Storm Proofing Facilities- Katrina
Storm Proofing Facilities- Katrina
(OP)
What worked and what didn't in preparation for major storm events? What lessons learned can you share?
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RE: Storm Proofing Facilities- Katrina
RE: Storm Proofing Facilities- Katrina
rmw
RE: Storm Proofing Facilities- Katrina
RE: Storm Proofing Facilities- Katrina
You're building a footbridge.
Next door to the footbridge lives a man that weighs 500 lbs.
You figure there is a 50% chance that he will try to cross your bridge.
Therefore, you can design the bridge for 250# load.
Seriously, one lesson learned is a lesson we knew already. Most things are designed for a certain reliability. You design a building for a windspeed such that there is a 90% chance that it won't be exceeded in 10 years. That means there IS a 10% chance that it will be exceeded. It all sounds good when you design it, but then when that 10% case comes along and destroys what you built, you don't feel so good about it.
When Rita was headed for the Texas coast, it had 175 mph winds. Stuff on the Texas coast is not designed for that speed. As it turns out, rightly so, in this case, because the wind speeds did drop as it came in. But if you tried to design everything for the worst case, no one could afford to build anything.
People criticize the gov't because New Orleans' levee system was only adequate for Category 3 hurricane, not Category 5. What would it take for a Category 5? You'd turn those levees into the Great Wall of China. They already had concrete walls sticking 12' high. Just add another 25' or so, then make them 4 times as thick for wind loading, etc.
RE: Storm Proofing Facilities- Katrina
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RE: Storm Proofing Facilities- Katrina
N'Awlins was founded as a trading post on a high spot of land, which is why the French Quarter didn't get much flooding. Everything else grew up around that. If a couple of direct-hit hurricanes had happened earlier in the history, then folks would have probably wised up and said "the heck with this place, let's move up river to Red Stick".
When I was at LSU my roommate took to me to visit his home in N.O. I got out of his car and looked up 30+ feet to the top of the levee of the Miss. River located not 50 feet from his house. That means the surface of the river was above the roofline of his house. Rising another 50 feet above the top of the levee was an ocean-going cargo ship tied up at a wharf. Even as a young invincible hotshot college kid I thought living in this place was insane.
But the opposite almost happened in the floods of 1973. Follow on a map the course of the Miss. River. Upstream from Baton Rouge the river takes a sharp turn to the Southeast. At that point the river wants to follow a course due south through the Atchafalaya Basin to the Gulf. The US Army Corps of Engineers put the Old River Control Structure to keep this from happening and keep the Miss River flowing through B.R. & N.O. This structure almost, but not quite, got washed away in '73. The crawfishing was great because of the flooding ($0.12 a pound, yum!), but NOT having water flow through B.R. & N.O. would have had crippling effects on the US economy at the time.
TygerDawg
RE: Storm Proofing Facilities- Katrina
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RE: Storm Proofing Facilities- Katrina
Jim Treglio
Molecular Metallurgy, Inc.