Mevcut bir betonarme yapının deprem performansının Japon sismik indeks yöntemi ve RYTEİE 2019 yönetmeliğine göre değerlendirilmesi ve sonuçlarının karşılaştırılması
Comparison of the seismic evaluation of a existing reinforced concrete building according to the Japanese seismic index method and RYTEIE 2019
Yazar: BURAK EFE
Danışman: DR. ÖĞR. ÜYESİ PINAR ÖZDEMİR ÇAĞLAYAN
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:
Ülkemiz aktif fayların yoğunlukta bulunduğu bir bölgede olmasından dolayı deprem açısından önemli risklere sahip bir ülkedir. Deprem sonrası binalarda meydana gelecek hasarların azaltılması için yapılacak en etkin çalışma, depreme dayanıklı yapılar inşa etmektir. Depreme dayanıklı yapıların inşa edebilmenin ilk koşulu ise, yapının mevcut deprem yönetmeliklerine uygun olarak tasarlanmasıdır.
Ülkemizdeki yapı stoku dikkate alındığında, 2000 yılı öncesinde inşa edilmiş yapıların büyük bir bölümü, deprem yönetmeliklerinin yeteri düzeyde uygulanmadığı ve mühendislik hizmetlerinden yoksun inşa edilen yapılardır. Bu yapıların deprem etkisi altındaki dayanımlarının tespit edilmesi ve sismik performanslarının incelenmesi gerekmektedir. Özellikle riskli olarak adlandırılan yapıların hızlıca tespit edilmesi için, göçme riski bulunmayan yapıların ayıklanması ve riskli yapılar üzerinde detaylı analiz yapılabilmesi sağlanmalıdır.
Mevcut yapıların deprem performanslarının belirlenmesi ve risk unsuru barındırmayan yapıların ayıklanmasında, en ekonomik ve en hızlı çözümlerin kullanılması gerekmektedir. Detaylı mühendislik analizleri ile deprem performanslarının belirlenmesi, uzun zaman alacak ve maliyet açısından kabul edilebilir seviyelerin çok üzerinde olacaktır. Dolayısıyla mevcut yapıların belirlenmesinde hızlı tarama yöntemlerinin kullanılması zaman ve maliyet çıktısının optimum noktada kalmasını sağlayacaktır.
Bu çalışma kapsamında, hızlı değerlendirme yapabilen ve detaylı mühendislik hesaplamaları gerektirmeyen Japon Sismik İndeks Yöntemi ile ülkemizde kullanılan Riskli Yapıların Tespit Edilmesine İlişkin Esaslar (RYTEİE 2019) yönetmeliği kullanılmıştır.
Altı bölümden oluşan yüksek lisans tezinin birinci bölümünde, tez konusunun açıklaması yapılmış, çalışmanın amacı ve kapsamı hakkında bilgi verilmiştir. İkinci bölümde, Japon Sismik İndeks Yönteminin detayları verilmiştir. Üçüncü bölümde, Riskli Yapıların Değerlendirilmesine İlişkin Esaslar yönetmeliğinin detayları verilmiştir. Dördüncü bölümde, her iki yönetmeliğe göre değerlendirilmesi yapılacak binanın özellikleri, binanın modellenmesi ve yapılan kabullere ilişkin detaylar, malzeme bilgileri ve bazı temel analiz sonuçları verilmiştir. Beşinci bölümde iki yönetmeliğe göre yapılan analizlerin sonuçları birbirleri ile kıyas edilmiştir. Ayrıca referans alınan bir kolon kesiti üzerinde her iki yönetmeliğe göre hesaplanmış moment ve kesme kuvveti kapasiteleri karşılaştırılmıştır. Altıncı bölümde ise, beşinci bölümde verilen analiz sonuçları ve karşılaştırmalara ilişkin elde edilen bulgular ve değerlendirmeler verilmiştir.
Yapılan tez çalışmasının sonuçlarına göre, Japon Sismik İndeks Yönteminin moment kapasitelerini %2 ile %15 arasında değişkenlik gösterecek şekilde daha fazla hesapladığı, ancak Riskli Yapıların Tespitine İlişkin Yönetmeliğin, Japon Sismik İndeks Yöntemine göre referans olarak belirlenen kolon kesitinin kesme kuvveti kapasitesini daha fazla hesapladığı görülmüştür. Aynı zamanda Japon Sismik İndeks Yöntemi ile Riskli Yapıların Tespitine İlişkin Yönetmeliğin birbirine benzer sonuçlar verdiği gözlemlenmiştir. Eğer yeterli sayıda bina, Japon Sismik İndeks Metodu ile analiz edilirse, JSİY'in Türk tipi yapılara uygulanabilirliği çok daha net ortaya konabilir.

Abstract:
Due to the fact that our country is in a region where active faults are concentrated, it is a country with very important risks in terms of earthquakes. In addition to the high risk of earthquakes, the construction of existing building stock without Engineering Services leads to the loss of life and property that will rise to serious levels after the earthquake. The loss of life and property caused by earthquakes in Düzce, Gölcük, Erzincan and Van provinces in the past years reveal the earthquake risk potential of our country. The most effective method to be done to reduce the buildings damage after an earthquake is to build earthquake-resistant structures. The first condition for building earthquake resistant structures is that the building is designed in accordance with the Building Earthquake Code.
Considering the building stock in our country, most of the buildings built before year 2000 are structures that were designed without earthquake codes and were built without engineering services. For this reason, in many buildings, there are problems such as insufficient quality of concrete and low reinforcement ratio, not using transverse reinforcement, poor workmanship.  It is necessary to determine the resistance of these structures and examine their seismic performance under the effect of earthquakes. Structures that do not have an earthquake risk need to be sorted out quickly. After the buildings without earthquake risk are sorted, the buildings defined as risky buildings should be analyzed in more detail.
Considering the number of the existing buildings, it takes long time to make performance assessment with the current methods. The most economical and fastest solutions should be used to determine the earthquake performances of existing structures and to sort out the structures that do not have any risk under the earthquake. Because, the detailed structural analysis of the buildings will take a long time and go beyond the acceptable levels as cost. For this reason, there are lots of rapid evaluation methods in the literature in order to evaluate existing structures. In addition to simple and very fast evaluation methods in the form of visual evaluation, there are methods that allow more detailed analyzing.
Within the scope of this thesis study, the Japanese Seismic Index Method, which can quickly evaluate the buildings and does not require detailed engineering calculations, and the Principles for the Determination of Risky Buildings (RYTEIE 2019) were used. An existing reinforced concrete building was evaluated according to both the Principles for the Determination of Risky Buildings 2019 and the Japanese Seismic Index Method and the results were compared.
Explanation of the thesis subject, purpose of this study and scope are presented in first chapter. Also in this section, information was given about rapid assessment methods such as Rapid Visual Screening of Buildings for Potential Seismic Hazards: A Handbook (FEMA 154), Handbook for the Seismic Evaluation of Buildings (FEMA 310, 1998), Japanese Seismic Index method and Principles for the Determination of Risky Buildings 2019.
The principles of the Japanese Seismic Index Method is explained in the second chapter. This standard applies to the seismic assessment of existing low-rise and mid-rise reinforced concrete buildings and to the verification of seismic retrofitting. On the other hand, this standard includes three screening levels that have been prepared for the seismic evaluation of the reinforced concrete structures. The names of these evaluations procedures are the first, second and third screening levels. As the level of screening increases, the amount of information needed to evaluate structures increases and more detailed analyses are made. The first level investigation should be done on the following research items, which are mainly required to calculate the seismic index of the structure in the first level scanning procedure; material strength, cross-sectional dimensions of structural elements, structural cracks and deformation for evaluation of time index and floor plan for evaluation of irregularity index. In the second level, the following items are mainly required to calculate the seismic index of the structure: Material strengths and cross-section of structural members, degrees of the strcutural cracks and deformation and grades and ranges of aging and deterioration. According to the Japonese Seismic Index Method, if the Seismic Index of Structure (Is), is more than Seismic Demand Index (Is0), the building may be assessed to be "Safe".  Otherwise, the building should be assessed to be "Uncertain" in seismic safety. If the seismic safety of the building is calculated as "Uncertain", the building is evaluated according to the next screening level
In the third chapter, Principles for the Determination of Risky Buildings 2019 is explained. The principles for determining risky structures were first published in 2013, then expanded with new additions and revisions and re-published in 2019. Principles for the Determination of Risky Buildings that published in 2013 included only the risk analysis of reinforced concrete buildings that are 25 m high and not exceeding eight floors from the ground also masonry building. With the Principles for the Determination of Risky Buildings 2019 also medium and high-rise reinforced concrete buildings can be evaluated. On the other hand, Principles for the Determination of Risky Buildings 2019 have not to used for determining of the seismic performance of the structures. The main scope of this standard is risk assessment of buildings.
The specifications of the existing building, details of the finete element model and main results of the assesment of the building according to the Japanese Seismic Index Method and Principles for the Determination of Risky Buildings 2019 are presented in fourth chapter. The evaluated building is a 5-storey reinforced concrete structure and contains reinforced walls. The basement floor height of the building is 3,575 m, the ground floor and normal floor heights are 2,875 m and the total building height is 15,075 m. The strength of concrete of the existing building is approximately 12 N/mm2, and the longitudinal and transverse reinforcements used are S220 grade. The concrete elasticity module is 17320 Mpa. In addition, when creating a finete element model of building, the rigid basement floor was not included in the calculations. Beams and columns are modeled as frame elements, while reinforced concrete walls and floors are modeled as shell elements. Columns, beams and walls, which are structural elements, are modeled by considering their effective stiffness. While structural analyzing according to Principles for the Determination of Risky Buildings 2019, third part computer software was used. Also, this building was evaluated according to the first and second level scanning method, which are the levels of the Japanese Seismic Index Method. 
In the fifth chapter, the evaluation results of the buildings are given. At the same time, the solutions made by two methods were compared and the applicability of the Japanese Seismic Index Method to the structures in our country was evaluated. In addition, the moment and shear force capacities of a column section selected as a reference were calculated according to Japanese Seismic Index Method and Principles for the Determination of Risky Buildings 2019. The moment and shear force capacities of the column section determined as a reference were calculated according to variables such as reinforcement ratio, section dimensions, spacing of transverse reinforcement and concrete compressive strength.
In the sixth chapter, the results given in the fifth chapter are explained.  In the evaluation made according to the first and second screening levels of the Japanese Seismic Index Method, it was seen that the structure was evaluated as "uncertain". Therefore, a third level evaluation is required for this building for detailing analyze. The ratio of the shear force of each floor to the total weight of the upper floor was found to be similar to the seismic structure index calculated according to the Japanese Seismic Index Method. At the same time, when the moment capacity of the column determined as a reference is taken into account, the Japanese seismic index method calculated the moment capacities more, ranging from 2% to 15%.  However, it has been observed that the Principles for the Determination of Risky Buildings 2019 calculates the shear force capacity of the column more than the Japanese Seismic Index Method.
To sum up, The topic of this  thesis requires analysis with Japanese Seismic Index method and Principles for the Determination of Risky Buildings 2019  on more buildings. ıf a sufficient number of buildings are analyzed according to the Japanese seismic index method, the applicability of this sesimic evaluation method to Turkish type structures can be revealed more clearly.