Concrete Dome Wind Analysis

  • November 16, 2011, 2:55am UTC
  • by Dr. Arnold Wilson
Wind Speed: Pressure:
70mph 22 psf
100 mph 50 psf
150 mph* 100 psf
300 mph* 404 psf

* Force 5 hurricane (worst)
** Force 5 tornado (worst)

Example 1

Commercial building 30 feet high in exposure C (most severe exposure in open at terrain). Using design wind pressure from UBC 1985 Edition, section 2311.d, of 70 mph. V = 300 mph

P=CeCqQS I (commercial building)
I= 1.0
Qs = 1.3 psf (pressure from wind)
Ce =1.3 (building height 30 ft = exposure C)
Cq =1.3 (method 2)

Example 2

Assume same building and same exposure but with wind speed of 300 mph.

Preference: Finte, Mark, Handbook of Concrete Engineering; Non Nostrand Reinhold, 1974.

Assume everything is constant except for the wind speed.

P = CVh = 22 psf for V = 70 mph (example 1)
Therefore C = (22)/ (70) = 0.00449
Then p = (0.00449) Vh2 for V = 300 mph; 404 psf

The maximum concrete stress in dome 100 feet in diameter by 35 feet high with p= 400 psf is 1,098 psi compression. From the “Concrete Dome Seismic Analysis” example we see the allowable stress is significantly higher at 2,394 psi.

Conclusion

The forces caused by the wind and earthquake on a concrete dome generally do not control the design. Domes are very strong and durable and in a realistic situation would probably still be standing when all conventional structures had failed.

Filed in: Durability
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