Levees in New Orleans
Levees in New Orleans
(OP)
After Hurricane Katrina hit Lousiana, more destruction is occurring because of levee failures around the city. Does this mean the factor of safety was too low, they were old, what? They seem to be failing at the purpose for which they were designed. Please explain.





RE: Levees in New Orleans
ChemE, M.E. EIT
"The only constant in life is change." -Bruce Lee
RE: Levees in New Orleans
RE: Levees in New Orleans
My experience with the USACE is, such that, they make design decisions/indecisions by committee where it is next to impossible to find a culpable individual or department. No one has any legal responsibility for the consequences of the action/inaction of the agency or themselves. So I can say that there is little chance of finding the responsible party for the misguided authorization. The problem I have with this issue is that when I work I am financially responsible for my decisions and actions. When an USACE engineer work, I am again financially responsible for their actions (through my tax dollars). I am disgusted with the waste of resources that goes to this agency. And in addition, the lack of accountability that the USACE employees believe they are an entitlement to.
RE: Levees in New Orleans
Initially, Katrina was headed directly for NO and then altered somewhat to the east at the last minute. The counter-clockwise turning of the storm sent winds headed in a northwesterly direction (from SE to NW)which sent a strong storm surge of water right into Lake Pontchatrain (sp?). Then, as it slipped by the east side, the CCW winds became northerly winds (from the north to the south) and began pushing all that water directly toward the city from the lake.
So its seems that the specific orientation of the storm track was the worst possible for the NO layout.
RE: Levees in New Orleans
RE: Levees in New Orleans
The property insurance aspects of will probably be the deciding factor. Commerical insurance only covers hurricane wind damage. Flood insurance is covered by policies backed solely by the Federal Government. All of the "new" damage in New Orleans, beginning August 30, is flood damage. Floods historically reoccur, and now there will be a "real" muli-billion dollar pricetag on flooding in New Orleans. Will there be a National decision to subsidize reconstruction of New Orleans? I don't know.
I do know that in my state, South Carolina, rebuilding/replacing structures on sites that have been proven to be "water damage prone" in hurricanes is severly restricted.
www.SlideRuleEra.net
RE: Levees in New Orleans
Houston found out in tropical storm Allison that a lot of flooding can happen without much wind. When you get 20 inches of rain in a day, and you live on a bayou, flooding is going to happen.
-The future's so bright I gotta wear shades!
RE: Levees in New Orleans
Just remember that the "authorization" made it "illegal" to use anything more than a category 3 in the design level of protection. Flood control projects are cost-shared between the locals (state, town, etc.) and the Feds. Even if it costs the locals ten cents on the dollar, they're going to scream poverty. On top of that, their representative(s) have to fight for enough funding and sometimes they'll have to compromise just to get some money. On the USACE side, you have to obey what Congress authorizes you to do. It might be pollitically suicidal to support a zillion dollar project for a cat 4, when you can "get away" with the million dollar project for cat 3. Is the risk worth it? Depends...
Bottom line: any public works project will have its critics on both sides, it's too much, it's too little, why do it at all? The Government shouldn't be involved in this stuff. Charity begins at home... yada-yada-yada.
And on top of that, you have a project manager who has a schedule and money that has to get spent...
AND DON'T FORGET THAT THERE IS A VERY GOOD POSSIBILITY THAT THE USACE DISTRICT IN CHARGE OF THE PROJECT FARMED IT OUT TO A PRIVATE COMPANY. Awarding A/E contracts is a big part of the Corps' business process...
RE: Levees in New Orleans
They know how to build a levee system. New Orleans voted 75 % for Democrats in the last two electrions, they probably wern't due any pork.
RE: Levees in New Orleans
Look at the most recent law which funds major civil engineering projects, the $286+ billion SAFTEA-LU transportation bill.
The chairman of the House Transportation and Infrastructure Committee is Don Young, the sole representative from Alaska. More than $200 million will be spent to build a bridge to Gravina Island in Alaska, which has only 50 residents. More than $200 million will be spent to build another bridge which will be named Don Young's Way. The full name of the bill is the Safe, Flexible, Efficient Transportation Equity Act: A Legacy for Users. Don Young's wife is named Lu.
Citizens Against Government Waste, a watchdog group, estimates that the transportation bill funded $24 billion of special projects, which means over 8 percent of that budget went to pork.
"This transportation bill is one of the biggest boondoggles in the history of federal spending," said Tom Schatz, the group's president.
Tonight, the corpses of hundreds of poor people who could not afford to leave are floating in New Orleans because the floodwalls have failed.
Is building Don Young's Way in Alaska instead of building floodwalls in New Orleans the proper way to "promote the general welfare"?
This is one reason why American kids don't become engineers. Nobody listens to us. Who wants to volunteer to be a doormat?
Will anyone be surprised if Congress holds hearings next month and calls the Corps of Engineers on the carpet to explain why they were "negligent" enough to allow New Orleans to flood? Don Young will probably lead the witch hunt. He's the Chairman of the "Infrastructure" committee.
The Corps of Engineers should recommend that the $24 billion of projects identified as pork in SAFTEA-LU should be cancelled. The money saved should then be spent to build levees and seawalls and restore wetlands around New Orleans.
http://t
http://abcnews.go.com/GMA/Politics/story?id=994308
http:
RE: Levees in New Orleans
http://www.geoengineer.org/auburn.htm
http://sactax.org/auburndam/index.asp
RE: Levees in New Orleans
The death toll will probably be in the thousands before its over. Think about what would have happened if the the parts that are currently flooded had an additional 20' storm surge.
RE: Levees in New Orleans
Then again, considering how horrifying it is, I'm not sure it could've been too much worse.
Good Luck
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As a circle of light increases so does the circumference of darkness around it. - Albert Einstein
RE: Levees in New Orleans
Am I completely off base?
RE: Levees in New Orleans
Flood insurance is heavily subsidized by the Feds. I have had flood insurance in the past but have never had to use it.
RE: Levees in New Orleans
"Often leading the chorus was Alfred C. Naomi, a senior project manager for the corps and a 30-year veteran of efforts to waterproof a city built on slowly sinking mud, surrounded by water and periodically a target of great storms."
"It would take $2.5 billion to build a Category 5 protection system, and we're talking about tens of billions in losses, all that lost productivity, and so many lost lives and injuries and personal trauma you'll never get over," Mr. Naomi said. "People will be scarred for life by this event."
That's a bit more than 10% of the $24 billion in pork in the civil engineering bill Congress passed less than a month ago.
Cancelling the two bridges that Chairman Young is going to build would pay for almost 20% of the cost of the system.
h
RE: Levees in New Orleans
RE: Levees in New Orleans
It's not Monday morning quarterbacking -- it's democracy. It's what we're supposed to do, hold our elected representatives up to scutiny, vote them out of office if they screw up. If we don't, they'll just continue to screw up.
Jim Treglio
Molecular Metallurgy, Inc.
RE: Levees in New Orleans
BitTwiddler, if you knew the contract history of the State of Alaska, with the Federal Government, you would agree that we have been ripped off. If you don’t agree, either you are unaware of the contract history with the Federal Government or are a party to double deals. I am a financial conservative that fully appreciates every nickel we can legally high-jack from the US Government. I would much rather the Feds keep out of our affairs and stick to the Statehood deal as authored and intended by all parties in 1959, instead of Congressional appropriations coming into the State with all of the strings attached. So instead of focusing on the pork of the Transportation Bill, you should look at this in the full context of the State being financial rip-off by the Feds.
I can go on for pages discussing the Carpet Baggers and the clowns from the USACE that recklessly endangered and impacted my life in Alaska. These clowns (USACE) have come to my State and made countless problems. Sorry for the tirade but unless you have been here to witness the blunders by the USACE you cannot understand my perspective.
RE: Levees in New Orleans
Next time a Democratic-leaning state gets hit by a disaster, tornado, hurricane or otherwise, maybe they should change the name of their state to Iraq!
RE: Levees in New Orleans
Good Luck
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As a circle of light increases so does the circumference of darkness around it. - Albert Einstein
RE: Levees in New Orleans
This also assumes that the number of refugees is 250,000 and all the other people providing services brought their own supplies.
Now do I think the support role was performed well? NO.
People at the state government, city government, FEMA I believe under estimated the size and severity of the disaster. The sites chosen to house the refugees the Astro Dome and the San Antonio site are still inadequate to house the number of people and are too distant from the site. Lack of competent leadership is the real cause of the lack of response for the people in the gulf coast.
RE: Levees in New Orleans
"Lack of competent leadership is the real cause of the lack of response for the people in the gulf coast."
...Instead of 8 minutes to respond, this time it took GeeDub 3 days??? <ducking>
RE: Levees in New Orleans
I can't wait to hear what Bill Maher has to say about all this.
RE: Levees in New Orleans
"So instead of focusing on the pork of the Transportation Bill, you should look at this in the full context of the State being financial rip-off by the Feds."
I have never been to Alaska and I know very little about your state politics. However, I fail to see how wasting resources by building a $220+ million dollar bridge to an island with only 50 inhabitants is going to improve the "general welfare" of either the USA or the citizens of Alaska.
The combined cost of Chairman Young's two bridge projects is about $450 million. If those two "porkjects" are cancelled, that money could be used to send a refund of about $692 to all of the 650,000 or so citizens of Alaska. A family of four would get about $2770.
If a referendum was held, do you think that the good people of Alaska would choose the refund or the two bridges? Congress is supposed to think in these terms instead of trying to supersize the amount of pork for their district.
Our leaders should stop viewing the public treasury as a bank they can rob once a year. It appears that the most powerful politicians are the ones that care the least about the public good.
This country has amazing resources of talent and money but our elected representatives are misallocating them in an almost criminal manner. Their behavior reminds me of the theory of "conspicuous consumption", which states that people will intentionally waste resources by buying frivolous luxury goods to signal to potential mates that they are high status individuals. Unfortunately, our leaders are doing this at the expense of the taxpayers.
Even the richest country in the world cannot afford to continue to waste its resources indefinitely. Our leaders are elected to Congress to serve the entire country. They have failed miserably.
Don Young is the chairman of the Infrastructure committee. In early August a law named after "safety" and his wife was passed which spent $24 billion in pork on civil engineering projects, including a bridge named Don Young's Way. In late August, the most disastrous civil engineering failure in American history killed hundreds if not thousands of people.
Will you hold him responsible for his decisions in the next election or will you vote to keep him?
The best civil engineers in the world are useless if they are controlled by the most inept politicians on the planet.
RE: Levees in New Orleans
Welcome back to the "Old World" gentlemen.
If it's any consolation, we are having very similar arguments and resentment about the EU and Brussels - or the fledgling "United States of Europe" as I like to think of it.
If you create a very large honey pot, the largest bears will fight their way to it and take it for themselves.
:-(
RE: Levees in New Orleans
Where'd you hear that??
And a belated response to someone else:
"I see the levees as being successful if they allow evacuation of the area. Without the levees, there's no telling what that body count could be."
Without the levees, there wouldn't have been a city there to begin with to provide the body count.
Funny thing about levees. The higher they are, the higher the water can rise on the other side before there's a problem. But if there's a breach and the water does come pouring in, then it's the level on the wrong side that gets to rise that much higher, and the flooding is that much worse. Once the lake stopped rising and started to come back down, the water in New Orleans was actually higher than that in the lake.
Hg
Eng-Tips guidelines: FAQ731-376
RE: Levees in New Orleans
American history, the founding of the constitution, Thomas Jefferson, Adam Smith, Abraham Lincoln et-al. Maybe you didn't study history at school.
RE: Levees in New Orleans
Blacks in this country couldn't vote until 1870. Women couldn't vote until 1920. There has ALWAYS been a division of haves and have-nots, and nothing in anything you cite was ever intended to eliminate that; it's only communist and socialist countries that have really tried for social and economi equality across the board, "all men are created equal" notwithstanding. Political corruption has ALWAYS been part of this country's history, or didn't your history books cover such amusements as Tammany Hall or the Harding or Nixon administrations?
Get real.
Hg
Eng-Tips guidelines: FAQ731-376
RE: Levees in New Orleans
Also, they probably won't do anything that doesn't meet the 1-20 cost to benifit ration the govt. has. THey used to have a 1-1 cost to benifit ratio on projects, but not since Bush 1 was president. So lots of stuff should have been done under Clinton during good times rather than taxing, and building????
RE: Levees in New Orleans
The $2.5 billion estimate was from a senior project manager of the Corps of Engineers. There was a proposed study to be done for the levees and the study was going to cost $430 million. Money was cut from the Corp budget and the study has never been started. The links that follow gives some of the details about the levees.
h
www.publichealth.hurricane.lsu.edu/ Adobe%20files%20for%20webpage/LevitanHurrVulnBR&NO.pdf
h
RE: Levees in New Orleans
RE: Levees in New Orleans
I'd have thought that failure analysis should have asked what happens if the levees break and how valuable are the pumps then?
If they are valuable in this circumstance then why do they not have emergency power i.e. shouldn't they be self contained and in protected bunds to stop the installation flooding out?
WHo's responsibility is it to install, maintain and manage the flood defences for New Orleans? Is it the fedral government's or local state or city? If either of the latter then there are surely some local politicians pretty glad GW's in power because his fault or not, the way the press are laying into him he will be the scapegoat; and it seems from the coverage that the press are well on the way to laying all the blame at his door. An enquiry will be too late once the press have done their worst and whatever it says will be considered niether side will be happy.
JMW
www.ViscoAnalyser.com
RE: Levees in New Orleans
i'm willing to bet that the pumps are only usefull if the levees are intact, ie pumping water to the other side of the levee.
as for who's responsible ... you can see the fingers pointing already. basically i think of the levees like insurance (or the armed forces), invaluable when you need it, but a money pit when you don't. and if you don't need it NOW, then you don't spend money on it.
RE: Levees in New Orleans
Jim Treglio
Molecular Metallurgy, Inc.
RE: Levees in New Orleans
==> Who's responsibility is it to install, maintain and manage the flood defences for New Orleans?
That depends on who you ask, and when you ask. The levees were originally built just after WWII in the late 1940's and after Hurricane Betsy (category 4) in 1965, a 10-year federal project was approved to build up the levess. Every administration and congress since then has gradually eroded funds form the US Army Corps of Engineers, and now, 40 years later, the 10 year project was about roughly 75-80% complete before Katrina. The low water mark (no pun intended) was in 1995 when President Clinton refused all federal monies for the Corps, stating that flooding concerns were strictly local issues. He was talked out of that position, but at late as 1999, President Clinton cut the Corp's budget request for southeaster Louisiana flooding control projects in half. President Bush turned an equally blind eye to warnings of New Orlenas vulnerability. No one president or political party is to blame for the complancy that put New Orleans in the position it is now. This is the result of 40 years of bi-partisan neglect.
With respect to this particular disaster, there is plenty of blame to go around between Mayor Nagin, Governor Blanco, and President Bush for the preparations, or lack thereof, in the days and hours prior to landfall, and even more damning, the lack of coordinated and timely response thereafter. They all screwed up.
I also think the major news networks, especially FOX and CNN, both reporting live from downtown New Orleans, need to accept some degree of responsibility because in the first few hours after Katrina moved north of New Orleans, they were all reporting that New Orleans had been spared, that the storm had turned east at the last minute and that New Orleans again dodged a bullet. They were reporting that this was not "the big one". But I'll bet you'll never hear them say that.
Good Luck
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As a circle of light increases so does the circumference of darkness around it. - Albert Einstein
RE: Levees in New Orleans
http://cryptome.org/nola-breach.htm
HAZOP at www.curryhydrocarbons.ca
RE: Levees in New Orleans
"I also think the major news networks, especially FOX and CNN, both reporting live from downtown New Orleans, need to accept some degree of responsibility..."
What?! How is reporting what had happened at that moment wrong or somehow shift some blame on them for ANYTHING? That was the current state of affairs and they reported it correctly. Are you honestly faulting them for not predicting the future correctly?
RE: Levees in New Orleans
THEY WERE WRONG!! It wasn't a matter of not predicting the future, then were very wrong about the present. The levee breach made it worse, but it was already far more devasting than the press was leading people to believe.
Good Luck
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As a circle of light increases so does the circumference of darkness around it. - Albert Einstein
RE: Levees in New Orleans
I normally can't stand 'journal-tainment' but in this case I believe they did just fine. Even Fox news began to critize their golden boy 'W' and the feds for their slow reponse.
RE: Levees in New Orleans
Actually I disagree, and I do have a good idea of the accuracy because I, along with family members from New Orleans, watched every minute of the coverage on that Monday. Upon hearing the initial reports, we were relieved, and somewhat hopeful about the outcome. There was a very noticable drop in the sense of urgency. Unfortunately, the initial reports were very wrong, and two of those family members lost everything. I do not consider giving people a false sense of hope doing just fine.
I don't blame the press for the ineptness of the governmental response. Even if the government (local, state, or federal - take your pick) relaxed somewhat from the initial reports, that would have, at most, made a difference of only a few hours.
But I do blame the press for contributing to the frustration because of their inability to get it right at the start.
Good Luck
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As a circle of light increases so does the circumference of darkness around it. - Albert Einstein
RE: Levees in New Orleans
Not to beat this into the ground but you stated:
"I also think the major news networks, especially FOX and CNN, both reporting live from downtown New Orleans, need to accept some degree of responsibility because in the first few hours after Katrina moved north of New Orleans, they were all reporting that New Orleans had been spared, that the storm had turned east at the last minute and that New Orleans again dodged a bullet. They were reporting that this was not "the big one". But I'll bet you'll never hear them say that. "
Saying the networks shoulder some reponsibility for either discussion topic is a silly statement at best.
RE: Levees in New Orleans
There can probably be made an economic analysis which would show whether rebuilding is justified, as opposed to relocating the people and building a Walt Disney style bourbon street on higher ground.Its not likely to be the same , nor would future Mardi Gras be the same. But there are also a lot of other facilities equally affected by the potential of future flooding or hurricane damage. It will be interesting to see how the current admin allocates cost recoveries to their petroleum supporters vs the displaced poor (read: democrats) people.
The several refineries that were shuttered will always be potential candidates for future damage, as will the new LNG terminals scheduled for that area.
Similar damage had occured circa 1905 in Galveston Tx ( also by a hurricane) , but it is still used as a residential area. Its main source of economic damage was the 1952 laws that made it a dry town and made gampbling illegal- that hurt galveston more than the 1905 hurricane.
RE: Levees in New Orleans
http://www.1900storm.com/rebuilding/index.lasso
www.SlideRuleEra.net
RE: Levees in New Orleans
It is said that a significant portion of the areas affected are occupied by low income families.
If the rebuilding and inner city development projects elsewhere are anything to go by e.g. London Englans Covent Garden, The Canary Wharf development, Paliapolis Rhodos etc, what usually happens is that the poor folks have to live in bad conditions for decades and then, when some initiative provoked by whatever cause (from hurricanes, flooding, EU development money, re-election years etc) produces an influx of funding to put things right then the porr folk can no longer afford to live there.
SO the future for N.O. may also look bleak for some families. If/when they rebuild any portion of the city I'd be interested to see how many of the original inhabitants get to see some of the silver lining to every cloud.
I think Davefitz's comment on a "Walt Disney" style redevelopment has some merit, however after WWII in the UK a travesty of redevelopment meant that any bomb damaged houses could be pulled down and the sites re-developed. Bomb damage was interpreted pretty liberally and even a few tiles loose were sufficient to see some pretty characterful buildings demolished and replaced with "post war manic depressive" concrete utilitarian cubes. On the other hand, in Germany many buildings, towns and even cities were largely rebuilt exactly as they were before and even today we can see old building gutted and new structures errected within the skins of the old resulting in a modern building within a shell that retains its place in the cityscape.
So the appraoch to New Orleans has various directions to go and I can bet there will be no concensus.
Sure, a "Walt Disney" style reconstruction may initially appear to be a travesty in wiating but some of the alternatives are no better. But creating the right environment is a key element in trying to recapture the original spirit of the city and a recreation of the original may be a lot better than using this as an excuse to build new or build kitsch. Of course the key is to enable the people to return to the city as it is the people who generate the real spirit and this is why imention the history of other "good intentions".
JMW
www.ViscoAnalyser.com
RE: Levees in New Orleans
"Engineers and scientists are getting a better idea of exactly how the New Orleans area flooded. In addition to several breaks in the city's floodwalls, engineers now say the Ninth Ward in the eastern part of the city was hit by a huge wave coming over a levee."
http://www
RE: Levees in New Orleans
RE: Levees in New Orleans
RE: Levees in New Orleans
One of the large pumps(14') at pump station #6 was brought online yesterday and is being brought up to capacity slowly. They don't know what flow the canals can take without scouring the banks.
Supposedly the wave/waves came over the flood walls erected on top the dikes and eroded the dry banks allowing the flood wall to collapse and the rest is history.
There is an underlying problem of the natural seepage that has to be accounted for to the tune of 500,000 to 1,000,000 gals/day.
RE: Levees in New Orleans
I'm trying to wrap my head around a set of pumps that can move 25000 tons of water per minute, particularly since they were designed in the late 1800s. That'd bail out the Titanic in a couple of minutes!
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Levees in New Orleans
my 2-cents worth . . .
pay each citizen of new orleans & flooded area 2 million bucks and abandon the city in place. certainly cheaper than rebuilding (assume 0.5 million population).
as far as the industry (oil & gas), these facilities can rebuild incorporating innovative storm surge designs to minimize future damage.
bitwiddler - the prudent option is to not vote financially irresponsible individuals into office, forceably remove the incompetent ones, or you may run for office yourself. i do not agree with "pork" spending and frankly perfer a system that allows for the taxpayers to decide, rather than the elected officials. yes, AK may rely heavily on fed gov (military strategic presence) funds for employment or otherwise, but i certainly have a hard time accepting a fed tax funded bridge used by a very small population.
i've no doubt that new orleans will be rebuilt, but at great expense to the taxpayers of the usa.
RE: Levees in New Orleans
It is especially cruciual to agriculture because of the amount of barge traffic up and down the Mississippi, which in New Orleans, is transferred to and from ocean freighters, not to mention grain elevators and other processing plants in and around the port of New Orleans. The harvest is rapidly approaching and if the port is not re-opened fairly soon, it will get very expensive. Storage costs, shipping cost, and processing costs will all be considerably higher, which will feed inflation across the country. Almost all USA agricultural exports flow through the Port of New Orleans, via the Mississippi river.
On the flip side, huge amounts of imported goods come through the Port of New Orleans where they are transferred onto barges for up-river shipping.
In will be far more expensive to not rebuild New Orleans.
Good Luck
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As a circle of light increases so does the circumference of darkness around it. - Albert Einstein
RE: Levees in New Orleans
RE: Levees in New Orleans
RE: Levees in New Orleans
And it is not just agricultural product exports. Tons of imports come through the Port of New Orleans, such as coffee, sugar, steel, and rubber which are used as raw materials to manufacturing processes. And of course, you've got the shipping of petro-chemical products shipped out to other parts of the country from New Orleans.
Good Luck
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As a circle of light increases so does the circumference of darkness around it. - Albert Einstein
RE: Levees in New Orleans
The price paid farmers has little to do with the price of food delivered to you and I. In a loaf of bread there is about $.05 of wheat. Assume the price of wheat drops in half you save $.025 per loaf or does the production system just absorb the price drop as additional profit.
When this savings occurs that additional farmers go belly up. By the way I live in Kansas the wheat state and have worked in Ag equipment for many years.
RE: Levees in New Orleans
Thanks BillPSU.
I understand what you are saying, but will a closed New Orleans make agricultural products "very expensive"?
RE: Levees in New Orleans
And again, that applies in both directions, and it's not just agricultural products. Exports from all over the heartland are barged to New Orleans predominately via the Ohio, Missouri, and Mississippi rivers. Similarly, imports coming into New Orleans are transferred to barges for shipping into the heartland. Almost 150 million tons of cargo pass through the Port of New Orleans annually.
Good Luck
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As a circle of light increases so does the circumference of darkness around it. - Albert Einstein
RE: Levees in New Orleans
Chris
RE: Levees in New Orleans
Reengineering The Mississippi
Good Luck
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As a circle of light increases so does the circumference of darkness around it. - Albert Einstein
RE: Levees in New Orleans
Thank You. I will look closer later at the LCA site mentioned, but, estimated cost $14 Billon vs. cost of Katrina (so far) $100 Billion. Sounds comparatively low cost to me.
Chris
RE: Levees in New Orleans
htt
RE: Levees in New Orleans
The water overtopped the walls. If you notice the walls are built on top of earthen berms. The water started eroding the earth berms below the wall until headcut erosion started occuring. Once the headcut happened, erosion happened very fast with the amount of CFS that was flowing at these points.
The headcut erosion started undercutting the foundation of the wall itself until the foundation gave way. It was the berm and the foundation of the wall that caused the walls to fail once high volumes of water were going over the walls.
Also note that these walls were built decades ago, but would have probably failed the same way if they were built 2 years ago. The walls needed a foundation. THe earthen berms and walls needed to be higher and wider for the high volumes of water.
She will be going down there next weekend, then on to a conference in Orlando.
RE: Levees in New Orleans
RE: Levees in New Orleans
So you should either build the levee entirely out of earth, or entirely out of cement, but not both. The failure originated in the middle of the levee, at the transition point from earth to cement.
No matter how high you build a levee, nature can build a bigger wave, but you don't have to protect from all overflow. You can allow a reasonable (whatever reasonable is in this context) amount of water over the levee, which you can take care of with the pumps. But under no circumstances can you allow the levee to breach. The flooding is not caused by large wave overflow. The flooding comes from continuous sea level flow.
Good Luck
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As a circle of light increases so does the circumference of darkness around it. - Albert Einstein
RE: Levees in New Orleans
RE: Levees in New Orleans
Anyways, my sister isn't having to go to NO now. They will be heading straight to Orlando.
I will be heading to NO the second or third week of October tosurvey speeding the recovery of our network.
RE: Levees in New Orleans
RE: Levees in New Orleans
From the little information gleaned, the report say the walls themselves failed, this is counter to the overtopping scenerio being expounded on. This has bother me from the start about the flood walls. Not knowing the proper names, but the absence of a flange either at the bottom of the wall or at the surface in my opinion is a no no. To me what I'm seeing is a lever with the backside top of the levee as a fulcrum.
Aside from the engineering point of view this would have a tremendous effect on the insurance questions.
RE: Levees in New Orleans
RE: Levees in New Orleans
I agree that some of the flood walls were the I-walls, but several sections were just vertical straight sided reinforced concrete. The sections that were only reinforced concrete appeared to have only vertical reinforcing bars, fairly large and somewhat large spacing of the bars. I have not one time seen concrete sticking to the rebar. A little information picked up this morning is that there is a CORE limit of 7' above grade and some of both types were at 11' above grade.
I have made several comments about these walls, especially the appearance of the concrete, based on snippets of visual information from fleeting TV coverage. Based on many years looking at failures I sure hope they have a geotechnical (concrete) look at failures. But they are using a lot of the wall rubble to help shore up the existing levees.
In construction of the I-walls is the two facings of concrete supposed to be reinforced and/or tied togather through the sheet piles?
RE: Levees in New Orleans
The report from LSU has as one of it's author/authors a gentleman named Paul Kemp. During his little time on TV it showed another problem with the flood wall. The joints between sections had varying widths and it looked like the elastomer/bitumen has deteriorated and created a leak. He stated that the failure wasn't form surge or overtopping of the walls.
vooter,
As you stated some of the walls were I-walls but during the interview it showed a small section of a failed flood wall of a different construction than has been mentioned. It was sheet piling with concrete faces as you described. This concrete appeared to be reinforced. All the concrete was
RE: Levees in New Orleans
RE: Levees in New Orleans
There's no CORPS limit on wall height as long as the design is sound - the NYTimes article (and others) that quoted the Corps's manual regarding 7 ft vs. 11 ft is misleading.
The wall panels look like they failed as cantilevered plates; the sheet pile is in good shape, no failure I could see at all.
RE: Levees in New Orleans
Repeat of 9/22/05 with the missing part.
As you stated some of the walls were I-walls but during the interview it showed a small section of a failed flood wall of a different construction than has been mentioned. It was sheet piling with concrete faces as you described. This concrete appeared to be reinforced. All the concrete was above grade. The below grade sheet piling appeared to be about 3 times the length of the concrete. Is this still called an I-wall?
RE: Levees in New Orleans
"I-wall: A special case of a cantilevered wall consisting of sheet piling in the embedded depth and a monolithic concrete wall in the exposed height."
That's what I described, concrete on (on top of, that is) sheet piles.
How many I-walls have you designed? I've only done four, myself.
RE: Levees in New Orleans
I did do some design work on a building on Pensacola Beach that has survived 5 Hurricanes with 3 storm surges including being about 20 miles East of the center of Ivan.
As far as being monolithic concrete, as I understand it is only in 30' sections and the sections are connected by a rubber seal. It is quite evident that the sections were operating independently from the pictures and the seal in many of the connections isn't in very good shape.
As far as the 7' height limit for this type construction I have seen this published, discounting the interviews on TV, by two supposedly reputable sources as being a standard.
Not saying it isn't possible, I have seen literally thousands of sheet pilings driven and have never seen a short section started on both ends to meet in the middle.
At last report the water in the lake behind this dam was 7' higher in than the water in the canals. They can't used the canals until the lake subsides. There appears to far less freeboard on the groin built around the big Industrial Canal breech that is now allowing water in.
I also understand that they “hope” to have a failure report by June 2006 and have the levees restored at the same time.
The current spin is that the flood walls were overtopped, but there is credible evidence that the case was not so. They missed a good opportunity very early on that would have answered part of the question. The empty grain barge so prominently displayed at the big breech on the Industrial Canal was first mentioned by one of evacuees as hitting and knocking down the flood wall.
RE: Levees in New Orleans
RE: Levees in New Orleans
Seems to me that the repairs to the levees were
not given enough sealing to prevent seepage.Perhaps non permeable geotextiles or bentonite mat laid on the outside.Then a covering on top to hold in position
The repairs were then sbjected to pressure before they had time to compact properly.
If possible and had time and materials permitted the large bags should have been covered and secured by concrete not gravel. Where gravel was used bentonite mat(self sealing]
should have been laid and covered with flexible concrete matting.
Matting would prevent wash out and the flexible mat should collapse into any depressions occuring due to seepage helping to seal and both indicating a pending problem.
Intrusion Prepakt
www.marineconcrete.com
RE: Levees in New Orleans
h
Here is the American Society of Civil Engineers Investigation Team.
http://www.asce.org/static/hurricane/team.cfm
Another disquieting situation is the lack of off the self plans for repair or remediation of existing levees. I heard two statements that they were working on conceptual ideas for repair or replacement. I could see this situation existing for an earthquake hitting NO, but not something that was inevitable.
RE: Levees in New Orleans
http://cal
JMW
www.ViscoAnalyser.com
RE: Levees in New Orleans
"Much of the city flooded not because water rushed over the tops of levees, but because two of the storm barriers that ring New Orleans actually shifted and then collapsed, a team of independent engineers said Friday.
The preliminary analysis contradicts initial reports by the U.S. Army Corps of Engineers, which said water may have pushed over the top of the levees, eroding the earthen embankments that support the flood walls."
h
RE: Levees in New Orleans
RE: Levees in New Orleans
JMW
www.ViscoAnalyser.com
RE: Levees in New Orleans
From USA Today:
Ground hasn't been broken yet, but the infamous "bridge to nowhere" that would connect Ketchikan, Alaska, to an offshore island where only 50 people live, appears to be indestructible. The highway bill allots $223 million for that project and $229 million for another boondoggle bridge near Anchorage. Coburn wanted to withdraw funds for the bridges and shift $75 million to rebuild a Louisiana bridge damaged by Hurricane Katrina. It should be a no-brainer that the needs of the devastated Gulf Coast are greater.
Sen. Ted Stevens (R-Alaska), was personally insulted, however. Alaska, which ranks No. 1 in per capita federal spending, was being unjustly singled out, he argued. The 37-year Senate veteran threatened to resign and "be taken out of here on a stretcher" if the Senate killed off perhaps the most egregious example of wasteful spending in the massive highway bill.
Senators were so moved by Stevens' sense of outrage - or the idea that their own pet projects could be next - that they voted 82-15 to keep funding the bridges. The Senate also refused to defund a $500,000 sculpture park in Seattle and $950,000 for a Nebraska museum parking facility.
Those wasteful projects are only a few of the 6,371 "earmarks" legislators pushed into the transportation bill alone.
http:
Why on Earth would any bright young American want to become a civil engineer? Would any sane person want to waste his or her time catering to the whims of these clowns?
There are over 200 lawyers and zero engineers in the 108th Congress. It shows.
Americans should expect more civil engineering disasters such as New Orleans for the rest of this century.
RE: Levees in New Orleans