Çok katlı çelik yapılarda düşey stabilite perdelerinin yatay yükler etkisi altında davranışlarının kıyaslanması
Çok katlı çelik yapılarda düşey stabilite perdelerinin yatay yükler etkisi altında davranışlarının kıyaslanması
Dosyalar
Tarih
1996
Yazarlar
Yıldız, Yaşar
Süreli Yayın başlığı
Süreli Yayın ISSN
Cilt Başlığı
Yayınevi
Fen Bilimleri Enstitüsü
Özet
Çok katlı çelik yapılarda; rüzgar, deprem vb, yatay yük ve etkilerin en az düşey yük ve etkiler kadar hatta kat sayısı arttıkça onlardan daha çok zorlayıcı olmaktadır. Bina stabilitesinin sağlanması için, taşıyıcı sistemin yatay yer ve şekil değiştirmelerin belirli sınır değerlerin altında kalması gerekmektedir. (Kat için 8j= - - ) Bu amaçla; binaya etkiyen yatay yükler; kendilerini taşımak üzere planlanan tabakalarından zemine ankastre düşey perdeler aracılığıyla, yapıtım diğer elemanlarını zorlamadan düşey stabilite perdeleri aracılığıyla zemine iletilmelidir. Bu çalışmada; dört farklı türde düşey stabilite perdesi seçilmiş ve bunların yatay yükler altında davranışı incelenmiştir. Perde tip 1 ve perde tip 2 rijit, perde tip 3 ve perde tip 4 ise yatay yük etkileri altında yan rijit çalıştınlmıştır. Düşey stabilite perdelerinin davranışı, birinci katta 3.6 m, diğer katlarda 3 m kat yüksekliği ve x-x doğrultusunda 7 m-2 m-7 m, y-y doğrultusunda 5 mx8 aks aralığına sahip sekiz katlı büro binasında davranışı incelenmiştir. Yapıda döşemeler kompozit, diğer bütün elemanlar çelik malzeme olarak hesaplanmıştır. Yatay kuvvetlerin hesabı,deprem kuvveti yeni deprem yönetmeliği ışığında Tek Titreşim Metoduna göre, rüzgar kuvveti ise p^pO-Sq^F^ey şeklinde hesaplanmış. Bunun sonucunda deprem kuvvetinin rüzgar kuvvetinden büyük olması nedeniyle, düşey stabilite perdelerinin davranışı deprem kuvvetine göre incelenmiştir. Deprem kuvveti etkisi altında, temelden zemine ankastre düşey kafes sistem olarak çalışan ve ilk aşamada dört perde tipinde de kesitler aynı seçilerek en çok zorlanan birinci kat için perde deplasmanları belirlenmiştir. İkinci aşamada, yükler altında gerçek kesit değerlerine göre deplasmanlar bulunmuştur. Sonuç olarak; yan rijit çalışan perdelerin, rijit çalışan perdelere göre; kirişlerde oluşan moment şekil değiştirmelerinden dolayı daha fazla deplasman yaptığı, fakat kirişlerdeki moment ve diagonallerdeki basınç etkisiyle kesitlerin daha büyük, dolayısıyla ağırlığın daha fazla olduğu görülmüştür.
The horizontal loads, like wind and eartquake, are vety effective on the design of multistory building. The effects of these kind of loads are at least equal to the effects of the vertical loads on tlie design and due to the increase in the number of tlie floors become greater. The values of the horizontal displacements and deflections of the frame must be under the limitation, for the stability of the buildings, (for floor 8~ 300 ) For this purpose, the horizontal loads which affect the building must be transmitted to the ground by only vertical bracing systems, of which the connections to the ground are rigid. In this study, four different types of vertical bracing systems have been selected and the behaviours of them under the horizontal loads have been examined. Under the effects of horizontal loads, the connections of the bracing system have been considered as rigid in type 1 and 2 and as semi-rigid in type 3 and 4. Type 1 of Vertical Bracing System (the connections of bracing system have been considered as rigid) XI -r- - -^ Type 2 of Vertical Bracing System (the connections of bracing system have been considered as rigid) - * 1 İ-- Type 3 of Vertical Bracing System (the connections of bracing system have been considered as semi-rigid) xu ı w -r r ^ - --.+- 1 4-- Type 4 of Vertical Bracing System (the connections of bracing system have been considered as semi-rigid) The height is 3.6 meters for the first floor and 3 meters for the other seven floors. Span lengths parallel to x-x and y-y axes are 7m-2m-7m and 8x5m respectively. The building has eight floors and is used as a business centre. X D, D, 5m * * 6 ! The Plan of Multi-Storey Structures -.£ A ?v 7m B 2m C 7m ^ D- Xlll 3m 3m 7 3m 3m V_ 3m 3m v_ 3m 3.6m -tf 7m **-* 7m ?* The Frame parallel to x-x axis xiv . B801 3m y 3m 3m 3m / 3m 3m / 3m 3.6m / The Fran» parcllel to y-y axis In the design of the building, the floors have been considered as composite and all the other structural elements are designed by steel. The horizontal forces affected the structure, are eartquake and wind forces. Wind force; 1 w U.BO^rmrfhe,, Pw-0.8x0. 1 10x(24.6x40.9)97. 1 5 t x v Eeartquake force; By using the instructions for the structures in the (disaster) region, the weight of the structure has been calculeted approximatley, in the predesign stage. The force Fe, which affects the structure, is calculeted as 693.305 t with R=4.5 and as 480 t with R=6.5 on the rigid and semi-rigid braces respectively, by the method of single vibration. The eartquake forces affected the floors, have been calculated by taking into account the torsion moment, because, the stiffness and the mass centres are located different points from each other. The behaviour of the vertical braces has been examined according to the eartquake forces because it was seen from the calculations of the horizontal forces that eartquake forces were more greater than the wind forces. In the first period, the same sections have been selected for the four types of bracing system which were fixed to the ground. By using the force method, the axial forces of the elements of the braces, and the brace displacements in the first floor, which was the most affected one, have been obtained. Sf=6.131xl0'3m, 52=3.381 lxlO'V 83-O.OI 17 m, o>5.2973xl0'3 m 5:EHsplacemeht The columns and the beams of the bracing system, behave like the other elements of the structure under the vertical loads. Because of this, tlie internal forces of them have been obtained for various unavailable loadings. The columns and the beams of every types of the bracing systems have been designed again under the real loads. According to the real sections of them, the behaviour of the braces, under the horizontal loads, have been re-examined. 8,=0.0101 m, 82=5.3784x10 V 83=0.01 186 m, S4=5.6916xl0~3 m W,=5834.6 kg, W2=4967.8 kg, W3=5659.1 kg, W4=6685.21 kg 8:Displacement W:Weight Consequently, it is seen that, among the braces fushich cross-sections are not different from each other and under the real loads and with real cross sections type 3 of which the connections are semi-rigid has the greatest displacement value than the others. Type 3 has less weight than the type of brace which has the rigid connections. This displacement value, the most close one to the limit value of the floor displacement.
The horizontal loads, like wind and eartquake, are vety effective on the design of multistory building. The effects of these kind of loads are at least equal to the effects of the vertical loads on tlie design and due to the increase in the number of tlie floors become greater. The values of the horizontal displacements and deflections of the frame must be under the limitation, for the stability of the buildings, (for floor 8~ 300 ) For this purpose, the horizontal loads which affect the building must be transmitted to the ground by only vertical bracing systems, of which the connections to the ground are rigid. In this study, four different types of vertical bracing systems have been selected and the behaviours of them under the horizontal loads have been examined. Under the effects of horizontal loads, the connections of the bracing system have been considered as rigid in type 1 and 2 and as semi-rigid in type 3 and 4. Type 1 of Vertical Bracing System (the connections of bracing system have been considered as rigid) XI -r- - -^ Type 2 of Vertical Bracing System (the connections of bracing system have been considered as rigid) - * 1 İ-- Type 3 of Vertical Bracing System (the connections of bracing system have been considered as semi-rigid) xu ı w -r r ^ - --.+- 1 4-- Type 4 of Vertical Bracing System (the connections of bracing system have been considered as semi-rigid) The height is 3.6 meters for the first floor and 3 meters for the other seven floors. Span lengths parallel to x-x and y-y axes are 7m-2m-7m and 8x5m respectively. The building has eight floors and is used as a business centre. X D, D, 5m * * 6 ! The Plan of Multi-Storey Structures -.£ A ?v 7m B 2m C 7m ^ D- Xlll 3m 3m 7 3m 3m V_ 3m 3m v_ 3m 3.6m -tf 7m **-* 7m ?* The Frame parallel to x-x axis xiv . B801 3m y 3m 3m 3m / 3m 3m / 3m 3.6m / The Fran» parcllel to y-y axis In the design of the building, the floors have been considered as composite and all the other structural elements are designed by steel. The horizontal forces affected the structure, are eartquake and wind forces. Wind force; 1 w U.BO^rmrfhe,, Pw-0.8x0. 1 10x(24.6x40.9)97. 1 5 t x v Eeartquake force; By using the instructions for the structures in the (disaster) region, the weight of the structure has been calculeted approximatley, in the predesign stage. The force Fe, which affects the structure, is calculeted as 693.305 t with R=4.5 and as 480 t with R=6.5 on the rigid and semi-rigid braces respectively, by the method of single vibration. The eartquake forces affected the floors, have been calculated by taking into account the torsion moment, because, the stiffness and the mass centres are located different points from each other. The behaviour of the vertical braces has been examined according to the eartquake forces because it was seen from the calculations of the horizontal forces that eartquake forces were more greater than the wind forces. In the first period, the same sections have been selected for the four types of bracing system which were fixed to the ground. By using the force method, the axial forces of the elements of the braces, and the brace displacements in the first floor, which was the most affected one, have been obtained. Sf=6.131xl0'3m, 52=3.381 lxlO'V 83-O.OI 17 m, o>5.2973xl0'3 m 5:EHsplacemeht The columns and the beams of the bracing system, behave like the other elements of the structure under the vertical loads. Because of this, tlie internal forces of them have been obtained for various unavailable loadings. The columns and the beams of every types of the bracing systems have been designed again under the real loads. According to the real sections of them, the behaviour of the braces, under the horizontal loads, have been re-examined. 8,=0.0101 m, 82=5.3784x10 V 83=0.01 186 m, S4=5.6916xl0~3 m W,=5834.6 kg, W2=4967.8 kg, W3=5659.1 kg, W4=6685.21 kg 8:Displacement W:Weight Consequently, it is seen that, among the braces fushich cross-sections are not different from each other and under the real loads and with real cross sections type 3 of which the connections are semi-rigid has the greatest displacement value than the others. Type 3 has less weight than the type of brace which has the rigid connections. This displacement value, the most close one to the limit value of the floor displacement.
Açıklama
Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Sosyal Bilimler Enstitüsü, 1996
Anahtar kelimeler
Yatay yükler,
Yüksek yapılar,
High structures,
Horizontal loads