and resisting forces of all structural members, including rubber bearings and columns, are assumed to exhibit perfect elastic-plastic behavior. The nonlinear restoring forces of the isolators and columns are simulated by the Bouc-Wen hysteresis model. The hybrid meta-heuristic searching algorithm adopted in this research is a method combing particle swan optimization (PSO) and simulated annealing (SA) named as PSO-SA method. The optimal combination of damping coefficients for the viscous dampers and stiffness for bearings installed on irregular isolated bridges will be designed for near field and far field ground motions, respectively. The validity of the proposed design methodology and the efficiency in mitigating the seismic response of the irregular isolated bridges when the optimal designed dampers and bearings are adopted will then be discussed.
