TALL BUILDING DRAFT DESIGN Joan Tresserras Pujol-Xicoy 1. Section dimensions οΆ Columns: • 1 – 5 floors: πΊ1 = 1.2π· + 1.4πΏ = 1.2 ∗ 5.5 + 1.4 ∗ 3.5 = 11.5 ππ/π2 πΊ1−4 = 11.5 ∗ 4 ∗ 8,4 ∗ 8,4 = 3245.8ππ πΊ1−35 = 11.5 ∗ 35 ∗ 8,4 ∗ 8,4 = 28400.4 ππ πΊ1−4 ∗ 1.3 3245.8 ∗ 103 ∗ 1.3 ππ βπ = = = 152992.7 ππ2 ππ 27.58 πΊ1−35 ∗ 1.3 28400.4 ∗ 103 ∗ 1.3 ππ βπ = = = 1338670.1 ππ2 ππ 27.58 π π 1−4 =β = 391.14 ππ = 0.4π π 1−35 =β = 1157.01ππ = 1.2π π π 1−4 π 1−35 1. Section dimensions • 5 – 10 floors: π • π 5−35 11 – 15 floors: π π 11−35 • 16 – 20 floors: π π 16−35 • • = 884.07ππ = 0.9π =β π 16−35 = 790.74ππ = 0.8π =β 26 – 30 floors: π 26−35 • 31 – 35 floors: π π 31−35 = 968.45ππ = 1π π 11−35 π 21−35 π π 5−35 =β 21 – 25 floors: π =β π 21−35 =β =β π 26−35 π 31−35 = 684.8ππ = 0.7π = 559.13ππ = 0.6π = 395.37ππ = 0.4π 1. Section dimensions οΆ Beams: 1 8.4 β= πΏ= = 0.56 π ≅ 0.6 π 15 15 1 0.6 π= β= = 0.24π ≈ 0.3 π 2.5 2.5 οΆ Slabs: πΏπ 8.4 π‘= = = 0.1867 π ≅ 0.2 π 45 45 2. Design requirements 2. Design requirements 3. Loading οΆ Wind • loading: According to the chinese code: • Return period of 50 years ο Wp = 0,55KN/m2. • Return period of 100 years ο Wp = 0,60KN/m2 • Building situated in Tianjin, China ο Roughness type C • When using the program we choose the Chinese 2002 code 3. Loading οΆ Earthquake loading: • Design with a basic fortification intensity of 7. • In consequence a ground acceleration of 0,15g is used. • Site classification is a site-class IV. • When using the program we choose the Chinese 2002 code. 3. Loading οΆ Dead • load: Automatically calculated the program (Self Weight Multiplier = 1). • It is necessary to add dead load to the slabs inside the shear wall areas, due to their very small thickness. These slabs help to transfer lateral stresses. • Add a dead load = 7,5kN/ π2 3. Loading οΆ Live • load: Following the chinese code: 4. Materials • Basically, the material used will be concrete. Default concrete given by ETABS is a C40 concrete. For structural reasons a new concrete C60 will be created. • Steel only used in the reinforcement bars. 5. Model elaboration • A 3-D grid with all the elevation and plan dimensions inputed has to be created. 5. Model elaboration • It is convenient to create a new set of columns every 5 stories to make it easy when dimensioning them. • In the first 4 floors the columns that don’t have floors on top will also be different than the ones with 35 floors on top 5. Model elaboration • When drawing shear walls it’s possible to distinguish into two kinds of shear walls: • The ones surrounding the elevators and stairs. • In the residential floors, the ones dividing the different apartments. 5. Model elaboration • There are two kinds of beams: • Primary beams that go from column to column. The moment release for this kind of beams will be continuous. • Secundary beams that go from beam to beam. The chosen distribution for this type of beams is a cross distribution. The moment release for this kind of beams will be pinned. • No beams should be drawn inside the shear walls. 5. Model elaboration • Two kinds of slabs: 1.Normal slabs ; 2.Inside shear walls slabs 6. Model analysis • • Three requirements should be met by the model: • First rotation period / x or y period < 0,9 • Story drift < 1/800 • Maximum story drift / average story drift < 1,4 To meet this three requirements a process of analysis and later dimensioning of the structural members will take place. • It will be necessary to look at the different modes of structure to determine which one is the first to have rotation. 6. Model analysis 1st mode 2nd mode 3rd mode 6. Model analysis Deformed shape 3-D View Longitudinal Reinforcing 6. Model analysis 7. Requirements οΆ First rotation period / x or y period < 0,9 The first rotation period is the one of the third mode = 1,85398 The first period with x or y movement is the first mode = 2,50081 1,85398 / 2,50081 = 0,741352 < 0,9 οΆ Story drift < 1/800 The maximum story drift is for the 35th floor: 1/811 < 1/800 οΆ Maximum story drift / average story drift < 1,4 The maximum story drift is for the 1st floor= 1/811 Average story drift = 9,5992*10^(-4) (1/811) / ( 9,5992*10^(-4)) = 1,285 < 1,4 THANK YOU! θ°’θ°’!