Wind Load Design of Astoria
8
STEP 1:DESIGN CRITERIA 1. Basic Wind Speed and Wind directionality Fa V=200 mph 2. Importance Factor 3. Exposure Category And Velocity Pressure Exp Exposure Category = C Building qualifies as Low-Rise Buil h= 13.4 + 0.6/2 h= 13.7 4. Topographic Factor where: kd =0.85 Iw = 1.15 kh = 1.073 kz = 2.01(z/ zg ) 2/α kz = 2.01(z / zg ) 2/α kz = 2.01(9.5/ 275) 2/9.5 kz = 1.07 kzt = 1.0 5. Gust Effect Factor G or Gf G = 0.925(1+1.7gQIzQ / 1+1.7gv Iz ) G = 0.925(1+1.7gQIzQ / 1+1.7gv Iz
-
Upload
gerald-oreiro -
Category
Documents
-
view
30 -
download
1
Transcript of Wind Load Design of Astoria
STEP 1:DESIGN CRITERIA
1. Basic Wind Speed and Wind directionality Factor V=200 mph
2. Importance Factor
3. Exposure Category And Velocity Pressure Exposure Coefficient Exposure Category = C Building qualifies as Low-Rise Building h= 13.4 + 0.6/2 h= 13.7
4. Topographic Factor
where:
kd =0.85
Iw = 1.15
kh = 1.073
kz = 2.01(z/ zg ) 2/α
kz = 2.01(z / zg ) 2/α
kz = 2.01(9.5/ 275) 2/9.5
kz = 1.07
kzt = 1.0
5. Gust Effect Factor G or Gf
G = 0.925(1+1.7gQIzQ / 1+1.7gv Iz )
G = 0.925(1+1.7gQIzQ / 1+1.7gv Iz )
Iz =
Q=
6. Enclosure Classification Partially enclosed
7. Internal Pressure Coefficient
b. Wall pressure
Leeward Windward Side wall c. Roof pressure
windward leeward
9. Velocity Pressure
10. Design Wind Load 1. For Wall
a. windward (+) p = 1.98((0.80)-(+0.55)) (-) p= 1.98((0.8)-(-0.55))
b. Leeward (+) p=1.98*(-0.426)-(0.55) (-) p= 1.98*(-0.426)-(-0.55) c. Sidewall (+) p=1.98*(-0.7)-(0.55) (-) p= 1.98*(-0.7)-(-0.55)
2. For Roof
a. Windward
gv =
gQ =
Gcpi = ± 0.55
8. External Pressure Coefficient Cp or GCpf
a. assume roof angle of 20⁰
qh = 47.3 x 10-6 Kz K zt KdV2 Iw
qh = 47.3 x 10-6 *1.07*1.0*0.85*200*1.15
qh =
p= qh [(GCpf )][(Gcpi)]
(+) p = 1.98((-0.502)-(+0.55)) (+) p= 1.98((-0.0612)-(+0.55)) (-) p = 1.98((-0.502)-(-0.55)) (-) p= 1.98((-0.0612)-(-0.55))
b. Leeward (+) p = 1.98((-0.6)-(+0.55)) (-) p= 1.98((-0.6)-(-0.55))
(table 207-1 )
(table 207-2)
Occupancy Category III ( section 207.5.5)
3. Exposure Category And Velocity Pressure Exposure Coefficient(section 207.5.6.3)(section 207.5.6.4.2)
table 270-4 ( via interpolation)
table 207-5
α= 9.5
z= h
section 507.5.7
(assumed since near open fields)
section 207.5.8
section 207.5.8.1
0.21 equation ( 207- 5)
note no. 2 For 4.5m ≤ z ≤ zg
zg = 275
c( 10/ z )1/6
0.903 equation ( 207- 6)
3.4 section 207.5.8.1
3.4 section 207.5.8.1
section 207.5.9section 207.2
section 207.5.11.1
0.55 figure 207-5-0.55 figure 207-5
section 207.5.11.2
L/B 20.505/ 14.96 = 1.37
-0.426 (by interpolation)0.8-0.7
h/L = 13.7/ 50.505 = 0.67 -0.502, 0.0612 by interpolation
-0.6
section 207.5.10
1.98
section 207.5.12.2.2
0.4952.673
-1.9320.246
-2.475-0.297
√ 1 / 1+ 0.63( B+ h / Lz ) 0.63
Cp
normal to ridge θ ≥ 10⁰
-2.083-1.210.0950.968
2.277-0.099
