橋梁藉由隔震系統延長自然振動週期，以降低上部結構引致之地震力，但其缺點為上部結構可能產生大位移反應，實務上可採用結構控制技術降低其位移反應。當隔震橋梁之工址地質優良時，其基礎型式可同時採用直接基礎，大地震發生時，直接基礎可能發生搖擺現象。本研究進行一系列振動台試驗，以直接基礎隔震支承橋梁為目標，探討直接基礎產生搖擺時，加裝被動控制元件之減震效應。由實驗數據與數值分析比對，確定數值模型之準確性後，建立一座五跨連續隔震支承系統梁橋，加裝黏滯性阻尼器，藉由參數分析求得其最佳配置方式與阻尼係數。研究結果顯示，黏滯性阻尼器，可有效降低橋梁反應，但阻尼係數過大，阻尼力增大，直接基礎搖擺現象放大，反而導致負面之影響，因此實務應用時，阻尼係數不宜過大，方可發揮最大之減震效能。;The isolation system extend the period of the bridge and reduce the earthquake force which caused by bridge superstructure. However, the shortage is isolation system would lead to the displacement of the superstructure would be increased. In practice, the control system is chosen to decrease the displacement effect. If the bridge is built on the excellent soil properties, the foundation type could be chosen as direct foundation. As the result, when the earthquake happened, rocking would be caused on direct foundation. In this research, based on direct foundation of isolator bridges, a series of shaking table test was done. The goal of this experiment is to find the effect of adding passive control system when direct foundation shaking. Then, the accuracy of the numerical model would be considered by compare experimental data and numerical analysis. After make sure the accuracy of the numerical model, a five-span continuous isolated bridge modal which added viscous dampers would be built. Then, the best configuration and damper coefficient would be found by parameter analysis. The research result shows that viscous dampers could reduce the effect of the bridge. However, if damper coefficient is too large lead to damping force increase, direct foundation rocking would become serious. It would contribute to negative impact. As the result, appropriate damper coefficient could provide optimal influence.
