Question 1

What wind procedure does AXIS use for wind load calculation?

Accepted Answer

AXIS uses the Directional Procedure (Chapter 27) from ASCE 7-22 for Main Wind Force Resisting Systems (MWFRS) of enclosed rigid buildings, which is the most common procedure for building design.

Question 2

How is the design wind pressure p calculated per ASCE 7-22?

Accepted Answer

p = qz × G × Cp – qi × GCpi, where qz is velocity pressure at height z, G = 0.85 for rigid structures, Cp is external pressure coefficient, and GCpi = ±0.18 for enclosed buildings.

Question 3

What is velocity pressure qz and how is it calculated?

Accepted Answer

qz = 0.613 Kz Kzt Kd Ke V² (in Pa), where Kz is the exposure coefficient at height z, Kzt is topographic factor, Kd is directionality factor (0.85 for buildings), Ke is ground elevation factor, and V is basic wind speed in m/s.

Question 4

What exposure categories are defined in ASCE 7-22?

Accepted Answer

ASCE 7-22 defines Exposures B (suburban/urban terrain with obstacles), C (open terrain with scattered obstructions), and D (flat unobstructed areas near water). Exposure B has the lowest wind pressures; D has the highest.

Question 5

What is the importance factor for wind loads per ASCE 7-22?

Accepted Answer

ASCE 7-22 replaced the importance factor with Risk Category-specific wind speed maps. The basic wind speed V already incorporates occupancy risk, so no separate importance factor is applied in ASCE 7-22.

Step	Formula	Substitution	Result
Kz	2.01(z/zg)^(2/α)	20	1.158 —
qh	0.613·Kz·Kzt·Kd·Ke·V²	0.613×1.158×1×0.85×1×45²	1222.3 Pa

Step	Formula	Substitution	Result
Kz	2.01(z/zg)^(2/α)	20	1.158 —
qh	0.613·Kz·Kzt·Kd·Ke·V²	0.613×1.158×1×0.85×1×45²	1222.3 Pa

Wind Load

Wind Load (MWFRS)

Wind Parameters

Building

Pressure Coefficients

Wind Load Analysis (MWFRS)