OVERVIEW OF BASE ISOLATION, PASSIVE AND ACTIVE VIBRATION CONTROL STRATEGIES FOR ASEISMIC DESIGN OF STRUCTURES

Recent development in passive and active vibration control of structures and their applications to earthquake resisting design is reviewed. Particular attention is given to the base isolation inethodology and passive control techniques. The performance of several base isolation devices including the Rubber Bearing, the Sliding-Joint, the French System, and the Resilient-Friction isolator for seismic protection of buildings is described. The use of recently developed passive frictional and viscoelastic dampers in structures is discussed. The active control methodologies for protecting the building during earthquakes is presented. The effectiveness of various base isolators, passive dampers and active control strategies under a variety of conditions are described, and their advantages and disadvantages are pointed out. It is shown that the acceleration transmitted to compact stiff structures during an earthquake can be effectively reduced by using properly designed base isolation systems. One the the passive dampers and active control methodologies may be used for protection of tal] buildings against earthquake. In addition, these latter techniques may become useful for seismic rehabilitation of existing structures.