Wind Force on Solid Freestanding Wall / Sign
Design wind force and Case B eccentric (torsion) moment on a solid freestanding wall, monument sign, or pylon.
Example
You enter
- Velocity pressure qh, including Kd (psf) 17
- Gust factor G 0.85
- Force coefficient Cf (net, Fig 29.3-1) 1.35
- Solid area As (ft²) 64
- Width B (ft) 8
You get
- Design wind force 1,248 lb
- Case B eccentric moment (torsion) 1,998 lb-ft
Checked against published worked examples from: ASCE 7-22 Section 29.3 (solid freestanding walls and signs).
Details, formula, and sources
ScopeASCE 7-22 Section 29.3, F = qh G Cf As with a net two-face Cf from Fig 29.3-1 (~1.2-2.0, not a building-wall +/- GCp). The 0.2B eccentricity, not the straight force, sizes the post and footing.
Formula or tableF = qh G Cf As; Case B eccentric moment M = F x 0.2 x B.
Source and editionThe ASCE 7-22 Section 29.3 design wind force on solid freestanding walls and signs, F = qh G Cf As, with Cf from Figure 29.3-1, by name.
Free accessASCE 7 is available through the ASCE Library at ascelibrary.org; the Section 29.3 provisions are public.
What governsEstimate. AHJ and licensed professional govern.
API field namesvelocity_pressure_psf, gust_factor, force_coefficient, solid_area_ft2, width_ft, wind_force_lb, moment_caseb_lbft
- Net force coefficient Cf ~1.2-2.0 from Fig 29.3-1 by B/s and s/h; net two-face, not building-wall GCpASCE 7-22 Fig 29.3-1
- Case B eccentricity the resultant acts at 0.2B, producing the torsion that sizes the post and footingASCE 7-22 29.3