A SLIDING ISOLATION SYSTEM FOR THE SEISMIC PROTECTION OF STRUCTURES

Seismic isolation provides an effective engineering solution for the prevention of earthquake damage to buildings, bridges and other structures. This paper presents some research results and examples of real applications of a sliding isolation system called the Friction Pendulurn System (FPS). Results from experimental and analytical studies on the use of FPS isolators in multistory buildings are presented. Quarter scale seven story building models having various braced and unbraced conditions were subjected to several shake table motions having a variety of frequency content and amplitude. Extreme motions resulted in individual isolators being subjected to local uplift forces and in some cases, the maximum isolator displacement restraint was also engaged. The use of isolators reduced structure shear forces and interstory drifts by factors of ۴ to ۶. Analytical models accurately predict the response of the isolation system and upper structure. Finally, examples of recent practical applications of the FPS isolators in major seismic retrofit and seismic strengthening projects are presented.