A comparative study of performances of various base isolation systems, part I: Shear beam structures

Abstract

AbstractA comparative study of performances of different base isolators for shear beam type structures is carried out. Several leading base isolation systems, including the laminated rubber bearing with and without lead plug, the resilient‐friction base isolator with and without sliding upper plate, and the EDF system are considered. Displacement and acceleration response spectra for a shear beam structure subject to the accelerograms of the N00W component of El Centro 1940 and the N90W component of Mexico City 1985 earthquakes and their magnified forms are evaluated. A series of parametric studies is carried out and advantages and disadvantages of various base isolation systems are identified. Comparisons of the results with the response spectra of a fixed‐base structure show that the base isolation systems are, in general, highly effective in reducing the peak acceleration transmitted to the superstructure. Thus, the deflections and stresses generated in a base‐isolated structure are significantly lower than those of a fixed‐base one. Furthermore, the results of the study also show that the friction‐type base isolators are less sensitive to severe variations in frequency content and amplitude of the ground acceleration.