http://www.nytimes.com/2008/01/13/ny...ac5&ei=5087%0A
Between Rock and the River, the Going Is Slow, and Costly
BELOW GROUND ZERO Excavation at the site of the World Trade Center. In one area, engineers had to go 120 feet below ground to find bedrock because of an ancient gorge in a former glacial streambed.
Tiebacks, essential support for the foundation, are made of 21 strands of steel bridge cabling. They must be anchored to bedrock.
By GLENN COLLINS
January 13, 2008
At the eastern portion of ground zero, hundreds of workers contend with a nasty subterranean nest: steel and concrete, a defunct railroad, forgotten foundations, landfill, quartz deposits and glacial remnants in a vast pit that the Hudson River ceaselessly tries to inundate with icy, brackish water.
Tiebacks, essential support for the foundation, are made of 21 strands of steel bridge cabling. They must be anchored to bedrock.
They are behind schedule.
For such an ambitious construction project, delays are hardly unusual. But in this case, being late is very expensive.
On Jan. 1, the Port Authority of New York and New Jersey began paying penalties of $300,000 a day — $3.3 million as of Friday — for missing its deadline to complete the site excavation and preparation for two office towers at the World Trade Center complex.
Since it won’t finish the job until next month, the authority’s penalty phase could top $13 million, all of it paid to Silverstein Properties, owned by the developer Larry A. Silverstein, whose company is the leaseholder on the site and will build on it.
Critics of the authority say that the missed deadline should have been a surprise to no one.
“It makes sense that penalties are worked into development deals with the Port Authority, since it has a history of slowing things up thanks to the bureaucratic maze that exists there,” said George J. Marlin, an investment banker who was executive director of the Port Authority from 1995 to 1997.
Mr. Marlin said he did not know the specifics at the site, but said “the bureaucracy of the Port Authority can slow down most anything,” adding, “What they define as fast track, and what a private developer defines as fast track, are two different things.”
But the authority insists that it has done everything possible to further an engineering project of stunning complexity. “Of course, we would have preferred to be on schedule,” said Anthony E. Shorris, executive director of the agency, which owns the site. “We weren’t slowed by paperwork or bureaucracy. It was the challenge of doing a project of this scale in this short a time.”
In the years since the twin towers fell, ground zero has been a magnet for dissent and dysfunction. Rebuilding efforts have been hampered by legal and political wrangling and construction delays, including the redesign and re-siting of the Freedom Tower; the off-again, on-again demolition of the black-shrouded Deutsche Bank building; and the announcement last month that the World Trade Center Memorial will be delayed two years until the 10th anniversary of the terrorist attacks in 2011.
The authority’s contractors are completing a year-old, 6.7-acre excavation called the East Bathtub — extending from Liberty Street to Vesey and from Church Street to Greenwich — to prepare the three acres that will be the sites for the towers. Tower 3, at 175 Greenwich Street, will have 2 million square feet of office space, and Tower 4 will have 1.8 million square feet of office space at 150 Greenwich Street.
So far the East Bathtub price tag is $250 million, a chunk of the $16 billion that will be spent on the entire site to build, among other things, “what is, in essence, five Empire State Buildings,” said Steven Plate, director of trade center construction at the authority.
“We are proud to accomplish what we have so far in such a short time,” especially since 80,000 people daily “have moved through the subway and PATH stations at the site,” he said.
Engineers who have worked at the site said that the subterranean geology is ever surprising. “It’s a very complex, challenging area with a lot of unpredictable obstructions,” said Guy Nordenson, a professor of structural engineering at Princeton, whose engineering firm helped design supports that will preserve the historic ground-zero wall, a feature of the future memorial museum.
“You can do a lot of mapping there,” he added, “and you’ll still find the unexpected.” When asked whether the delays were caused by bureaucratic failings or the imponderables of the site, he said, “I’m inclined to give the Port Authority the benefit of the doubt.”
Silverstein Properties, the new leaseholder of the trade center at the time of the terrorist attacks, has paid the Port Authority nearly $658 million in ground rent — which it received in insurance proceeds — since 2001. In a 2006 renegotiation that designated Silverstein the builder of four towers there, the authority insisted on a five-year limit for the completion of construction, and in turn, Silverstein successfully negotiated for penalties in case the authority failed to complete its excavations on time. That was when the authority signed off on the 2007 completion deadline.
Mr. Silverstein’s current rent — which his company is also paying from insurance proceeds — is $78,740,000 a year, or $215,726 a day. “Our people are anxious to get their boots dirty, and build,” said Janno Lieber, the World Trade Center project director at Silverstein Properties.
The clock will start ticking for Silverstein the moment the authority turns over the tower sites, and thanks to the 2006 deal, “we will lose our equity in these buildings if we don’t finish them within five years — a risk that many developers would not take,” said Mr. Lieber, who nevertheless hopes to finish sooner.
He added, “We won’t be able to accurately assess any impacts to the schedule until we start work.”
Although the Port Authority and Silverstein Properties have often sparred in the past, “we are not interested in perpetuating an atmosphere of recrimination,” Mr. Lieber said of the missed deadline, adding, “We can’t lose sight of the fact that in the scheme of things, this delay is not huge.”
Nevertheless, construction costs “are going up something like 15 percent a year,” he said. “Literally every day’s delay costs the project a lot of money.” Therefore, despite the receipt of the daily $300,000 penalty, he said, “we won’t come out ahead.”
The impact of the construction delay on the Port Authority “will ultimately be minimal,” Mr. Shorris said, because the agency did not have to pay Phoenix Constructors, its East Bathtub contractor, a $10 million bonus it would have won for completing the job on time.
Mr. Shorris added: “To be realistic about it, if we are a few weeks late on a quarter of a billion dollar project, you might say: ‘not so bad.’ “
The greatest factor in the delay “was the rock,” Mr. Shorris said. “Our initial estimates were based on test borings, but they’re not really maps. You only find out when you’re down there.”
Given the size of the planned towers, on a site to the east of the original trade center buildings, deep foundations were essential. But construction managers encountered twice the amount of bedrock they had anticipated. “We expected 2,000 cubic yards but it was double that,” Mr. Plate said. Furthermore, when the engineers reached a level 70 feet below the street, “we expected schist, but we found a much harder rock — quartz,” Mr. Plate said.
And in one area at Church Street near Liberty, the workers had to excavate down to 120 feet to reach bedrock because engineers encountered an ancient gorge in a former glacial streambed.
Especially hard has been the placement of tieback tendons — gleaming new anchors similar to the rusty tiebacks that supported the trade center slurry wall bathtub when the towers fell, withstanding the equivalent of an earthquake of 2.3 magnitude.
In “an exceptionally intricate process,” as Mr. Plate described it, the tiebacks — each made of 21 strands of steel bridge cabling that can be longer than 150 feet — must be drilled down and anchored into both the wall and the bedrock. Some 400 have been installed, with more than 50 to go.
Tieback placement has been daunting because “you don’t want to land the tiebacks in somebody’s building foundation or in the subway tunnel of the No. 1 train,” said Joseph Freglette, the project manager for EE Cruz & Company, a contractor on the site.
The East Bathtub is more than 90 percent completed, a desolate expanse scored with caterpillar treads and boot marks, and reverberating with the incessant whump, whump, whump of gargantuan jackhammers.
Roving 85 feet below the street, like tyrannosaurs in a mechanical Jurassic Park, are more than 20 heavy-duty earth movers and rock removers, including 26-foot-high, 150-ton claws that manhandle ancient steel pilings, which will be recycled for scrap.
So far a mountain of material has been removed, more than 300,000 tons of soil, rock and concrete — enough to top off Giants Stadium, or to fill a line of dump trucks 45 miles long. Each day 70 to 100 trucks carry away the loads.
Everywhere, tracked vehicles wallow like rhinoceroses in a sea of gray mud that can be three feet deep. For although the water-resistant, 1,000-foot-long new concrete bathtub is in place, workers and machines are constantly sloshing in groundwater from the Hudson that pushes up through fissures in the bedrock floor. Only pumping keeps the bathtub from filling.
A dozen self-propelled jackhammers called hoe rams, monsters with $10,000 hardened-steel noses like rock chisels, each remove 50 to 100 cubic yards per day. The waste fills a line of 36-ton dump trucks.
Nearby a 160-ton rock trencher roars; it resembles a mammoth belt sander as it crops flat areas at bedrock.
Thanks to its “sharp engineering learning curve” in the bathtub, Mr. Shorris said, the authority is on schedule to turn over the site for Tower 2 to Mr. Silverstein in June, adding that “we are on our goal for making the PATH station operational in 2011.”
For the workers in the pit, constantly on the lookout for fast-moving mammoth vehicles, “you really have to attend to details,” said Brian Cichetti, a site safety manager for EE Cruz. He said the job was especially significant to him because his wife, Lisa, worked on the 97th floor of the south tower. As he saw the trade center collapse on Sept. 11, 2001, he knew that she was not in danger because she had taken their son Mark to his first day of kindergarten that morning.
But the accelerated schedule has been nightmarish for neighbors like Andy Jurinko, a painter whose live-in, third-floor studio at 125 Cedar Street overlooks the future home of 4 World Trade Center.
He and his wife, Patricia, endure the din seven days a week. “They begin at 5 and keep going until nearly 2 a.m.,” said Mr. Jurinko, 68. “The Port Authority tries to be sympathetic, but the work goes on.”