I've been looking at what the media has been reporting about the tornado activity in the midwest - especially the EF4 that rolled through Illinois (and part of Missouri?) My heart goes out to those who have lost friends and family in those storms, but there is a question that's been nagging at me for quite some time...

In areas prone to earthquakes, structures are built with reinforcement throughout the building and in the foundation. Areas prone to flooding have structures that are elevated above the flood line. In areas that get a lot of snow, roofs tend to be pitched rather than flat. Etc., Etc....

However, I look at the pictures the media throws at us and one thing that sticks in mind are the houses - "stick-frame" houses. Also, the mobile homes... In my mind, an area that is prone to this kind of weather activity and where it happens every single year at about the same time every year (even though the media makes it out to look like it's never happened before) should be leaps and bounds over the rest of the country in engineering structures that can withstand a tornado.

I don't fully understand the dynamics of a tornado and I've seen maybe one real tornado in my life (in North Carolina) and I don't understand the thinking or reasoning that goes on after a tornado has gone through and devastated an area but, it makes absolutely no sense at all to me to build a house on a plot of land that had just been wiped out by a tornado and have that house be built exactly the same way the previous house was - especially if there's a good chance it will get wiped out the following year - and then the rebuilding process happens all over again... Seems like a vicious cycle to me and one that can maybe be lessened to some degree if not avoided...

I think, if it were me, I would either move underground or build a dome - a dome, with no protruding bits hanging off of it, seems like an ideal structure to withstand the forces a tornado produces. I could be wrong about that, of course - and, also, living inside a dome produces another unique set of problems altogether (like storage space, for example.) But, really, if you look at a structure that has been hit hard by a tornado, it seems to me you can learn from that and not repeat the same mistake when rebuilding - or am I way off track here?

Rebuilding like this is quite costly, but who pays for it? We all know the insurance industry is not always the greatest entity to deal with in situations like this, but I would think that even the insurance industry would help fund, promote, and/or encourage the study of tornado dynamics and the engineering of tornado-resistant buildings. Or have they been doing it this whole time and we just don't know it?

I'm genuinely curious about this and I'm hoping to learn from those who may have experienced this before.

Where I live isn't prone to tornadoes, but we do get the occasional earthquake tremor. If we did get a tornado like what you folks in the midwest get, we would be in one great, colossal, cluster**** of a mess. It amazes me how people who live in those areas deal with it...

 

One big difference between a tornado and an earthquake, flooding, or hurricanes is that a tornado affects a very small area, where earthquakes, floods, and hurricanes affect large areas. Even during a major tornado outbreak, the odds of a tornado hitting any one point are very small. However, during an earthquake, flood, or hurricane, nearly every building in the area is going to be affected.

Most houses are simply built to meet code, and building codes are different in areas that are prone to earthquakes and hurricanes. A house can certainly be built stronger than code requires, but it costs more money to do so.

Here's a great presentation on understanding tornado damage. I saw this presentation in person at the 2008 MN Skywarn workshop. (It is about 45 min long)

MSW 2008 Keynote Address

 

Tornadoes are hard to build for I would think. About the only sure thing is a storm cellar/basement safe room and that depends on you being able to get to it. You can look at the aftermath and see houses totally destroyed and have one little room from a building still standing. For me I don't worry about it much. Been through a couple and have been lucky to be honest. One thing I did read a while back was a suggestion by some group about when a tornado was to be in the area to put motorcycle or bicycle helmets on to help prevent against head injuries. Showed a motorcycle helmet that was pretty scratched up that a guy wore through one storm. Didn't really sound like that bad an idea.

 

There's no way you could build a house above ground that could withstand a direct hit from an f-3 or above tornado and be feasible. Underground would be the only way. Homes with a basement is about the only way to avoid death from a direct hit.

I wonder what the percentage is of tornadoes that do damage to homes and towns, and those that happen in farm country and never hit any buildings.

 

Oh yes, you can build a house to withstand a F3! Money is the problem! They built a "hurricane proof" here is Houston that was constructed 100% concrete/rebar. Along with some pretty impressive windows and cool stuff like geo-thermal sump, etc... The house was rated for 300 mph winds anyway. Not too shabby if you have the funds.

 

Only when there is no insurance or Federal disaster money will people stop building houses vulnerable to and in the know paths of hurricanes, tornados & floods.

And at that point, houses will be too expensive (as per prior post) and you will have migrations by some and others living homeless. Can we afford to depopulate flood, tornado and hurricane country?

Earthquake prep is childs play compared to flood, tornado or hurricane.

 

That was a very informative presentation - thanks for sharing that I kind of already had some idea of the uplift, but they way this guy describes the other forces involved helped put things in better perspective.

There were some other good points brought up in this thread, as well.

So, if I understand it correctly - what causes a structure to fail in a tornado is known, for the most part; what is needed to be done to lessen the chances of a structure failing in a tornado is known; but, because of elements such as time, money, and laziness, what is needed to improve the structure design doesn't get done, so it fails again the next time it's hit by a tornado...

I still can't help but think that the shape of the structure has something to do with it, as well. The guy in the presentation compared a pitched roof to an airplane wing - I never thought of it that way before, but it makes sense... Reduce the chance of the winds entering the structure and reduce the chance of the wind being able to "grab" the structure, then wouldn't that effectively reduce the chance of uplift or "ballooning" of the structure? I would think so, but then, I'm not an engineer so what do I know?...

I suppose the dynamics of a hurricane would be similar to a tornado only on a much grander scale and involving water as well as wind...

Sheesh, I think I would rather put up with seismic activity...

Thanks for helping me understand this a bit better

 

Building codes are supposed to address this problem a little bit, from what I understand.

A few years ago, a relatively new development near me got hit, and the damage was substantial. There were articles in the paper about some of the houses not being up to code. That apparently made them more vulnerable. I imagine that lawsuits appeared on the scene after that.

As has been mentioned, I'm not sure how much can reasonably be done for homes.

hj

 

live in tornado country as many of you do . from my experience i don't care how well designed a building is mother nature can and will find a way to defeat what man has accomplished . i got a niece and her 3 kids in harrisburg we can't find , that's the real toll . the human cost and suffering .... everything else is just stuff ..... we will never be able to tame our planet or maw nature !

 

I hope your niece and children are safe.

 

+1 - Hope you're able to find them OK and safe.

 

55 f350: Hopefully you will get some good news and they are safe.

85e150six4mtod: We cannot just depopulate area prone to natural disaster. If that was the case, everyone needs to depart the planet. You can't beat Mother Nature.

 

my niece was found with her babies . they for some odd reason ran for the car . this time it saved their lives . the house was gone ... looked like a bunch of snapped tooth pics according to my 2 brother in laws . they were trapped by debris for two days in it , denise had a broken leg , and was in not so good shape , and the kids were covered by cuts , abrasions , and bruises . wasn't a pretty sight as being trapped in the car they had to relieve themselves in there . she had food , water and blankets in the trunk due to it being winter in case of an unfortunate event . the boy ripped the back seat up and got in it to get too it . all i can say is thank you to the man above !!!!!! they're in the hospital for a few days now . they were scared witless according to those there , and no wonder they just rode out an f4 basically in the open in her drive in the car . dain car needs to be gold plated and mounted on a base as a statue !

 

That's great to hear that they are alive. My folks just got hit yesterday afternoon. They are OK, but the house suffered some damage. The barns and out buildings are all destroyed.

 

As others have touched on here, it primarily boils down to the cost vs. benefit. To make a structure tornado-resistant (never mind tornado-proof), it's not just a small cost premium, it would be a huge jump. As for the benefit, I live in a county with a population of about 170,000 and a land area of right at 500 square miles (Tippecanoe County, IN). In the 20+ years I've been in the area, there have only been less than a half dozen fatalities due to tornadoes (I think it's just 4--all from one event in 1994--and all in one factory that was hit). Maybe 3 dozen or so structures have been totally destroyed in 4-5 tornado touch downs. They're just not that common, and like someone else said, their path of destruction is quite small more often than not--the mile-wide EF5 wiping out whole towns you see in the movies are very rare. Yes, a major tornado just wiped out a small, southern Indiana town yesterday, but most small towns in Indiana are largely comprised of very old homes. New construction codes wouldn't help them.

Jason