** Louisiana PING **
Posted on 12/03/2005 9:25:37 AM PST by caryatid
An engineering firm involved in the design of the 17th Street Canal levee and floodwalls said Friday that the Army Corps of Engineers overruled its recommendation to drive sheet piling to a depth of 35 feet below sea level along a stretch of the floodwall that failed during Hurricane Katrina, causing massive flooding in Lakeview and other parts of the city.
William B. Conway, chairman of the Metairie engineering firm Modjeski and Masters, in a letter to The Times-Picayune, said the corps plan eventually led to pilings that were driven just 10 feet below sea level.
Modjeski and Masters was the lead design firm for the project. In an e-mail written in response to a Times-Picayune article Wednesday that quoted members of a Louisiana State University engineering team investigating the failure as saying a basic engineering mistake led to the disaster, Conway said the shorter sheet piles were not recommended by his company.
". . . we point out that the existence of a humus layer at the 17th Street Canal was known to us and the Corps of Engineers," Conway said in his e-mail. "It was reflected in the initial -35 sheet pile tip elevation for the east floodwall.
"The final sheet pile tip elevations shown on the contract plans were mandated by the Corps," he wrote. "Further, Modjeski and Masters was not employed for the field monitoring of the construction project in which the sheet piling was apparently not redriven, as required, to a final -17.05 tip elevation." Tip elevation is a measurement of how far the bottom of the pilings are below sea level. Conway produced no documents to support his contentions, and did not respond to requests for interviews.
[...]
(Excerpt) Read more at nola.com ...
[Continuation of the article]:
[...]
The corps, in a written statement, defended its actions. "M&M (Modjeski and Masters) was under contract to the Orleans Levee District," the corps statement said. "If the Corps did mandate this over M&M's design, M&M would have evidence of it because it would be documented. According to our information, -17 feet would have provided the protection. Did M&M not agree that -17 feet was sound?"
The corps has not released those as-built drawings, however, and a set marked "final review" shows the pilings at 10 feet below sea level. Recent sonar tests by both LSU and the corps indicate the surviving pilings adjacent to the break extend to only 10 feet below sea level.
The corps response to Conway's contention that his company recommended deeper piling reflects the agency's efforts to distance itself from what independent investigators have called the "costliest engineering mistake in American history."
Earlier this week, a corps spokesman said the two major engineering firms publicly associated with the levee wall project -- Eustis, which did the soil investigations, and M&M, which did the designs -- were hired by the Orleans Levee Board, which should be responsible for its own work.
But the corps, as required by federal law, reviewed all the work by the outside firms before accepting it as complete. Maj. Gen. Don Riley, director of civil works for the corps, told The Times-Picayune last month that his agency has final responsibility for the project because it accepted the plans of its partners, and should have investigated whatever work had been done at the site before it arrived.
And in a 1995 deposition during a legal dispute with Pittman Construction, which built the wall based on the corps-approved plans, Daniel Marsalone, who identified himself as "chief of engineering" for the New Orleans District, acknowledged that once the corps "took the plans and the specifications that were done by Modjeski and Masters," the corps adopted them as their own.
The controversy over how deep the sheet piling should have been driven at the 17th Street Canal as part of the corps project to increase the height of the levee wall has its roots in a joint project to deepen the canal by the Orleans Levee Board and the Sewerage & Water Board.
The water board needed a wider, deeper channel to funnel water from its Pump Station No. 6 at the canal's southern end, where it planned on adding two more pumps.
But if the channel was dredged, the existing levees would have to be moved and the old sheet piling, dating back to 1965, would have to be replaced.
According to Levee Board documents, the two agencies decided to use 22-foot sheet pilings to replace the existing pilings, with the bottom of the piling extending to only 9.3 feet below sea level.
At the same time the dredging project was taking place, the corps was working on design plans to raise the height of the walls along the canal. Corps memos show some agency engineers weren't satisfied with either the water board's sheet pile depths or the corps' own plans, and were unsettled about coming on the project after it had begun.
"The fact that a construction contract was awarded for the east side sheet pile work prior to our review of this (design memo) results in an undesirable situation for this office and the corps," said one memo. "The current Orleans Levee Board contract should either be modified to provide the additional lengths or the sheet piles should be driven as shown in the (corps design memo) and later driven to the revised penetration just prior to capping."
The memo goes on to recommend the sheet piling be sunk deeper than the 17.5 feet below sea level later approved by more senior officials.
However, that recommendation was rejected in 1990 by senior corps officials.
Eugene Tickner, listed in a memo as chief of the engineering division for the corps' New Orleans office, said the recommendation to increase the wall's depth was based on "unknown variations in ground surface elevations and soil conditions." But in listing reasons to support the 17.5-foot-below-sea- level decision, he discounted the potential problems, saying that "no other hurricane protection project has had the level of borings or surveys as the 17th St. Canal project," and no other recent project had required more stringent levee design requirements.
Still, Tickner said that decision could change based on what was learned during construction.
"We will monitor the sheetpile wall being constructed by the local interests on the Orleans side of the canal," he wrote. "We will consider driving the sheetpile deeper instead of cutting the sheetpile in 1994 during capping."
That apparently never happened. While the corps claimed it had been driven to 17.5 feet below sea level, copies of design drawings for the project obtained by the newspaper showed the pilings were sunk to just 10 feet below sea level on the New Orleans side, and only 8 feet below sea level on the Jefferson Parish side near the breach that flooded Lakeview.
The actual length was verified by Team Louisiana, a forensic engineering group of LSU professors and independent engineers working with the state Department of Transportation and Development, who used ground sonar to measure remaining sheet piling near the break.
On Thursday, the corps confirmed that it found the pilings to be just as short during their own tests, conducted at the end of October.
Corps spokesman Jim Taylor said the agency will pull several wall sections that are still intact adjacent to the breach this week to better determine how the wall was built. That procedure will be witnessed by investigators with the FBI and state criminal agencies, he said.
The wall sections will be stored in a secure building for further investigation, Taylor said.
. . . . . . .
** Louisiana PING **
Not that it was Clinton's fault either. The whole thing is madness. I wonder what positive changes would come of this mess if the press hadn't decided before the rain stopped falling that it was Bush's fault.
* PING *
1. Orleans Levee Board and the Sewerage & Water Board decide to dredge the canal, requiring new levees.
2. Modjeski and Masters recommend driving the new sheet piles to 35 feet below sea level.
3. Orleans Levee Board and the Sewerage & Water Board ignore this recommendation, accept a final design, and let contracts for sheet piles to be driven to 9.7 feet below sea level.
4. With work already begun, the Corps of Engineers is asked to review the plans.
5. The reviewers for the Corps of Engineers are uncomfortable with the pile depth, insist on 17.5 feet tip depth, and recommend even deeper piles.
6. The CoE's chief engineer decides that the reasons given for the recommendation may or may not be true, and decides to observe performance during the time between the piles are driven and when the wall is capped in 1994, but insists that the piles should still be driven to 17.5 feet.
7. Orleans Levee Board and the Sewerage & Water Board ignore this recommendation as well, and leave the piles as they are, at 9.7 feet below sea level.
8. The piles are capped in 1994, and no new piles are driven.
9. The New Orleans Times Picayune writes a deliberately confusing article based on these simple facts with a headline indicating that responsibility for the breaches rests solely with the Corps of Engineers.
Just what I'd expect from a city government whose police chief rides around in a stolen Cadillac.
Thanks for a very concise summary of what really transpired. It's seems that everything New Orleans officials did wasn't "good engineering" practice.
Obviously these are Clinton Piles. No wonder he has consistently refuse the public release of his personal medical records!
Now we have a great pile driver of a President, and of course he needs to git r done!
Once the piles are replaced, there will be a Republican governor in Louisiana!
The biggest pile of them all, Blanco? Well perhaps. Lets wait and see. She has a lot of commpetition!
I've been waiting for this - thanks for posting it. The big-time finger pointing has begun. Engineers love paperwork - let's see who has their ducks in a row. We will probably see some imaginative CYA work. Perhaps we should ping Backhoe and the Rathergate Gang when the actual papers begin to be made public. :o)
Used to short-sheet at hunting camps, but this is beyond rediculous.
I read the article to my husband over breakfast ... and that is exactly what I said: Aha! The finger pointing has commenced! This is going to be interesting!
LOL
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