İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / İnşaat Mühendisliği Anabilim Dalı / Yapı Mühendisliği Bilim Dalı
2007-2018 türk deprem yönetmeliklerinin ve AmerikanDeprem Yönetmeliğinin deprem hesapları açısından karşılaştırılması
Comparison of 2007-2018 turkish earthquake codes and usa seismic code
Ömer Faruk Nemutlu - 2019Teze Git (tez.yok.gov.tr)
Ülkemiz dünya üzerinde depremlerden en çok etkilenen ülkelerden biri olduğu, bu etkilerin önemli ölçüde can ve mal kaybına neden olduğu, bu sebeple yapıların tasarımında deprem etkilerinin dikkate alınmasının zorunlu bir şart olduğu bilinmektedir. Bu amaçla ülkemizde yürürlükte olan DBYBHY-2007, 18.03.2018 tarihinde yerini TBDY-2018'e bırakmıştır. Çağın gereksinimlerini karşılamakta güçlük yaşayan 2007 yönetmeliği, 2018 yönetmeliği ile birlikte büyük çaplı güncelleştirmeler ve yenilenmeler geçirerek günümüz inşaat teknolojilerine ve yapım yöntemlerine uyum sağlamıştır. Yüksek lisans tezi olarak yapılan bu çalışmada, 2007 ve 2018 yönetmeliği arasındaki farklar, getirilen yenilikler irdelenerek, 3 farklı betonarme yapı üzerinde bu değişimler yapılan analizler ile birlikte hesap üzerinde gösterilmiştir. Ayrıca Türk yönetmelikleri ile Amerikan yönetmelikleri teorik olarak karşılaştırılmıştır. Ele alınan örneklerdeki taban kesme kuvveti değerleri üzerinden 3 yönetmelik için gösterdiği farklılıklar belirlenmiştir. Bu çalışma kapsamında 3 örnek ele alınmıştır. Ele alınan örneklerden birincisi; 4 katlı konut amacıyla kullanılacak betonarme çerçeve sistem, ikincisi; 9 katlı konut amacıyla kullanılacak betonarme perde çerçeve sistem, son örnek ise 9 katlı perde çerçeve sistem örnek ile aynı plan özelliklerine sahip tünel kalıp sistem uygulamasına uyumlu olacak şekilde perdelerden oluşmaktadır. Örneklerin deprem hesapları ve analizler; gerekli yük ve yükleme kombinasyonlarını dikkate alarak, yönetmeliklerde belirtilen deprem analiz yöntemleri kullanılarak SAP2000 programında yapılmıştır. 6 bölümden oluşan çalışmanın ilk bölümünde ülkemizin depremselliğinin öneminden, daha önce yürürlüğe girmiş olan yönetmeliklerden, çalışmanın amacı ve kapsamını içermektedir. İkinci bölümde, çalışma kapsamında kullanılan analiz programı olan SAP2000 programıyla ilgili bilgiler ve analizlerde uygulanacak adımlar hakkında bilgiler verilmiştir. Üçüncü bölümde, ülkemizde yeni yürürlüğe girmiş olan Türkiye Bina Deprem Yönetmeliği ile birlikte gelen yenilikler, farklılıklar ve değişimlere yer verilmiştir. Dördüncü bölümde, 2007,2018 Türk yönetmelikleri ile Amerikan yönetmeliğinde deprem hesapları yapılırken dikkate alınacak önemli bölümlerle ilgili teorik olarak bir karşılaştırma yapılmıştır.Çalışmanın beşinci bölümünde, çalışma kapsamında 3 farklı örneğin deprem hesapları yapılarak çıkan sonuçlar verilmiş olup sonuçlar gerekçeleriyle birlikte irdelenmiş ve yorumlanmıştır. Çıkan sonuçlar tablolar ve grafiklerle desteklenmiştir. Son bölümde ise çalışmanın genel olarak verdiği sonuçlar, yeni yönetmeliğin temel özellikleri ve sayısal sonuçların değerlendirilmesi yapılmıştır.
It is known that our country is the one of the countries most effected by earthquakes in the world, and these effects cause significant loss of life and property. Therefore, earthquake effects should be considered in the design of structures. For this purpose, TEC-2007 has been replaced by TEC-2018 on March 18th,2018. The 2007 codehas passed major uptades and renewals in line with the 2018 code and has adapted to today's construction technologies and construction methods. In this study, conducted as a master thesis, the differences between the codes of 2007 and 2018, the innovations, were introduced and the analysis on three (3) different reinforced concrete structures were shown with the calculations. In addition, Turkish codes and US codes were compared theoretically. The differences in the base shear force values for the three codes were determined. Within the scope of this study, three examples were discussed. First one was Reinforced concrete frame system to be used as a 4 storey house, and the second one was 9-storey building with a reinforced concrete frame system with shear walls, the last one was the 9-storey reinforced concrete building with tunnel formwork system. Earthquake buildingsanalysis of these three buildings were performed utilizing SAP2000 program considering the the loads and load combinations required per the codes. In the first part of the study, which consists of 6 chapters, the importance of the seismicity of our country, the seismic building standards, the purpose and scope of the study were discussed. The document called the 'Zelzele Mıntıkalarında Yapılacak İnşaata Ait İtalyan Yapı Talimatnamesi' was published in 1940. The concept of earthquake codes started in our country with this document and 10 different seimic codes were published in our country before the 2018 earthquake code. The draft of the new code (2018 seismic code) was published in 2016 and the 2018 Turkish Building Earthquake Code announced by the Disaster and Emergency Management Presidency in the Official Gazette dated 18.03.2018 and numbered 30364. Ad; The new code, which abolishes the Turkish Earthquake Code-2007 that are currently in use, will enter into force as of 01.01.2019. In the second part inclyuded the abalyisis of the structures and methodology used in this study. Within the scope of the study, buildingsthe building structures were analyzed according to 2007-2018 Turkish earthquake codes and USUS codes utilizing SAP2000 program (Structural Analysis Program). This computer program is a structural analysis program and is based on the Finite Element Method. In accordance with the aim of the study, with the help of SAP2000 (Structural Analysis Program 2000) analysis program, a 4-storey reinforced concrete frame system, a 9-storey, reinforced concrete frame system with shear walls and a reinforced concrete tunnel-formwork system were analyzed. The earthquake analysis was carried out according to 2007, 2018 Turkish and IBC-2018 US codes. In the third section, the changes ın seimic design that wre included in 2018 Seismic Code were discussed. While preparing the 2018 Turkish earthquake code, it was aimed to be easy to apply and to be updated compared to the 2007 seismic code. It is clear that TS500 should also be updated to consider new studies in reinforced concrete design. The earthquake code in Turkey was updated for the first time in 21 years after the 1997 code, with the exception of a new section added to the DBYBHY 2007 and limited changes to the steel buildings section in order to evaluate and strengthen existing buildings. With the new seismic code, 4 different earthquake ground motion levels were defined which were not included in the 2007 code. Earthquake ground motions where the probability of exceedance in 10 years is 10% and the corresponding repetition period is 475 years was the basis of principles in 2007 code, was defined as earthquake ground motion level 2 in 2018 seismic code. The performance levels required for building carrier systems under earthquake impact were determined as 4 building performance levels: continuous use, limited damage, controlled damage and collapse prevention. The calculations created according to the life safety performance level in the 2007 seismic code were stretched with the use of 4 different performance levels in the new code. The earthquake zones map, which is in use as a map showing earthquake hazard in 2007 seismic code, has been replaced by earthquake hazard maps in 2018 seismic code. Seismic hazard maps taking soil characteristics, earthquake magnitudes and fault proximity into consideration are more accurate than zone maps with coordinate oriented approach. The overstrength coefficient introduced with the 2018 seismic code was provided in section 4 of the code together with response coefficients for each structural system seperately. Another new concept introduced with the new code is the concept of effective cross section stiffness. This concept is also given as cracked section stiffness in different sources. In principle, it is based on approximate linearization of the non-linear internal force-deformation relationship in a reinforced concrete section for linear elastic calculation. In 2018 code, this concept is defined as constant coefficients for each reinforced concrete structural member. In the new seismic code, the section of the principles of reinforced concrete calculation was the least modified section compared to the 2007 seismic code. It was observed that changes were in the arrangement of shear wall reinforcement, the calculation of in-plane stresses in the slabs, the force transfer from the beams to shear walls and the calculations in the slabs without beams. In the fourth chapter, 2007 and 2018 Turkish seismic codes and US codes were compared. Selected sections were taken into consideration regarding earthquake analysis. Buildings with a building importance factor of 1.4 in 2007 seismic code were evaluated together with usage class corresponding to 1.5 importance fator in 2018 seismic code. Although, the acceleration spectrum in the 2007 seismic code only depends on soil characteristics, the 2018 seismic code defines a spectrum that takes into account earthquake magnitude, soil properties and fault proximity characteristics with the introduction of spectral acceleration coefficients. This spectrum shows similar characteristics with the US code. However, there are differences due to the reduction coefficient used in the US seismic code. This classification from the best ground to the worst ground motion was found to be similar to the classification in the US code. In addition, it has been seen that all three codes allow analysis mode combination and time history analysis for use in earthquake analysis, andthey define limits for the equivalent lateral force method. In the fifth chapter of this thesis, the results of earthquake analysis were performed for threedifferent buildings and the results were evaluated and interpreted. The results are provided with tables and graphs. Shear forces for the three buildings were calculated. It is observed that there are 5-10% difference between the shear forces in 2007 and 2018 seismic codes In 2018 seismic code, it was determined that coordinate-oriented earthquake parameters were taken into consideration together with soil and earthquake magnitude characteristics and the effect of the over strength coefficient introduced in the 2018 seismic code. The short period zone, where the spectral coefficients take the highest values independently of the period, in the zone where acceleration is the highest, and the long period region, where the values decrease depending on the period and the velocity is effective, are taken into consideration while making the analysis in the new code separately, the results of the new code (2018 seismic code) are more realistic approach. In addition, it has been observed that this shift is due to the change of mechanical properties of different materials was accepted according to codes and the inclusion of effective crosssection stiffness coefficient in the new code(2018 seismic code). As seen in the calculations made by US codes, base shear force values were lower for all 3 buildingsbuildings compared to 2007 and 2018 seismic codes. The reason of the lower shear force values was observed to be caused by the fact that the spectral acceleration coefficients included in the analysis were used as the multiplier of the 2/3 coefficient used in the transition from the map spectral acceleration values to the design spectral acceleration values. For the 3 different buildings analyzed separately for 2007 and 2018 seismic codes, the change of period values in X and Y directions are given. The change in period values was changed independently of the earthquake forces it takes on in a structure. However, as it can be seen in the tables and the tables given, it has been observed that different values are produced according to different code analysis. As the cross-sectional effects of the elements with the effective cross-sectional stiffness coefficient are distributed to the elements at a certain rate, it is seen that the period values in 2018 seismic code are higher than the period values in 2007 seismic code. With the introduction of effective cross-sectional stiffness as a coefficient in the 2018 code, the rates of the elements to take over the loads are determined as coefficients. In the last chapter, the results of the study, the main features of the new code(2018 seismic code) and the numerical results are evaluated. Within the scope of the master thesis, the theoretical comparison of 3 different seismic codes has been made and the differences between the codes and the innovations brought; 3 different buildings were analyzed by taking into consideration the limitations of codes and the resulting changes were examined. While the classification was made according to the layer height in the 2007 seismic code, it was seen that the classification was made from the best ground to the worst ground in the new code. In addition to the design approach based on strength in 2018 seismic code, the analysis principles related to the design approach according to the deformation which are foreseen to be made according to the shape changes that occur on the basis of element are also included. It was observed that the effective ground acceleration coefficient A0 in use in the 2007 seismic code was replaced by the use of short period spectral acceleration coefficient SS and long period (1.0 sec) map spectral acceleration coefficient S1 in the 2018 seismic code. While the analysis in the 2007 seismic code are based on standard earthquake ground motion, 4 different earthquake ground motion levels are determined in 2018 seismic code. It is seen that the performance targets of 8 different earthquake design classes defined according to short period design spectral acceleration coefficients and the assessment / design approach to be applied in 2018 seismic code are used. It is seen that the shear force values in the analysis made according to 2018 seismic code are higher than 5% and 10% values compared to the values in 2007 seismic code. Important reasons for this difference; In 2018 seismic code, it was observed that the over strength coefficient, which is included in the analysis, is due to the fact that spectral acceleration coefficients can define earthquake magnitude and soil characteristics in more detail. In the following studies on this subject, it was suggested to the researchers to compare the analyzes to be carried out considering the design analysis principles according to the strength capacity analyzes to be made considering the design analysis principles according to the nonlinear analysis.