Comparative study of the inelastic response of base isolated buildings

Abstract

SUMMARYThis article presents a numeric comparative study of the inelastic structural response of base isolated buildings. The comparative study includes the following isolation systems: laminated rubber bearings, New Zealand one, pure friction and the frictional pendulum ones. The study is based on obtaining nonlinear response spectra for various design parameters using six earthquake records. Usually the base isolation of a new building seeks to maintain the structure in the linear elastic range. The response of old weak buildings or the response of new ones subjected to extreme earthquakes may not be, necessarily, in the aforementioned ideal elastic range. Consequently, it is important to characterize the response of isolated buildings responding inelastically. A conclusion from this research is that the isolators a ect signiÿcantly the structural response of weak systems. Rubber isolators seem slightly less sensitive to plastiÿcation that may occur in the structure compared to friction isolators. Ductility demands in the structure are a ected signiÿcantly by friction and neoprene protected systems, in particular sliding ones where larger demands are obtained.

An Efficient Order Reduction Strategy in Earthquake Nonlinear Response Analysis of Structures

“…For additional information about friction pendulum systems the reader is referred to the relevant literature (e.g. [33], [34], [35], [36], [37] and [38]). More detailed examination of this topic would lead beyond the scope of this paper, which should focus more on the methodical extension of the new MOR strategy as well as the application on a complex realistic system.…”

A Probabilistic Approach Towards an Evaluation of Existing Code Provisions for Seismically Isolated Structures

“…Constantinou and Quarshie [4], Ordonez et al [5], Kikuchi et al [6], Thiravechyan et al [7] and Cardone et al [8] investigated the response of inelastic seismically isolated structures and agreed that allowing base-isolated superstructures to yield requires careful consideration because of possible occurrence of large ductility demands. Vassiliou et al [9][10][11] concluded that designing typical seismically isolated structures to behave elastically, as prescribed by current seismic design codes, is not overly conservative but a necessity that emerges from the fundamental dynamics of such structures.…”

On the feasibility of structural metamaterials for seismic-induced vibration mitigation

“…The uncertain nature of these events renders their effective mitigation a non-trivial task. In addressing this issue, isolation systems have been developed and applied for protecting structural systems, by permitting relative motion with respect to the base (Mao and Li, 2005;Ordonez et al, 2003;Kelly, 1990). Nonetheless, the design of these systems is not straightforward, and a number of bottlenecks have been identified and reported (Providakis, 2009) including reduced resistance to vertical deformation, and large horizontal displacements, which call for additional damping elements, with increased costs and no guarantee of adequacy.…”