Performance based seismic design of reinforced concrete tall buildings


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2015

Öğrenci: ERHAN BUDAK

Danışman: HALUK SUCUOĞLU

Özet:

Cities, their economies and populations are steadily increasing all over the world. In parallel, the land prices in those cities are rising enormously, hence the need for new living spaces has been arisen. These results bring some obligations and new perspectives for those cities in order to address their needs. In addition, improvements and developments in technological equipment, material science and analyses methods have opened great opportunities to construct new life areas by rising the vertical direction instead of horizontal direction. Considering all these facts, the need for tall building are growing up and the design of tall buildings are increasing gradually day by day. However, most of those buildings are located in the regions of high seismicity. Unfortunately, the behaviour of tall buildings, especially under the effect of seismic loading, is one of the most sophisticated problems in earthquake engineering. In this study, the behaviour of tall buildings under seismic loading is investigated by utilizing performance based seismic design (PBSD) approach. Unlike regular buildings, tall buildings are special due to their specific architectural properties and building configurations. Accordingly, the behaviour of tall buildings under the effect of seismic actions is different since the contribution of higher mode effects is significant on the dynamic behaviour of tall buildings. Moreover, there exist some important differences from design to analysis to construction. In addition, current prescriptive seismic codes are too restrictive and inadequate to understand the anticipated behaviour of tall buildings and apply a reasonable design. In this study, all of these problems are explained elaborately and addressed. On the other hand, alternative high strength materials and innovative structural systems have growingly employed to resist unique challenges introduced by these structures in the regions of high seismicity. Considering all these facts, several institutions and building officials have proposed and published alternative consensus guidelines which are based on performance based design concepts by conducting nonlinear time history analysis. The methodology of these alternative non-prescriptive guidelines is investigated and compared with each other. Nowadays, performance based seismic design of tall buildings by conducting nonlinear dynamic analysis is being used increasingly for tall buildings. Some building departments and seismic codes obligate designer to use this method on tall buildings. PBSD approach is quite sophisticated and a time consuming process from creating nonlinear modelling to the interpretation of results. However, there are also a variety of uncertainties from modelling of the component to the selection of ground motions to define performance target levels. All of these issues are also examined in the scope of this study. Finally, a reinforced concrete unsymmetrical-plan tall building with 34 stories is designed according to the Turkish Seismic Code under design level earthquake. For both service level and collapse prevention levels, nonlinear time history analysis is employed by using a suite set of seven ground motions for checking the results in compliance with the determined target performance levels. The results have indicated that satisfactory seismic performance can be obtained through the use of performance based seismic design procedures.