Posted on 03/10/2006 7:23:38 PM PST by NormsRevenge
NEW ORLEANS - A foundation problem — although not the one targeted by earlier studies — caused the 450-foot-long break in a floodwall and levee on New Orleans' western edge when Hurricane Katrina hit, the U.S. Army Corps of Engineers said Friday.
A naturally occurring, 20-foot-thick layer of clay that helped support the floodwall was too weak for the job, according to a report by a Corps task force set up to find out why the levees broke. Had the floodwall and levee held, much of the western half of the city would have escaped flooding.
Previous analyses by other groups had targeted the layer of sand and peat over the clay as a likely culprit.
"The failure plane was not in the peat. It was in the clay below the peat. That became the weakest part of the system," said Ed Link, project director for the study by the Interagency Performance Evaluation Task Force.
Part of the levee was pushed 40 feet backward, and can be seen above the water — along with that section of floodwall — in an aerial photograph published as part of the task force's second report.
High water pushed back the floodwall, which is set into the center of the earthen levee. Once water got between the floodwall and the front half of the levee, it effectively cut the levee in half lengthwise.
The floods then pushed the floodwall, and the half of the levee behind it, backward on a layer of soft clay below the surface, the report said.
The floodwall's design didn't include either the possibility that water could get between it and the levee or that the clay might be unstable, corps officials and others said in a news conference. The two factors combined created the breach, they said.
"We are incorporating the information into our current repairs, and incorporating it into our assessments for the future," said Col. Lewis Setliff, who is in charge of the levee repairs that the Corps wants completed by the beginning of next hurricane season on June 1. "We are also evaluating the repairs we are making ... to see if we need a change of course."
Setliff said the corps is looking at all the "I-walls" — vertical concrete barriers anchored by vertical sheet steel pile — in New Orleans-area levees.
The 17th Street Canal and two others that broke during and after Hurricane Katrina will be cut off at the mouth by new floodgates if a hurricane approaches this year, to keep high water in Lake Pontchartrain from stressing their levees and floodwalls.
And, wherever it can, the Corps is replacing I-walls with "T-walls," which have a horizontal concrete base and are anchored by steel beams driven diagonally through the levee.
Those should be "significantly more resistant" to such failures Link said in a news conference after the 332-page report and more than 400 pages of appendices were released Friday on the Internet.
The report released Friday is preliminary. The final report is due June 1.
___
On the Net:
https://ipet.wes.army.mil/
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Ray Nagin,, "looks like they should have used a darker chocolata for the levee foundation."
Water flows into New Orleans through a breech of the17th Street canal levee shown in this undated aerial photo provided by the Army Corps of Engineers. A foundation problem _ although not the one targeted by earlier studies _ caused the 450-foot-long break in a floodwall and levee on New Orleans' western edge when Hurricane Katrina hit, the U.S. Army Corps of Engineers said Friday March 10, 2006. (AP Photo/Army Corps of Engineers, HO)
< /sarcasm >
Now, why in the world couldn't the President have foreseen this?
According to Brother Farakan da Joooos AKA White Devils blew up da levee.
This means that Karl Rove started planting phony engineering studies when he was in the second grade.
I'm shocked, according to Farrakhan it was supposed to have been caused by explosives.
Shovelling sh*t against the tide.
The final report is due June 1.
Spitting against the wind?
Easy to see it was pushed back in that picture.
Are you just trying ut a few old bromides?
It's also easy to see that you can't build anything on mud and shifting sand that water can't move. Period.
I'm a Mechanical Engineer, since I was never nice enough to be Civil.
"Joshua led his armies
To the walls of Jericho.
He knew he must get in
But not which way to go.
One blast from his trumpet
Left them nothing more to fear.
For the walls had been constructed
By a Civil Engineer."
I hate to think we're taking taxing the social security benefits of people who worked their whole lives to pay to rebuild levees and replenish beaches so a class of fools can resume their lifestyle. This is not confined to New Orleans by any means.
L
We knew he was an evil genius, just didn't know how precocious he was, too!
"The 17th Street Canal and two others that broke during and after Hurricane Katrina will be cut off at the mouth by new floodgates if a hurricane approaches this year, to keep high water in Lake Pontchartrain from stressing their levees and floodwalls."
If these floodgates had been there in the first place, as they should, New Orleans would have been spared the brunt of this disaster. I'm still trying to find out why the flood gates were not built. It was the Corps' responsibility. They are now trying to blame the environmentalists. No one has been assigned responsibility yet. Until that happens, New Orleans will continue its free fall into insignificance.
Of course, not seen is the construction barge that did the initial damage when is rammed through the levee earlier that day.
It appears as a (my) disconnected response to several private emails received this evening regarding NOLA.
That and alternating stories of billions set aside, though uncollected, along with stories of fraud so deep and long they'll be waiting to be solved after the 9/11 scammers meet justice.
More levee failure mode reports. Pinging you before I even read the thing, apologies in advance if it's a report with shallow engineering-based assertions.
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