Yer hareketi karakteristik özelliklerinin betonarme perdeli binaların yapısal enerji davranışı üzerindeki etkileri
Effects of ground motion characteristics on structural energy response of RC buildings with shear walls
Yazar: SEMANUR EYLÜL TAŞ
Danışman: DR. ÖĞR. ÜYESİ FATİH SÜTCÜ
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / Deprem Mühendisliği Ana Bilim Dalı / Deprem Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2022
Konu: Deprem Mühendisliği = Earthquake Engineering
Dizin: Betonarme binalar = Reinforced concrete buildings ; Betonarme perdeler = Reinforced concrete shear walls ; Yer hareketleri = Ground motions

Özet:
Gelişen teknoloji ve imkanlar ile birlikte her alanda olduğu gibi inşaat mühendisliği alanında da yenilikçi yaklaşımlar gelişmekte ve daha doğru, ekonomik ve güvenli tasarım ve değerlendirme yapmak için inşaat ve deprem mühendisleri bu olanakları kullanmaktadırlar. Son yıllarda yenilenen deprem mühendisliği alanındaki yönetmelikler, elde edilen yeni ve büyük hacimdeki veriler ışığında güncellenmektedir ve buna bağlı olarak tasarım yöntemleri günden güne gelişmektedir. Son zamanlarda daha çok kullanılan şekil değiştirmeye göre tasarım yönteminin (ŞGDT) dayanıma göre tasarım (DGT) yönteminden daha gerçeğe yakın sonuçlar verdiği bilinmektedir. Tez çalışması kapsamında yer hareketlerinin özelliklerinin perdeli betonarme türü yapıların enerji davranışı üzerindeki etkisinin araştırılması hedeflenmiştir. Tezde enerji esaslı tasarım yönteminin geliştirilmesine yönelik veriler sağlayacak  çalışmalar gerçekleştirilmiş ve değerlendirmeler sunulmuştur.
DGT'ye göre hesapta bir deprem süresince oluşması beklenen dinamik tepkilerin en büyük anına göre hesap yapılırken, enerji esaslı tasarımda deprem süresince oluşan etkilerin toplamı göz önüne alınır. Deprem yüzünden binaya giriş yapan enerji ile yapı içerisindeki çeşitli mekanizmalar tarafından sönümlenen enerji arasındaki dengeyi esas alan enerji esaslı tasarım yönteminde, yer hareketinin karakteristik özellikleri en önemli parametrelerdendir. 
Tez kapsamında yer hareketlerinin karakteristik özellikleri ile enerji arasında ilişki kurulması amaçlanmıştır. Yer hareketlerinin karakteristik özellikleri ile giriş enerjisi veya çevrimsel enerji arasında bir ilişki kurulduğu taktirde henüz deprem meydana gelmeden bölgenin yer hareketi özelliklerinden yapıya girebilecek enerji (yapının enerji talebi) tahmin edilebilecektir. Ayrıca bu giriş enerjisinin, hasara sebep olan çevrimsel enerji bileşeninin yüzdesi tahmin edilecek ve binanın yapısal elemanlarının deprem sonrası alacağı hasar öngörülebilecektir. Olası durumlar için önlem alınabilecek; yapıların performanslarında iyileştirmeler yapılabilecektir. 
Bu amaçlar doğrultusunda; Japonya'da bulunan E-defense test merkezi sarsma masasında deneyleri yapılmış 4 katlı ve tam ölçekli test yapısı ETABS yazılımında modellenmiş ve seçilen yer hareketi kayıtları simule edilerek yapının perdeli doğrultusunda zaman tanım alanında analizler gerçekleştirilmiştir. Yer hareketleri belirli kriterler çerçevesinde seçilmiş ve ölçeklenmeden, yakın kaynaklı ve uzak kaynaklı olmak üzere iki set halinde kullanılmıştır. Yapılan analiz sonuçları incelenerek deprem karakteristik özelliklerinin binanın yapısal elemanlarının enerji davranışı üzerindeki etkileri, giriş enerjisi bileşenleri (kinetik enerji, elastik şekildeğiştirme enerjisi, sönüm enerjisi, çevrimsel/histeretik enerji) ve çevrimsel enerjinin elemanlar ile katlar arasındaki dağılımı incelenmiştir. 
İlk değerlendirmenin ardından, bu sefer yakın kaynaklı ve uzak kaynaklı yer hareketi kayıtları 2018 TBDY'ye göre ölçeklenmiş ve tüm analizler tekrarlanmıştır. Analiz sonuçları değerlendirilmiş ve depremin karakteristik özellikleri ile yapının enerji davranışı arasında bir ilişki önerilmiştir.

Abstract:
Along with the developing technology and opportunities, innovative approaches are developing in the field of civil engineering as well as in every area, and civil and earthquake engineers use these opportunities to make more accurate, economical, and safe designs and evaluations. The regulations issued in the past years are updated in the light of the new data obtained, and the design methods are developing day by day. It is known that the design method according to strain (ŞGDT), which has been used more recently, gives more realistic results than the design according to strength (DGT) method. In this thesis, the effects of ground motion characteristics on the energy behavior of reinforced concrete buildings with shear walls are investigated. The results are expected to contribute to develop energy-based design methods, and conclusions have been presented.
While the strength method takes into consideration the maximum of the dynamic responses expected to occur during an earthquake, the energy-based design includes the sum of the effects that occur during an earthquake. In the energy-based design method, which is based on the input energy should be less than the dissipation capacity of the structural members, the ground motion characteristics are one of the most significant parameters.
Input energy depends on many parameters. These parameters are grouped into 3 groups for the ease of examination: the characteristics of the earthquake, the structure and the ground. These parameters can be defined as the characteristic features of the earthquake, the structure and the ground.
In the energy-based approach, the input energy, which is representative of the intensity of the seismic action, is transmitted to the structure by kinetic energy, damping energy, elastic strain energy, and hysteretic energy. Kinetic energy represents the work done by inertia forces, and elastic strain energy is the stored energy in the form of elastic deformation. Damping energy reflects the dissipated energy by damping material. Hysteretic energy represents the dissipated input energy through cumulative plastic deformation, and it shows damage potential of the structure.
When a relationship is correlated between ground motion characteristics and the input energy or cyclical energy, the input energy (the energy demand of the structure) can be estimated before the earthquake occurs. In addition, the percentage of the cyclic energy component of the input energy that causes damage can be estimated. The post-earthquake structural damage potential of buildings can be predicted and seismic performance of structures can be enhanced. 
For this purpose; full-scale and a 4-story reinforced concrete building, which is tested on the shaking table of the E-defense test center in Japan, is modeled in ETABS software. The reinforced concrete wall-frame building to be examined has a length of 14.4 m in the direction of the frame (x-direction) and two-bay moment frame system was used, while its length in the direction of the wall (y-direction) is 7.2 meters and has one-bay system was used. Story heights at all levels for both buildings were 3 m, for an overall height of 12 m. The walls are located on the outer axes of the building in the y direction. After the assignments made to the analysis model, 25%, 50% and 100% JMA-Kobe 1995 earthquakes, which were recorded on the shaking table, respectively, were applied to the building as in the experiments on the E-defense test center shaking table. By restricting the frame direction of the building, it is possible to analyze in the wall direction. As a result of the analysis, the period of the cracked section stiffness in the wall direction was calculated by the software as Tcr=0.344 seconds. The results were noted and compared with the experimental results. After the non-linear time history analysis, the results are examined. 
The ground motions used in the analyzes were selected by considering certain parameters. These parameters are duration, magnitude (Mw), Arias intensity (IA), effective duration (teff), maximum ground acceleration (PGA) and velocity (PGV), shear wave velocity (Vs)30 observed in the top 30 m thick layer of the ground. It can be listed as the breaking distance (Rrup) and whether it has a sudden impact. Considering the relevant features, ground motions were grouped into two groups as near-fault and far-field. The first set involves the ground motion data that shows near-fault and the second set includes the ground motion data with far-field. Non-linear time history analyzes were made on the building tested on the shaking table of the E-defense test center, whose properties are modeled with ground motions, the properties of which are explained in detail. The results were evaluated in terms of the energy behavior of the structure. After the analysis, the input energy components (kinetic energy, elastic energy, damping energy, cyclic/hysteretic energy) and the distribution of cyclical energy between structural members and floor levels have been assessed.
Within the scope of the thesis, it is aimed to relationship is correlated between the characteristic features of ground motions and the amount of input energy they cause. As predicted, there was a high energy input in near-fault earthquakes. It has been determined that there is a close linear relationship between the equivalent velocity of the earthquake, corresponding to the cracked section period of the building, and the input energy and cyclic energy. The distribution of the input energy and the cyclical energy dissipated by the structural members has been investigated. Most of the energy was dissipated by the first floor. The distribution of energy to the floors was similar between earthquakes. When the distribution according to the members is examined, it is seen that most of the energy is dissipated by the walls. Beams and columns followed, respectively.
Unlike near-fault earthquakes, energy input remained at very low values in far-field earthquakes. The low input energy caused the cyclic energy not to be formed in some earthquakes. It has been obtained that there is linear relationship between the equivalent velocity of the earthquake corresponding to the cracked section period of the building and the input energy and cyclic energy, as in the near-source ground motions. Since far-field ground motions have low input energy, it has been observed that cyclical energy is not generated as a result of some ground motions, and the distribution of the small amount of cyclical energy generated in some ground motions to the floors is irregular. The distribution to the members, on the other hand, showed similarity in far-field ground motions as well as near-fault ground motions.
After the evaluations, it was decided to use the period of the cracked section stiffness in  scaling the ground motions and the spectral acceleration value corresponding to this period in the design spectrum and this time near-fault and far-field ground motion records are scaled according to 2018 TBDY and all analyzes are repeated. 
In near-fault earthquakes, a decrease in energy input has occurred compared to pre-scaling. The decrease in the energy input caused the cyclical energy to remain at a lower level. Ground motions, which had a linear distribution before scaling and an R2 as high as 0.89, were collected in a small region after scaling. The distribution of energy to floors and members was similar between earthquakes.
In far-field earthquakes, compared to pre-scaling earthquakes, the energy input increased. The increase in the input energy caused an increase in the cyclic energy. R2=0.88 between VelCR (spectral equivalent velocity of the period corresponding to the cracked section stiffness of the study building model) and Ei (input energy) far-field ground motions before scaling, but after scaling the results of ground motions became dispersed on the graph and the results diverged. Most of the energy is dissipated by the ground floor and the energy distribution among the members is mostly in the form of walls, beams and columns, respectively.
While investigating the relationship between the characteristics of ground motions and the input energy affecting the structure and the cyclical energy, the best result among the controlled parameters (such as Ei-SaCR, Ei-SvCR, Ei-SdCR, Ei-IA) was obtained with the relationship established between Ei-VelCR. Although the research and evaluations made within the scope of the thesis study were made for a specific building (E-defense test center shaking table test building), for buildings with similar geometric properties, the input energy (Ei) and the spectral equivalent velocity belonging to the period corresponding to the "cracked section stiffness of the structure." There is a linear relationship between VelCR and between the cyclic energy (Eh) and the "spectral equivalent velocity of the period corresponding to the structure cracked section stiffness" VelCR. The fact that near-fault ground motions generate more input energy than far-field ground motions, most of the cyclic energy is dissipated by the first floor in all near-fault and far-field ground motions, and the structural members that dissipate the most cyclic energy for all ground motions are walls, and it is envisaged that the results, such as beams and columns following the walls, will also be obtained in buildings with similar geometric properties.