q_z at z_max
37.85
psf
K_z at z_max
1.315
—
V_eff at z_max
121.6
mph
p_net at z_max
32.55
psf
Velocity Pressure qz(z)
Effective Wind Speed Veff(z) & Kz(z)
| Symbol | Expression | Value | Reference |
|---|---|---|---|
| V | Design 3-sec gust wind speed, Risk Cat II | 115.0 mph = 51.41 m/s | Fig 26.5-1A–D |
| Risk Cat | II | 700-yr MRI | Table 1.5-1 |
| Exposure | C | C — Open terrain | §26.7 |
| α | Power law exponent (3-sec gust profile) | 9.5 | Table 26.11-1 |
| z_g | Nominal gradient height | 900 ft (274 m) | Table 26.11-1 |
| z_min | Minimum evaluation height for K_z | 15 ft (4.6 m) | §26.10.1 Note |
| Symbol | Expression | Value | Reference |
|---|---|---|---|
| K_zt | Topographic factor (flat site = 1.0) | 1.00 | §26.8 / Fig 26.8-1 |
| K_d | Wind directionality factor (buildings) | 0.85 | Table 26.6-1 |
| z_eff | max(z_max, z_min) = max(120.0, 15.0) ft | 120.0 ft | §26.10.1 Note |
| K_z | 2.01 × (z_eff/z_g)^(2/α) = 2.01 × (120.0/900)^(2/9.5) | 1.3151 | Eq 26.10-1 |
| Symbol | Expression | Value | Reference |
|---|---|---|---|
| q_z | 0.00256 × K_z × K_zt × K_d × V² [psf, V in mph] | 0.00256 × 1.3151 × 1 × 0.85 × 115.0² | Eq 26.10-1 |
| q_z | 37.847 psf = 37.847 psf | ||
| V_eff | V × √(K_z × K_zt × K_d) [reference only] | 115.0 × √1.1179 = 121.6 mph | Derived |
| Symbol | Expression | Value | Reference |
|---|---|---|---|
| G | Gust factor (rigid structure) | 0.85 | §26.11.4 |
| C_p | External pressure coeff. (windward wall) | -0.8 | §27.3 / Fig 27.3-1 |
| GC_pi | Internal pressure coeff. | 0.18 | §26.13 / Table 26.13-1 |
| p_ext | q_z × G × C_p | -25.736 psf = -25.736 psf | Eq 27.3-1 |
| p_int | q_z × GC_pi | 6.812 psf = 6.812 psf | Eq 27.3-1 |
| p_net | p_ext − p_int | -32.548 psf = -32.548 psf | §27.3.1 |
Profile Data — all n points
Imperial units
| z [ft] | z_eff [ft] | K_z | q_z [psf] | V_eff [mph] | p_ext [psf] | p_int [psf] | p_net [psf] |
|---|---|---|---|---|---|---|---|
| 15.0 | 15.0 | 0.849 | 24.43 | 97.7 | -16.61 | 4.40 | -21.01 |
| 20.5 | 20.5 | 0.907 | 26.10 | 101.0 | -17.75 | 4.70 | -22.44 |
| 26.1 | 26.1 | 0.954 | 27.44 | 103.5 | -18.66 | 4.94 | -23.60 |
| 31.6 | 31.6 | 0.993 | 28.57 | 105.6 | -19.43 | 5.14 | -24.57 |
| 37.1 | 37.1 | 1.027 | 29.56 | 107.5 | -20.10 | 5.32 | -25.42 |
| 42.6 | 42.6 | 1.058 | 30.44 | 109.0 | -20.70 | 5.48 | -26.18 |
| 48.2 | 48.2 | 1.085 | 31.23 | 110.4 | -21.24 | 5.62 | -26.86 |
| 53.7 | 53.7 | 1.110 | 31.95 | 111.7 | -21.73 | 5.75 | -27.48 |
| 59.2 | 59.2 | 1.133 | 32.62 | 112.9 | -22.18 | 5.87 | -28.05 |
| 64.7 | 64.7 | 1.155 | 33.24 | 113.9 | -22.60 | 5.98 | -28.58 |
| 70.3 | 70.3 | 1.175 | 33.81 | 114.9 | -22.99 | 6.09 | -29.08 |
| 75.8 | 75.8 | 1.194 | 34.36 | 115.8 | -23.36 | 6.18 | -29.55 |
| 81.3 | 81.3 | 1.212 | 34.87 | 116.7 | -23.71 | 6.28 | -29.99 |
| 86.8 | 86.8 | 1.229 | 35.36 | 117.5 | -24.04 | 6.36 | -30.41 |
| 92.4 | 92.4 | 1.245 | 35.82 | 118.3 | -24.36 | 6.45 | -30.80 |
| 97.9 | 97.9 | 1.260 | 36.26 | 119.0 | -24.66 | 6.53 | -31.18 |
| 103.4 | 103.4 | 1.275 | 36.68 | 119.7 | -24.94 | 6.60 | -31.55 |
| 108.9 | 108.9 | 1.289 | 37.08 | 120.4 | -25.22 | 6.68 | -31.89 |
| 114.5 | 114.5 | 1.302 | 37.47 | 121.0 | -25.48 | 6.75 | -32.23 |
| 120.0 | 120.0 | 1.315 | 37.85 | 121.6 | -25.74 | 6.81 | -32.55 |