Wind Load Calculation As Per Asce 7-05 Extra Quality
ASCE 7-05
The design wind pressure ( ) for a structure as per is determined using the following primary formula:
Main Wind Force Resisting System (MWFRS)
The design wind pressure ($p$) is calculated differently for the and Components & Cladding (C&C) . wind load calculation as per asce 7-05
- (q) = (q_z) for windward wall, (q_h) for leeward wall, side walls, and roof.
- (G) = gust effect factor (Section 6.5.8.1). For rigid buildings: (G = 0.85) (simplified) or calculated exactly via: [ G = 0.925 \left( \frac1 + 1.7 I_z \sqrtg_Q^2 Q^2 + g_v^2 R^21 + 1.7 g_v I_z \right) ] (For most rigid applications, 0.85 is acceptable.)
- (C_p) = external pressure coefficient (Figures 6-6 through 6-11). Depends on wall/roof zone and L/B ratio.
- (q_i) = internal velocity pressure = (q_h) at mean roof height.
- (GC_pi) = internal pressure coefficient (Table 6-5). Typically ±0.18 for enclosed buildings.
Thus C&C pressures are often the governing load for cladding design. ASCE 7-05 The design wind pressure ( )
qz=0.00256⋅Kz⋅Kzt⋅Kd⋅V2⋅Iq sub z equals 0.00256 center dot cap K sub z center dot cap K sub z t end-sub center dot cap K sub d center dot cap V squared center dot cap I Kzcap K sub z (q) = (q_z) for windward wall, (q_h) for
Enclosed Buildings:
The wind doesn't just push on the outside; it can "inflate" or "deflate" a building if there are openings (like broken windows). Minimal internal pressure.