Hurricane Wind Forces On Levee Flood Walls

FORCES ON WALLS (PDF File) ^ | Sep 89 | www.usace.army.mil

[xrhopsiomega]

On the Failure of New Orleans levees:

Has anyone asked if the hurricane wind forces comprimised the flood walls?

The flood walls are segmented I-beams without any backfill. Is it possible that the wall segment interfaces were comprimised by winds and water seepage between the segments eventually caused the failure?

Section IV. Supplemental Forces

3-25. Wind Load.
Wind loads should be considered for retaining and flood walls during construction, prior to placing backfill. Wind loads can act any time in the life of a flood wall. In locations subjected to hurricanes, a wind load of 50 lb/sq ft can be used conservatively for walls 20 feet or less in height for winds up to 100 miles per hour (mph). In locations not subjected to hurricanes, 30 lb/sq ft can be used conservatively for the same height of wall and wind velocity conditions. For more severe conditions, the wind loads should be computed in accordance with ANSI A58.1 using a coefficient Cf equal to 1.2.<.tr>

Army Corp PDF file:
EM 1110-2-2502 29 Sep 89 CHAPTER 3 FORCES ON WALLS Section I. Introduction 3-1. General.

[rabair]

don't know about all that... just know that Katrina's eye struck MS, and word out now (but for obvious reasons not heavily reported) is that only strong category 2 conditions hit New Orleans.. in fact it never even came close to "overtopping" the levees.. the experts believe the breakdown is either do to a design or construction failure...

http://www.washingtonpost.com/wp-dyn/content/article/2005/09/20/AR2005092001894_pf.html

anyway... let's all unconstitutionally have $200 billion pay to rebuild this city, so it can just happen again every year, right?...

[Nitro]

I beleive wind loads only hold with bridges...

as wind can only put an influence on the surface of water.

I was in the US Navy and I would be the guy you wanted working if you fell overboard....

the search pattern is as follows...

5% of wind without flotation....

10% of wind with flotation.

Determine last known time aboard and then commence an expanding square search.

Factoring in the above variables.

[patriciaruth]

Last I heard the levees were seeping, and the water level in New Orleans has risen some.

The Eastern levees were destroyed by the storm surge of Katrina. Those levees didn't hold back any water, they were there to protect against storm surge. Now there is no Eastern levee to protect against storm surge.

The media haven't told this story well at all. Apartment complexes, projects at the edge of St. Bernard's parish (perish) were swept away when the storm surge rolled over and destroyed the Eastern levees and surged into the parish. Those projects didn't go under water from slowly rising water from a break in the 17th Street levee; they were already gone when the water rose more from the break. I believe there are still a lot of unrecovered bodies in that area, and I am still mad at Blanco for not allowing our military to enter homes while 'searching' for survivors and bodies.

[Nitro]

I was watching a show on the Discovery Channel about a guy who thinks that not only do we have a short 30 year cycle on hurricames, but he beleives we are entering a 1500 year high cycle.

In other words last year and this year are bad but next is going to be worse and years to come worse still.

[Free Vulcan]

Dude, George Bush blew up those levees. We all know that. Don't give me any conspiracy theories about wind load or water seepage. ;-)

[Mercat]

All you have to do is look at the coastlines down there... they have been shaped over the years by some really serious stuff.

[Nitro]

Did you know that the Yucatan was hit 65,000,000 years ago and was most likely the rise of mammals.

That was what most likely caused all that area being flood plane and kiiled the dinosaurs.

[Nathan Zachary]

No way! I heard it was 85,000,000,000 years ago and this big blob of goo got washed up, everything sprang forth from that.

[rabair]

Dude, George Bush blew up those levees. We all know that. Don't give me any conspiracy theories about wind load or water seepage. ;-)

sadly, there is a discussion board somewhere on the internet, where that is being said... and they're serious! Worse yet, there are countless people who believe the 9/11 conspiracy theories. We have some real idiots running around..

[Fierce Allegiance]

Ping the CE list

[sgtbono2002]

Cindy Sheehan, Jesse Jackson, Maxine Waters, John Conyers, Al Gore, Hillary Clinton, Nancy Pelosi, Barbara Boxer,Sheila Jackson Lee, Calypso Louie Farrakhan, Al Sharpton, Bill Moyers, Eleonor Clift.

Geez naming morons could be a full time job and I forgot to mention fat Teddy and Harry Reid.
The list is long and scandalous.

[Fierce Allegiance]

I beleive wind loads only hold with bridges... as wind can only put an influence on the surface of water.

Wind loading should be considered for all structures. Think about your statement, then think about sticking your hand out a moving cars window. There definitely is a force acting on your habd, right?

?While wind isn't usually much of a consideration for levees, it certainly was a leading cause in the failure of the Tacoma Narrows bridge.

BTW, on second reading, you are correct to a point. The wind would only have an efect on the portion of the levee above the waterline.

[rabair]

anyone want to start a bigger conspiracy theory to counter the "they blew up the levees to kill blacks" theory?

Here goes: I have evidence that the Antichrist is here, and he was living in New Orleans... God sent Katrina after him, but stopped short of coming down himself and "outing" the Antichrist because that is against the age old rules.. no direct influence in the battle for the souls of man between God and Satan(see the movie Constantine... although I clearly stretched it).

Anyway, Satan tipped off the Antichrist who didn't want to do anything rash to give himself away, so he blended in with the crowd of evacuees (not refugees, remember? that's racist) and headed off to Houston. Hangin' out in the Astrodome awaiting word from Hell on the next move, God unleashed Rita. However due to modern technology, the Antichrist, along with the rest of the world saw Rita coming almost a week ahead of time, and before the traffic jam inducing evacuation we now see, the AC skipped town on a plane to _______. So as not to make something unbelievable happen, and have the storm disappear or rapidly change direction completely and cause the "obvious act of God" reaction (again, no direct influence allowed).. he decided to have it change direction slowly to spare our oil refineries and begin to weaken as the edges begin to take apart the storm as they hit land across the gulf... .... okay, I'm bored now.. but that is clearly the truth, no?

[greasepaint]

Do the two canals, 17th St., and London Ave.,
have floodgates were they enter the lake.
If so, what happened?

[bobjam]

Wind loading was probably not much of a factor. As the water level rose, the face exposed to winds decreased. Furthermore, at 62.4 lbs per cubic foot, the additional water placed a far higher load on the levee than the wind.

I believe the major levee failure may have occurred because it was struck by a barge (something designers may not have considered).