An Improved Design Methodology for Seismic Isolation Systems Using Nonlinear Response Spectra


Abstract eng:
The authors have recently developed a new and improved design methodology for seismic isolation systems. The approach uses nonlinear acceleration and displacement spectra that are developed for the fundamental seismic isolation system properties of characteristic strength and post-yield stiffness (which is referred to as characteristic stiffness, and expressed as an equivalent period). The methodology has been previously investigated for site-specific seismic designs in New Zealand, the U.S., Canada, and Turkey and this paper continues the development. The present study has two main objectives: first, to demonstrate the power and efficiency of the method in the preliminary design process for seismically-isolated structures through several illustrative design examples, and second, to further develop ADRS spectra and to explore their potential standardization to further streamline and improve the seismic isolation system design. The ADRS methodology represents a valuable and intuitive visual tool to enable designers to quickly determine isolation system design parameters likely to be most effective for a given site and specific project structural design criteria, with the ability to rapidly identify the “trade-offs” of different isolation periods and yield values (characteristic stiffness and strength). The design process is directly based upon practical isolation design physical parameters (strength, or friction coefficient, and post-yield stiffness, or period). Selected examples are given and discussion provided to illustrate the benefits of the approach. The further development and potential standardization of ADRS spectra for isolation system design is also explored as part of the current work, and this has been undertaken in the context of seismic design in Chile. In just the last five years, Chile has experienced three very large earthquakes, with M w magnitudes of 8.2, 8.3 and 8.8. A broad set of strong ground motion records from these three major events was selected and ADRS isolation design spectra developed. The resulting spectra are compared with the seismic isolation design requirements of the Chilean code, NCh2745:2013. The set of spectra also presented the opportunity to investigate general response “patterns” in the ADRS plots, for the possibility of defining simplified ADRS plots for quick, preliminary design that do not require direct nonlinear analysis.

Contributors:
Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
Rights:
Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 4554.:
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