Betonarme Binalarda Doğrusal Analiz Yöntemlerinin Tdy 2007 Ve Ec 8’e Göre Karşılaştırılması

Abstract

Binalarda en çok hasar oluşturan doğa afetleri çoğunlukla depremlerdir. Betonarme bina tasarımında da deprem yüklerine göre hesap yapılır ve bu deprem yüklemeleri yapısal elemanlarda oluşma olasılığı yüksek en elverişsiz iç kuvvetlerini görmemizi sağlar. Dünyada kullanılan çeşitli deprem yönetmeliklerinde çözüm için farklı yöntemler mevcuttur. Genellikle dünyada kabul gören ve örnek alınan yönetmeliklerin analiz yöntemleri birbirine yakın çözüm yöntemleri içermektedir. Tasarlanacak binada taşıyıcı sistemin bina kullanımına uygunluğu önem arz etmektedir. Çerçeveli, perde – çerçeveli ve perdeli taşıyıcı sistem türlerinde binanın deprem esnasındaki davranışları birbirinden farklı olmakla birlikte, mimari bakımdan uygunluk ve maliyet konusu da taşıyıcı sistem seçiminde etkilidir. TDY 2007 ve EC 8 yönetmeliklerinde her taşıyıcı sistem ve sistemin süneklik durumu için çeşitli katsayılar ve formüller verilmiştir. Bu yönetmeliklerde doğrusal ve doğrusal olmayan davranış için birbirinden farklı analiz yöntemleri mevcuttur. TDY 2007 ve EC 8 için doğrusal analiz yöntemlerinden Eşdeğer Deprem Yükü Yöntemi ve Mod Birleştirme Yöntemi, kullanımı en sık olan doğrusal analiz yöntemleridir. TDY 2007 için gerek ülkemizde, EC 8 için de gerek Avrupa ülkelerinde bina tasarımında bu yöntemler esas alınarak depreme dayanıklı bina tasarımı yapılır. Eşdeğer Deprem Yükü Yöntemi, TDY 2007 için Mod Birleştirme Yönteminin de esas aldığı en önemli yöntemdir. “Yarı dinamik yöntem” ya da “eşdeğer statik yöntem” olarak da bahsi geçmektedir. Bu yöntemde binaya etkiyecek yük; yerel zemin sınıfı, deprem bölgesi, bina kullanım türü, taşıyıcı sistem türü, binanın doğal hakim periyodu ve bina ağırlığı gibi durumlara göre belirlenmektedir. Eşdeğer Deprem Yükü Yöntemi, hesap için tasarımcı mühendise kolaylık sağlar. Ancak, TDY 2007 ve EC 8’de Eşdeğer Deprem Yükü Yöntemi’nin kullanımı bakımından çeşitli sınırlamalar getirilmiştir. Bunlar; bina toplam yüksekliği, deprem bölgesi, planda ve düşeyde olan düzensizlikler gibi etmenlerdir. Betonarme analiz ve tasarım paket programlarının çoğunda, Eşdeğer Deprem Yükü Yöntemi’ndeki kısıtlamalar nedeniyle Mod Birleştirme Yöntemi ile çözüm yapılır. Mod Birleştirme Yöntemi herhangi bir kısıtlama olmaksızın tüm binalarda kullanılabilecek bir yöntemdir. Mod Birleştirme Yöntemi, “dinamik analiz” olarak da adlandırılır. Süperpozisyon ilkelerini esas alan bu yöntemde, maksimum iç kuvvetler ve yerdeğiştirmeler binada yeterli sayıdaki titreşim modunun her biri için hesaplanan maksimum katkıların istatistiksel olarak birleştirilmesiyle elde edilir. Bu yöntemde binanın serbestlik derecesi kadar ayrı ayrı serbestlik dereceli sistem davranışı esas alınarak yapılan çözümlemeler süperpozisyon yöntemi kullanılarak birleştirilir. Yönetmeliklerin içindeki analiz yöntemlerinde birbirinin tamamen aynı sonuçlar çıkmamaktadır. Bununla birlikte farklı yönetmeliklerde bulunan sonuçlar da birbirinden farklı çıkmaktadır. Bu sebeple, yönetmelik ve analiz yöntemlerindeki sonuçlardan biri diğerine göre daha güvenli ya da daha büyük sonuçlar vermekteyken, biri diğerine göre ekonomi bakımından daha düşük maliyet sağlamaktadır. Yedi bölümden oluşan bu tez çalışmasında, farklı yerel zemin sınıflarındaki yapısal davranışı da içerecek şekilde farklı kat adetlerine ve farklı taşıyıcı sisteme sahip planda ve düşeyde düzenli ve düzensiz binaların TDY 2007 ve EC 8 yönetmeliklerinin doğrusal analiz yöntemlerinde bulunan sonuçların karşılaştırmaları yapılmıştır. Birinci bölümde, giriş başlığı altında analizi yapılan binaların kat adetleri ve türlerinden bahsedilerek, genel bilgiler verilmiştir. İkinci bölümde, betonarme bina tasarımında kullanılan taşıyıcı sistem türleri ve deprem esnasında bu binaların davranışı anlatılmıştır. Üçüncü ve dördüncü bölümde, depreme dayanıklı betonarme bina tasarımı için TDY 2007 ve EC 8’de belirtilen koşular, formüller ve bilgiler verilmiştir. Beşinci bölümde, hem TDY 2007 hem de EC 8 için yapılan analizlere göre yönetmeliklerin kendi içerisindeki analiz yöntemleri birbiriyle karşılaştırılarak grafikler çizilmiştir. Altıncı bölümde, beşinci bölümde bulunan değerlere göre TDY 2007 ve EC 8 yönetmelikleri karşılaştırmaları yapılmış ve grafikler halinde verilmiştir. Son bölümde her iki yönetmeliğe göre elde edilen sonuçlar ayrıntılı bir şekilde değerlendirilmiştir.

Earthquake is the most important natural disaster in the world. Considerable losses of life and properties as a result of the destruction caused by the earthquakes necessitated new earthquake and construction regulations for the earthquake zones. In order to reduce the damages caused by this natural disaster, the earthquake and construction regulations give importance to the precise calculation of the force of earthquakes affecting the buildings. If an earthquake’s occuring time, direction and magnitude were previously known, design of structures could made avoid of the damage. All buildings have sufficient strength against earthquakes using this uncertainty because it is possible to build safety coefficients. Regulations, according to seismic and ground conditions using various coefficients and provides designs accordingly do. National and international standards present different linear and nonlinear methods to calculate the seismic load. However, choosing the appropriate method, calculating the seismic load and distributing it over structural elements have important consequences, since different methods would yield different results from that of the appropriate one. Limitation of displacements in linear analysis according to TSC 2007 (Turkish Seismic Code 2007) and EC 8 (Eurocode 8) regulations and limitation of damages are based accordingly. Moved in the earthquake forces and horizontal forces in addition to the vertical force must be transmitted to the base of structure. Therefore, it is necessart to design a system with vertical and horizontal loading, the column and the beam have emerged as rigid frame formed by the interconnected system. This carrier system is robustness against to horizontal loads, depends on the rigidity of the point. Frame system known as the most simple multi carrier system of freedom. Frames are located in the direction of two orthogonal axes in a regular structure. Earthquake forces during the impact each other in the framework of this direction, but does not take into consideration the torsional effect; horizontal movement is important. Frames are considered to carry the load in the plane they were too small to be close to each other while the stiffness interaction. Frames are made relative displacements depend story stiffnes and shear forces acting on the story. In counterpoising the walls are horizontal and vertical load bearing elements which effectively limited displacements. Element that is greater than the ratio of the short sides of the long sides 7, plan are called wall at TSC 2007. Walls with frame in counterpoising the horizontal load or used single. A wall acts as a cantilever beam length alone. Walls; the bending moment of horizontal forces is under the influence of the normal force due to vertical shear force next. With wall systems, building geometry can also be rectangular in plan with a different geometry with building. Assuming that the frame of the horizontal load to accept that carried by walls of all lateral loads are not always safe approach. Therefore, the contrubution of the frames should be considered in the handling of the horizontal load. At horizontal displacement of the frame, story shear is very effective. At frame system; on the upper storys, shear force is small and horizontal displacement stiffness is small. On the lower storys, situation is opposite. While base story shear is increasing, horizontal displacement stiffness does not increase at the same rate. Number of story in wall very rigid structure is less than the horizontal displacement of the frame is limited by the wall and the wall is moved by a large portion of the horizontal load. In contrast, the scenes of the size of the effective area on the stiffness of the floor plan to the normal force becomes more decisive. Core system with a high load of the building in all or a significant portion is moved with the aid of a single core or cores in various parts of the building. In the systems of this structure as an adjunct to the core, walls or cable systems can use. Cores are the huge beams in the floor console against lateral load. One of the most recently developed system of reinforced concrete structures are tubular system. At tube desing, the cover of the floor console front element is assumed to resist lateral loads such as a hollow box beam. The world’s highest structures can be created with tubes. Compliance with building will be designed to use the carrier system in the building is important. Framed, wall-framed and wall systems have different typed of structure behavior during the earthquake, architecture, maintenance and cost of compliance is also effective in the structural system selection TSC 2007 and EC 8 regulations in the various coefficients for each carrier status of the system and the system ductility and formulas are given. These regulations have different from each other analysis methods for linear and nonlinear behavior. It is important to choose the appropriate methods to calculate the force of earthquakes that affect the buildings, which are referred as seismic load calculation methods. For TSC 2007 and EC 8, Equivalent Seismic Load and Mode Superposition methods are most common linear analysis methods in these regulations. These methods are based on earthquake resistant design is done in our country, both in the design of buildings in European countries. Equivalent Seismic Load Method, also of Mode Superposition Methods for TSC 2007 is the most important method that is based on. It was named “semi-dynamic method” or “static method”. This method will be applied to the building use type, carrier system type, the structure of the natural dominant period is determined according to conditions such as weight and structure. Equivalent Seismic Load Method provides convenience to design engineers to account. However, TSC 2007 and EC 8 Equivalent Seismic Load Method has brought several limitations regarding the use of the method. They are total height of the building, earthquake zone, as are the factors that irregularities on plan and vertical. In most of the concrete analysis and design software, due to restrictions in Equivalent Seismic Load Method, are used Mode Superposition Method for solution. Mode Superposition is a method that can be used in all buildings without any restrictions. Mode Superposition is also called as “dynamic analysis”. In these methods are based on the superposition principle, the maximum internal forces and displacements are calculated for each of the maximum participation of a sufficient number of vibration modes are obtained by combining statistical. This method is building up individual degrees of freedom single degrees of freedom behavior based on the analysis performed are combined using superposition method. Each other in the analysis of the regulations does not go exactly the same results. However, the results are different. Therefore, one of the consequences of regulations and analysis methods safer or greater results than the other, one of which provide a lower cost than the other in terms of economy. In this study, structural system of reinforced concrete frame, wall-frame and wall systems for building area are the same, under the influence of horizontal and vertical loads of buildings with different story heights TSC 2007 and EC 8 Equivalent Seismic Load Method and Mode Superposition Method according to regulations and linear analysis based on is made. Frame systems are 6 story, 9 story and 13 story; wall-frame systems 13 story, 19 story and 25 story; wall systems 13 story, 19 story and 25 story as modeled. Story heights are 3 m in regular buildings. Also 15 story wall-frame building with irregular plan and vertical were obtained. Both in the calculation, TSC 2007 as well as the comparison of EC 8 regulations to be healthy in TSC 2007 corresponds to the first degree earthquake ground acceleration coefficient of 0.40 was obtained. Four types of buildings for each calculation in the analyzes done separately for local site class is made comparisons among themselves. TSC 2007 by Z1, Z2, Z3 and Z4 although class EC 8 by A, B, C and D evaluation was made. Analysis in building made of concrete classes according to the number of story the carrier system and C25, C30, C35 and C40 are taken as. Both of these regulations in the concrete, story of the building with the same number were the same. The carrier system of structure and earthquake condition were modeled and solved by ETABS. Columns and beams frame element, the walls were modeled as shell elements. Slabs can also be modeled assuming that each story level of the current rigit diaphragm behavior. Seven section in this thesis consists, comparison of the results are conducted in the linear analysis of the different local ground class, different carrier systems, plan and vertical of regular and irregular structure TSC 2007 and EC 8 regulations. In the first section, input the title of general information given story number and types of structures under analysis are given. In the second section, the carrier system type used in the design of reinforced concrete structures and described the behavior of these structures during earthquake. The third and fourth sections, TSC 2007 and EC 8 earthquake resistant design of reinforced concrete buildings in the conditions, formulas on specified information is given. In the fifth section, for TSC 2007 and EC 8 based on their analysis compared regulations inside between each other. In the sixth section, according to the values found in the fifth section TSC 2007 and EC 8 regulations are given in graphs and comparisons. The results obtained by both regulations last section is reviewed in detailed.