Can Buildings BeDesigned to Resist Terrorist Attack?

In the aftermath ofthe terrorist attack on the World Trade Center,structuralengineers are trying hard to

solve a questionthat a month ago would have been completely unthinkable.Can buildings bedesigned to

withstandcatastrophic blasts inflicted by terrorists?

Ten days after theterrorist attacks on the twin towers,structural engineers from the Universityat Buffalo

and the Multidisciplinary Center for Earthquake EngineeringResearch(MCEER)headquartered at UB

traveled to groundzero as part of a project funded by the National Science Foundation.Visitingthe site as

part of an MCEERreconnaissance visit,they spent two days beginning the task of formulatingideas about

how to design suchstructures arid to search for clues on how to do so in buildings that weredamaged but still

are standing.

"Our objectivein visiting ground zero was to go and look at the buildings surrounding theWorld Trade

Center,thosebuildings that are still standing,but that sustained damage,"saidM.Bruneau,Ph.D."Our im-

mediate hope is thatwe can develop a better understanding as to why those buildings remainstanding,while

our long-term goalis to see whether earthquake engineering technologies can be married toexisting technolo-

gies to achieveenhanced performance of buildings in the event of terrorist attacks,"headded.

Photographs taken bythe investigators demonstrate in startling detail the monumental damageinflicteed

on the World Trade Center towers andbuildings in the vicinity.One building a block away from the towers

remains standing,butwas badly damaged."This building is many meters away from the World Trade Center

and yet we see acolumn there that used to be part of that building,"explainedA.Whittaker,Ph.D."The

column became amissile that shot across the road,through the window arid through thefloor."

The visit to thearea also revealed some surprises,according to the engineers.For example,thefloor

framing system inone of the adjacent buildings was quite rugged,allowing floors that werepierced by tons of

falling debris toremain intact. " Highly redundant ductile（有延展性的）framing systems may provide a sim-

pie,but robuststrategy for blast resistance,"he added.Other strategies may includeproviding alternate paths

for gravity loads inthe event that a load一bearingcolumn fails."We also need a better understanding of the

mechanism ofcollapse,"said A.Whittaker."We need to find out what causes abuilding to collapse and how

you can predictit."

A.Reinhorn,Ph.D.notedthat"Earthquake shaking has led to the collapse of many buildings in the

past.It inducesdynamic response and extremely high stresses and deformations in structuralcomponents.So-

lutions developedfor earthquake-resistant design may be directly applicable to blast engineeringand

terrorist-resistantdesign.Part of our mission now at UB is to transfer these solutions and todevelop new ones

where none exist atpresent."The project fundedby the National Science Foundation_________.

A.was first proposedby some engineers at UB

B.took about twodays to complete

C.was to investigatethe damage caused by the terrorist attack

D.was to find outwhy some buildings could survive the blasts