DEP Invoice or Financial Record, September 30, 2001

OGfenoirg NYC 9/11 Public Portal Document

can better survive earthquakes. lesser damaged in a collision with a cement flower pots, like those placed “The concrete wall prevents the motorcycle. around the World Trade Center after steel from buckling,” Dr. Astaneh- Much of the fuel would have then the 1993 bombing, keep a car bomb a Asl said. “The steel prevents the splashed against the outside of the safe distance from-the structural coir concrete from cracking and shatter­ building instead of igniting inside. umns. Concrete walls around loading ing. When you marry them, they be­ Dr. Astaneh-Asl said. docks and mail rooms can be thick­ come very good.” The World Trade Center attack ened to protect against bomb blasts. may lead developers to regard a Jackets of graphite fibers wrapped In tests, a half-scale, three-story terrorist attack as a risk to be around columns make them less like­ building proved capable of surviving planned for instead of an unthinkable ly to collapse. Protective glaze can four magnitude-9 earthquakes. While one-time tragedy. be added to windows to make them “The perception of the terrorist less likely to shatter. threat is where earthquake hazards In planning for new buildings, were in the mid- to late 196O’s,” said structural designers are now more ‘Given enough Dr. Jeremy Isenberg, president and likely to add more redundancy where chief at Weidlinger Associates, a con­ the collapse of one column does not money, we can sulting firm that once helped design lead to the collapse of the entire resilient military bases and missile building, as occurred in the 1995 design anything.’ silos, and now offers its expertise for bombing of the Alfred P. Murrah federal and commercial buildings. Federal Building in Oklahoma City. “It took a series of three or four Dr. Thornton said that in one the wreckage of the 767’s flew into damaging earthquakes to drive sense, taller buildings are safer than the interior of the World Trade Cen­ home to owners of buildings that midrise buildings; taller buildings ter, the extra mass of concrete and they had financial assets at risk.” are less likely to topple because their steel walls would have absorbed Developers may now request that builders generally provided more re­ more resilience be built into new dundancy into the structures. The much of the planes’ momentum. buildings and into old ones being design of skyscrapers 50 stories or “Most of the fracturing of the remodeled, Dr. Isenberg said. more, has been “generally very ro­ plane will take place outside of the While perhaps not much can pro­ bust,” said Dr. Thornton. “For 40 or building, not inside,” Dr. Astaneh-Asl tect against kamikaze jetliners, oth­ less, it’s not” said. That is the same fundamental er simple steps may help protect But the taller buildings make a physics that make the S.U.V. the against lesser attacks. Large, heavy more tempting target for terrorists.

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