replicas of new tower endure nature’s fury and a test blast

By DAVID W.
The World Trade Center has not yet emerged from the ground, but its front has survived earthquakes, hurricanes and explosions that rocked the Earthmile away.
In recent months, twosize mock-
Ups on several floors of glass and aluminum facades have been built and tested.
One is outside Los Angeles, Ontario, California.
The other is a location in central New Mexico that can only be reached on four dirt roadswheel-drive vehicles.
1,368 feet, 23 acres of glass
The coverage area of World Trade Center 1 will be affected by huge natural forces.
This building, also known as the Freedom Tower (
At a symbolic 1,776 feet, when its mast is calculated)
It will be the tallest building in New York City and the target of a terrorist attack.
The Port Authority of New York and New Jersey, which is building a world trade center, and Skidmore, Owings and Merrill, who designed the center, said the two models
Ups did well.
The facade, known as the curtain wall, was made by Benson Industries in Portland, Oregon.
The engineering company Weidlinger was involved in the explosion of consultants.
Design resistant.
The advertising \"physical test is the curtain-
\"Wall contractors actually meet performance requirements,\" says Carl Galioto, a partner at Skidmore . \".
\"The complete production of the curtain wall cannot start unless simulated
The Up sample passed these tests.
Passers-by can hardly see advertisements
The foundation of the World Trade Center is rising to the streets every day. The first mock-
Up was tested for explosion at N. Socorro. M.
At the center for research and testing of new energy materials, a Department of the New Mexico Institute of Mining and Technology.
Because details could help potential attackers.
Provide information such as how strong curtain wall design can withstand
Officials said almost nothing about the simulation test. up.
\"The simple answer is, yes, it passed,\" said Port Authority project director John McCullough . \".
He was more frank about the tests he conducted last month at the western California construction consulting laboratory.
Simulation of $537,000
The Up was built to represent a corner of the three typical tower floors, with a layer of laminated glass half an inch thick.
The biggest is 5 feet by 13 feet, weighing half a ton.
A closed steel chamber was built behind the glass and aluminum cladding.
The goal is to find out how much air and water are expected to leak under storm conditions at least once in 50 years.
Spray water jets that simulate 74 miles of wind per hour on the front. During the 15-
Each square foot of glass is hit by more than a gallon of water.
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In another test, a disassembled aircraft propeller was opened to simulate even numbers-
Stronger and moreScattered wind
\"It\'s very colorful,\" he said . \"
Witnessed the test of Galioto
\"It\'s noisy here.
Water blows in all directions and smoke blows out of the engine.
\"Air penetration is measured by an instrument.
Witnesses in the room measured the penetration of water.
\"The water is entering the surface of the curtain wall at such a strong intensity that you can\'t see,\" said Bruce Fox, deputy project director at the Port Authority . \".
\"Then you will investigate and open all the different parts to see if there is evidence of a leak.
\"No.
Hydraulic jacks are used to simulate different levels of shaking on various floors, whether full or empty.
The surface is also cooled to 10 degrees (
Application of refrigerated pipes on glass)
100 degree baking (by heat lamps).
Gusts up to 167. p. h.
Simulation by using a pump to pull air out of the chamber creates conditions where the external air pressure is much greater than the internal pressure.
The process has also been reversed by delivering air to the chamber to simulate conditions on the side of the tower away from the wind.
Jack pulled the model to simulate an earthquake.
In different directions.
Finally, a stronger earthquake was simulated.
At this point, designers no longer expect simulation
Keep seal and water tight.
But the standard requires that no glass will break and no glass will fall off. Mr.
McCullough of the Port Authority said
Meet all performance standards. And Mr.
Fox was surprised to say: \"Sometimes in these tests you have to do forensics and corrections.
Here we have not failed at all.
\"A version of this article appears on the print on page B3 of The New York edition, with the title: a replica of the new tower endured the wrath of nature and the explosion of tests.
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