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Design displacements and accelerations are determined and compared for typical seismic isolation systems and locations designed in accordance with site-specific seismic demands in New Zealand, California and Turkey. The design demands are estimated by nonlinear time-history analyses using suites of scaled strong motion records following the provisi...
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... The concept has been applied to Christchurch-New Zealand, Vancouver-Canada, San Francisco Bay area-USA and Chile based on relevant codes [11] [12]. This concept has also been performed for two specific structures in Istanbul and Erzurum-Turkey following ASCE 7-10 [13] provisions [14]. However, none of the above studies considers different seismic input levels and site classes. ...
In this study, base shear and inelastic displacement limits of seismic isolation systems are presented through acceleration-displacement response spectra considering the ground motion and design provisions of the Turkish Building Seismic Design Code. A series of nonlinear response history analyses are performed using a combination of eight site-specific design spectra, six isolation systems having six different periods and five yield levels. As a result, eight spectra presented herein can be used for the preliminary design stage of seismic isolation systems in Turkey.
... The initial work by the authors [1, 2] explored the use of ADRS to understand the response behavior of single-degree-of-freedom nonlinear isolation systems to a suite of actual strong motion records from the Canterbury earthquake sequence. In subsequent papers [3, 4], the methodology has been applied to sites in Wellington (NZ), San Francisco (USA) – near fault, Vancouver (Canada) and two locations in Turkey (Zones 1 and 2). In each case, a suite of recorded ground motions, scaled to meet appropriate code and/or design requirements was used. ...
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.
ZET: Son yıllarda deprem yönetmeliklerinde doğrusal olmayan tepki spektrumlarının hesap tekniği sürekli olarak güncellenmekte, bununla birlikte tasarımında yer hareketinin titizlikle değerlendirilmesi gereken deprem yalıtım sistemlerin kullanımı yaygınlaşmaktadır. Deprem yalıtım sistem parametrelerinin tepki spektrumuyla ilişkilerinin doğru kurulması hesap süreci için oldukça önemlidir. Spektrumların oluşturulmasında; yer hareketi seçim kriterleri, ölçeklendirme tekniği ve ortalamasının alınma yöntemi gibi pek çok değişken etkili olmaktadır. Uygun deprem yalıtım sisteminin belirlenmesinde ise, deprem yalıtım birimlerinin detaylı modellenmesi öncesi tasarım kriterleri olan etkin periyot, etkin sönüm ve üst yapıya aktarılan kesme kuvveti gibi parametrelerin belirlenmesi tasarımın ilk aşamasını oluşturmaktadır. Söz konusu parametrelerin birbirlerine doğrudan bağımlı olması çözümü iteratif bir yaklaşıma götürmektedir. Bu aşamada iterasyonların azaltılması ve en etkin yalıtım sistemi özelliklerinin belirlenmesi için bir yöntem önerilmiştir. Bu yöntemde, Türkiye Bina Deprem Yönetmeliği'nde belirtilen yer hareketi ve tasarım kuralları kullanılmıştır. Farklı yalıtım periyotları ve akma dayanımlarına sahip sismik yalıtım sistemleri, farklı deprem etkileri altında çözülerek söz konusu kriterleri sağlayan çözüm bölgeleri bulunmuştur. Bir dizi doğrusal olmayan tepki analizi yapılmıştır ve sismik yalıtım sisteminin ivme-yerdeğiştirme tepki spektrumları grafiksel gösterimle elde edilmiştir. Söz konusu çalışmanın farklı deprem düzeyleri, belirli yalıtım periyodu ve akma dayanımları için doğrusal olmayan ivme-yerdeğiştirme tepki spektrumları elde edilebilir. Bunun sonucunda da sismik yalıtım sistemlerinin ön tasarımında daha çabuk ve hızlı çözüm elde edilmesi sağlanabilecektir. ABSTRACT: In recent years, principles of nonlinear response spectra analysis techniques have been permanently updated in seismic codes and besides the use of seismic isolation systems which require detailed evaluation of ground motions has been significantly increased. The determination process of the isolation system parameters through response spectrum concept is the initial phase of isolation system design. The procedure used in the ground motion simulation in terms of scaling and averaging is an important factor on the isolation system design. In the determination of the most appropriate isolation system, as the preliminary phase before detailed modeling an analysis of the overall system, determination of the effective period, effective damping and base shear ratio constitutes the first phase of the isolation system design. Since the above-mentioned parameters are internally connected to each other, the design process of the isolation system becomes an iterative process. At this point, a methodology has been proposed for reducing the iterative process and determining the most effective isolation
