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Earthquake House Tested at UCSDAired July 11, 2000 - 1:19 p.m. ET
THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.
DARYN KAGAN, CNN ANCHOR: Well, talk about reality-based television. Researchers -- we'll have to find out who came up with this idea -- but they are about to stimulate a powerful earthquake to find out what it does to one particular house.
KYRA PHILLIPS, CNN ANCHOR: It is being done at the University of California at San Diego. And CNN's Greg LaMotte is there. He joins us with more on the ultimate jolt -- Greg.
GREG LAMOTTE, CNN CORRESPONDENT: Well, for anyone who lives in an area where earthquakes are possible, which, indeed, is about anywhere in the United States, what's about to happen here is definitely worth paying attention to.
Behind me is a two-story wood frame house. I am going to move out of the way here so that my cameraman can get just a straight on shot on it. In less than a minute, this structure will be subjected to the forces of a 6.7 earthquake, the same forces that struck Northridge, California in 1994, killing dozens of people and damaging -- or causing tens of billions of dollars in damage.
This house has been equipped with 300 sensors, as well as a half- dozen cameras, as part of a $6.8 million study being funded by FEMA. It is about to start. Let's watch.
That is not something a person who lives in Southern California cares to view very much.
Joining me right now, if I can have him turn around, is John Hall, who is the project manager.
John, what do you think of what you just saw?
JOHN HALL, PROJECT MANAGER, CALTECH: Well, I was pretty amazed by how the structure actually held up. Your eyes were probably caught by the inside, the inside is totally demolished, as far as I can see, and people would have been hurt, had they been inside. But if you look at the building itself, it is hardly damaged. You can see some cracks, most of which were there before because of shrinkage. And I think the main reason why the structure did so well is that white stucco we see on the outside.
Inside are plywood sheer walls, which is what the engineers would mainly consider to be the most important part of the structure. But I think they hardly carried any load. Everything was carried by the stucco and the dry wall on the inside, which is good news for most homeowners, because that's what your home has on the outside.
LAMOTTE: Just so we all know, what is the purpose of this study and experiment?
HALL: Well, we're trying to investigate in detail how wood structures perform in earthquakes. As you can see, the structure itself doesn't create too much of a life safety issue. It is more of a damage issue. In Northridge earthquake, we had about $20 billion in damage to the wood frame structures. So what we're really interested in is to improving the codes in some ways so that we can reduce the damage, So it would appear here, even though this is a fairly simple house, we were successful.
LAMOTTE: John, this house has been tested before with a shaking motion, you said 30-40 times you told me earlier. What makes this significant?
HALL: Well, this is bigger motion than we've used before and it's also the first time we have really put the finishing materials on. And the finished materials have dramatically changed the performance. For the same earthquake, without the stucco and the dry wall, we had about five inches of displacement at the roof, compared to the shake table. And that would produce quite a bit of damage. In fact, after that test, we had to do an expensive repair of the house. But with the stucco, you could see that top roof of the base hardly moved at all.
LAMOTTE: So our audience understands, how were you able to shake this house?
HALL: Beneath the house we have a table, and that table is driven by big hydraulic jacks, and we are able to move back and forth about 0.9 G, that is almost a full G, which is what we saw in the earthquake. And also the base moved about six inches.
LAMOTTE: Living in Southern California, I don't necessarily enjoy seeing something like that, given the fact that I've already experienced several earthquakes of my own. This information will presumably be used to help construction folks and engineers and architects build safer homes.
HALL: That's right. Our results will be going directly into the building codes to improve them. But also we want to create educational materials to train contractors and builders on the importance of doing the structures right. So everything you see here will be used in a variety of ways.
LAMOTTE: Thank you very much, John Hall, the project manager for what we just saw, which was a fairly significant earthquake, a 6.7 measured, similar to the one in Northridge, California that happened in 1994 that caused so much damage and loss of life -- Kyra, Daryn.
KAGAN: Greg LaMotte, thank you very much.
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