Image: Figure 1. Elevation diagram of wind forces affecting a concrete dome. - Monolithic Dome Institute

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Figure 1. Elevation diagram of wind forces affecting a concrete dome. — Figure 1. Elevation diagram of wind forces affecting a concrete dome.

Figure 1. The elevation profile of wind forces affecting a concrete dome.

Concrete dome wind analysis

Example 1

Commercial dome building 30 feet high in exposure C — the most severe exposure in open, flat terrain. Using wind design pressure from UBC 1985 Edition, section 2311.d, of 70 MPH.

p = C_e C_q Q_s I

I = 1.0 (commercial building)

Q_s = 13 psf (pressure from wind)

C_e = 1.3 (building height 30-feet, exposure C)

C_q = 1.3 (method 2)

Therefore, p = 1.3 × 1.3 × 1.3 psf × 1.0 = 22 psf

Example 2

Assume same building from Example 1 and same exposure but with a wind speed of 300 MPH. (Reference: Fine, Mark, Handbook of Concrete Engineering; Nan Nostrand Reinhold, 1974.)

p = ½ C_s C_a C_g P V_h² (H/h)^2/φ

Assume everything is constant except the wind speed.

P = C V_h² = 22 psf for V = 70 MPH (example 1)

Therefore, C = 22 / 70² = 0.00449

Then, p = 0.00449 V_h² for V = 300 MPH; p = 404 psf

The maximum concrete stress in a dome 100 feet in diameter by 30 feet high with p = 400 psf is 1,098 psi compression. From the “Concrete dome seismic analysis” example (below) we see the allowable stress is significantly higher at 2,394 psi.

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