ASCE 7-22 Wind Load: Velocity Pressure and MWFRS Design per Chapter 26
Summary: Calculate velocity pressure at mean roof height for Main Wind Force Resisting System per ASCE 7-22 Chapter 26, Table 26.9-1, and Equation 26.10-1. Free…
Overview
Building / scenario
- Occupancy / use: Office, Risk Category II
- Geometry / size: 80 ft × 60 ft, h = 30 ft
- Site / exposure: ASCE 7-22
Problem statement
A Risk Category II office building is 80 ft × 60 ft in plan with 30 ft mean roof height. Basic wind speed 115 mph, Exposure B. Determine velocity pressure qh for MWFRS design per ASCE 7-22 Chapter 26 and Table 26.10-1.
Workflow in StructSuite
In StructSuite Wind Loads, complete Steps 1–3 (risk, V, Kd, exposure, Kzt, Ke, enclosure, GC_pi). In Step 4, enter Mean Roof Height h = 30 ft and confirm Kh from Table 26.10-1; Step 4 blue summary also shows roof angle after you enter θ in Step 6 (enter flat roof, θ = 0°). Step 5 displays qh from Equation 26.10-1. For full MWFRS zone pressures, select Chapter 27 or Chapter 28 and complete Steps 6–7.
Design considerations (excerpt)
V drives q ∝ V²—115 mph vs 130 mph = 28% higher pressure. Risk Category affects importance factor. Coastal (130–170 mph) and hurricane (180 mph) require robust connections. Inland 90–115 mph typical.
Step 4: Enter h and confirm Kh from Table 26.10-1; Chapter 27 Directional also lists Kz at listed heights z. Step 6: Enter L, B, roof type, and θ; then Step 4 accordion shows Roof angle = …°. Mean roof height h sets Kh: higher h = higher Kh. 30 ft in Exposure B: Kh≈0.70.
Exposure B (suburban): Kh lower. C (open): ~30% higher qh than B. D (waterfront): highest. Site within 1500 ft of open water triggers D. Kzt: ridge/escarpment can double pressure at crest. Ke for elevation >1000 ft.
qh =…
Related terms
- StructSuite
- structural engineering
- design example
- wind
- ASCE 7-22
- MWFRS
- simple building velocity pressure
Open the live example
Use the interactive, read-only wizard: Open this example in StructSuite (pre-filled inputs and step-by-step UI).