40 Katlı Betonarme Bir Yapının Yerli Ve Yabancı Yönetmelikler Dikkate Alınarak Tasarım Depremi Ve Deprem Kayıtlarına Göre Yapısal Davranışının İncelenmesi

Abstract

Yer küre üzerindeki aktif fay hatlarının bulunduğu bölgede yer alan ülkemizde ve benzer ülkelerde meydana gelen depremlerin ağır hasarlara ve can kayıplarına neden olması depreme dayanıklı yapı tasarımının önemini zorunluluğunu ve kaçınılmaz hale getirmiştir. Bu nedenle ülkemizde yapıların deprem davranışı ve hasar durumu hakkında daha detaylı bilgiler veren yaklaşımlar ve hesap yöntemleri Deprem Bölgelerinde Yapılacak Binalar Hakkında Yönetmelik (TDY) 2007’de yer almıştır. Bu tez çalışmasında İstanbul’da yapımı devam eden TDY-2007’ye göre projelendirilmiş, Etabs’ta modellenmiş 40 katlı betonarme bir binanın TDY-2007, Eurocode-8 ve UBC-97 yönetmeliklerine göre doğrusal analizi, Kocaeli ve Erzincan Depremlerine göre Zaman Tanım Alanında Doğrusal Olmayan Analizi gerçekleştirilerek elde edilen veriler incelenmiştir. Birinci bölümde, tez çalışmasının amacı ve kapsamı, performans kavramı ve mevcut yapıların performansının değerlendirilmesinde kullanılan doğrusal ve doğrusal olmayan hesap yöntemleri genel olarak açıklanmıştır. İkinci, üçüncü ve dördüncü bölümde, performans kavramı ve 2007 yılında yürürlüğe giren “Deprem Bölgelerinde Yapılacak Binalar Hakkında Yönetmelik 2007” kapsamında doğrusal olmayan analiz yöntemlerinden Zaman Tanım Alanında Hesap Yönteminin incelenmesi, İstanbul Yüksek Binalar Deprem Yönetmeliği hakkında genel bilgi verilmektedir. Verilen teorik bilgilerden sonra beşinci bölümde, İstanbul’da yapımı devam eden 40 katlı betonarme bir binanın yapısal olarak incelenmesi ve Etabs programında modellenmesi ve doğrusal olmayan analiz yöntemlerinden Zaman Tanım Alanında Hesap Yöntemi ile deprem performansının değerlendirilmesi anlatılmış, gerçek ivme kaydı olan Kocaeli ve Erzincan Depreminin yapıya uygulanma aşamaları açıklanmış TDY-2007, UBC ve Eurocode’a göre karşılaştırmalar yapılmıştır.

Catastrophic earthquakes that caused severe damage and loss of lives in our country and similar countries, which are located in a region on the earth where active fault lines exist, has made the importance of earthquake resistant design mandatory and inevitable. Therefore some approaches and calculation methods, which provide more detailed information regarding earthquake behaviour and damage status, are included in the “ Turkish Earthquake Code, 2007” nowadays. A 40 storeys under construction reinforced concrete building, which designed as per Turkish Earthquake Code and mathematically modelled with etabs software, has been analysed and investigated in this thesis study according to TEC-2007,EC-8 and UBC-97 linear method and also nonlinear time history method by using Kocaeli and Erzincan Earthquake Records. In the first section, purpose and scope of the thesis study, performance concept and linear/non linear calculation methods, which are used for performance evaluation of existing structures, have been explained in general. In the second, third and fourth sections, performance concept and non linear time history analysis from Turkish Earthquake Code that published at 2007 has been investigated. And also general information has been given regarding “İstanbul High Buildings Earthquake Code”. After all given theoretical informations in the previous sections, structural investigation, mathematical modelling with etabs software and evaluation of earthquake performance with non linear time history method of a 40 storeys reinforced concrete building, which is under construction in İstanbul, have been explained in the section five. In addition, application steps of real accelaration records of Kocaeli and Erzincan Earthquakes to the structure have been explained and comparisons have been made as per TEC-2007,EC-8 and UBC-97. At the final section of the thesis study, study is summarized in general and analysis results of the 40 storeys reinforced concrete building, which performance evaluation is made with non linear time history method, have been presented at conclusions and recommendations section. And also necessary recommendations have been made in this final section. Performance of the link beams, which interconnect elevator shear walls, are investigated separately due to their proximity to the center of rigidity of the structure. And these link beams are found satisfactory in terms of capacity (FEMA-356). Traditionally, codes are designed by taking into account current scientific rules and the facts of the country that they belong to. In the light of this, results that are obtained on the basis of the 3 codes used in this study (TEC-2007,EC-8 and UBC97) have been summarized below: - EC-8 and UBC-97 codes are based on European norms as is known. The quality of materials in these countries are more realist and feasible for usage of safety factors economically in terms of construction in comparison with TEC-2007. - However it should not be forgotten that our country is located on a very active seismic zone compared to most of the European countries. When the manufactured material quality in European countries is compared to ours along with the many other factors in our country, it is inevitable that the TEC2007 is more conservative than the other European codes. Results of the structure presented in this thesis study have been summarized below in order to clarify above. Maximum earthquake shear force obtained at x-x direction is 1660 kN as per UBC97. And maximum earthquake shear force obtained at y-y direction is 1600 kN as per EC-8. These values are obtained as approximately 1450 kN as per TEC-2007. Maximum story displacement is found as 340 mm at y-y direction as the analysis that run as per TEC-2007. And also maximum base earthquake force is calculated as 50.000 kN at basement of the structure according to TEC-2007. Eventually, maximum displacements and maximum earthquake shear forces are obtained from the analyses that run as per TEC-2007. Regardless of the code used in the analysis of the structure, some geometric and physical effects can never be ignored. In other words, vertical and horizontal discontinuities should be minimum or never exist in the high structures. For example, basement shear walls of the structure should exist along the perimeter of the structure and they should be continuous. When the shear force diagrams (Figure 5.27, Figure 5.28, Figure 5.29) are viewed, sudden direction and value changes at the basement level can be seen due to the discontinuities of basement shear walls. With a similar example, story displacements and story shear forces that occur due to the serious horizontal and vertical rigidity changes of the structure at some floors like 17. floor should be considered in detail. In the light of the above design criteria, A1 type torsional irregularity is determined as per TEC-2007 as a result of occurred displacements at the structure. B2 irregularity is not obtained in the structure. As a result, it is concluded that the architectural rigidity decrements should be linear instead of a sudden change at the vertical direction of a high structure. Basement shear walls that interact with soil should be continuous along the structure.