Wind MWFRS Calculator — ASCE 7-22 Directional Procedure

Wind

V from Figures 26.5-1 for your risk category (ASCE 7 Hazard Tool). K_zt = 1.0 away from hills and escarpments (§26.8).

Building

G = 0.85 for rigid buildings (§26.11.1). Flexible buildings need G_f from a dynamic analysis — a desktop feature.

Story forces

Tributary-height story forces at h·k/n. Windward q_z varies with height, leeward rides q_h; GC_pi cancels in the net frame force. The bottom half-storey reacts at the foundation — the table says how much bypasses the diaphragms. Drawn diaphragm elevations are a desktop feature.

Results

Coefficients each names its table

Design pressures Eq. 27.3-1: p = q·G·Cₚ ∓ qᵢ·(GCₚᵢ)

Both internal-pressure cases are design cases (§27.3.1) — positive pressure acts toward the surface, negative away. Sign convention: + inward.

Story forces tributary heights, net frame pressure

q_z profile ASCE 7-22 Table 26.10-1 up the windward wall

How this is calculated

Run a calculation to see the chain.

q_z = 0.00256·K_z·K_zt·K_d·K_e·V² (Eq. 26.10-1, K_d = 0.85 buildings) · p = q·G·C_p ∓ q_h·(GC_pi) (Eq. 27.3-1). Base shear sums EXTERNAL windward + leeward pressures — internal pressure acts on both faces of the envelope and cancels.