From what I can see, you are wrong and here's why I think that.I thought that this issue deserved a thread of it's own. It looks as if NIST have applied short span cnnections to the long span floor trusses at the core column connection end.
View attachment 67228574
I feel that I must be getting something wrong here, because this would invalidate NIST's whole model if it were the case, and is not something that would get past the scrutiny of any competent investigative engineer that had access to the drawings.
As an interstate agency, the Port Authority was not subject to local laws and regulations of the City of New York, including building codes. Nonetheless, the Port Authority required architects and structural engineers to follow the New York City building codes. At the time when the World Trade Center was planned, new building codes were being devised to replace the 1938 version that was still in place. The structural engineers ended up following draft versions of the new 1968 building codes, which incorporated "advanced techniques" in building design.[53]
From what I can see, you are wrong and here's why I think that.
1. You are using drawings from a document published in 1964 and NOT using the actual engineer stamped structural drawings for the trusses. They probably had made MANY changes to their designs since that 1964 publication due to having to use a draft of the newly revised codes in 1968.
https://en.wikipedia.org/wiki/Construction_of_the_World_Trade_Center
2. The photos of the actual floor trusses not look anything shown in the details within your 1964 publication drawings. In your detail of the short span truss below, the component I circled in red is not round bar. Round bar is what is seen seen going between the angles of the the trusses. below is the side view.
View attachment 67228581
Next is the long span trusses from your publication. It also does not show the component I circled in red to be round bar.
View attachment 67228583
Below is a cross section of the trusses. The component I circled in red is not round bar. Also in this section, there is no "round bar knuckle" shown coming through the decking at the top.
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Below is a photo showing the "round bar knuckle" (circled in red) coming through the decking.
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Bottom line is that you need the proper drawings from the engineer stamped structural construction set showing how the trusses were design and put together and not use some drawings from a document published in 1964, especially when the engineers had to use newly revised codes from 1968 for their designs.
You can't read can you? The publication you are citing came out in 1964. The structural engineers were using a draft of the newly revised codes from 1968! How can you say that those drawings from the 1964 publication is what went out in the final, approved construction set? They don't even match what was actually seen! I've pointed out that the diagonal members of the trusses shown in your details from 1964 are not round bar going between the angles.ADD - I am actually prepared to be wrong on this, and will accept a reasonable explanation for what looks like a howling error by NIST if there is one, but trying to say that a booklet which was published beore ground was broken came from anything other than the structural drawings makes zero sense.
Reading comprehension for the win gerrycan.Keep in mind that this document is so accurate as to have the (hypothetical) differential floor shortenings down to 1/100th of an inch. Where do you think they got the info for this publication if not from the drawings ??
You can't read can you? The publication you are citing came out in 1964. The structural engineers were using a draft of the newly revised codes from 1968! How can you say that those drawings from the 1964 publication is what went out in the final, approved construction set? They don't even match what was actually seen! I've pointed out that the diagonal members of the trusses shown in your details from 1964 are not round bar going between the angles.
I will.Try again Gamelon.
I will.
See your drawing below. See the component circled in red? That is not "round bar". That is a "T" shaped cross member that is cut so the vertical leg of the "T" fits between the angles.
View attachment 67228595
If this is wrong then show me a photograph or and actual stamped construction drawing from the final set of drawings that show this. If I am wrong, then I will say I'm wrong.
(my emphasis)See your drawing below. See the component circled in red? That is not "round bar". That is a "T" shaped cross member that is cut so the vertical leg of.
You are completely wrong!(my emphasis)
You're looking for the wrong thing in the wrong place.
This is round bar...
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Do you see it ? It's that sort of round shaped steel stuff lying around in precut lengths eady to be installed. :2wave:
You are completely wrong!
View attachment 67228616
The stuff lying around in precut lengths is #4 rebar as noted in my picture. Here is a link to the rebar, #4 Rebar - #4 Reinforcing Bar | Harris Supply Solutions. That is the same #4 bar that is called out in your detail below. Do you see the "#4 Bar" callout just below the word "Telephone"? That #4 rebar is what lies HORIZONTALLY across the top of the decking and is what will sit inside the concrete.
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The "knuckles" are formed by the bending of the "round bar" (different from rebar) that comes up through the decking and form a kind of shear stud for the concrete to be poured. That round bar that forms the knuckles continues in a "W" pattern to form the truss. Your details from the 1964 booklet show "T" shaped components for the "W" pattern of the trusses and not "round bar".
Your Detail "X" below proves this. The #4 bar callout in this detail shows a cross section of the #4 bar that runs HORIZONTALLY across the top of the decking. That #4 bar does NOT go through the decking to form the "W" shape pattern below.
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Point it out on this....
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You are saying that this component circled in red from your 1964 documentation drawing...
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...is the same component circled in red here.
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They are not.
I'm trying to explain to you that the drawings you are using from the 1964 publication are NOT what was installed. Look at the drawings you provided and match them to pictures. It's YOUR turn to match components and try and explain what you think matches.I am not saying that AT ALL. The bit you circled in the top pic - what is it YOU think that is ?
No, that's not what I "thought".Gamolon - you thought that the truss was a "T" piece - You wrote it on this thread.
Here.
View attachment 67228632
For a long span truss it's obvious because of the direction of the knuckles that are formed. That's the whole point.
You though it was a "T" piece of some sort 5 minutes ago - you need to start being honest here..
I'll make this easy for you.
Using the picture below, please match both the area in the green and red boxes...
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...with their matching areas in the photo below.
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If you think both or just one don't match the photo, just say so.
I will.
See your drawing below. See the component circled in red? That is not "round bar". That is a "T" shaped cross member that is cut so the vertical leg of the "T" fits between the angles.
View attachment 67228595
If this is wrong then show me a photograph or and actual stamped construction drawing from the final set of drawings that show this. If I am wrong, then I will say I'm wrong.
No.What you thought was a " T shaped cross member" is a truss at 90 degrees.
No, you just can't read drawings which is why you want to "move on" so quickly now.Answered your pic question already - you need to do some 'fessing up - You thought that the truss at 90 degrees was a T piece.
Now let's move on please.
No.
What I said was a "T" shaped member was the "web diagonal" (again, the term used in your picture just recently). I am saying that is what your 1964 publication drawings show it to be. I am saying that all the pictures show not a "T" shaped "web diagonal" (like your drawings show), but "round bar" as seen in the pictures.
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