Wind
Wind can be a killer on a construction project
Consider the following cases in which fatalities occurred
Average of 47 wind-related deaths per year in the United States
Deaths Due to Wind
gust of wind blew a cover off an enclosure on a tower under construction.
worker yelled a warning to personnel below.
a worker at the 400′ level saw the falling cover, and unhooked his safety line to get out of the way of the falling object.
the cover struck worker and the worker fell approximately 350′ to the base below.
structure was severely weakened by the vertical columns
2 workers inside a building being demolished cutting
20+ mph north wind with gusts of 30 mph + structure became even more unstable structure collapsed on worker trying to exit
Five aluminum concrete forms (8′ x 3′, 80 pounds each) were standing vertically
strong gust of wind blew them over
victim was knocked down and his head struck a wale bracket that was sticking out of a 5 gallon bucket
installing roof trusses on a building
installing 2X4″ by 12′ supports onto the trusses unexpected gust of wind from the south west
trusses collapsed and the victim to fell to the concrete floor below
Pressure on a Surface?
How Does Wind Speed Translate to
P = K V2
P = pressure in PSF
K = Constant (~0.0033) V = wind speed (mph)
Pressure and Wind Speed
When the wind speed is doubled, the pressure is quadrupled
For wind speed of 20 mph, P = 1.3 psf For wind speed of 75 mph, P = 18.5 psf For wind speed of 150 mph, P = 74 psf For wind speed of 155 mph, P = 79 psf
Pressure PSF
Wind Speed
33
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