Çok katlı betonarme bir yapının projelendirilmesi
Design of multistorey reinforced concrete building
Yazar: HİDAYET ÖZDEMİR
Danışman: PROF.DR. NAHİT KUMBASAR
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü
Derece: Yüksek Lisans, 1994
Konu: İnşaat Mühendisliği = Civil Engineering
Dizin: Betonarme yapılar = Reinforced concrete structures ; Bina bilgisi = Building information ; Projelendirme = Projecting

Özet:
ÖZET Yüksek lisans tezi olarak sunulan bu çalışmada çok katlı betonarme bir yapının düşey ve yatay yükler altında statik ve betonarme hesabı yapılmıştır. Yapının statik hesabında SAP90 (Yapı Analiz Programı) bilgisayar programı kullanılmıştır. Programın kapasite sinin sınırlı olmasından dolayı döşemeler düğüm noktası sayısına göre bölümlere ayrılarak hesaplanmıştır. Döşeme tipinin kirişsiz döşeme olmasından dolayı yaklaşık yöntemler kullanılmış ve kabuller yapılmıştır. Yapı sistemi 4 normal kat ve 2 bodrum kattan oluşmuş altı katlı betonarme bir yapıdır. Yapının bodrum katlarının etrafı perde duvarlarla çevrilmiştir. Döşeme sistemi; kat yüksekliğinin sınırlı olmasından ve düz bir tavan istenmesinden dolayı kirişsiz döşeme uygun görülmüştür. Döşeme kalınlığı 20 cm olarak seçilmiştir. Normal kat yüksekliği 2,79 m dir. Düşey yükler altında hesapta; sabit yükler 1.4 ve hareketli yükler 1.6 katsayısıyla arttırılmıştır. Yatay yük hesabında; yapının ağırlığı bulunmuş ve her kata gelen kuvvetler hesaplanmıştır. Kata gelen kuvvetler iki aksa paylaştırılmış ve depremin her iki doğrultusu içinde hesap yapılmıştır. Düşey ve yatay yüklerden oluşan kesit tesirleri hesaplanmış, bunların süperpozisyonu sonucunda elde edilen en elverişsiz etkilere göre kesit hesapları yapılmıştır. Yapının temel kısımında iki farklı tip temel uygulan mıştır. Perde duvarların altına perde altı temeli ve çekirdek, kolon ve iki büyük perdeyi içine alan bir radye temel düzenlenmiştir. Radye plağın statik hesabı; kirişsiz döşemelere ben zetilerek SAP 90 bilgisayar programıyla yapılmıştır. vıı

Abstract:
SUMMARY DESIGN OF MULTISTOREY REINFORCED CONCRETE BUILDING In this thesis, the static and reinforced concrete calculation of a multistorey building under vertical and horizontal loads are made. The static calculations are made by the use of computer software SAP90 (Static Analysis program). On the other hand the reinforced concrete design is achived by using tables prepared to design all kinds of concrete structures. The building designed has a reinforced concrete skeleton, four normal storey, and two basement storeys. First level of basement is partially surrounded by shear wall and the second level of basement is fully surrounded by shear walls from three sides. The second basement is designed as a car park, the other storeys are designed as offices. Above the basement, the normal storeys have cantilevers on three sides. Building support system is composed of columns, 415 by 25 cm shear walls, a core in which elevator hall is located and slab without beam. The columns are not used in the middle of the slab, but they are used on the sides and at the beginning of consoles. Because of the height of storeys is limited and a smooth ceiling is desired, slab without beam is thought to be the best choice. Measures chosen concerning the building are given below: The thickness of the. slab Height of normal storeys besides first floor Height of the first floor Height of the first basemnt Height of the second basement 20 cm 279 cm 387 cm 271 cm 320 cm To compare with the computer results calculation of two axes which perpendicular to each other of the slab of a normal storey is done by equivalent frame method. For this purpose, assuming a beam which has the same rigidity with the slab between two columns, a frame composed of columns and equivalent beams is formed on the 4-4 axis. The calculation of this frame is made by the help of the Hardy Cross-method for the loads on it. The loads viiiwhich are used in the solution of that frame, are calculated by the weights of equivalent beams that per unit lenght. Load Analysis. Loads of Normal storey for reinforced concrete design. Reinforced concrete slab (20 cm) = 0,500 t/m Coating + Ceiling Plaster = 0,150 t/m2 Dead load Live load g = 0,650 t/m q = 0,350 t/m2 Multipliying dead loads by 1.4 and live loads by 1.6 final loads are determined, then for this final loads, cross section effects are determined. Multipliying by a coefficient, the determined moment are distributed to middle and column strips. In two direction of the axis of the column or shear wall, the span length smaller then 0,25 li and 0,25 İ2 is choosen as column strip and the length smaller than 0,5 1 i and 0,5 lz is choosen to the middle strip. (Figure-1 ) * L2/4 L2/2 L2/4 LI - -4- ffl- li>İ2 Figure-1. Column and Middle Strip Width The solution of slab is achieved by using SAP90's (Strucural Analysis Program) Frame data. While solving for the slab's unknown properties, dividing the slab in to two parts in two direction, a grid system is formed. In this grid system, crossing points of grid elements called cruical nodes are numbered. Because of the restriction of the 100 crucial points education version SAP90 program. Normal storey's slab are divided into two parts and each of them is solved as if they are two different slabs. The following assumption are made the border conditions of the slab. while determining Side beams do not displace The crucial points on the column and shear wall are IXristrected to displacement. The other crucial points are not allowed to horizontal displacement, but only vertical displacement is allowed.. Along the axis dividing the slab's grid members do not rotate around it's axis. The other floor slabs are also divided into parts in the same way, explained above and nodes are formed not to exceed the capacity of the program. In order to determine slab's loads, an approximate load calculation is done for easiness. To achieve this approximate calculation, drawing straight lines at the midepoints of the grid elements intersected in a node the area is created. Total slab load in created area assumed to be applied as a single vertical force. As a result of the calculation that are made under these loads, the cross section effects of each member are determined. Then the moments per unit length are determined by dividing the cross section effects to the with of members. The slab is divided in columns and middle strip and using the cross section effects which are the most unfavourable one on these bands, reinforced concrete design of these slabs is made. These calculations are repeated for the other direction and so the slab without beam design in two directions is made. Another calculation for the system under vertical and horizontal loads are made and the cross section effects which are occured on columns and shear walls are determined. The structure is defined totaly as a three dimensional frame which is composed of equivalent beams which connects columns and shear walls. In this system, for the vertical loads; beams ' s load per unit lenght are defined and under these loads the calculation result is superposed by the result under the horizantal loads. Calculating of the system under lateral loads; The building which is in the 1. st degree earthguake area and the purpose of usage is as an office. In the outer sides of the building wall, complete hallow bricks which have holes on them are used and in the inside walls of the building half bricks are used. First of all the total weight of the building is calculated. C = The coefficient of earthquake. C = Co. K.S.I Co= 0,1 K = 1,0 I = 1,0 S = 1,0 (calculated)These coefficients are used for semi -dynamic earthquake design forces. Under earthquake forces behaviour of the support system of the building below the ground level is different than that of the support system of the building above the ground level. In order the design the building for earthquake forces, forces acting on each floor due to earthquake and coefficient of structural behavior, K, is determined assuming ground surfaces to be as foundation of the structure for the part of the structure above ground level and the part of the structure from the structure above the ground level. As the basement's rigidity is bigger than the other stories because of the shear walls around the underground floor. The coefficient K is assumed to be 1,5. For normal stories C = 0,1 For basement stories C = 0,15 (shear wall system) The Fi lateral forces that effect at the stories level of the building are calculated according to the weight and height of the building. Fi forces determined are divided in to two axes of the structure and calculations carried out for earthquake forces acting in two direction perpendicular to each other of the building. Reinforced concrete design of the building is made by using the most unfavourable cross section effect resulted from loads due to earthquake and vertical loads. Reinforced concrete design of the beams in the building is done by the use of cross section effects of the beams at opening and support points and reasonable amount of bar determine from calculation is exceeded the minimum bar required which is minAs=12/f yd. bw. d. If the magnitude of the shear stresses of beams at the point which have a distance d from the support surface is greater than the magnitude of Vcr=0,65. f ctd. bw. d. Reinforced concrete design of beams are made by taking shear forces into consideration. The minimum dimension of the rectangular cross sections of columns of the building design is 25 cm. ' The thickness of concreate cover exposed to outside effects is choosen to be 2,5 cm on the other hands, the thickness of concrete cover exposed to inside is choosen to be 2 cm. Wrapping horizontal bar around vertical bar, buckling of vertical bar of columns is restricted and vertical strength of columns is increased. Diameter of shear reinforcement used the condition below. 1/3 S < 120 1 S < 20 cm xx