huangyhg

engineer society accused of cover - ups
what does everyone think about this? i uploaded a pdf of the article. i am not sure if it worked.
here is a paragraph from the article:
"critics now accuse the group of covering up engineering mistakes, downplaying the need to alter building standards, and using the investigations to protect engineers and government agencies from lawsuits."
j
there will always be skeptics, just as there are always fool. (implication intended)
also, no one is ever going to know what happened regarding anything... we will only ever know the probable mechanisms. this applies equally to bridges, buildings, planes, trains, etc, etc, etc. differing opinions on such matters are a close cousin to "he said, she said" and "he started it" from school yard fights, bar brawls, affairs, etc.
there are three positions: my side, your side, and the truth. this applies in all things.
b.eng (carleton)
working in new zealand, thinking of my snow covered home...
i just lost a little respect for uc berkely.
this sounds more like a political argument than a technical one. look at the players.
there are many extremely qualified experts that disagree with these gentlemen.
as usual, the press will report things that they feel will boost readership. not necessarily a fair and objective reporting of all the facts and opinions. and in a world run by politicians and corporations, public policy is always affected by personal interests.
i find it interesting that they are promoting an argument that the design of buildings (pre 9/11) should have been done to protect against possible jet aircraft collision. hindsight is 20-20 and these buildings were designed to the "standard of care" at the time. in fact, the current standard of care has changed very little as the risk of attack by hijacked jet aircraft is not a typical criteria for design of buildings today and is not being promoted by anyone that i know of. that being said, i would contend that a building code that required resistance to jumbo jet impact for every building built in the country would be quite unreasonable and should not be pursued. there are far better ways to protect against this which asce rightly recommended.
how realistic is it to design for an airplane flying into a building? i mean, how many possible iterations can you run through of taking out columns and beams on a given floor and finding alternate load paths? it seems you might be able to design the structure to stand if several known
quote:
i just lost a little respect for uc berkely.
you had some to begin with?
well from my understanding (which is my understanding so dont quote me), i beleived that the twin towers structural design was adequate. i dont think that the force of the impact or anything relating to the impact or physical destruction to the members was the fault of the collapse.
i beleive it was the fire that ensued that caused the members to buckle and therefore that is the reason it came down. as we know the americans like to spray their steel with concrete, where as we in the uk prefer intumescent coatings or totally encasing the
some rogue professors aside, berkely is a great school- especially in engineering.
just as you cannot design airplanes to be as rugged as the black boxes (there isn't enough thrust in current engines to build airplanes as hardened as the black boxes), you cannot design even tall expensive buildings to withstand every possible scenario for induced damage. that much is clear. all you can do is develop reasonable design standards and hold everyone to those standards. now that an 800 passenger airplane has been built, should every skyscraper built from now on, into perpetuity, be built to withstand a 500 mile per hour impact with a 1.5million pound airplane (700,000 kilos), fully loaded with flammable jet fuel?
respect uc-berkeley or not, it is interesting the hubris this astaneh-asl guy exhibits; the attitude that comes across is "my simulation said the buildings could withstand the impact of the airplanes, therefore the conclusions of other engineers that don't agree with my conclusions must somehow be tainted by conflict of interest." imo it's one thing to say "my conclusions are different" and another to say "my conclusions are different because the other conclusions are tainted by moral or ethical deficiencies."
a number of years ago one of the designers for the verrazano-narrows told me that the towers had to withstand the impact of a boeing 707. that was required because the bridge is near jfk airport (idelwild, at the time of design).
practically speaking, how often do planes crash into skyscrapers, intentionally or not? aside from the wtc, i believe there were only two such incidents in nyc over the past 60+ years.

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