Farklı yaklaşımlar kullanılarak modellenen izolatörlü hastane binasının deprem performans karşılaştırması

In Turkey, seismic base isolation have become mainly used passive earthquake control system especially among hospital structures after the amendment of Ministry of Health in 2014, regulating the design of hospitals in high seismic zones. Rubber and sliding type of isolators have been applied, and several different hysteresis models, which are essentially acceptable in seismic codes, were used in their design process. However, due to the complexity in the development of highly nonlinear models, engineers tend to use more practical ones such as smoothed or sharp bilinear models. Literature and experience have shown that differences in hysteresis characteristics may lead to variance in performance parameters resulting in possible overdesign or underdesign. In this thesis, to assess the effect of the modeling approach on seismic performance, for a selected hospital building, high damping rubber bearing, and friction pendulum-type isolators were designed according to Turkish Building Seismic Code and evaluated in terms of structural performance. For both designs, commonly used bilinear and highly nonlinear isolator hysteresis models from the literature were adopted, and structural models were created for 2475 years, and 475 years return period seismic ground motions. Three-dimensional nonlinear time history analyses were conducted on the building model under a set of 11 ground motions. For each model, structural performance is evaluated and compared in terms of (i) maximum isolator displacements, (ii) base shear reactions, (iii) story accelerations, (iv) inter-story drifts, (v) isolator hysteretic response and (vi) uplift behavior conforming the international code limitations. The results show that when bilinear models are used instead of more accurate nonlinear models, there is a significant variation in the superstructural response, especially for sharply bilinear models.