Yes, napalm burns pretty hot... I'm a former residential woodframer , and code for joist bearing is 1 3/4" inches in my state. Are you saying highrises are built like single family residences? JohnnyK
How heavy is the joist How long is the joist What is the joist made of What is it sitting on How is it fastened Static or dynamic Load factors, etc, etc, etc,. All this factors in on the bearing edge. Don't get me started woodpecker. And you've never hung a joist short of the bearing specs, right? Carpenters...(sigh)
Without much effort I came up with this (for the cut-n-paste crowd): http://www.wanttoknow.info/020302nytimes
Actually, we only go code when we are forced to by some circumstance...and that's not often. Otherwise, we always go beyond code, bearing typically 3 1/2" and even as much as a foot. Everything is inspected so it's not worth going less than code, and I don't think I ever have because 1 1/2" or less is just too wacko...especially on large beams. Note that hangers have at least 1 3/4" bearing, and more for hangers designed for larger loads. I can't imagine any beam or joist, no matter how small, bearing less than 3" for a downtown commercial steel highrise. But since I've never worked on one, I can't say. But I have a journeyman ironworker/welder freind and she'll kick yer... ...I mean she may be able to shed some light on the subject. JohnnyK
Johnny you gotta remember highrises are built like weebles--very heavy on the bottom and progressively lighter to the top. They'll make the upper members as light as possible. Now I don't know what the specs were for the trade centers, but it wouldn't take much to knock'em off their seat. They're stronger than shit when tied together and the WHOLE diaphram can give as a unit. That's why towers can sway with the wind. But if one wall starts going in one direction and the other wall does the opposite...oh boy.
Uhhh.... You should do some homework before you grace us with your 'expert' opinion. Flame color is indicative of heat. Thats why intense fires burn brighter. Look it up. Coming from a guy who counters documented fact with maybe's and there-can't-possibly-be's, i'd say your full of shit. In fact, I know you are. How do I know? Because Underwriter Laboratories has already weighed in their expert opinion on joist strength, which oddly enough, refutes your baseless claims: "I'm aware of UL's attempts to help, including performing tests on models of the floor assemblies. But the results of these tests appear to indicate that the buildings should have easily withstood the thermal stress caused by pools of burning jet fuel." and... "We know that the steel components were certified to ASTM E119. The time temperature curves for this standard require the samples to be exposed to temperatures around 2000F for several hours. And as we all agree, the steel applied met those specifications." http://www.septembereleventh.org/newsarchive/2004-11-11-ryan.php That was an excerpt from an email written by Kevin Ryan, Site Manager Environmental Health Laboratories A, Division of Underwriters Laboratories - the company that certified ALL the steel used in the WTC. Even your precious little joists. Look it up. No, dumbass. THE ENGINEERS who BUILT THE TOWERS designed them to withstand a 500 mph collision by a fully fueled airliner. Remember??? Guess not. Also, the NIST collapse modeling, which is the closest thing we have to scientific proof as to why the Towers fell in the first place, *prove* the trusses could support FAR MORE weight in 'raging inferno' conditions than your baseless opinion has brought to the table thus far. Wrong again. You're a real armchair quarterback, aren't you? The NIST report stated the collapse was precipitated by joist failure AND expanded joists pulling perimeter walls in, causing them to buckle. The key point: the NIST contradicted its own report - max 250C temps don't provide sufficient thermal softening to allow the perimeter columns to 'buckle'. Out of chart? Where in the statement, 'we designed the Towers to take a fully loaded 707 impact', does it suggest out of chart? Please, enlighten us. Sorry to hear. But knowing acquaintances who meet untimely deaths from collapsing roofs doesn't make you an expert in skyscraper design or structural failure. We should all listen to you because you know a guy, who knows a guy that had a roof fall on his head?? uhh.... ok. Yea, the chief structural engineers who intellectually birth these behemoths can't hold a candle to the 'real egineers' -- the grunts -- who merely fit the pieces together. Sure. The base columns had slabs of steel running through their centers, making them almost solid. The entire core structure itself served as a 'tower within a tower'; upper core columns had their own 'floors' that crossed braced the core structure its entire length. This enabled the building to withstand 140 mph winds. Thats the cores job. To withstand and bear the vast weight of the buildings static and dynamic load. What you're suggesting is ludicrous. That somehow, these flimsy truss connectors that easily snapped off of the one end, exhibited unbelievable strength on the other --- sufficient to literally TEAR DOWN the core tower rooted in the bedrock. Total bs. No support vertically? Except the PURE STEEL COLUMNS holding each successive column erect. No support laterally? Except the cores steel reinforced concrete floors that cross-braced the core for its entire width. Glad you did some original research. Coming from a guy whose countered scientific documents and empirical fact with nothing but baseless speculation and uncorroborated opinion, I'd say you're full of shit. Try backing up your argument with facts next time.
Arguing for the sake of arguing tires me. Stick this in your pie hole: http://www.channel4.com/science/microsites/S/science/engineering/news_towers.html A little common sense could help you along in life.
The federal reserve is a private organization owned by a handful of families. Much of the B.S. against average individuals is carried out by a cabal of powerful satanic individuals who fancy themselves as being in war with god. http://video.google.com/videoplay?docid=-4577741442485197199&q=illuminati&pl=true Quote from achilles28: "The real truth of the matter is, as you and I know, that a financial element in the large centers has OWNED the government ever since the days of Andrew Jackson.." - President Franklin D. Roosevelt, November 21, 1933 If you are serious, start with a history of the Federal Reserve. Incidentally, which is neither Federal nor a reserve. The same Money Powers that OWN this country, OWN every single nation on the planet. By proxy or fiat. Industrialists, politicians, heads of state, media - merely loyal subjects who've sworn undying allegiance to the realization of the System.
You haven't argued squat. You've just regurgated recycled propaganda. Try addressing my points with original thought. Its hard to think for yourself, but give it a try.