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Design Gust Wind Speeds in the United States.

pdf icon Design Gust Wind Speeds in the United States. (577 K)
Simiu, E.; Filliben, J. J.

Journal of Structural Engineering, 1077-1080, September 1999.


wind velocity; climate; structual design; statistics; structural engineering


The main result of the authors' work is Fig. 5, a map containing 5O-year peak gust wind speeds specified for structural design purposes. Except for (1) the states of California, Oregon, and Washington; (2) areas affected by hurricanes; and (3) a few small special wind regions, that map specifies a wind speed of 90 mph (40 m/s) regardless of geographical location. The question arises whether the true 50-year peak gust speeds are indeed close to 90 mph (40 m/s) over that entire geograph-ical area, or whether the map is in fact masking real differences among distinct extreme wind climates. The contours of the 50-year map based on the authors' own calculations (Fig. 3) contain estimated speeds varying from 80 mph (35.8 m/s) in northern Minnesota and Wisconsin to 95 mph (42.5 m/s) in portions of Oklahoma and New Mexico. The difference between the largest and the smallest estimated speeds is almost 20%; if, as is done by the authors. we consider the difference in terms of the corresponding wind loading. the percentage is about 40%.