Dynamic response characteristics of seismic isolation systems for building structures

Abstract

Isolation is an effective method of reducing effects of seismic events on building structures. Steel-reinforced elastomeric isolator (SREI) is one kind of isolation system which is used extensively, but there are some problems associated with its use, such as cost and weight. Fiber-reinforced elastomeric isolator (FREI) has been developed in an attempt to solve the problems of high cost and heavy weight for SREI. In this study, mechanical properties for the SREI and the FREI are investigated. Systematic dynamic response analyses are performed for three different models such as a fixed based, an SREI based and an FREI based low-story building structures. Two-dimensional and threedimensional dynamic response analysis results for each model are compared in terms of displacement, drift, acceleration and shear force in this study. In the two-dimensional dynamic response analysis, the SREI and the FREI based structures are proven to be the more effective isolation systems against seismic events by comparing with the fixed based one. As a result, the FREI has shown better isolation performances than that of the SREI. Furthermore, to extract the characteristics of the FREI on building structure resisting the seismic effects, two models of three-dimensional framed structure with fixed bases and FREI isolated bases are built, respectively. After the dynamic response analysis of these two structures subjected to bi-directional ground motions, the analyzed results are compared with each other. It is shown that the FREI could effectively absorb the seismic energy, and decreases the destructive effects acting on a building structure due to ground horizontal motions that could occur in an earthquake.

Effects of Building Height and Seismic Load on the Optimal Performance of Base Isolation System

“…Similar trend of distribution of shear forces along the height of the considered buildings were also obtained by [46], and in experimental studies by [49,50]. The observed increase of shear forces as the building height increases has also been observed by other researchers [18], but for only one building height.…”

Protecting vibration-sensitive contents: an investigation of floor accelerations in seismically isolated buildings

“…Recent analytical and experimental research studies show that properly designed seismic base isolation systems can reduce peak floor accelerations effectively. Kang et al (2009) have shown that seismic base isolation systems composed of steel-reinforced or fiber-reinforced elastomeric isolators reduce peak floor accelerations significantly. Ismail et al (2009b) have shown that the peak accelerations sustained by an equipment housed in the top story of an eight-story building model can effectively be reduced by seismically isolating the building via a rolling-based seismic isolation system.…”

“…However, the distribution of peak floor accelerations of a seismically isolated building may be different due to the presence of the seismic isolation system. In the literature, only a limited number of studies on seismically isolated buildings considered all peak floor accelerations rather than only top floor accelerations (Nagarajaiah et al 1991a,b;Şahin 2008;Kang et al 2009;Providakis 2009). Reviewing these studies, we see a tendency in the floor accelerations to decrease towards mid-floors and then increase towards upper floors.…”

Seismic Assessment of Steel-frame Buildings Mounted with Base-Isolated System

“…As per the references, the first modern technique of base isolators was carried out in 1969 in a school building by using rubber isolators in Skopje, Macedonia [1,15]. But, in the last few decades, the base isolation concept has rapidly gained visibility across the globe, resulting in, development of various isolation systems [16]. In the current scenario, various base isolation devices are being used i.e.…”