Mevcut 44 katlı betonarme yüksek bir binanın TBDY 2018'e göre deprem performansının zaman tanım alanında doğrusal olmayan yöntemle belirlenmesi
Determination of the seismic performance of an existing 44-storey reinforced concrete high-rise building according to TSC 2018 by nonlinear time history analysis
Yazar: ERKAN YILDIZ
Danışman: DOÇ. DR. ABDULLAH NECMETTİN GÜNDÜZ
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / İnşaat Mühendisliği Ana Bilim Dalı / Yapı Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2021
Konu: İnşaat Mühendisliği = Civil Engineering

Özet:
Depremsellik bakımından aktif fay hatları üzerinde bulunan ülkemizde sıklıkla deprem olmaktadır. Bu depremlerden çoğunluğu küçük şiddette meydana gelirken, büyük şiddetteki depremler can ve mal kaybına yol açabilmektedir. Yakın zamanda meydana gelen Elazığ ve İzmir depremlerinde çok sayıda bina yıkılmış ve birçok insan enkaz altında kalarak hayatını kaybetmiştir. Yıkılan binaların çoğunluğunun eskiden yapılan, malzeme kalitesi düşük ve yönetmelik şartlarını sağlamayarak göçme tehlikesi içeren binalar olduğu görülmektedir. Bu binaların çok yakın zamanda yıkıldıkları göz önüne alındığında ülkemizde bu binalara benzer ve herhangi bir deprem meydana geldiğinde yıkılabilecek çok sayıda riskli bina olduğu görülmektedir. Riskli binaların tespiti için mevcut yapıların deprem performanslarının belirlenmesi konusu büyük önem arz etmektedir. Riskli binaların bu yöntemle tespit edilerek güçlendirme çalışmalarının yapılması ve güçlendirme yapılamayacak düzeyde olanların ise yıkılması sonucunda birçok can ve mal kaybının önüne geçilebilmektedir. Ülkemizde 18 Mart 2018 tarihinde Resmi Gazete'de yayınlanan ve 1 Ocak 2019 tarihi itibariyle yürürlüğe giren Türkiye Bina Deprem Yönetmeliği'nde performans dayalı değerlendirme ve tasarım yaklaşımının kapsamı ve içeriği genişletilerek konu daha detaylı bir şekilde incelenmiştir. 
Bu tez çalışmasında TBDY 2018 kapsamında verilen kurallar ve hesap esasları doğrultusunda mevcut 44 katlı betonarme yüksek bir binanın zaman tanım alanında doğrusal olmayan yöntem kullanılarak deprem performansı incelenmiştir.
Tez çalışması beş ana bölümden oluşmakta olup birinci bölümde giriş kısmına yer verilerek tezin amacı ve kapsamından bahsedilmiştir.
İkinci bölümde, depreme dayanıklı yapı tasarımı için temel ilkeler olan taşıyıcı sistem seçimi, yeterli dayanım ve rijitlik, süneklik, kapasite tasarımı ilkesi, yapısal çözümleme yöntemleri, yapısal çözümün sağlaması gereken koşullar, yapı sistemlerinin dış yükler altında doğrusal olmayan davranışı ve doğrusal olmayan davranış modelleri konularına değinilmiştir.
Üçüncü bölümde, TBDY 2018 5. bölümde yer alan şekildeğiştirmeye göre değerlendirme ve tasarım için hesap esasları konusu incelenmiştir. Bu konu kapsamında bina performans düzeyleri, bina performans hedefleri, deprem etkisinin tanımlanması ve diğer etkilerle birleştirilmesi, doğrusal olmayan hesapta kullanılacak taşıyıcı sistemin modellenmesi ile ilgili kurallar, doğrusal olmayan hesap yöntemleri, şekildeğiştirmelerin ve iç kuvvetlerin değerlendirilmesi başlıklarına değinilmiştir.
Dördüncü bölümde, tez kapsamında deprem performansı incelenen mevcut 44 katlı betonarme yüksek bina ile ilgili olarak bina genel bilgileri, bina deprem parametreleri, bina yapısal modelinin oluşturulması, deprem kayıtlarının seçilmesi ve ölçeklendirme işleminin yapılması, zaman tanım alanında doğrusal olmayan hesap yönteminin bilgisayar programına tanımlanması ve analiz sonuçlarının incelenmesi konularına değinilmiştir.
Beşinci bölümde, tezden elde edilen sonuçlar incelenmiş ve öneriler sunulmuştur.
Yapılan 22 adet doğrusal olmayan analizlerin sonucunda yapıda bulunan 3275 adet kirişin %30.35'i sınırlı hasar bölgesinde, %59.82'si belirgin hasar bölgesinde, %5.37'si ileri hasar bölgesinde, %4.46'sı göçme bölgesinde bulunmaktadır. 914 adet kolonun %59.74'ü sınırlı hasar bölgesinde, %40.26'sı belirgin hasar bölgesinde bulunmaktadır. 524 adet perdenin %99.43'ü sınırlı hasar bölgesinde, %0.57'si ileri hasar bölgesinde bulunmaktadır. Yapıda sadece kirişlerden göçme bölgesine geçenler olup kolon ve perdelerden hiçbiri göçme bölgesine geçmemiştir. Binanın deprem performansının göçmenin önlenmesi performans düzeyi olduğu belirlenmiştir. TBDY 2018 kapsamında BYS=1 sınıfına giren mevcut yüksek binaların bina performans hedefleri tablosundan, tez konusu binanın normal performans hedefinin göçmenin önlenmesi performans düzeyi olduğu belirlenmektedir. Binanın deprem performansının, normal performans hedefi olan göçmenin önlenmesi performans düzeyini sağladığı görülmektedir.

Abstract:
Earthquakes occur frequently in our country which is located on active fault lines in terms of seismicity. While the majority of these earthquakes occur with small intensity, destructive earthquakes of great intensity give rise to loss of life and property. In the recent eartquakes in Elazığ and İzmir, many buildings were destroyed and many people lost their life under the rubble. It is observed that the majority of the destroyed structures have low material quality and risk of collapse because of not meeting the regulations. Considering that these buildings have been demolished very recently, it is seen that there are many risky buildings similar to these buildings in our country that can be demolished in case of an earthquake. For the detection of risky structures, it is significant to determine the earthquake performance of existing structures. Many losses of life and property can be prevented as a result of detecting and retrofitting risky buildings with this method and demolishing the ones that cannot be retrofitted. The scope and content of the performance-based evaluation and design approach in the Turkish Seismic Code for Building, which was published in the Official Gazette on March 18, 2018 and entered into force as of January 1, 2019, was expanded. Additionally, the subject was examined in more detail. 
In this thesis, the seismic performance of an existing 44-storey reinforced concrete high-rise building was examined using nonlinear time history analysis method accordance with the rules and principles of calculation given within the scope of TSC 2018.
This study comprises of five main chapters and in the first chapter, which is described as introduction, scope and purpose of the thesis were defined. 
The second chapter includes that the basic principles for earthquake resistant building design are; selection of structural system, adequate strength and stiffness, ductility, capacity design principle, structural analysis methods, the conditions that structural solution must provide, nonlinear behavior of building systems under external loads and nonlinear behavior models were explained.
In the third chapter, the displacement based design in the 5th chapter of TSC 2018 was examined. Within the scope of this topic; building performance levels, building performance targets, definition of earthquake effect and combining it with other effects, the rules of modeling the structural system to be used in nonlinear calculations, nonlinear calculation methods, evaluation of deformations and internal forces were mentioned.
The general information of the building, the building seismic parameters, structural modelling of the building, the selection and scaling of the earthquake records, the definition of the nonlinear time history analysis method into the computer program and the examination of analysis results of the existing 44-storey reinforced concrete high-rise building that examined in the thesis were mentioned in the fourth chapter.
The results acquired from the thesis were evaluated and recommendations were presented in the fifth chapter.
The building which is the topic of the thesis has 44 floors and wall-frame structural system (dual system). This building was designed in accordance with the Seismic Code 2007. All static projects of the building are available. All information about the structural member was taken from existing static projects. According to TSC 2018, the building knowledge level was taken as comprehensive. Although the floor heights of the building vary on some floors, the height of the majority of the floors is 3.8 meters. The building's total height is 163.1 meters.
The 3D structural model of the building was created with the ETABS V18.0.2 software in accordance with the static projects of the building. While modeling the building, the rules given in TSC 2018 were followed. Columns and beams were modeled as frame finite elements and shear walls as shell finite elements. Slabs were not added into the structural model in order to bring the calculation time to the appropriate level, but the self-weight of the slab, the cladding loads and the live loads on the slab were distributed to the structural members. It was assumed that the slabs exhibit rigid diaphragm behavior. Reinforced concrete elements were modeled considering their cracked section stiffness. The foundation of the building was not added into the structural model, and fixed supports were assigned to the nodal points.
In the existing building the concrete grade is C40 and the reinforcement grade is B420C. Confined concrete model, unconfined concrete model and reinforcement steel models were created by considering the equations given in TSC 2018 Annex 5A. Confined concrete model was used in the cap of the shear walls and unconfined concrete model was used in the body area of the shear walls.
The rules given in TSC 2018 were taken into consideration when determining nonlinear behavior models of the structural members. Within the framework of these rules, the lumped plastic hinge behavior model was used for column and beam members and the distributed plastic hinge behavior model was used for shear wall member. Section cell (Fiber) hinge was assigned to the shear walls. While defining the section cell (fiber), the confined concrete model in the cap of the shear walls and the unconfined concrete model in the shear wall body region were taken as basis.
A total of 11 earthquake acceleration records were selected for use in nonlinear time history analysis, taking into account the conditions given in TSC 2018 5.7.2.1. The axes of the selected earthquake acceleration records were rotated 90° and the analyses were repeated and a total of 22 analyses were performed. Earthquake acceleration records to be used in the analysis were selected by filtering from the "PEER Ground Motion Database". The design spectrum of the building created according to TSC 2018 was defined in the "PEER Ground Motion Database", and the earthquake records suitable for the structure were selected based on the soil properties of the location, the distance to the fault and the earthquake magnitudes.
Nonlinear time history analysis results were found by averaging the largest absolute values of the results obtained from the 22 analyzes performed. Since the building that is the topic of the thesis is within the scope of a high-rise building, TBDY 2018 chapter 13 13.6.4.2 was taken into account while calculating the critical internal forces. A standard deviation value was added to the average of the largest absolute values of the internal forces obtained from analyses, and this value was evaluated not more than 1.5 times and not less than 1.2 times the average.
As a consequence of 22 non-linear analyses, of the 3275 beams in the structure, 30.35% are in the limited damage zone, 59.82% are in the significant damage zone, 5.37% are in the advanced damage zone, and 4.46% are in the collapse zone. Of the 914 columns, 59.74% are in the limited damage zone and 40.26% are in the significant damage zone. Of the 524 shear walls, 99.43% are in the limited damage zone and 0.57% in the advanced damage zone. In the structure, only the beams passed into the collapse zone, and none of the columns and shear walls passed into the collapse zone. The building's seismic performance was assessed to be at the collapse prevention level. From the building performance targets table of the existing high-rise buildings that are classified as BYS=1 in the context of TBDY 2018, it is determined that the normal performance target of the building, which is the topic of the thesis, is the collapse prevention performance level. The building's seismic performance provides the collapse prevention performance level, which is the normal performance target.