Nonlinear Dynamic Analysis of Curved Surface Slider Systems Under Harmonic, Near-Fault, and Long-Period Ground Motions

Abstract

Seismic isolation is a widely adopted technology for the protection of building infrastructure from earthquakes. As one of the most effective seismic protection devices, curved surface slider (CSS) systems have been studied extensively in the last few decades and are nowadays widely used all over the world. However, due to their relatively recent adoption for the seismic isolation of buildings and bridges, critical aspects of their behavior and possible causes for their malfunctioning are still under thorough experimental and analytical investigation. After recent severe earthquakes, such as Kobe (1995) and Tohoku (2011), considerable attention has been devoted to the effects of near-fault and long-period earthquakes, with specific reference to tall buildings and base-isolated structures. However, no reference has been made in the literature to the resonant effects of nearly periodic ground motions on CSS systems. For the low friction coefficient values used in seismic isolation, the linear theory currently used for the analysis of the response of friction-based systems leads to an unbounded resonant response. It is the focus of this work to investigate the effects of geometric nonlinearity on the response of such systems and to assess the performance of the CSS system under critical ground motions. Dynamic analyses are carried out under harmonic, near-fault, and long-period ground motions. The results are presented in the form of displacement response spectra for different values of the friction coefficient.