Wind Loads on Building
Wind Loads on Building
(OP)
How do you calculate the wind loads (specifically, the uplift forces) on an enclosed building (36'L x 15'W x 12'H) that is resting 17' above water on 2 cantilevered beams? ASCE 7-10 shows how to do this with a building on solid ground, but how do you determine the effects of a 160-mph gust on a building with an exposed underside? Thanks for your help






RE: Wind Loads on Building
Otherwise, ASCE has books on loads on buildings.
RE: Wind Loads on Building
RE: Wind Loads on Building
http://www.fema.gov/media-library/assets/documents...
Since your scope of work is only wind loads, this chapter should help.
Note that ztengguy is right that designing a building for what resembles a coastal hurricane event involves a lot more than just wind. For a complete design, the all off FEMA P-55 needs to be considered in its entirety. However, I understand that is not what you need at this time.
www.SlideRuleEra.net
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RE: Wind Loads on Building
Further, the wind speed at ground level is very low (going asymtopically to zero at zero elevation) so the effect of "raising the top" of the building up into ever-faster and faster wind speeds far overwhelms to little bit of reduction you get by trying to assume the building is resting in mid-air.
Now, water resistance is another story at all regards: there, minimizing the "between ground and building floor" water resistance IS critical because water is 1000x the weight of wind, though far slower, and water is 100% concentrated down low under the building against the foundations and posts and stairs.
RE: Wind Loads on Building
i read somewhere that to find the uplift forces due to wind underneath the house, just treat the floor like a roof overhand and Cp = 0.8. However, if i do it this way, the uplift force is greater than the force of the wind hitting the windward wall, which doesn't make any sense to me. is there a way to figure out the predicted velocity pressure on the underside of the house from the velocity pressure on the windward wall?
RE: Wind Loads on Building
RE: Wind Loads on Building
MWFRS
RE: Wind Loads on Building
For a cube, you don't get any airfoil effect.
RE: Wind Loads on Building
1. wind velocity vector underneath the bldg may have a vertical component for a considerable distance as it enters the space below the bldg.
2. the density of the air this close to the water may be heavily influenced by the entrainnment of water thru spray, etc. and affect(increase) the calculated wind loads.
3.wave action...depending on the site exposure, reach,etc ...17ft clearance may not be enough..
RE: Wind Loads on Building
RE: Wind Loads on Building
RE: Wind Loads on Building
American Water Works Association has a publication D100 devoted to wind loads. Although not directly related to building structures,
it may give some insight in the calculation of wind loads.