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Giant Lab Replicates Category 3 Hurricanes
Pickens writes "The WSJ reports that a new $40 million research center built by the Institute for Business & Home Safety in Richburg, SC features a massive test chamber as tall as a six-story building that can hold nine 2,300-square-foot homes on a turntable where they can be subjected to tornado-strength winds generated by 105 giant fans to simulate a Category 3 hurricane. The goal is to improve building codes and maintenance practices in disaster-prone regions even though each large hurricane simulation costs about $100,000. The new IBHS lab will be the first to replicate hurricanes with winds channeling water through homes and ripping off roofs, doors and windows. The new facility will give insurers the ability to carefully videotape what happens as powerful winds blow over structures instead of relying on wind data from universities or computer simulations. The center will also be used to test commercial buildings, agriculture structures, tractor-trailers, wind turbines, and airplanes."
This makes me wonder if they are doing this because scientists say that Global Warming will increase the strength and frequency of hurricanes, tornadoes, earthquakes and other natural disasters.
Why not try to combat the sources of global warming at the same time? Green, renewable energy might also help the insurance industry save money.
He who knows best knows how little he knows. - Thomas Jefferson
Yeah, generally you don't even try to build to withstand a direct hit from a tornado, it'd just be way too expensive. The odds of any particular building getting smacked by a tornado are fairly small, and even a big tornado affects a much smaller area than your average landfall hurricane.
Designing to survive hurricane force winds is much more feasible, and it's cool to watch some actual experimentation. Note from the video, that right before the house on the left collapses, the front door is pushed open. Once the wind gets into the house, it needs to go somewhere, and it basically lifts the house up allowing it to fall over. You have to bolt the whole house together vertically, from the foundation all the way up to the rafters.
One time I threw a brick at a duck.
If they wanted to see what the effect of a class 3 hurricane, they should come to my house and look at my kids rooms. Some people already think I was simulating an F5 tornado.
I asked someone from Environment Canada what the difference between an F4 and F5 tornado was, his answer was "an F4 destroys everything, an F5 destroys everything and cleans up after itself". Given those parameters, it sounds like your kids are only simulating an F4. ;)
They say a little knowledge is a dangerous thing, but it's not one half so bad as a lot of ignorance. - Terry Pratchett
How much cheaper, really? Let's take the example of having modular prefabbed floors & exterior walls that are available in many configurations so you have design freedom to build what you like. These prefabbed sections can be mass produced, cheaply, and the right combination shipped to the location. Once there, you flip it up, use whatever connection method is needed for the walls and lay down the interlocking floor sections. The prefab sections I saw near Munich even had insulation built into them.
With wood, the wood has to be processed, granted at a much lower cost than the concrete section fabbing. Then it has to be shipped just like the prefabbed. But then it changes - The amount of labour that goes in to laying floor joists, laying & fastening floor sheets (which all results in a boing-ey floor anyway), framing wall sections on the floor then raising them, then ultimately installing insulation and poly, is quite a lot more than I imagine an efficient prefab production line would be.
Note that I have no actual idea of the relative costs of anythign above, but i'm genuinely curious as i'm sure that an efficient prefab system could turn out cheaper, or at least on-par. Then you get the benefit of stronger houses. Oh and there's nothing to stop you doing the internal framing with wood/metal studs, so you still get the freedom to change/customise the internal layout.
I do agree, however, that pure brick or poured concrete buildings would be more expensive. I also agree that *right now* it would be more expensive as an efficient prefab infrastucture would need to be built up over time. With the "PROFIT NOW, NOT LATER!!!" mentality of businesses over here, this is not likely to ever happen.
A professor once said "an EF4 will clear the concrete slab the house was built on, an EF5 will clear the ground the concrete slab was built on". Don't know if it is a little bit of an exaggeration, but I would rather not find out.
I always wonder this. Even in non-hurricane zones, houses in Europe (England & Germany is all I know about) are made of brick or poured/prefabbed concrete.
In England at least, this has a lot to do with the first building codes brought in after the Great Fire Of London in 1666 . The codes specified non-flammable building materials, eg brick or stone.
To this day, almost all (if not all) houses are brick built, including the suburban tracts that would look familiar to Americans. AFAIK pre-fab concrete was a big thing in the 1950s-60s, mostly for government-built 'council houses' and especially tower blocks (what a USian might call a 'project'). This method fell out of favour in the UK after a pre-fab concrete tower block partially collapsed after a gas explosion in 1968: http://en.wikipedia.org/wiki/Ronan_Point
This is a substitute for a clever sig that fits within the maximum number of characters.
It's not that much quicker. A good framing crew can put the whole house up in a few days. It's weird when you're monitoring a job. The sitework seems to take forever and it doesn't look like that much is going on. Then the framing starts and in a couple days there's this big wooden house that appeared out of nowhere. And you think damn, this thing is like 80% done, we'll be finished in no time. Then all of the interior build-out starts, and it takes months and feels like it'll never end.
Also framing tends to be very mistake tolerant. If the designer or the builder did something wrong, it's generally not a big deal to tear it out and rebuild it better. All of the framing works together to provide strength to the house, so temporarily removing any single stud/joist/section of wall/whatever usually won't result in collapse, as there's plenty of redundancy in the structure.
One time I threw a brick at a duck.
The wooden frame house I'm living in now was built in the early 50's and has survived three hurricanes and several tropical storms. It creaked and groaned a bit, ok a lot, during Ike in 2008 but didn't suffer any damage. Not so much as a broken window. IIRC my neighborhood had sustained winds in 90mph range with recorded gusts up around 110mph. The house endured that beating for good four hours while the massive storm passed over.
Wood is much stronger than most people realize. The softwoods commonly used in home construction are also quite flexible and can deflect a lot before failing in a structural situation. When a wood frame house suffers a structural failure it's often somewhat graceful and the structure retains some of strength and doesn't just collapse on the people inside. A brick or concrete structure will hold up well until it hits a breaking point, then failure is complete and often catastrophic. Also concrete is ugly, I'd hate living in a concrete house.
Cheers,
Josh
"Listen: We are here on Earth to fart around. Don't let anybody tell you any different!" - Kurt Vonnegut
And I agree. One of my co-workers in Scotland was commenting that they had a force 7 gale going there. I looked it up. 31-38 mph winds. We have a word for that in Kansas: Spring.
A gale is really just the step after breeze (force 6 is strong breeze), you go through all the gale levels (7-9) then all the storm levels (10-12) before you get to a hurricane. Not sure where he's from in Scotland for a gale to be all that special, they should be getting roughly the same weather as us here in Norway over the North Sea and it's not that uncommon.
Even though storms have the full force of the Atlantic to build on, the strongest hurricane we've measured here in Norway was in 1992 and it was only a class 2, most years go without a single hurricane of any category. Gale is a windy day, storms are the only kind of storm and hurricanes are on TV. Same with tornadoes, very rare.
Live today, because you never know what tomorrow brings
A buddy with a construction company in Florida built his house as a 40 foot square (1600 sq. feet) with a pyramidal shaped roof (cathedral ceiling inside and all interior walls end at 9' high) so that there are no flat roof surfaces for the wind to build up agains. For the framing, there were the standard threaded rod ties coming up from the slab, through the footers of the wall, and bolted down but he also put additional ties running up from the slab all the way up through the outside walls, that then go through a 1/2" thick steel band that circles the entire top of the walls. This band was welded together so the walls are in compression between slab and band. The roof trusses are also welded/bolted to this band. The walls are basic OSB with decent insulation and waterproofing applied and vinyl siding (with construction adhesive on every piece. He's gone and made it as hurricane proof as possible. Of course, he has the polycarbonite coverings for all the windows.
He's also constructed separate building on his property as a workshop and store room. He went and built it just like his company builds walk in bank vaults. It has 12" of concrete all around and 2000 gals of rainfall collection. This is his tornado shelter. He did this second building last year as a way to keep his guys employed. Building trade in Florida has really taken a hit since the real estate crash.
I drank what? -- Socrates
For some reason it seems like it is much cooler or more respectable, these days, to hate on things than to be excited about them. In the existence of building a really big toy that rips shit apart, a lot of people will find fault with it being a big, wasteful, over-power-hungry, ego driven monstrosity. I find that, while this sentiment is reflected to some degree on slashdot, it is much calmer here than it is in many other cultural niches of society in general. Being the person that sees something and says, right off the bat, "Holy shit! That is amazing!" is, for whatever reason, taken to mean that the observer is gullible, stupid, or incapable of critical thinking. I can't really tell you why that trend seems so dominant in culture today (to me at least), but that's just what I've noticed.
For the record, as soon as I read the summary, my first thought was, "Fucking Epic!" Then I started thinking about all of the bad ideas that could go along with a machine like this that might involve a flying-squirrel suit and a helmet. So, no, you're not alone. =)
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