OYERALL 为 MGUME EYACE 怡←与学 FLOOR eurracna 4Pa纠pL似LRN
Answer: 1.(a)Total dead load at foundation=8 w A=8x7.175 x 1116.3=64075.62kN w=150 Pound/ft2=150x4.45N/0.3052m2=7.175kN/m2 A=140x60+60x60ft2=12000ft2=12000x0.3052m2=1116.3m2 (b)Total area units =20 (c)Load per area unit 64075.62/20=3204kN/unit 2.Column axial force of dead loads Na=1.5x3203.78=4806kN;Nb=Nc=1X3203.78=3204kN;Nd=0.5x3204=1602kN; Ne=2x3204=6408kN 3.Column axial force of wind load in main wind direction,Nb=Ne=0 4.5Ndx60x0.305=20x47.84x8x3mx80x0.305x12m, Nd=Nc=81.65kN,Na=0.5x81.65=40.83kN 4.Column axial force of wind load in another direction if Na=x.Ne=Nc=3x.Nd=7x, 60x0.305x24x12x20x47.84=2Nax0.305(7x140+5x100+3x60+1x20) Na=4.92kN,Ne=Nc-14.76kN,Nd=34.44kN, 0.5Nb=34.44x2/1.5/2=22.96kN 5.Column axial force of wind load in another direction 1.5Nbx60x0.305+1.5Nb/3)x20x0.305=60x0.305x24x12x20x47.84, 0.5Nb=0.5x(180.69)=90.34kN Therefore Nb=22.96+90.34=113.3kN. Ne=0.5x180.69/3+0.5x14.76x2/1.5=30.12+9.84=39.96kN Na=90.34+0.5x4.92x2/1.5=93.62kN 6.The Maximal Wind Load: Na=93.62kN,Nb=113.3kN,Nc=81.65kN,Nd=81.65kN,Ne=39.96kN
Answer: 1.(a) Total dead load at foundation =8 w A=8x7.175 x 1116.3=64075.62kN w=150Pound/ft²=150x4.45N/0.305²m²=7.175kN/m² A=140x60+60x60ft²=12000 ft²=12000x0.305 ²m ²=1116.3 m ² (b) Total area units = 20 (c) Load per area unit = 64075.62/20=3204kN/unit 2. Column axial force of dead loads Na=1.5x3203.78=4806kN; Nb= Nc = 1X3203.78=3204kN; Nd=0.5x3204=1602kN; Ne=2x3204=6408kN 3. Column axial force of wind load in main wind direction, Nb=Ne=0 4.5Ndx60x0.305=20x47.84x8x3mx80x0.305x12m, Nd=Nc=81.65kN,Na=0.5x81.65=40.83kN 4. Column axial force of wind load in another direction if Na=x,Ne=Nc=3x,Nd=7x, 60x0.305x24x12x20x47.84=2Nax0.305(7x140+5x100+3x60+1x20) Na=4.92kN, Ne=Nc=14.76kN, Nd=34.44kN, 0.5Nb=34.44x2/1.5/2=22.96kN 5. Column axial force of wind load in another direction 1.5Nbx60x0.305+1.5(Nb/3)x20x0.305=60x0.305x24x12x20x47.84, 0.5Nb=0.5x(180.69)=90.34kN Therefore Nb=22.96+90.34=113.3kN, Ne=0.5x180.69/3+0.5x14.76x2/1.5=30.12+9.84=39.96kN Na=90.34+0.5x4.92x2/1.5=93.62kN 6. The Maximal Wind Load: Na=93.62kN, Nb=113.3kN,Nc=81.65kN,Nd=81.65kN,Ne=39.96kN
Summary of tube action -Very good in strength and stiffness Flange part of square tube takes 75 total bending moment Web part of square tube takes 90%shear force -Horizontal and vertical subsystems work together to achieve tube action
Summary of tube action -Very good in strength and stiffness - Flange part of square tube takes 75 % total bending moment - Web part of square tube takes 90% shear force -Horizontal and vertical subsystems work together to achieve tube action
Fig 3-18 Interaction of vertical and horizontal subsystem of tube structure TOTAL SYSTEM: SHEAR TRANSFERRED BENDING STRESSES IN BENDING STRESSES IN 4 VERTICAL PLANES BY PLANES WHICH ARE SHEAR RESISTING PLANES TOTAL SYSTEM(TRANSVERSE JOINED AT CORNERS PARALLEL TO (H) PLANES ACT BECAUSE AND ONE HORIZONTAL JOINED TO SHEAR PLANES) PLANE CLOSING TOP (oc TENDENCY TO BUCKLE
Fig 3-18 Interaction of vertical and horizontal subsystem of tube structure
Fig 3-21 Horizontal subsystem increase stiffness of vertical subsystem DL VERTICAL SECTIONS A-A b he e ne 1 ZONES WHERE BUCKLING LOCALIZED BUCKLING STIF FNESS INCREASES- Is POSSIBLE AS h EFFECTIVE DECREASES
Fig 3-21 Horizontal subsystem increase stiffness of vertical subsystem