Ground Zero draws brief tribute, long-term study

Debris removal nears completion as rebuilding plans for WTC site progress and studies expand
August 11, 2010

As crews near completion of the cleanup operation and concrete slurry wall stabilization at Ground Zero, progress is being made on plans to rebuild on the site of 7 World Trade Center, part of the World Trade Center complex. Additionally, the Bush administration has agreed to finance an expanded investigation into the collapse of the Trade Center's Twin Towers.

All this occurred within the short life span of the Tribute in Light Memorial, which was erected in New York's Battery Park near Ground Zero as a temporary memorial to the 3,000 people killed in the terrorist attacks on the towers last Sept. 11. High-powered lights evocative of the Twin Towers threw beams of blue high into lower Manhattan's night sky for 32 days from March 12 to April 13.

Meanwhile, the major components of the plan to rebuild the World Trade Center area — including smaller towers than the 110-story twins — are expected to be completed by June, according to John Whitehead, chairman of the Lower Manhattan Development Corp., who made his remarks to New York businessmen March 26. To ensure that lower Manhattan has enough power in the summer of 2003, Whitehead said rebuilding of 7 World Trade Center will have to begin soon. This is because a Con Ed substation is on the lower floors of the building, and construction on the station must start this year to be operational by next year.

The site's developer, Larry Silverstein, has reportedly scaled down the size of his proposed building replacement from 2 million square feet to about 1.5 million square feet, and moved it to a "more suitable spot," Whitehead said.

Dollars in, debris out

In Washington, D.C., the White House asked Congress March 22 to add $16 million to the Federal Emergency Management Agency budget for the expanded investigation into the causes of the towers' collapse. Though Congress has yet to approve the funds, supporters of the move believe it will be approved.

Meanwhile, to visitors standing on the public platform overlooking what seven months ago was a mountain of broken concrete and twisted steel, the site now more closely resembles a typical excavation site.

The name given to the site by workers reflects the progress that has been made since Sept. 11. "The site once was called 'The Pile.' Now it's called 'The Pit," says Matthew Monahan, assistant commissioner of public affairs for the New York City Department of Design and Construction.

Debris removal crews now are working six levels below grade. By the end of March, 1.28 tons of debris and 181,000 tons of steel had been cleared from the site, says Andy Sosa, senior project manager for AMEC Construction Management, who with Bovis Lend Lease, comprises the New York-based management team overseeing work on the site.

Though declining to specific about the deadline for cleanup completion, Monahan says June is the target. Buoyed by mild winter weather, some work at the site could be completed in May, he adds.

Sosa concurs. "It's going well," he says, adding that the latest milestone in the cleanup effort was the March 29 opening of West Street. The thoroughfare had been damaged and blocked by debris since September. Tully Construction, New York, is the subcontractor performing the roadway restoration.

As crews moved below grade, the stability of the concrete slurry walls — the watertight "bathtub" of the Twin Towers' foundation that surrounds the site and the six basement levels within — became a concern.

"Early on in the process we had an emergency condition on Liberty Street where the wall was pretty much unsupported for its full height and began moving on us," says George Tamaro, a senior partner with Mueser Rutledge Consulting Engineers, New York City, the firm hired to engineer the installation of 950 to 1,130 steel tieback anchors to stabilize the walls.

         
 

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