Çok katlı bir çelik yapının Türkiye Bina Deprem Yönetmeliği-2018'e göre tasarımı
Design of a multi-storey steel Structure According to Turkey building earthquake code-2018
Yazar: BURAK TÜTÜNCÜ
Danışman: PROF. DR. GÜLİZ BAYRAMOĞLU
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / İnşaat Mühendisliği Ana Bilim Dalı / Yapı Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2019
Konu: İnşaat Mühendisliği = Civil Engineering

Özet:
Yüksek lisans tezi olarak hazırlanan bu çalışmada, sosyal konut kullanım amacıyla inşa edileceği varsayılan 10 katlı çelik bir binanın, 2019 yılı Ocak ayı ndan itibariyleen yürürlüğe giren TBDY'nin getirmiş olduğu yeni hesap şartlarına göre tasarımı yapılmıştır. Yönetmelikte belirtildiği şekilde taşıyıcı sistem elemanlarının ve birleşimlerinin, yapının işletme süresi boyunca kendilerinden beklenen tüm işlevleri belirli bir güvenlik altında yerine getirebilecek düzeyde dayanım, stabilite ve rijitliğe sahip olacak şekilde boyutlandırılması amaçlanmıştır. Hesaplarda yönetmelik şartlarına tamamen uyulmasının ilave olarak yapının güvenli, ekonomik ve hafisi olarak tasarlanması amaçlanmıştır.

770 m2 oturma alanına sahip olan bina, her bir kat yüksekliği 4 m olan 10 kattan oluşmaktadır. Yeni yönetmeliğe göre deprem yükleri altında sade bir tasarım yapılabilmesi için taşıyıcı sistemin simetrik ve düzenli olarak yerleştiği bir mimari plan tercih edilmiştir. Yerel zemin sınıfı "ZC" olarak seçilmiştir. Zemin tasarım taşıma gücü, q_t=300 kN/m^2, düşey yatak katsayısı, k_v=20000 kN/m^3 olarak kabul edilmiştir.

Yapının, Kocaeli ilinde, 40.845803/29.716728 koordinatlarında inşa edileceği kabul edilmiştirvarsayılmıştır. Bu koordinatlarda, DD-2 deprem yer hareketi düzeyi ve ZC yerel zemin sınıfı için "Türkiye Deprem Tehlike Haritaları"sı kullanılarak elde edilen kısa periyot spektral ivme katsayısı, S_DS=1.523≥0.75 olduğundan dolayı Deprem Tasarım Sınıfı, DTS = 1 olarak tasarım yapılmıştır.kabul edilmiştir.

Bina taşıyıcı sistemi, boyuna yönde yatay yük sönümleme kapasitesinin fazla fazla olması ve yüksek rijitlik sağlaması özelliğini bir arada taşıması avantajları nedeniyle süneklik düzeyi yüksek dışmerkez çaprazlı çelik çerçevelerden, enine yönde süneklik düzeyi yüksek çerçevelerden oluşmaktadır. Kullanılan tüm eleman enkesitleri, yüksek süneklik düzeyi şartlarını sağlayacak şekilde seçilmiştir.
Deprem yükü hesapları için Eşdeğer Deprem Yükü yöntemi kullanılmıştır. Bu yöntemin kullanılabilirlik koşulları için izin verilen bina yükseklik sınıfı, burulma düzensizliği katsayısı ve komşu katlar arası rijitlik düzensizliği durumları incelenmiş ve binadaki bu durumların deprem yönetmeliğinde belirtilen şartları sağladığı gösterilmiştir. 
Sabit ve hareketli yükler için "TS-498 Yapı Elemanlarının Boyutlandırmasında Alınacak Yüklerin Hesap Değerleri" standardı, kar yükü hesaplarında "TS-EN 1-3 Kar Yükleri" standardı, rüzgar yükü hesaplarında "TS-EN 1-4 Rüzgar Etkileri" standardı kullanılmıştır. Deprem yükleri ile ilgili parametreler ve kurallar için "TBDY--2018", çelik taşıyıcı elemanların,  ve birleşimlerinin hesabı ve enkesit koşullarının uygunluğu için "ÇYTHYE--2018" koşulları dikkate alınmıştır. Taşıyıcı sistemin boyutlandırılması ve eleman iç kuvvetlerinin elde edilmesinde, Yük ve Dayanım Katsayıları ile Tasarım Yöntemi için belirtilen hesap kuralları ve yük birleşimleri kullanılmıştır.

Taşıyıcı sistemi oluşturan kolonların ve kirişlerin yapısal çelik sınıfları sırasıyla, S355 ve S275 olarak seçilmiştir. Boru profillerden teşkil edilen çapraz elemanlar için  S275 sınıfındaki çelikler kullanılmıştır. Kolon taban levhaları S355, diğer tüm levhalar S235 kalitesinde kullanılmıştır. Radye temel ve kompozit döşemeler için C35 kalitesinde beton ve S420 kalitesinde donatı çeliği kullanılmıştır. 
Bina taşıyıcı sistemin yapısal analizleri, genel analiz yöntemi kullanılarak gerçekleştirmiştir. Taşıyıcı sistem elemanlarının gerekli dayanımları, azaltılmış eleman rijitlikleri ve ikinci mertebe etkileri dikkate alınarak bulunmuştur.

Taşıyıcı sistemin boyutlandırılması ve eleman iç kuvvetlerinin elde edilmesinde, Yük ve Dayanım Katsayıları ile Tasarım yöntemi için ÇYTHYE-2018' de belirtilen yük birleşimleri kullanılmıştır.

Yapının tüm statik ve dinamik analizleri için Sap-2000 v19.0.0 bilgisayar programı kullanılmıştır. Oluşturulan hesap modelinde kolloon, kiriş ve çapraz profiller için çubuk elemanlar, temeller için kabul kabuk elemanlar tanımlanmıştır. Çelik genel konstüksiyon kat planları, enine ve boyuna doğrultuda kesitler, temel aplikasyon planı ve birleşim detay çizimleri Tekla- v19 ve Autocad programları ile yapılmıştır.

Abstract:
In this study, which is prepared as a master thesis, design of a 10-storey steel structure is made according to Turkey Building Earthquke Code-2018. it is assumed that the structure will be built for social housing use. It is intended that the structural system elements and the steel connection details be dimensioned in such a way that they have the strength, stability and rigidity of the structure to perform all the functions expected from them during a certain period of time under a certain safety.
The structural system of the building consists of 11 grid with 5 m openings in the longitudinal direction and 3 grid with 6 m, 2 m and 6 m openings respectively in the transverse direction. The total length of the building in the plan is 55 m x 14 m as shown in Figure 1.1. The building is designed as 10 floors. Floor heights are 4 m on all floors including ground floor.The building has 770 m2 settlement area and consists of 10 floors each with a height of 4 meters. An architectural plan with symmetrical and regular structural system was chosen in order to make a simple design under earthquake loads according to new calculation rules in TBDY-2018. Local site class selected as "ZC". The soil bearing capasity and vertical coefficient of soil reaction were accepted as  q_t=300 kN/m^(2 ) and k_v=20000 kN/m^3.
It is assumed that the building will be constructed in Kocaeli with 40.845803 latitude and 29.716728 longitude coordinates. Short period spectral acceleration coefficient was obtained for "DD-2" earthquake ground motion class and "ZC" local site class by using Turkey Earthquake Hazard Map. Since short period spectral acceleration coefficient, S_DS=1.523≥0.75, earthquke design class accepted as, DTS=1.
Seismic loads are fully resisted by eccentrically braced frames in longitudial direction and resisted by only steel frames in transverse direction.The building lateral load carrying system which consists of eccentrically braced frames in longitudial direction, has high damping capacity and provides high rigidity. Under horizontal loads such as earthquake loads and wind loads, eccentrically braced frames have a regular cross-elastic behavior and good energy-damping capacities. Therefore, considering the fact that the structure will be constructed in a high seismicity like Izmit, eccentric bracedsteel frames are preferred. All element cross-sections were selected to meet high ductility requirements. 
Equivalent Seismic Load Method is used for earthquake load calculations. The permissible conditions for using of this method, such as the height of the building, the torsional irregularity coefficient, and the irregularities of stiffness between the floors were investigated and these circumstances were shown to meet the conditions specified in the earthquake code. In order to ensure that earthquake behavior is predictable and to prevent additional effects due to eccentricities, the structural system should be designed as simple, simple, orderly and symmetrical as possible. The cases that caused irregularities regarding irregular buildings whose design should be avoided due to the negative behavior of the earthquake were examined in terms of substances. There are no irregularities in the structure.
Building usage class, building importance coefficient, earthquake design class, building height class and building performance target have been determined in accordance with TBDY-2018. The dominant natural vibration period of the building was calculated according to the horizontal fictitious loads given to the structure and the displacements resulting from these loads. It has been shown that these period values are smaller and appropriate than the empirical dominant vibration period values specified in the regulation. Earthquake load reduction coefficient and total equivalent earthquake load of the building were calculated. Since the equivalent earthquake load value is smaller than the minimum shear force specified in the regulation, the minimum equivalent earthquake load is used in the earthquake calculations. According to these loads, the additional equivalent earthquake load acting on the tray of the building was calculated and earthquake loads acting on the floors were obtained.
The vertical earthquake effect, which has to be taken into account with the new regulation, is included in the coefficient G load using the approximate calculation method given in the regulation and taken into account in the calculations. Equivalent earthquake loads acting on the floors were applied to the determined points by shifting + 5% and - 5% of the building width in the direction perpendicular to the earthquake direction considered in order to take into account the additional eccentricity effect and also to the floor mass center.
Generally "TS-498 Calculation Values of Loads to be Taken in Design of Structural Elements" regulation used for dead and moving loads. "TS-EN 1-3 General actions – Snow Loads" and "TS-EN 1-4 General actions – Wind Loads" used for snow and wind loads calculations. To be used in wind load calculations, the land is classified as an area class (Category IV) covered by buildings with at least 15% of the surface and an average height exceeding 15 m. According to the meteorological data, the maximum snow height is assumed to be 80 cm for the Izmit region where the structure is located. For parameters and rules related to earthquake loads "Turkey Building Earthquake Code 2018", for calculations of steel structural elements and connection details and for the cross-sectional conditions "Design of Steel Structures, Regulation on Design and Construction Principles-2018" conditions are taken into consideration. For the dimensioning of the structural system and obtaining the internal forces of the element, the calculation rules and load combinations specified for the Load and Resistance Factor Design method were used.
The slabs are dimensioned in 3 different ways as simple beam, composite beam and castellated beam. As a result of stress and deflection checks, it has been shown that the floor beam should be formed from IPE240 in case of simple beam, IPE180 in case of composite beam and IPE200 in case of castellated beam. It has been found to be more advantageous and preferred that the composite flooring is both lightweight as the profile used and its in-plane stiffness is provided by the combination of concrete and steel thanks to the studs produced, since no cross-system is required in the additional plane. The force transfer between the structural steel element and the concrete (longitudinal shear force) is provided by steel anchors embedded in concrete.
In the design of the building, not only the structure has sufficient strength but also an economic solution has been taken into consideration. The total steel profile is calculated as 9609 tons and the total usage area of the building is 7700 m2. Accordingly, the weight of the steel corresponding to one square meter area is calculated as 0.125 tons/m2.
As a foundation system, a raft foundation with a height of 100 cm placed at a depth of 2 m was preferred. In the case of 1.4G + 1.6Q and earthquake loads, the ground stresses were examined and the stresses were shown to be less than 300 kN/m2. Then, the minimum reinforcement is placed and it is checked whether these reinforcement can meet the incoming moments. Additional reinforcements have been added to the lower areas of the column. Shear force calculations were made and it was shown that stand reinforcement which was discarded with 160 cm intervals was sufficient. It is also shown in the calculations that the punching detail of the 140 cm*100 cm reinforced concrete column headed foundation is sufficient.
It has been shown that for the steel frame systems with high ductility levels, the condition of the columns to be stronger than the beams in the direction of the earthquake in the beam-column joint.
In cases specified by the regulation, increased earthquake loads calculated using the strength coefficients for steel structural elements and joint details are used. However, the internal forces enlarged by the coefficient D shall not be greater than the internal forces compatible with the yield boundary condition in the section as required by the capacity design principle. For steel frames with high ductility level, the strength coefficient is taken as D = 3, and for the eccentric diagonal steel frames with high ductility level, the strength coefficient is taken as D = 2.5.
The structural steel classes of the columns and beams forming the structural system were chosen as S355 and S275. Also S275 class steels were used for the brace members which formed from pipe profiles. Column base plates were used in S355 quality. All other plates are in S235 quality. Concrete class "C35" and reinforcement steel class "S420" were used for raft foundation and composite slabs. Bolts of grades 6.8 and 10.9 are used in the steel joining details. In addition, the weld metal class is selected as E550.
The structural analysis of the building carrier system was carried out using the general analysis method. The required strengths of the structural system elements were determined by considering the reduced element stiffness and second order effects.
Sap-2000 v19.0.0 computer program was used for all static and dynamic analysis of the structure. In the calculation model, frame elements were defined for columns, beams and braces and shell elements were defined for raft foundation. Steel general construction floor plans, cross sections in the both directions, foundation application plan and steel connection detail drawings were prepared with Tekla-v19 and Autocad programs.