Semi-active isolation systems for seismic structures

• Main Authors: Ging-Long Lin, 林錦隆
• Other Authors: Lyan-Ywan Lu
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/91622685759917301180

博士 === 國立高雄第一科技大學 === 工程科技研究所 === 96 === Base isolation technology may be used for seismic protection of critical structures or equipments. However, recent studies have revealed that a conventional passive isolation system may induce an excessive base displacement when subjected to a near-fault earthquake with strong long-period components. In order to enhance the efficiency and safety of seismic isolation for structures in near-fault areas, a semi-active isolation system (SAIS) that consists of isolators and a variable damper is proposed in this study. Three kinds of variable dampers are discussed in this study. The first is the variable stiffness damper, the second is the variable friction damper, and the third is the variable viscous damper. The resistant force of a variable damper can be adjusted by its controllable parameter according to an on-line control law and the measured system response. The seismic response of the SAIS system equipped with each of the three types of variable dampers mentioned previously and subjected to near-fault earthquakes was simulated numerically in this study. In addition, its isolation performance was also evaluated and compared with the performance of a passive and an active isolation system. The results of these comparisons are discussed in this study. The simulation result demonstrates that the SAIS system is able to prevent the excessive displacement and acceleration response of structure induced by long-period pulse components of near-fault earthquakes.