Tornados

[MillR]

I keep thinking I am all grown up and know every kind of engineering, and then the humble gods come around and say: tornadoes.

So I've engineered high seismic (CA), high wind (FL), bad soil (CO), every kind of structure but ... nothing in Kansas, as it turns out. And suddenly am in a position of having to sound like I know what up. Is there anything specific to tornadoes that is structurally significantly different from other bad ass areas?

I mean, besides get in the basement and pray.

 

[JAE]

Go to the FEMA site and get FEMA 361 (free copy) here: FEMA 361 link
Also the ICC has published ICC 500 - found here: ICC 500 link
The ICC is not free.

Basically tornadoes require higher wind speeds than hurricanes (possibly 250 mph vs. 150 mph) and also require projectile resistant walls and roofs.

The FEMA 361 document (which is really a guide, not a specification) provides a lot of background and is sort of an educational resource...probably want to start with that.



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[IRstuff]

see: thread507-299352 for a previous discussion. You've not specified the type of building. Residential would be quite different than commercial.

http://pbadupws.nrc.gov/docs/ML0036/ML003691207.pdf

http://codes.iccsafe.org/app/book/c...Fs/Chapter 3 - Structural Design Criteria.pdf

http://www.seakm.com/uploads/Joplin_Committee_Report_05262012.pdf

https://www.oksea.org/sites/osea/up...f/OKSEA_Meeting-Wind_Design_for_Tornadoes.ppt

TTFN
I can do absolutely anything. I'm an expert!
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[ornerynorsk]

If you can keep the roof on and everything tied to the foundation . . .

Here's a fair description -

http://www.popularmechanics.com/adv...-four-seconds-how-a-tornado-destroys-a-house/

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[MillR]

that's funny, the other thread seems to have concluded you can't design buildings for tornadoes. seems pretty similar to hurricane in terms of design, attach everything and use strong windows. it'll be commercial buildings, assisted living, etc but not residential. thanks for the resources.

 

[mike20793]

I second FEMA 361 and ICC 500 for shelter design. Pay careful attention to the section that talks about atmospheric pressure change and how to avoid it or design it. The 250 mph wind was developed based on the strength of EF5 tornadoes. I have a hard time imagining all the domes and other FEMA shelters I've designed during FEMAs latest funding campaign would ever risk collapse or failure under an actual tornado.