Yüksek bir binada çelik çözümle kompozit çözümün karşılaştırılması

Abstract

ÖZET Yüksek Lisans tezi olarak hazırlanan bu çalışmada çok katlı bir yapı önce çelik karkas olarak çözülmüş olup, aynı karkas sistemdeki kirişlerin bir de kompozit olarak çalış maları halinde moment tasıma kapasiteleri hesap edilip karşılaştırılması yapılmıştır. Sistem karşılıklı iki kısa kenarlarında B.A. çekirdek bulunan kısa doğrultuda 6,0 m açıklıkları olan 3 açıklıklı çerçevelerden oluşmaktadır. Bu çerçeveler kirişlerle çekirdeğe bağlanılmaktadır. Yapının ilk katı 4,0 m, diğer katları 3,20 m yüksekligindedir. Yapının döşemesi 10 cm kalınlığında yerinde dökme betonarmeden teşkil edilmiştir. Kolon kesitleri 1 ile 3. katlar arasında, birleşik kesit (IPB500 + IPB280 ) 4 ile 7. katları arasında, IPB500, 8 ile 12. katlar arasında IPB300 olarak ele alınmıştır. Yapının çelik olarak boyutlandırı İmasında elastik hesap yöntemi esas alınmıştır. Sistemin çelik çözümünde düşey yükler herhangi bir katsayı ile arttırılmadı. Düşey yükleri çelik çerçeveler, yatay yükleri B.A. yüksek kiriş gibi çalışan B.A. döşeme vasıtasıyla çekirdek kısımlar taşırlar. Yatay yük olarak dikkate alınan deprem yükü ise arttırılmamıştır. Her katta hareketli yük olarak 500 kg/m2 alındı. Ara bölme duvar yükü hareketli yüke dahil olduğu için, ara duvarı altındaki kirişlerin hesabında ayrıca duvar yükü alınmadı. Yapının boyutlandırı İmasında yapının y-y doğrultu sundaki mesnetleri elastik mesnet olarak kabul edildi ve Uç açıklıklı elastik bir çerçeve olarak hesabı yapıldı. x-x doğrultusunda ise rijit bir çerçeve ele alındı. Düşey yükler altında kirişlerin ve kolonların aldıkları kesit tesirleri elde edildi. Yatay yükler, çekirdek kısımlar tarafından taşındığı için kiriş kesitleri her katta aynıdır. Ancak x-x doğrultu sundaki Uç açıklıklı çerçevede orta açıklıkta kolon kiriş birleşim hesaplarında birleşim elemanlarının mevcut kesit tesirlerini taşıyamaması nedeniyle kiriş kesiti değişti rilmiştir. Kolonların boyutlandırılmasında en Us t kattan başlayarak kolon kesitinin değiştiği katlarda ve diğer ara katlarda tali kiriş çözümlerinden elde ettiğimiz değerleri göz önüne alarak kat çerçevesi çözümü yapılmıştır.

THE COMPARISION OF A- MULTISTOREY BUILDING WITH STELL AND COMPOSITE SOLUTIONS: SUMMARY In this study, prepared as a M.S. thesis, the steel and composite solutions of a multistorey building are compared. The system consists of 3 spanned continous beams which are 6,0 meters in width and langıtudınal ly 10 spanned continous beams which are supported with 11 columns and each span is 4,0 meters. For the slab 10 cm thick reinforced concrete plates are chosen. The first storey is of 4,0 meters high and normal storeis are of 3,20 meters high. The structure has two closed stiffening core which were built by reinforced concrete and has got length and width of 6,30 meters on the short sides of the structure. This stiffening cores were connected to the storey frames by langitudional continuos beams. Steel ST37 and conoretc B225 were used as constraction materials. The structure was built on the 40,0x18,0 = 720 meter sguare of area as a bussines center. In the colculation, the normal storey loads which were taken as dead load and 500 kg/nr of live loads were taken as vertical loads. The horizantal loads which are wind and earthguake loads were calculated by assuming that our structure has a hight of 39,20 meters from sea level and set on the hard sand and gravel soil and in the second degree eartguake region. Since the earthguake load is more unsuitable than the wind load, it is taken as the horizantal load. VIAll of the vertical loads were carried by means of beams, girders and columns. However all of the horizantal loads which were effected in two directions (X-Y) were carried by the closed stiffening core. According to this assumption beams, girders and columns were designed for the vertical loads. Girders were combined to the columns as rigid by means of prestressed bolts and the calculation of them was done acording to the plastic design method. The closed stiffening care was designed for the horizantal loads. The calculation of the system for steel solution was done according to the elastic design method. During the calculations vertical and earthguake loads are not increased. In the design of the structure as a steel system the beams in the langitudinal direction which were assumed continous were calculated by using the table. The girders and columns in width direction which were assumed storey frames were calculated by static method. The calculated earthguak load was dirtributed to the closed steffening cores by means of reinforced concrete plate under these horizantal loads the section forces of the stiffening core calculated. The calculation of the reinforced concrete for the stiffening core was made by using the analogous to the T section of the reinforced concrete. After distributing the effect of the horizantel load to the stiffening core some steel beam sections have been found unsuf f icient, these steel beam sections have been changed and checked for normal and shear forces, buckling and deflection limit. The reinforced concrete plate calculation was made two times. One of them was made by using the analogous to the restangular section of the reinforced concrete. The ather one was made by assuming the reinforced concrete plate as a high reinforced concrete beam for this solution were mesh is chosen as reinf orcedment. The sections were approximately chosen from the preliminary calculations. Which were done by assuming that inertia moments of girders and columns are the same in a storey frame. The exact dimensions were abtained by considering normal force, shear force, buckling and deftection limit. VIIFor the selutions `JPB` sections for columns, `I` section for beams were used. But special column section which is called connected section was used for the 1st, 2nd and 3th floores. The connected column section was made by welding IPB280 profile to the IPB500 profile. Load analysis for a normal storey; Reinforced concrete slab (10cm) Marble (3cm) Protecting layer (10cm) Flaster (1cm) 240 kg/m2 280 ` 250 ` 200 ` g = 442 kg/mj Live load q = 500 kg/m2 Unsuitable loadings for storey frames were chosen as shown below. f 6.0m 2.0m.1.0.. f^^luf y 6.0m RMA). 1 2-0m > *19T Fig. la. Unsuitable load in Fig. lb. Unsuitable load in first spane. mid spane. Fig 1: Unsuitable loadings for storay frames in width direction. VIII2* 3' E o ro e o CM ro TCKRg t/m TlflxR[) naxRs -M ` 2.0m ` 2.0m ` 2.0m ` 2.0m ` 2.0m ` 2.0m, f f f f f f f Fig. 2a. Unsuitable load in first and third spanes /x ` 2.0m ` 2.0m r 2.0m,, 2.0m,, 2.0m r 2.0m. T T T T T T 1 Fig. 2b. Unsuitable load in second spane. Fig. 2. Unsuitable loadings for stores frames in longitudinal direction. IXThe composite calculation of structure was only done for the stell beam sections which were defined by elastic design method in the steel solution of structure. The moment bearing capasity of compaite beam sections were calculated in the positively and negatively moment zones. The effects of shear force which are maximum in the support zone and normal forces were researched. The deflecion analysis of the composite beams were being also done by elastic method and the deflection limit was not effective in any beam. In the deflection analysis; the inertia moments of composite sections were recalculated by assuming that the working part of the reinforced concrete plate as rigid as steel. The first of the moments is being found from stell solution and the second one from composite solution, were compered. As a result; it was observed that the ratio of moment bearing capasity for the beam section that found from elastic design method was being incroesed about %87 in positive and %44 in negative moment zones by means of working with the reinforced concrete slab as composite section beam. On the other hand, composite working of a steel beam with reinforced concrete slab provides beams to have capability of transporting big section forces by not increasing the height of beams.In this composite colution,about 35860 shear materials were used for the beams of structure. d2 > 1,5xdj Fig. 3. Geometrical dimentions for a shear material. As a result; it was observed that, the ratio of moment bearing capasity for the beam section, that found from elastic design method, was being increased about %87 in positive and %44 in negative moment zones by means of working with the reinforced concrete slab as composite section beam. On the ather hand ; composite working of a steal beam with reinforced concrete slab provides beams, to have capability of transporting big section effects by not increasing the height of beams. XIBÖLÜM 1. SİSTEMİN ÇELİK ÇÖZÜMÜ ©. 0. 0. ©- 0. ©- 0- ©- 0- 0- 0- I ?m w 53=- a İl §s a» ?>' -H5- -fS~ m T2T -M>j §i §ı ıg TJT Tir <> sı u 8 BM ©000 Sekil 1.1 Sistemin planı