QUOTE (NEU-FONZE+Feb 10 2007, 03:10 AM)
Lozenge 124:
Well, I think DBB and Grumpy have pretty much said what I would have said about the energy absorbing capacity of the lower section of a tower.
The column splices were the weak link in the chain of steel supporting the Towers.
The large number of neatly cut column sections in the rubble pile confirms that the columns mostly failed at their splices - the welds for the core columns and the A325 bolts for the perimeter columns.
Impact damage was concentrated in the concrete and steel within a few floors of the collapse front. This means that the impact kinetic energy exceeded the elastic strain energy absorbing capacity of steel in the collapse front/zone by a factor of about 3. Thus, even in the worst case scenario of the WTC 1 collapse, there was sufficient impact energy to entirely destroy 3 floors-worth of column support.
And BTW, the upper block of 14 to 30 floors did not need to drop entirely in free fall through 3.7 meters. It could drop while being simply hinged at one corner or on one side, and the impact damage to the floor below would still be sufficient to initiate a progressive collapse that would bring down the entire structure...
NF
@NEU-FONZE:
All I have seen so far, is this floor by floor E1 consideration (based on Greening), and again I do not think this is valid.
All I have seen so far, is this floor by floor E1 consideration (based on Greening), and again I do not think this is valid.
The column splices were the weak link in the chain of steel supporting the Towers.
The large number of neatly cut column sections in the rubble pile confirms that the columns mostly failed at their splices - the welds for the core columns and the A325 bolts for the perimeter columns.
Is this based on your observations? Again it's a shame the NIST doesn't have much to say about this or what went on after collapse initiation.
It's also a shame that the steel column remains were carted off so quickly, because this is the kind of thing that would have been interesting to investigate.
I agree that this is what appears to be happening, the tower below the collapse front doesn't appear to be damaged. But that is what is so strange to me. Hit the tower on top with a giant sledgehammer, why should the damage be concentrated within a few floors of the impact? With an interconnected core and perimeter, the entire structure is going to absorb the shock. This concentrated area of damage moving down the tower (at close to free fall speed) is one of the reasons to invoke another source of destructive energy aside from gravity.
Well, I think DBB and Grumpy have pretty much said what I would have said about the energy absorbing capacity of the lower section of a tower.
The column splices were the weak link in the chain of steel supporting the Towers.
The large number of neatly cut column sections in the rubble pile confirms that the columns mostly failed at their splices - the welds for the core columns and the A325 bolts for the perimeter columns.
Impact damage was concentrated in the concrete and steel within a few floors of the collapse front. This means that the impact kinetic energy exceeded the elastic strain energy absorbing capacity of steel in the collapse front/zone by a factor of about 3. Thus, even in the worst case scenario of the WTC 1 collapse, there was sufficient impact energy to entirely destroy 3 floors-worth of column support.
And BTW, the upper block of 14 to 30 floors did not need to drop entirely in free fall through 3.7 meters. It could drop while being simply hinged at one corner or on one side, and the impact damage to the floor below would still be sufficient to initiate a progressive collapse that would bring down the entire structure...
NF
@NEU-FONZE:
QUOTE
Well, I think DBB and Grumpy have pretty much said what I would have said about the energy absorbing capacity of the lower section of a tower.
All I have seen so far, is this floor by floor E1 consideration (based on Greening), and again I do not think this is valid.
QUOTE (->
| QUOTE |
| Well, I think DBB and Grumpy have pretty much said what I would have said about the energy absorbing capacity of the lower section of a tower. |
All I have seen so far, is this floor by floor E1 consideration (based on Greening), and again I do not think this is valid.
The column splices were the weak link in the chain of steel supporting the Towers.
The large number of neatly cut column sections in the rubble pile confirms that the columns mostly failed at their splices - the welds for the core columns and the A325 bolts for the perimeter columns.
Is this based on your observations? Again it's a shame the NIST doesn't have much to say about this or what went on after collapse initiation.
It's also a shame that the steel column remains were carted off so quickly, because this is the kind of thing that would have been interesting to investigate.
QUOTE
Impact damage was concentrated in the concrete and steel within a few floors of the collapse front.
I agree that this is what appears to be happening, the tower below the collapse front doesn't appear to be damaged. But that is what is so strange to me. Hit the tower on top with a giant sledgehammer, why should the damage be concentrated within a few floors of the impact? With an interconnected core and perimeter, the entire structure is going to absorb the shock. This concentrated area of damage moving down the tower (at close to free fall speed) is one of the reasons to invoke another source of destructive energy aside from gravity.
QUOTE (lozenge124+Feb 10 2007, 04:43 PM)
@shagster:
thanks for taking a look at Hoffman's model.
Like I have mentioned in my post about Greening's paper I do not think E1 considerations are valid. The core and perimeters are interconnected you can not look at them on a floor by floor basis. You have to consider them as a whole.
When I said "mentally add into the model the supporting strength of 47 core columns and the perimeter walls (again, because up to now we have just considered the inertia of the floor mass in slowing down the collapse)". I mean just that, the supporting strength, not the mass.
So what happens to the columns in the lower portion that aren't subject to axial strikes? I don't see how this is favorable to your model.
Again, I think you are comparing upper block kinetic energy with E1 do determine this. (correct me if I'm wrong). The core is a single large structure. I like the model Grumpy proposed where all the floors are removed, and you drop a block onto the remaining steel core and perimeter. I would like to know what you think happens next.
Agreed, and that's why we need a model/analysis of these things after collapse initiation. To me it is not at all self-evident that the collapse would proceed all the way down, let alone at the speed witnessed.
Can you please elaborate on this maybe with a picture or two of the interconnection links?
The problem I see is the very tilting of the upper block and the tilting of the core destroys he interconnectivity of the very core near the initiating of the collapse, this can be seen in the photos that show floor slabs tilting below the collapse zone, before initiation.
If the core was not tilting and buckling along the length of the columns then the floor slabs would never have collapsed, ahead of the blocks tilting.
I believe you are implying a stronger structure than was actually present in the core.
I would just like to see some proof of this.
thanks for taking a look at Hoffman's model.
Like I have mentioned in my post about Greening's paper I do not think E1 considerations are valid. The core and perimeters are interconnected you can not look at them on a floor by floor basis. You have to consider them as a whole.
When I said "mentally add into the model the supporting strength of 47 core columns and the perimeter walls (again, because up to now we have just considered the inertia of the floor mass in slowing down the collapse)". I mean just that, the supporting strength, not the mass.
So what happens to the columns in the lower portion that aren't subject to axial strikes? I don't see how this is favorable to your model.
Again, I think you are comparing upper block kinetic energy with E1 do determine this. (correct me if I'm wrong). The core is a single large structure. I like the model Grumpy proposed where all the floors are removed, and you drop a block onto the remaining steel core and perimeter. I would like to know what you think happens next.
Agreed, and that's why we need a model/analysis of these things after collapse initiation. To me it is not at all self-evident that the collapse would proceed all the way down, let alone at the speed witnessed.
Can you please elaborate on this maybe with a picture or two of the interconnection links?
The problem I see is the very tilting of the upper block and the tilting of the core destroys he interconnectivity of the very core near the initiating of the collapse, this can be seen in the photos that show floor slabs tilting below the collapse zone, before initiation.
If the core was not tilting and buckling along the length of the columns then the floor slabs would never have collapsed, ahead of the blocks tilting.
I believe you are implying a stronger structure than was actually present in the core.
I would just like to see some proof of this.
QUOTE (Chainsaw,+Feb 10 2007, 02:59 PM)
The problem that caused the rapid collapse was oscillation, that caused the residual strain that is inherent in all welds to break, you can not have any weld without some residual strain. That racing ahead of the collapse front weakened the beams. Residual stain is caused by the very practice of welding when the heated metal contracts placing some strain energy on the joint.
If you calculate the tensile strength of the steel then subtract the residual strain of the welds you will find the answers your looking for.
Or at least that is where all the information I have found seems to point, although I could be wrong, that is the problem with the Scholars for truth they declare that something is impossible when in fact they can not prove it.
They declare they have all the answers! Honest researchers would definitely not do so!
http://scitation.aip.org/getabs/servlet/Ge...=cvips&gifs=yes
http://scitation.aip.org/getabs/servlet/Ge...=cvips&gifs=yes
http://www.appliedultrasonics.com/pdf/pdf1.pdf
http://www.scientific.net/0-87849-978-4/10/
Metals get their strength from their Crystalline structures, destroy the Crystalline structure and you destroy the strength of the metals. Heat and wave energy are know to have powerful effects on the breakup of such crystalline structures.
I have been looking for calculations on the residual strain values in the towers and I have not found any, Has anyone here ran across such information?
I certainly haven't read everything the "scholars for truth" have written. But I've never seen any claims put forth that they know everything. Rather, they are point out flaws and shortcomings of the official theories where they do not pass scrutiny.
I think your concept of oscillations breaking welds is interesting, and if we consider a block falling onto the core and perimeter, sure I can buy that oscillations would be created in the structure and that this would cause some damage. (though again, I do not accept that the damage would be restricted to the top floor or 3, the oscillations would spread thoughout the entire interconnected core and perimeter)
But, if this is what brought down the towers, I would like to see it in the NIST report as an official explanation, or at least in some kind of a publication. I would like to see an estimate of the time the towers took to collapse based on this scenario, I would like to see visualizations of the towers collapsing as calculated by models. Is this too much to ask?
The NIST took it upon themselves to generate an official explanation for the WTC collapses, so the burden of proof for their theory is on them. I agree with the many critics who claim that they have not adequately proven that "global collapse ensues" after initation.
If you calculate the tensile strength of the steel then subtract the residual strain of the welds you will find the answers your looking for.
Or at least that is where all the information I have found seems to point, although I could be wrong, that is the problem with the Scholars for truth they declare that something is impossible when in fact they can not prove it.
They declare they have all the answers! Honest researchers would definitely not do so!
http://scitation.aip.org/getabs/servlet/Ge...=cvips&gifs=yes
http://scitation.aip.org/getabs/servlet/Ge...=cvips&gifs=yes
http://www.appliedultrasonics.com/pdf/pdf1.pdf
http://www.scientific.net/0-87849-978-4/10/
Metals get their strength from their Crystalline structures, destroy the Crystalline structure and you destroy the strength of the metals. Heat and wave energy are know to have powerful effects on the breakup of such crystalline structures.
I have been looking for calculations on the residual strain values in the towers and I have not found any, Has anyone here ran across such information?
I certainly haven't read everything the "scholars for truth" have written. But I've never seen any claims put forth that they know everything. Rather, they are point out flaws and shortcomings of the official theories where they do not pass scrutiny.
I think your concept of oscillations breaking welds is interesting, and if we consider a block falling onto the core and perimeter, sure I can buy that oscillations would be created in the structure and that this would cause some damage. (though again, I do not accept that the damage would be restricted to the top floor or 3, the oscillations would spread thoughout the entire interconnected core and perimeter)
But, if this is what brought down the towers, I would like to see it in the NIST report as an official explanation, or at least in some kind of a publication. I would like to see an estimate of the time the towers took to collapse based on this scenario, I would like to see visualizations of the towers collapsing as calculated by models. Is this too much to ask?
The NIST took it upon themselves to generate an official explanation for the WTC collapses, so the burden of proof for their theory is on them. I agree with the many critics who claim that they have not adequately proven that "global collapse ensues" after initation.
QUOTE (Chainsaw+,Feb 10 2007, 07:09 AM)
Bin Laden was already tried and convicted for the embassy bombings, that is why they come first DA! PS. his trial was in a regular court as well as in the court of the country where the embassy bombings took place.
He is already a convicted murderer, and your defending him?
Try to get your history correct.
OBL was indicted for the embassy bombings.
They did not have a Trial because that would require PROOF.
OBL was a CIA asset (useful patsy and most likely dead) so their will never be a trial.
The world would be a much better place without OBL or other CIA assets.
Most people don't know about the inconstancies in the OCT because the MSM for some reason does not publish anything that goes against the official fairy tale.
He is already a convicted murderer, and your defending him?
Try to get your history correct.
OBL was indicted for the embassy bombings.
They did not have a Trial because that would require PROOF.
OBL was a CIA asset (useful patsy and most likely dead) so their will never be a trial.
The world would be a much better place without OBL or other CIA assets.
Most people don't know about the inconstancies in the OCT because the MSM for some reason does not publish anything that goes against the official fairy tale.
lozenge124
The cleanup took over six months. The steel was segregated at the Freshkill site and available for examination to qualified investigators for months. This mantra about evidence being hurriedly removed is just a red herring put forward by the "troothers", don't buy into such disinformation.
The cleanup took over six months. The steel was segregated at the Freshkill site and available for examination to qualified investigators for months. This mantra about evidence being hurriedly removed is just a red herring put forward by the "troothers", don't buy into such disinformation.
I agree that this is what appears to be happening, the tower below the collapse front doesn't appear to be damaged. But that is what is so strange to me. Hit the tower on top with a giant sledgehammer, why should the damage be concentrated within a few floors of the impact? With an interconnected core and perimeter, the entire structure is going to absorb the shock. This concentrated area of damage moving down the tower (at close to free fall speed) is one of the reasons to invoke another source of destructive energy aside from gravity.
The visible collapse front comes along somewhat behind the floor pancaking collapse and the wedging action of the top block only has to push the outer frame outward, requiring very little energy(think an axe through a chunk of firewood) and to stress the INDIVIDUAL columns of the core to the point where the welded joins fail(a matter of just a few degrees, thus the straight sections of those columns strewn over the footprint).
The 2/3 G is in congruence with the observed rate of fall. Whatever mathematical calculation one does of the energies is not valid unless the outcome matches with reality. The energies required for observed collapse rates are well within the kenetic energies available from gravitational collapse.
Grumpy
The cleanup took over six months. The steel was segregated at the Freshkill site and available for examination to qualified investigators for months. This mantra about evidence being hurriedly removed is just a red herring put forward by the "troothers", don't buy into such disinformation.
The steel was removed from WTC7 in weeks and their are plenty of photos to prove it. As usual Grumpster does not let the truth stand in the way of his BS.
The visible collapse front comes along somewhat behind the floor pancaking collapse and the wedging action of the top block only has to push the outer frame outward, requiring very little energy(think an axe through a chunk of firewood) and to stress the INDIVIDUAL columns of the core to the point where the welded joins fail(a matter of just a few degrees, thus the straight sections of those columns strewn over the footprint).
Grumpy
No genius, it would be similar to forcing the same size steel pipe inside another steel pipe (the towers were not made of wood).
Try it and tell everyone how easy it is.
QUOTE
It's also a shame that the steel column remains were carted off so quickly, because this is the kind of thing that would have been interesting to investigate.
The cleanup took over six months. The steel was segregated at the Freshkill site and available for examination to qualified investigators for months. This mantra about evidence being hurriedly removed is just a red herring put forward by the "troothers", don't buy into such disinformation.
QUOTE (->
| QUOTE |
| It's also a shame that the steel column remains were carted off so quickly, because this is the kind of thing that would have been interesting to investigate. |
The cleanup took over six months. The steel was segregated at the Freshkill site and available for examination to qualified investigators for months. This mantra about evidence being hurriedly removed is just a red herring put forward by the "troothers", don't buy into such disinformation.
I agree that this is what appears to be happening, the tower below the collapse front doesn't appear to be damaged. But that is what is so strange to me. Hit the tower on top with a giant sledgehammer, why should the damage be concentrated within a few floors of the impact? With an interconnected core and perimeter, the entire structure is going to absorb the shock. This concentrated area of damage moving down the tower (at close to free fall speed) is one of the reasons to invoke another source of destructive energy aside from gravity.
The visible collapse front comes along somewhat behind the floor pancaking collapse and the wedging action of the top block only has to push the outer frame outward, requiring very little energy(think an axe through a chunk of firewood) and to stress the INDIVIDUAL columns of the core to the point where the welded joins fail(a matter of just a few degrees, thus the straight sections of those columns strewn over the footprint).
The 2/3 G is in congruence with the observed rate of fall. Whatever mathematical calculation one does of the energies is not valid unless the outcome matches with reality. The energies required for observed collapse rates are well within the kenetic energies available from gravitational collapse.
Grumpy
QUOTE (reasonwhy+Feb 10 2007, 12:21 PM)
And your point is?
Are you the best researcher the OCT can put forward?
To indict OBL would take a Grand Jury and the OCT fairytale would be exposed.
Nobody will be indicted or tried in a regular court.
You might have military show trials with new rules (no proof required ).
The point is that OBL is a criminal and he is being actively pursued, contrary to what you claimed.
Are you the best researcher the OCT can put forward?
To indict OBL would take a Grand Jury and the OCT fairytale would be exposed.
Nobody will be indicted or tried in a regular court.
You might have military show trials with new rules (no proof required ).
The point is that OBL is a criminal and he is being actively pursued, contrary to what you claimed.
QUOTE (Grumpy+Feb 10 2007, 10:46 AM)
The cleanup took over six months. The steel was segregated at the Freshkill site and available for examination to qualified investigators for months. This mantra about evidence being hurriedly removed is just a red herring put forward by the "troothers", don't buy into such disinformation.
The steel was removed from WTC7 in weeks and their are plenty of photos to prove it. As usual Grumpster does not let the truth stand in the way of his BS.
QUOTE (Grumpy+Feb 10 2007, 10:46 AM)
The visible collapse front comes along somewhat behind the floor pancaking collapse and the wedging action of the top block only has to push the outer frame outward, requiring very little energy(think an axe through a chunk of firewood) and to stress the INDIVIDUAL columns of the core to the point where the welded joins fail(a matter of just a few degrees, thus the straight sections of those columns strewn over the footprint).
Grumpy
No genius, it would be similar to forcing the same size steel pipe inside another steel pipe (the towers were not made of wood).
Try it and tell everyone how easy it is.
QUOTE (adoucette+Feb 10 2007, 08:10 AM)
False on both counts.
Arthur
Why don't you name all the people convicted in this global conspiracy?
Arthur
Why don't you name all the people convicted in this global conspiracy?
QUOTE (Capracus+Feb 10 2007, 10:54 AM)
The point is that OBL is a criminal and he is being actively pursued, contrary to what you claimed.
http://www.whitehouse.gov/news/releases/20...20020313-8.html
The President of the US is not concerned about the biggest mass murder in recent history.
OBL has never been convicted of any crimes that I am aware.
QUOTE
THE PRESIDENT: Well, as I say, we haven't heard much from him. And I wouldn't necessarily say he's at the center of any command structure. And, again, I don't know where he is. I -- I'll repeat what I said. I truly am not that concerned about him. I know he is on the run. I was concerned about him, when he had taken over a country. I was concerned about the fact that he was basically running Afghanistan and calling the shots for the Taliban.
http://www.whitehouse.gov/news/releases/20...20020313-8.html
The President of the US is not concerned about the biggest mass murder in recent history.
OBL has never been convicted of any crimes that I am aware.
reasonwhy
And was available for months for examination at Freshkills. The claim that the steel was whisked off to Japan before anyone could examine it is just a big lie by those who know nothing about which they speak a lot.
And was available for months for examination at Freshkills. The claim that the steel was whisked off to Japan before anyone could examine it is just a big lie by those who know nothing about which they speak a lot.
No genius, it would be similar to forcing the same size steel pipe inside another steel pipe (the towers were not made of wood).
Try it and tell everyone how easy it is.
Actually, at the scale you could hold in your hand it would be more like two tubes(one internally braced, one with bracing removed) made out of sheet steel thinner than aluminum foil. A suitable bracing material would be something like styrofoam.
A suitable replacement for the core at this scale might be dry spaghetti.
It should be pretty easy to overcome that resistence.
Grumpy
QUOTE
The steel was removed from WTC7 in weeks and their are plenty of photos to prove it. As usual Grumpster does not let the truth stand in the way of his BS. biggrin.gif
And was available for months for examination at Freshkills. The claim that the steel was whisked off to Japan before anyone could examine it is just a big lie by those who know nothing about which they speak a lot.
QUOTE (->
| QUOTE |
| The steel was removed from WTC7 in weeks and their are plenty of photos to prove it. As usual Grumpster does not let the truth stand in the way of his BS. biggrin.gif |
And was available for months for examination at Freshkills. The claim that the steel was whisked off to Japan before anyone could examine it is just a big lie by those who know nothing about which they speak a lot.
No genius, it would be similar to forcing the same size steel pipe inside another steel pipe (the towers were not made of wood).
Try it and tell everyone how easy it is.
Actually, at the scale you could hold in your hand it would be more like two tubes(one internally braced, one with bracing removed) made out of sheet steel thinner than aluminum foil. A suitable bracing material would be something like styrofoam.
A suitable replacement for the core at this scale might be dry spaghetti.
It should be pretty easy to overcome that resistence.
Grumpy
QUOTE (Grumpy+Feb 10 2007, 11:19 AM)
reasonwhy
And was available for months for examination at Freshkills. The claim that the steel was whisked off to Japan before anyone could examine it is just a big lie by those who know nothing about which they speak a lot.
Again Grumpster does not let the truth get in the way of his beliefs (BS). It is easy when grumpster does not use refrences or facts.
The House hearing covering the removal of steel before it could be investigated:
COMMITTEE ON SCIENCE
U.S. HOUSE OF REPRESENTATIVES
HEARING CHARTER
Learning from 9/11: Understanding the Collapse of the World Trade Center
Wednesday, March 6, 2002
Noon to 2:00 p.m.
2318 Rayburn House Office Building
The 23-member BPAT team conducted an analysis of the wreckage on-site, at Fresh Kills Landfill and at the recycling yard from October 7-12, 2001, during which the team extracted samples from the scrap materials and subjected them to laboratory analysis. Why the analysis was conducted only after a delay of three weeks after the attacks remains unclear. Since November, members of the Structural Engineers Association of New York (SEAoNY) have volunteered to work on the BPAT team’s behalf and are visiting recycling yards and landfills two to three times a week to watch for pieces of scrap that may provide important clues with regard to the behavior of the buildings
In the month that lapsed between the terrorist attacks and the deployment of the BPAT team, a significant amount of steel debris – including most of the steel from the upper floors – was removed from the rubble pile, cut into smaller sections, and either melted at the recycling plant or shipped out of the U.S. Some of the critical pieces of steel – including the suspension trusses from the top of the towers and the internal support columns – were gone before the first BPAT team member ever reached the site. Fortunately, an NSF-funded independent researcher, recognizing that valuable evidence was being destroyed, attempted to intervene with the City of New York to save the valuable artifacts, but the city was unwilling to suspend the recycling contract. Ultimately, the researcher appealed directly to the recycling plant, which agreed to provide the researcher, and ultimately the ASCE team and the SEAoNY volunteers, access to the remaining steel and a storage area where they could temporarily store important artifacts for additional analysis. Despite this agreement, however, many pieces of steel still managed to escape inspection.
http://www.house.gov/science/hearings/full...r06/charter.htm
http://www.house.gov/science/hearings/full...r06/charter.htm
Actually, at the scale you could hold in your hand it would be more like two tubes(one internally braced, one with bracing removed) made out of sheet steel thinner than aluminum foil. A suitable bracing material would be something like styrofoam.
A suitable replacement for the core at this scale might be dry spaghetti.
It should be pretty easy to overcome that resistence.
Grumpy
No, Even a piece of steel as thin as aluminum foil would take considerable force to shove one pipe inside another and would quickly get stuck.
And was available for months for examination at Freshkills. The claim that the steel was whisked off to Japan before anyone could examine it is just a big lie by those who know nothing about which they speak a lot.
Again Grumpster does not let the truth get in the way of his beliefs (BS). It is easy when grumpster does not use refrences or facts.
The House hearing covering the removal of steel before it could be investigated:
QUOTE
COMMITTEE ON SCIENCE
U.S. HOUSE OF REPRESENTATIVES
HEARING CHARTER
Learning from 9/11: Understanding the Collapse of the World Trade Center
Wednesday, March 6, 2002
Noon to 2:00 p.m.
2318 Rayburn House Office Building
The 23-member BPAT team conducted an analysis of the wreckage on-site, at Fresh Kills Landfill and at the recycling yard from October 7-12, 2001, during which the team extracted samples from the scrap materials and subjected them to laboratory analysis. Why the analysis was conducted only after a delay of three weeks after the attacks remains unclear. Since November, members of the Structural Engineers Association of New York (SEAoNY) have volunteered to work on the BPAT team’s behalf and are visiting recycling yards and landfills two to three times a week to watch for pieces of scrap that may provide important clues with regard to the behavior of the buildings
In the month that lapsed between the terrorist attacks and the deployment of the BPAT team, a significant amount of steel debris – including most of the steel from the upper floors – was removed from the rubble pile, cut into smaller sections, and either melted at the recycling plant or shipped out of the U.S. Some of the critical pieces of steel – including the suspension trusses from the top of the towers and the internal support columns – were gone before the first BPAT team member ever reached the site. Fortunately, an NSF-funded independent researcher, recognizing that valuable evidence was being destroyed, attempted to intervene with the City of New York to save the valuable artifacts, but the city was unwilling to suspend the recycling contract. Ultimately, the researcher appealed directly to the recycling plant, which agreed to provide the researcher, and ultimately the ASCE team and the SEAoNY volunteers, access to the remaining steel and a storage area where they could temporarily store important artifacts for additional analysis. Despite this agreement, however, many pieces of steel still managed to escape inspection.
http://www.house.gov/science/hearings/full...r06/charter.htm
QUOTE (->
| QUOTE |
COMMITTEE ON SCIENCE U.S. HOUSE OF REPRESENTATIVES HEARING CHARTER Learning from 9/11: Understanding the Collapse of the World Trade Center Wednesday, March 6, 2002 Noon to 2:00 p.m. 2318 Rayburn House Office Building The 23-member BPAT team conducted an analysis of the wreckage on-site, at Fresh Kills Landfill and at the recycling yard from October 7-12, 2001, during which the team extracted samples from the scrap materials and subjected them to laboratory analysis. Why the analysis was conducted only after a delay of three weeks after the attacks remains unclear. Since November, members of the Structural Engineers Association of New York (SEAoNY) have volunteered to work on the BPAT team’s behalf and are visiting recycling yards and landfills two to three times a week to watch for pieces of scrap that may provide important clues with regard to the behavior of the buildings In the month that lapsed between the terrorist attacks and the deployment of the BPAT team, a significant amount of steel debris – including most of the steel from the upper floors – was removed from the rubble pile, cut into smaller sections, and either melted at the recycling plant or shipped out of the U.S. Some of the critical pieces of steel – including the suspension trusses from the top of the towers and the internal support columns – were gone before the first BPAT team member ever reached the site. Fortunately, an NSF-funded independent researcher, recognizing that valuable evidence was being destroyed, attempted to intervene with the City of New York to save the valuable artifacts, but the city was unwilling to suspend the recycling contract. Ultimately, the researcher appealed directly to the recycling plant, which agreed to provide the researcher, and ultimately the ASCE team and the SEAoNY volunteers, access to the remaining steel and a storage area where they could temporarily store important artifacts for additional analysis. Despite this agreement, however, many pieces of steel still managed to escape inspection. |
http://www.house.gov/science/hearings/full...r06/charter.htm
Actually, at the scale you could hold in your hand it would be more like two tubes(one internally braced, one with bracing removed) made out of sheet steel thinner than aluminum foil. A suitable bracing material would be something like styrofoam.
A suitable replacement for the core at this scale might be dry spaghetti.
It should be pretty easy to overcome that resistence.
Grumpy
No, Even a piece of steel as thin as aluminum foil would take considerable force to shove one pipe inside another and would quickly get stuck.
QUOTE (Grumpy+Feb 10 2007, 06:46 PM)
The 2/3 G is in congruence with the observed rate of fall. Whatever mathematical calculation one does of the energies is not valid unless the outcome matches with reality.
OK, but I am asking for your (or someone's) calculations that give the 2/3g result for this simplified model we are postulating of a tower core and perimeter minus floors when a block falls on it.
OK, but I am asking for your (or someone's) calculations that give the 2/3g result for this simplified model we are postulating of a tower core and perimeter minus floors when a block falls on it.
QUOTE (reasonwhy+Feb 10 2007, 06:20 PM)
Try to get your history correct.
OBL was indicted for the embassy bombings.
They did not have a Trial because that would require PROOF.
OBL was a CIA asset (useful patsy and most likely dead) so their will never be a trial.
The world would be a much better place without OBL or other CIA assets.
Most people don't know about the inconstancies in the OCT because the MSM for some reason does not publish anything that goes against the official fairy tale.
http://www.cnn.com/WORLD/meast/9902/04/egy...eref=sitesearch
He has also been tried in Albania, and Kenya.
Please get your History strait.
You did know did you not that Bin Laden is Qualified to comment on the engineering of the world trade center, did you not?
http://www.answers.com/topic/osama-bin-laden
As a college student at King Abdulaziz University in Jeddah, bin Laden studied civil engineering[citation needed] and business administration[citation needed]. He earned a degree in civil engineering in 1979 and also one in economics[citation needed] and public administration[citation needed], in 1981.
He infact over saw the building of a tube frame buildings in Lebannon, by the Bin Laden constructuction firm.
I never said his trial was in the US. did I ?
OBL was indicted for the embassy bombings.
They did not have a Trial because that would require PROOF.
OBL was a CIA asset (useful patsy and most likely dead) so their will never be a trial.
The world would be a much better place without OBL or other CIA assets.
Most people don't know about the inconstancies in the OCT because the MSM for some reason does not publish anything that goes against the official fairy tale.
http://www.cnn.com/WORLD/meast/9902/04/egy...eref=sitesearch
He has also been tried in Albania, and Kenya.
Please get your History strait.
You did know did you not that Bin Laden is Qualified to comment on the engineering of the world trade center, did you not?
http://www.answers.com/topic/osama-bin-laden
As a college student at King Abdulaziz University in Jeddah, bin Laden studied civil engineering[citation needed] and business administration[citation needed]. He earned a degree in civil engineering in 1979 and also one in economics[citation needed] and public administration[citation needed], in 1981.
He infact over saw the building of a tube frame buildings in Lebannon, by the Bin Laden constructuction firm.
I never said his trial was in the US. did I ?
QUOTE (lozenge124+Feb 10 2007, 05:46 PM)
I certainly haven't read everything the "scholars for truth" have written. But I've never seen any claims put forth that they know everything. Rather, they are point out flaws and shortcomings of the official theories where they do not pass scrutiny.
I think your concept of oscillations breaking welds is interesting, and if we consider a block falling onto the core and perimeter, sure I can buy that oscillations would be created in the structure and that this would cause some damage. (though again, I do not accept that the damage would be restricted to the top floor or 3, the oscillations would spread thoughout the entire interconnected core and perimeter)
But, if this is what brought down the towers, I would like to see it in the NIST report as an official explanation, or at least in some kind of a publication. I would like to see an estimate of the time the towers took to collapse based on this scenario, I would like to see visualizations of the towers collapsing as calculated by models. Is this too much to ask?
The NIST took it upon themselves to generate an official explanation for the WTC collapses, so the burden of proof for their theory is on them. I agree with the many critics who claim that they have not adequately proven that "global collapse ensues" after initation.
OK then why does Dr. Steven Jones not know anything about natural thermite reactions?
Why does he intentionally mislead, on the aspect of black body radiation?
I mean the man tried to get a hydrogen reaction by spraying water on molten aluminum in a furnace, now that is just stupid I would not have wasted my time doing that!
Why did he not know about sono chemical reactions, or about energetic metallic dust or carbon explosions?
How about, the actions of high pressure water on aerations of jet fuel in fires?
Which can literally cause Kerosene to mix with oxygen in air rapidly, an increase the temperature of the fire where steel would virtually melt.
I talked personally with Dr. Jones and as soon as he told me it was impossible to get a hydrogen reaction from aluminum, I knew he did not know what he was talking about!
If the scholars for truth are actually for truth, then there are several serious problems with them!
I think your concept of oscillations breaking welds is interesting, and if we consider a block falling onto the core and perimeter, sure I can buy that oscillations would be created in the structure and that this would cause some damage. (though again, I do not accept that the damage would be restricted to the top floor or 3, the oscillations would spread thoughout the entire interconnected core and perimeter)
But, if this is what brought down the towers, I would like to see it in the NIST report as an official explanation, or at least in some kind of a publication. I would like to see an estimate of the time the towers took to collapse based on this scenario, I would like to see visualizations of the towers collapsing as calculated by models. Is this too much to ask?
The NIST took it upon themselves to generate an official explanation for the WTC collapses, so the burden of proof for their theory is on them. I agree with the many critics who claim that they have not adequately proven that "global collapse ensues" after initation.
OK then why does Dr. Steven Jones not know anything about natural thermite reactions?
Why does he intentionally mislead, on the aspect of black body radiation?
I mean the man tried to get a hydrogen reaction by spraying water on molten aluminum in a furnace, now that is just stupid I would not have wasted my time doing that!
Why did he not know about sono chemical reactions, or about energetic metallic dust or carbon explosions?
How about, the actions of high pressure water on aerations of jet fuel in fires?
Which can literally cause Kerosene to mix with oxygen in air rapidly, an increase the temperature of the fire where steel would virtually melt.
I talked personally with Dr. Jones and as soon as he told me it was impossible to get a hydrogen reaction from aluminum, I knew he did not know what he was talking about!
If the scholars for truth are actually for truth, then there are several serious problems with them!
QUOTE (Chainsaw+,Feb 10 2007, 11:57 AM)
http://www.cnn.com/WORLD/meast/9902/04/egy...eref=sitesearch
He has also been tried in Albania, and Kenya.
Please get your History strait.
You did know did you not that Bin Laden is Qualified to comment on the engineering of the world trade center, did you not?
http://www.answers.com/topic/osama-bin-laden
As a college student at King Abdulaziz University in Jeddah, bin Laden studied civil engineering[citation needed] and business administration[citation needed]. He earned a degree in civil engineering in 1979 and also one in economics[citation needed] and public administration[citation needed], in 1981.
He infact over saw the building of a tube frame buildings in Lebannon, by the Bin Laden constructuction firm.
I never said his trial was in the US. did I ?
Sorry, Your reference does not say OBL was convicted or even charged:
It does say it was a military trial as I speculated:
It does say it was a military trial as I speculated:
"The trial will not be a fair trial. This military court has no legitimacy," he said.
I am well aware of OBL education and past history (as a CIA asset).
Proving the OCT wrong lately is like shooting fish in a barrel (not much sport). I see why people intersted in the truth have moved on or been banned.
http://cns.miis.edu/pubs/reports/binladen.htm
Oh the Saudis have also tried Bin laden, Internatially he is wanted by about 20 nations besides the United States.
I wanted to make you happy then dash your joy his trial in Kenya was in open court and he was tried in absentia.
WOW, he was convicted in Kenya on the testimony of a convicted terrorist and admitted embezzler testifying to reduce his sentence. Do they announce your guilt before or after the trial in Kenya?
He was probably wanted by the Russians and Afghanistan’s for terrorism when working for the CIA.
Last I checked Kenya , Tanzania and Saudi Arabia were not part of the US legal system .Is a second wife even illegal in these countries?
The Al-Qa’ida group sure has a hard time keeping secrets.
How many years in advance did Al-Qa’ida supposedly plan 9/11?
Can you post some of you math formulas so we can have a look at them please?
If I had the time and resources (to get the model from EAI), I would start by asking ENGINEERING ANALYSIS INC. for the model of the WTC and take a HEXDAM, VEXDAM, VASDIP, HEXFRAG TRAINING COURSE.
http://jmcleland.home.mindspring.com/EAIprs83.html
http://eai.home.mindspring.com/5WTCanim.gif
Notice the vapor cloud explosion does not go down the elevator shafts.
Then I could experiment with all the different explosives until the model matched what we saw on 9/11.
For some reason their are models of most everything al qaida and domestic terrorist have blown up.
http://eai.home.mindspring.com/
I could also use the model of WTC7 and show how CD could bring the building down.
He has also been tried in Albania, and Kenya.
Please get your History strait.
You did know did you not that Bin Laden is Qualified to comment on the engineering of the world trade center, did you not?
http://www.answers.com/topic/osama-bin-laden
As a college student at King Abdulaziz University in Jeddah, bin Laden studied civil engineering[citation needed] and business administration[citation needed]. He earned a degree in civil engineering in 1979 and also one in economics[citation needed] and public administration[citation needed], in 1981.
He infact over saw the building of a tube frame buildings in Lebannon, by the Bin Laden constructuction firm.
I never said his trial was in the US. did I ?
Sorry, Your reference does not say OBL was convicted or even charged:
QUOTE
Trial begins for Egyptian militants, including bin Laden aide
It does say it was a military trial as I speculated:
QUOTE (->
| QUOTE |
| Trial begins for Egyptian militants, including bin Laden aide |
It does say it was a military trial as I speculated:
"The trial will not be a fair trial. This military court has no legitimacy," he said.
I am well aware of OBL education and past history (as a CIA asset).
Proving the OCT wrong lately is like shooting fish in a barrel (not much sport). I see why people intersted in the truth have moved on or been banned.
lozenge124 --- The (2/3)g agrees with NEU-FONZE's measurements for the first second or so. I am planning to run a better fit than (2/3)g for an acceleration only model. When done, I'll post it here.
You seem to fail to understand that, with appropriate value of E1, the measured drops agree well with the Greening-style model (B & V's crush-down equation is Greening-style). So that settles that.
You also fail to understand the construction of the towers. Try reading NCSTAR1-2. The ordinary trussed floors were connected to the core and also the exterior walls via welded truss seats. Once these fail, a matter of only about 0.01 GJ, the floor falls down.
The exterior walls really do not matter, once the floor connections are destroyed.
With regard to the core, once the column members are no longer concentrically axial (and sufficiently vertical) the top block simply punches through the concrete, destroying welds along the way. The welds between column members might have be damaged via vibrations. Another possibility is an off-center (eccentric) sudden strike by a large weight. (I'm currently working this up for presenting here).
Finally, NIST's "global collapse ensued". Read NCSTAR1-6. Ask me questions. Although it is perhaps not emphasized enough the tilting. Let us just consider WTC 1. After the oscillations of the tower top due to the aircraft strike had ceased, the tower top tilted slightly to the north. Over the next 1 hour and 52 minutes it tilted further and further towards the south. This was sufficiently noticeable to the NYPD helicopter observer, about 20 minutes prior to collapse, that he issued a warning. He did it again about 6 minutes before collapse. This non-verticality is very important to understanding the lack of stability of the structure.
You seem to fail to understand that, with appropriate value of E1, the measured drops agree well with the Greening-style model (B & V's crush-down equation is Greening-style). So that settles that.
You also fail to understand the construction of the towers. Try reading NCSTAR1-2. The ordinary trussed floors were connected to the core and also the exterior walls via welded truss seats. Once these fail, a matter of only about 0.01 GJ, the floor falls down.
The exterior walls really do not matter, once the floor connections are destroyed.
With regard to the core, once the column members are no longer concentrically axial (and sufficiently vertical) the top block simply punches through the concrete, destroying welds along the way. The welds between column members might have be damaged via vibrations. Another possibility is an off-center (eccentric) sudden strike by a large weight. (I'm currently working this up for presenting here).
Finally, NIST's "global collapse ensued". Read NCSTAR1-6. Ask me questions. Although it is perhaps not emphasized enough the tilting. Let us just consider WTC 1. After the oscillations of the tower top due to the aircraft strike had ceased, the tower top tilted slightly to the north. Over the next 1 hour and 52 minutes it tilted further and further towards the south. This was sufficiently noticeable to the NYPD helicopter observer, about 20 minutes prior to collapse, that he issued a warning. He did it again about 6 minutes before collapse. This non-verticality is very important to understanding the lack of stability of the structure.
QUOTE (reasonwhy+Feb 10 2007, 08:15 PM)
Sorry, Your reference does not say OBL was convicted or even charged:
It does say it was a military trial as I speculated:
I am well aware of OBL education and past history (as a CIA asset).
Proving the OCT wrong lately is like shooting fish in a barrel (not much sport). I see why people intersted in the truth have moved on or been banned.
http://cns.miis.edu/pubs/reports/binladen.htm
Oh the Saudis have also tried Bin laden, Internatially he is wanted by about 20 nations besides the United States.
I wanted to make you happy then dash your joy his trial in Kenya was in open court and he was tried in absentia.
It does say it was a military trial as I speculated:
I am well aware of OBL education and past history (as a CIA asset).
Proving the OCT wrong lately is like shooting fish in a barrel (not much sport). I see why people intersted in the truth have moved on or been banned.
http://cns.miis.edu/pubs/reports/binladen.htm
Oh the Saudis have also tried Bin laden, Internatially he is wanted by about 20 nations besides the United States.
I wanted to make you happy then dash your joy his trial in Kenya was in open court and he was tried in absentia.
QUOTE (Chainsaw+,Feb 10 2007, 12:58 PM)
http://cns.miis.edu/pubs/reports/binladen.htm
Oh the Saudis have also tried Bin laden, Internatially he is wanted by about 20 nations besides the United States.
I wanted to make you happy then dash your joy his trial in Kenya was in open court and he was tried in absentia.
WOW, he was convicted in Kenya on the testimony of a convicted terrorist and admitted embezzler testifying to reduce his sentence. Do they announce your guilt before or after the trial in Kenya?
QUOTE
Both Usama Bin Laden and the government of Sudan have publicly denied any connection, either present or past, to Al-Fadl.(2) Some question the informant’s credibility and character for a number of reasons. First, the circumstances surrounding Al-Fadl’s purported break with Bin Laden and Al-Qa’ida center on his willingness to deceive the group in order to reap illicit financial gains. He also provided information to the U.S. government in exchange for reduced prison time (he pleaded guilty in New York to a terrorism charge during secret proceedings and was promised a sentence of no more than 15 years), along with U.S. residency and personal and financial protection for himself and his family. During cross-examination, defense attorneys highlighted this fact, noting that it had cost the U.S. government approximately $945,000 to protect and house Al-Fadl since he began to cooperate with the United States.(3) Furthermore, his long police record (including a series of arrests in Hungary and Sudan, and a secret second marriage) provides grounds to question his overall reliability.
He was probably wanted by the Russians and Afghanistan’s for terrorism when working for the CIA.
Last I checked Kenya , Tanzania and Saudi Arabia were not part of the US legal system .Is a second wife even illegal in these countries?
The Al-Qa’ida group sure has a hard time keeping secrets.
How many years in advance did Al-Qa’ida supposedly plan 9/11?
QUOTE (Chainsaw,+Feb 8 2007, 05:16 PM)
Do you remember the story of William Rodriguez, hearing bombs in the basements?
http://en.wikipedia.org/wiki/William_Rodriguez
I have explained this to several people, sound travels at roughly 5000 meters per second, though steel, the steel beams in the core are contiguously welded steel, so they are naturally perfect sound conduits.
If William Rodriguez had stated he did not hear a big boom in the basement (reflections of impact sounds when they hit the foundations)before the impact sounds reached him from above, I would have to conclude he was lying.
The sound from he impact in air was traveling at about 600 meters per second, the sound from the crash could have rebounded though the metal structure four times before the sound reached William Rodriguez.
What you have in the center of that buildings is a giant tunning fork, all you have to do is free it from the connections. With enough oscillation energy it will do that itself.
If you weaken certain sections, by heating and other sections remain cold, unheated the saturation gets even worse. I do not think all the insulation was stripped off every where. I think that pockets of heated metal and pockets of cooled metal made it impossible for the structure to dissipate fracture waves in a unified manor, making the components work Independently and destroying the structure that way.
I do not believe the Controlled Demolition argument because aluminum in thermites is vulnerable to the same sound energy that Mr. Rodriguez confirms was in the buildings and trinitrotoluene compounds would also not survive fires or the impact sounds and energies.
In theory the oxide coating on one particle of aluminum in a charge of thermite could create a thermite spark, destroying the entire charge!
I have tested this myself and the theory is accurate.
The only thing that makes since to me is a natural extreme chemical reaction, or failure do to a Fracture wave energy build up!
I do not have all the answers and that is why I am here!
Interesting, but you ignore the fact that Mr. Rodriguez also goes into great detail about the physical evidence of the explosion which accompanied the pre-impact boom. He names the man who was severely burned by the explosion and whom he helped to an ambulance. He, and others, describe specific damage (50 ton press destroyed, etc.) and the location of that damage from the explosion.
Can "sound energy" account for all those physical conditions described by Mr. Rodriguez and others who were in the basement areas?
http://en.wikipedia.org/wiki/William_Rodriguez
I have explained this to several people, sound travels at roughly 5000 meters per second, though steel, the steel beams in the core are contiguously welded steel, so they are naturally perfect sound conduits.
If William Rodriguez had stated he did not hear a big boom in the basement (reflections of impact sounds when they hit the foundations)before the impact sounds reached him from above, I would have to conclude he was lying.
The sound from he impact in air was traveling at about 600 meters per second, the sound from the crash could have rebounded though the metal structure four times before the sound reached William Rodriguez.
What you have in the center of that buildings is a giant tunning fork, all you have to do is free it from the connections. With enough oscillation energy it will do that itself.
If you weaken certain sections, by heating and other sections remain cold, unheated the saturation gets even worse. I do not think all the insulation was stripped off every where. I think that pockets of heated metal and pockets of cooled metal made it impossible for the structure to dissipate fracture waves in a unified manor, making the components work Independently and destroying the structure that way.
I do not believe the Controlled Demolition argument because aluminum in thermites is vulnerable to the same sound energy that Mr. Rodriguez confirms was in the buildings and trinitrotoluene compounds would also not survive fires or the impact sounds and energies.
In theory the oxide coating on one particle of aluminum in a charge of thermite could create a thermite spark, destroying the entire charge!
I have tested this myself and the theory is accurate.
The only thing that makes since to me is a natural extreme chemical reaction, or failure do to a Fracture wave energy build up!
I do not have all the answers and that is why I am here!
Interesting, but you ignore the fact that Mr. Rodriguez also goes into great detail about the physical evidence of the explosion which accompanied the pre-impact boom. He names the man who was severely burned by the explosion and whom he helped to an ambulance. He, and others, describe specific damage (50 ton press destroyed, etc.) and the location of that damage from the explosion.
Can "sound energy" account for all those physical conditions described by Mr. Rodriguez and others who were in the basement areas?
QUOTE (David B. Benson+Feb 10 2007, 08:39 PM)
lozenge124 --- The (2/3)g agrees with NEU-FONZE's measurements for the first second or so. I am planning to run a better fit than (2/3)g for an acceleration only model. When done, I'll post it here.
You seem to fail to understand that, with appropriate value of E1, the measured drops agree well with the Greening-style model (B & V's crush-down equation is Greening-style). So that settles that.
You also fail to understand the construction of the towers. Try reading NCSTAR1-2. The ordinary trussed floors were connected to the core and also the exterior walls via welded truss seats. Once these fail, a matter of only about 0.01 GJ, the floor falls down.
The exterior walls really do not matter, once the floor connections are destroyed.
With regard to the core, once the column members are no longer concentrically axial (and sufficiently vertical) the top block simply punches through the concrete, destroying welds along the way. The welds between column members might have be damaged via vibrations. Another possibility is an off-center (eccentric) sudden strike by a large weight. (I'm currently working this up for presenting here).
Finally, NIST's "global collapse ensued". Read NCSTAR1-6. Ask me questions. Although it is perhaps not emphasized enough the tilting. Let us just consider WTC 1. After the oscillations of the tower top due to the aircraft strike had ceased, the tower top tilted slightly to the north. Over the next 1 hour and 52 minutes it tilted further and further towards the south. This was sufficiently noticeable to the NYPD helicopter observer, about 20 minutes prior to collapse, that he issued a warning. He did it again about 6 minutes before collapse. This non-verticality is very important to understanding the lack of stability of the structure.
1) the 2/3g that was posted by Grumpy has nothing to do with the Greening model. It is in the case of a thought experiment we were doing considering the tower perimeter and core only.
I would be interested in your thoughts on what happens when you drop a falling block onto a tower whose "frame will still be standing, as will the core, but all of the floors of the building will be in the basement." And please to not invoke Greening once again because there are no floors in this scenario!
2) I am not interested in Greening style models with this E1 parameter. As I said, this is not a valid way of looking at things. If you want to refute my arguments on why this is, please do so, but you cannot use this model to generate numbers that prove anything (especially as the NIST doesn't endorse it, nor does Greening endorse the NIST models)
3) "With regard to the core, (...) the top block simply punches through the concrete, destroying welds along the way."
Forgive me for asking, but are you saying the core is made of concrete? It was a network of 44-47 steel,cross-braced columns ( 911research.wtc7.net/wtc/arch/core.html ) You can't just punch through that.
4) "the tower top tilted slightly to the north (...)This non-verticality is very important to understanding the lack of stability of the structure."
I think we all agree that the towers below the airplane impact points were for the most part undamaged. That's why I like the model of a block dropping down onto the tower. Though I am not convinced that the towers even got to the "collapse initiation" phase, for the sake of argument here we are taking this worse case scenario where a gap of one floor is magically created at the impact point of the airplane and trying to determine what happens next. This is actually worse than what actually happened and works in the favor of the global collapse sequence. And the exact amount of damage above the plane impact becomes irrelevant, so it's a good model to debate with.
You seem to fail to understand that, with appropriate value of E1, the measured drops agree well with the Greening-style model (B & V's crush-down equation is Greening-style). So that settles that.
You also fail to understand the construction of the towers. Try reading NCSTAR1-2. The ordinary trussed floors were connected to the core and also the exterior walls via welded truss seats. Once these fail, a matter of only about 0.01 GJ, the floor falls down.
The exterior walls really do not matter, once the floor connections are destroyed.
With regard to the core, once the column members are no longer concentrically axial (and sufficiently vertical) the top block simply punches through the concrete, destroying welds along the way. The welds between column members might have be damaged via vibrations. Another possibility is an off-center (eccentric) sudden strike by a large weight. (I'm currently working this up for presenting here).
Finally, NIST's "global collapse ensued". Read NCSTAR1-6. Ask me questions. Although it is perhaps not emphasized enough the tilting. Let us just consider WTC 1. After the oscillations of the tower top due to the aircraft strike had ceased, the tower top tilted slightly to the north. Over the next 1 hour and 52 minutes it tilted further and further towards the south. This was sufficiently noticeable to the NYPD helicopter observer, about 20 minutes prior to collapse, that he issued a warning. He did it again about 6 minutes before collapse. This non-verticality is very important to understanding the lack of stability of the structure.
1) the 2/3g that was posted by Grumpy has nothing to do with the Greening model. It is in the case of a thought experiment we were doing considering the tower perimeter and core only.
QUOTE
Actually, if you take off the top ten floors and then suspend a sandbag with ten times the weight of sand necessary to collapse one floor diaphram, one floor height above the first exposed floor(and core and frame). Release all the sand at one time.
The frame will still be standing, as will the core, but all of the floors of the building will be in the basement.
Now drop the ten stories, tilted, so it will wedge into the bottom sections. The outer frame will peel away and the top block will accelerate into the ground at roughly 2/3G.
Grumpy cool.gif
The frame will still be standing, as will the core, but all of the floors of the building will be in the basement.
Now drop the ten stories, tilted, so it will wedge into the bottom sections. The outer frame will peel away and the top block will accelerate into the ground at roughly 2/3G.
Grumpy cool.gif
I would be interested in your thoughts on what happens when you drop a falling block onto a tower whose "frame will still be standing, as will the core, but all of the floors of the building will be in the basement." And please to not invoke Greening once again because there are no floors in this scenario!
2) I am not interested in Greening style models with this E1 parameter. As I said, this is not a valid way of looking at things. If you want to refute my arguments on why this is, please do so, but you cannot use this model to generate numbers that prove anything (especially as the NIST doesn't endorse it, nor does Greening endorse the NIST models)
3) "With regard to the core, (...) the top block simply punches through the concrete, destroying welds along the way."
Forgive me for asking, but are you saying the core is made of concrete? It was a network of 44-47 steel,cross-braced columns ( 911research.wtc7.net/wtc/arch/core.html ) You can't just punch through that.
4) "the tower top tilted slightly to the north (...)This non-verticality is very important to understanding the lack of stability of the structure."
I think we all agree that the towers below the airplane impact points were for the most part undamaged. That's why I like the model of a block dropping down onto the tower. Though I am not convinced that the towers even got to the "collapse initiation" phase, for the sake of argument here we are taking this worse case scenario where a gap of one floor is magically created at the impact point of the airplane and trying to determine what happens next. This is actually worse than what actually happened and works in the favor of the global collapse sequence. And the exact amount of damage above the plane impact becomes irrelevant, so it's a good model to debate with.
QUOTE (forthetrees+Feb 10 2007, 09:30 PM)
Interesting, but you ignore the fact that Mr. Rodriguez also goes into great detail about the physical evidence of the explosion which accompanied the pre-impact boom. He names the man who was severely burned by the explosion and whom he helped to an ambulance. He, and others, describe specific damage (50 ton press destroyed, etc.) and the location of that damage from the explosion.
Can "sound energy" account for all those physical conditions described by Mr. Rodriguez and others who were in the basement areas?
Actually he hears the sound energy from the explosion then he helps the man so by that time the fuel has already went down the elevator shaft.
That is his testimony under oath.
Can "sound energy" account for all those physical conditions described by Mr. Rodriguez and others who were in the basement areas?
Actually he hears the sound energy from the explosion then he helps the man so by that time the fuel has already went down the elevator shaft.
That is his testimony under oath.
QUOTE (lozenge124+Feb 10 2007, 09:32 PM)
2) I am not interested in Greening style models with this E1 parameter. As I said, this is not a valid way of looking at things.
Then you are simply wrong. In any case, the trussed floors offered so little resistance that leaving them out makes little difference. Apply homogenization of structure to re-derive the B & V crush-down differential equation. Compute E1 as best fits the measured data. You'll still get about 0.5+ GJ per story.
The only place there was cross-bracing was on the mechanical floors and below about floor 11. And 14 stories with the additional mass of the upper mechanical floors and hat truss develops the necessary 0.5+ GJ of kinetic energy after falling at (2/3)g for about 2 meters. Yup. Punches right through the concrete floors in the core.
NIST is not the only source of physics or structural engineering. Just because they did not say something does not mean it is relevant.
While I can understand NEU-FONZE's objections to FEA, I don't agree with him regarding NIST's analysis. I do agree with him that sometimes the sections of NCSTAR1 seem to contradict each other. Inevitable in such a large, multi-authored report series...
Edited to add: Aha! In the above I am assuming that the mass of the trussed floors is simply moved elewhere. Other wise, one would not have the drops that were measured. So maybe I am really not very interested in your thought experiment. For without the floors, the exterior wall could not stand. Neither could the core stand alone...
Then you are simply wrong. In any case, the trussed floors offered so little resistance that leaving them out makes little difference. Apply homogenization of structure to re-derive the B & V crush-down differential equation. Compute E1 as best fits the measured data. You'll still get about 0.5+ GJ per story.
The only place there was cross-bracing was on the mechanical floors and below about floor 11. And 14 stories with the additional mass of the upper mechanical floors and hat truss develops the necessary 0.5+ GJ of kinetic energy after falling at (2/3)g for about 2 meters. Yup. Punches right through the concrete floors in the core.
NIST is not the only source of physics or structural engineering. Just because they did not say something does not mean it is relevant.
While I can understand NEU-FONZE's objections to FEA, I don't agree with him regarding NIST's analysis. I do agree with him that sometimes the sections of NCSTAR1 seem to contradict each other. Inevitable in such a large, multi-authored report series...
Edited to add: Aha! In the above I am assuming that the mass of the trussed floors is simply moved elewhere. Other wise, one would not have the drops that were measured. So maybe I am really not very interested in your thought experiment. For without the floors, the exterior wall could not stand. Neither could the core stand alone...
QUOTE (lozenge124+Feb 10 2007, 09:32 PM)
1) the 2/3g that was posted by Grumpy has nothing to do with the Greening model. It is in the case of a thought experiment we were doing considering the tower perimeter and core only.
I would be interested in your thoughts on what happens when you drop a falling block onto a tower whose "frame will still be standing, as will the core, but all of the floors of the building will be in the basement." And please to not invoke Greening once again because there are no floors in this scenario!
2) I am not interested in Greening style models with this E1 parameter. As I said, this is not a valid way of looking at things. If you want to refute my arguments on why this is, please do so, but you cannot use this model to generate numbers that prove anything (especially as the NIST doesn't endorse it, nor does Greening endorse the NIST models)
3) "With regard to the core, (...) the top block simply punches through the concrete, destroying welds along the way."
Forgive me for asking, but are you saying the core is made of concrete? It was a network of 44-47 steel,cross-braced columns ( 911research.wtc7.net/wtc/arch/core.html ) You can't just punch through that.
4) "the tower top tilted slightly to the north (...)This non-verticality is very important to understanding the lack of stability of the structure."
I think we all agree that the towers below the airplane impact points were for the most part undamaged. That's why I like the model of a block dropping down onto the tower. Though I am not convinced that the towers even got to the "collapse initiation" phase, for the sake of argument here we are taking this worse case scenario where a gap of one floor is magically created at the impact point of the airplane and trying to determine what happens next. This is actually worse than what actually happened and works in the favor of the global collapse sequence. And the exact amount of damage above the plane impact becomes irrelevant, so it's a good model to debate with.
There is in fact no way to tell what the damage to the floors below the impact actually is, that is one of the problems, the situation is more complicated than simple impact of a plane.
I would be interested in your thoughts on what happens when you drop a falling block onto a tower whose "frame will still be standing, as will the core, but all of the floors of the building will be in the basement." And please to not invoke Greening once again because there are no floors in this scenario!
2) I am not interested in Greening style models with this E1 parameter. As I said, this is not a valid way of looking at things. If you want to refute my arguments on why this is, please do so, but you cannot use this model to generate numbers that prove anything (especially as the NIST doesn't endorse it, nor does Greening endorse the NIST models)
3) "With regard to the core, (...) the top block simply punches through the concrete, destroying welds along the way."
Forgive me for asking, but are you saying the core is made of concrete? It was a network of 44-47 steel,cross-braced columns ( 911research.wtc7.net/wtc/arch/core.html ) You can't just punch through that.
4) "the tower top tilted slightly to the north (...)This non-verticality is very important to understanding the lack of stability of the structure."
I think we all agree that the towers below the airplane impact points were for the most part undamaged. That's why I like the model of a block dropping down onto the tower. Though I am not convinced that the towers even got to the "collapse initiation" phase, for the sake of argument here we are taking this worse case scenario where a gap of one floor is magically created at the impact point of the airplane and trying to determine what happens next. This is actually worse than what actually happened and works in the favor of the global collapse sequence. And the exact amount of damage above the plane impact becomes irrelevant, so it's a good model to debate with.
There is in fact no way to tell what the damage to the floors below the impact actually is, that is one of the problems, the situation is more complicated than simple impact of a plane.
QUOTE (Chainsaw+,Feb 10 2007, 10:07 PM)
Actually he hears the sound energy from the explosion then he helps the man so by that time the fuel has already went down the elevator shaft.
That is his testimony under oath.
Ahhhh yes, the magic fuel.
The whole topic is well plowed ground.
WTC 1 - elevator shafts, jet fuel and fire balls, Why so much damage to lower floors?
http://forum.physorg.com/index.php?showtopic=4491&st=0>
That is his testimony under oath.
Ahhhh yes, the magic fuel.
The whole topic is well plowed ground.
WTC 1 - elevator shafts, jet fuel and fire balls, Why so much damage to lower floors?
http://forum.physorg.com/index.php?showtopic=4491&st=0>
QUOTE (David B. Benson+Feb 10 2007, 02:13 PM)
Then you are simply wrong. In any case, the trussed floors offered so little resistance that leaving them out makes little difference. Apply homogenization of structure to re-derive the B & V crush-down differential equation. Compute E1 as best fits the measured data. You'll still get about 0.5+ GJ per story.
The only place there was cross-bracing was on the mechanical floors and below about floor 11. And 14 stories with the additional mass of the upper mechanical floors and hat truss develops the necessary 0.5+ GJ of kinetic energy after falling at (2/3)g for about 2 meters. Yup. Punches right through the concrete floors in the core.
You have to understand DBB doesn't’t realize beams connecting the columns in the core would add considerable resistance even if not cross braced. This has been pointed out many, many times and the OCT just ignores it and continue with the calculations.
The only place there was cross-bracing was on the mechanical floors and below about floor 11. And 14 stories with the additional mass of the upper mechanical floors and hat truss develops the necessary 0.5+ GJ of kinetic energy after falling at (2/3)g for about 2 meters. Yup. Punches right through the concrete floors in the core.
You have to understand DBB doesn't’t realize beams connecting the columns in the core would add considerable resistance even if not cross braced. This has been pointed out many, many times and the OCT just ignores it and continue with the calculations.
QUOTE (reasonwhy+Feb 10 2007, 10:29 PM)
You have to understand DBB doesn't’t[sic] realize beams connecting the columns in the core would add considerable resistance even if not cross braced.
Correct. What I do understand is that most of the beam connections in the core floors were shear connections, incapable of transferring much lateral load and similarly for vertical. I have pointed this out many, many times and continue to be ignored by some.
But you are more than welcome to go find some actual data on the ability of both shear and moment connected beams to withstand having very heavy loads on them. For shear connections, I already know the answer. :roll eyes:
Correct. What I do understand is that most of the beam connections in the core floors were shear connections, incapable of transferring much lateral load and similarly for vertical. I have pointed this out many, many times and continue to be ignored by some.
But you are more than welcome to go find some actual data on the ability of both shear and moment connected beams to withstand having very heavy loads on them. For shear connections, I already know the answer. :roll eyes:
William Rodriguez, a worker at the towers. He now says he heard explosions in the basement but that's not what he said before he became a media star and sued the government.
William Rodriguez worked on the basement level of the north tower and was in the building when the first plane struck his building.
"We heard a loud rumble, then all of a sudden we heard another rumble like someone moving a whole lot of furniture," Rodriguez said. "And then the elevator opened and a man came into our office and all of his skin was off."
http://archives.cnn.com/2001/US/09/11/new.york.terror/
Here he is describing something very different than an explosion. The change in his story came after he became a media star and plaintiff.
He also flew to Venezuela to meet Chavez with conspiracy theorist Jimmy (Nutcase) Walters.
"In 2006 he accompanied Jimmy Walter in a trip to Venezuela, in which they met with the President of the Assembly and will soon meet with Venezuelan President Hugo Chávez in anticipation of an official Venezuelan government investigation into 9/11."
http://en.wikipedia.org/wiki/William_Rodriguez
William Rodriguez worked on the basement level of the north tower and was in the building when the first plane struck his building.
"We heard a loud rumble, then all of a sudden we heard another rumble like someone moving a whole lot of furniture," Rodriguez said. "And then the elevator opened and a man came into our office and all of his skin was off."
http://archives.cnn.com/2001/US/09/11/new.york.terror/
Here he is describing something very different than an explosion. The change in his story came after he became a media star and plaintiff.
He also flew to Venezuela to meet Chavez with conspiracy theorist Jimmy (Nutcase) Walters.
"In 2006 he accompanied Jimmy Walter in a trip to Venezuela, in which they met with the President of the Assembly and will soon meet with Venezuelan President Hugo Chávez in anticipation of an official Venezuelan government investigation into 9/11."
http://en.wikipedia.org/wiki/William_Rodriguez
forthetrees
Or a possible Fuel Air Explosion from the vaporized fuel from the aircraft detonating in the closed(bottom) end of the express elevator or other elevator shafts are also partly responsible for some of the effects Rodriguez reported. So he probably heard sound from under his feet(sonic transfer at ~ 5000 ft/sec, The detonation in the elevator shaft that blew out the brick and the doors of the elevator, incidently parboiling people in the vicinity. And then he would hear the noise transfered through the air~650 ft/sec.Many of the elevators seem to have blown out in just this way.
Grumpy
QUOTE
Interesting, but you ignore the fact that Mr. Rodriguez also goes into great detail about the physical evidence of the explosion which accompanied the pre-impact boom. He names the man who was severely burned by the explosion and whom he helped to an ambulance. He, and others, describe specific damage (50 ton press destroyed, etc.) and the location of that damage from the explosion.
Can "sound energy" account for all those physical conditions described by Mr. Rodriguez and others who were in the basement areas?
Can "sound energy" account for all those physical conditions described by Mr. Rodriguez and others who were in the basement areas?
Or a possible Fuel Air Explosion from the vaporized fuel from the aircraft detonating in the closed(bottom) end of the express elevator or other elevator shafts are also partly responsible for some of the effects Rodriguez reported. So he probably heard sound from under his feet(sonic transfer at ~ 5000 ft/sec, The detonation in the elevator shaft that blew out the brick and the doors of the elevator, incidently parboiling people in the vicinity. And then he would hear the noise transfered through the air~650 ft/sec.Many of the elevators seem to have blown out in just this way.
Grumpy
Grumpy --- 5100 m/s, not your shrimpy ~5000 ft/s!
QUOTE (David B. Benson+Feb 10 2007, 02:38 PM)
Correct. What I do understand is that most of the beam connections in the core floors were shear connections, incapable of transferring much lateral load and similarly for vertical. I have pointed this out many, many times and continue to be ignored by some.
But you are more than welcome to go find some actual data on the ability of both shear and moment connected beams to withstand having very heavy loads on them. For shear connections, I already know the answer. :roll eyes:
Beams are for vertical loads and the lateral loads were small so no need for cross bracing.
This is the type of connection I am writing about:
http://i111.photobucket.com/albums/n122/xzvgpz/image5.jpg
Bolted and welded joints in the core area.
But you are more than welcome to go find some actual data on the ability of both shear and moment connected beams to withstand having very heavy loads on them. For shear connections, I already know the answer. :roll eyes:
Beams are for vertical loads and the lateral loads were small so no need for cross bracing.
This is the type of connection I am writing about:
http://i111.photobucket.com/albums/n122/xzvgpz/image5.jpg
Bolted and welded joints in the core area.
reasonwhy --- I have difficulty making much out of that visual, even expanded. From what little I can, this appears to be a sizable core column still connected to a sizable beam. So I suspect this comes from an area below floor 11.
Instead, try to find a decent diagram for the core floor beam connections. Then learn about moment connections and shear connections. Then learn why at least shear connections cannot withstand a suddenly applied vertical load. (Hint: as in an earthquake)
Instead, try to find a decent diagram for the core floor beam connections. Then learn about moment connections and shear connections. Then learn why at least shear connections cannot withstand a suddenly applied vertical load. (Hint: as in an earthquake)
QUOTE (David B. Benson+Feb 10 2007, 03:05 PM)
reasonwhy --- I have difficulty making much out of that visual, even expanded. From what little I can, this appears to be a sizable core column still connected to a sizable beam. So I suspect this comes from an area below floor 11.
Instead, try to find a decent diagram for the core floor beam connections. Then learn about moment connections and shear connections. Then learn why at least shear connections cannot withstand a suddenly applied vertical load. (Hint: as in an earthquake)
How about giving an example of a steel framed building collapsing from an earthquake?
Shear connections can be extremely strong (how did they hold up the l12 arge large elevator motors).
What is your calculation for the force required to break the beam connections?
Instead, try to find a decent diagram for the core floor beam connections. Then learn about moment connections and shear connections. Then learn why at least shear connections cannot withstand a suddenly applied vertical load. (Hint: as in an earthquake)
How about giving an example of a steel framed building collapsing from an earthquake?
Shear connections can be extremely strong (how did they hold up the l12 arge large elevator motors).
What is your calculation for the force required to break the beam connections?
QUOTE (reasonwhy+Feb 10 2007, 11:20 PM)
How about giving an example of a steel framed building collapsing from an earthquake?
Shear connections can be extremely strong.
What is your calculation for the force required to break the beam connections?
Not collapse, but significant damage to shear connections can be found by searching appropriately for the 1994 Northridge earthquake.
The general consensus of the structural engineering community is that shear connections cannot transfer lateral forces and are easily damaged or destroyed by suddenly applied vertical forces. The use of moment connections alone in earthquake prone areas is now building code. Even these are not considered sufficiently capable for buildings thought to be at risk of progressive collapse and newer connecting techniques are being developed.
Nobody appears to understand how to calculate the dynamic loadings for the critical point of welded connections in a progressive collapse scenario. If you find something, do keep me informed. Thanks.
Shear connections can be extremely strong.
What is your calculation for the force required to break the beam connections?
Not collapse, but significant damage to shear connections can be found by searching appropriately for the 1994 Northridge earthquake.
The general consensus of the structural engineering community is that shear connections cannot transfer lateral forces and are easily damaged or destroyed by suddenly applied vertical forces. The use of moment connections alone in earthquake prone areas is now building code. Even these are not considered sufficiently capable for buildings thought to be at risk of progressive collapse and newer connecting techniques are being developed.
Nobody appears to understand how to calculate the dynamic loadings for the critical point of welded connections in a progressive collapse scenario. If you find something, do keep me informed. Thanks.
QUOTE (David B. Benson+Feb 10 2007, 10:13 PM)
Neither could the core stand alone...
OK, now I know you have no idea what you are talking about.
@reasonwhy
thanks for the tip.
OK, now I know you have no idea what you are talking about.
@reasonwhy
QUOTE
You have to understand DBB doesn't’t realize beams connecting the columns in the core would add considerable resistance even if not cross braced. This has been pointed out many, many times and the OCT just ignores it and continue with the calculations. biggrin.gif
thanks for the tip.
If a bomb blew up and burned the person in the elevator it should have damaged the elevator. If jet fuel fell down the shaft into the elevator it should have burned the person in the elevator leaving the elevator operational enough to open the doors. Otherwise, how did the explosive blast get into the elevator without distroying it???
William's story is consistant with jet fuel and not the conspiracy story. Even the second story he's using now...
William's story is consistant with jet fuel and not the conspiracy story. Even the second story he's using now...
QUOTE (David B. Benson+Feb 10 2007, 03:28 PM)
Not collapse, but significant damage to shear connections can be found by searching appropriately for the 1994 Northridge earthquake.
The general consensus of the structural engineering community is that shear connections cannot transfer lateral forces and are easily damaged or destroyed by suddenly applied vertical forces. The use of moment connections alone in earthquake prone areas is now building code. Even these are not considered sufficiently capable for buildings thought to be at risk of progressive collapse and newer connecting techniques are being developed.
Nobody appears to understand how to calculate the dynamic loadings for the critical point of welded connections in a progressive collapse scenario. If you find something, do keep me informed. Thanks.
I take it that means you ignored the beam shear connections?
The general consensus of the structural engineering community is that shear connections cannot transfer lateral forces and are easily damaged or destroyed by suddenly applied vertical forces. The use of moment connections alone in earthquake prone areas is now building code. Even these are not considered sufficiently capable for buildings thought to be at risk of progressive collapse and newer connecting techniques are being developed.
Nobody appears to understand how to calculate the dynamic loadings for the critical point of welded connections in a progressive collapse scenario. If you find something, do keep me informed. Thanks.
I take it that means you ignored the beam shear connections?
QUOTE (Common Sense+Feb 10 2007, 03:41 PM)
If a bomb blew up and burned the person in the elevator it should have damaged the elevator. If jet fuel fell down the shaft into the elevator it should have burned the person in the elevator leaving the elevator operational enough to open the doors. Otherwise, how did the explosive blast get into the elevator without distroying it???
William's story is consistant with jet fuel and not the conspiracy story. Even the second story he's using now...
What conspiracy story? The official conspiracy or not sure how it happened?
William's story is consistant with jet fuel and not the conspiracy story. Even the second story he's using now...
What conspiracy story? The official conspiracy or not sure how it happened?
QUOTE (reasonwhy+Feb 10 2007, 11:50 PM)
I take it that means you ignored the beam shear connections?
I really don't understand were the lateral loads that break the connections are coming from?
NIST ignored the shear connected beams in the core when doing their final FEA to determine tower degradation. When the core columns in their analysis began to deform, this would develop lateral loads. They only considered lateral load transfer via the moment connections (which I think are only along column lines and not between them).
Since these shear connections cannot transfer (much) lateral load, this seems a good approximation to me.
In my own work so far, I have considered the building as a whole to calculate the energy actually expended. Other than the calculations which agree with shagster's regarding destroying all the truss seats of a suspended floor, and also the energy necessary to punch through the concrete in the floor I have left to details of energy consumption to others.
I really don't understand were the lateral loads that break the connections are coming from?
NIST ignored the shear connected beams in the core when doing their final FEA to determine tower degradation. When the core columns in their analysis began to deform, this would develop lateral loads. They only considered lateral load transfer via the moment connections (which I think are only along column lines and not between them).
Since these shear connections cannot transfer (much) lateral load, this seems a good approximation to me.
In my own work so far, I have considered the building as a whole to calculate the energy actually expended. Other than the calculations which agree with shagster's regarding destroying all the truss seats of a suspended floor, and also the energy necessary to punch through the concrete in the floor I have left to details of energy consumption to others.
QUOTE (lozenge124+Feb 10 2007, 11:40 PM)
OK, now I know you have no idea what you are talking about.
Then you have no idea how the towers were engineered to stand up. Maybe you ought to go read about it?
Try NCSTAR1-2 and 1-2A for starters.
Edited to add: Portions of 1-1 and 1-1A are also helpful.
Then you have no idea how the towers were engineered to stand up. Maybe you ought to go read about it?
Try NCSTAR1-2 and 1-2A for starters. Edited to add: Portions of 1-1 and 1-1A are also helpful.
http://www.livingsteel.org/structural-safety-9
http://www.nsf.gov/pubs/1998/nsf9836/nsf9836.htm
Earthquake studies on steel buildings.
http://www.nsf.gov/pubs/1998/nsf9836/nsf9836.htm
Earthquake studies on steel buildings.
Eccentric sudden loads of short duration ---
I looked at model B in
George J. Simitses
Dynamic Stability of Suddenly Loaded Structures
Springer, 1990
which offers a perfect column, pinned at the bottom, with attached linear spring to hold it up. A sudden load of short duration is applied off-center, i.e., eccentrically. For a sufficiently large load, called critical, the column will become unstable and fall over.
Applying the developed equations to core column members, 36 feet long, we can obtain an estimate of the sudden load required to reach the critical point. As the linear spring is supposed to represent the weld at the bottom of the member, I placed it 1/4 foot above the pin. Using a loading time of 0.1 seconds and an eccentricity of 1 foot, we find that about one million lbf is the required load!
Even accounting for the self-load due to gravity on the column lowers this figure only a little. However, another approach is possible. First, the critical point is reached for this highly idealized system when the angle reaches 45 degrees. But it seems obvious that the weld would fracture at a much smaller angle, say a.
Then multiply the one million lbf by sin a to find the force required. Using a = 5.75 degrees, the sine is 0.10. Is one hundred thousand lbf too much to expect?
Seems too big for the situation in the towers to me... 
I looked at model B in
George J. Simitses
Dynamic Stability of Suddenly Loaded Structures
Springer, 1990
which offers a perfect column, pinned at the bottom, with attached linear spring to hold it up. A sudden load of short duration is applied off-center, i.e., eccentrically. For a sufficiently large load, called critical, the column will become unstable and fall over.
Applying the developed equations to core column members, 36 feet long, we can obtain an estimate of the sudden load required to reach the critical point. As the linear spring is supposed to represent the weld at the bottom of the member, I placed it 1/4 foot above the pin. Using a loading time of 0.1 seconds and an eccentricity of 1 foot, we find that about one million lbf is the required load!
Even accounting for the self-load due to gravity on the column lowers this figure only a little. However, another approach is possible. First, the critical point is reached for this highly idealized system when the angle reaches 45 degrees. But it seems obvious that the weld would fracture at a much smaller angle, say a.
Then multiply the one million lbf by sin a to find the force required. Using a = 5.75 degrees, the sine is 0.10. Is one hundred thousand lbf too much to expect?
Seems too big for the situation in the towers to me...
QUOTE (David B. Benson+Feb 10 2007, 04:32 PM)
Eccentric sudden loads of short duration ---
I looked at model B in
George J. Simitses
Dynamic Stability of Suddenly Loaded Structures
Springer, 1990
which offers a perfect column, pinned at the bottom, with attached linear spring to hold it up. A sudden load of short duration is applied off-center, i.e., eccentrically. For a sufficiently large load, called critical, the column will become unstable and fall over.
Applying the developed equations to core column members, 36 feet long, we can obtain an estimate of the sudden load required to reach the critical point. As the linear spring is supposed to represent the weld at the bottom of the member, I placed it 1/4 foot above the pin. Using a loading time of 0.1 seconds and an eccentricity of 1 foot, we find that about one million lbf is the required load!
Even accounting for the self-load due to gravity on the column lowers this figure only a little. However, another approach is possible. First, the critical point is reached for this highly idealized system when the angle reaches 45 degrees. But it seems obvious that the weld would fracture at a much smaller angle, say a.
Then multiply the one million lbf by sin a to find the force required. Using a = 5.75 degrees, the sine is 0.10. Is one hundred thousand lbf too much to expect? Seems too big for the situation in the towers to me...
36 feet without support?
The large beams braced the columns every 12 feet.
You really don’t understand the core construction do you?
I looked at model B in
George J. Simitses
Dynamic Stability of Suddenly Loaded Structures
Springer, 1990
which offers a perfect column, pinned at the bottom, with attached linear spring to hold it up. A sudden load of short duration is applied off-center, i.e., eccentrically. For a sufficiently large load, called critical, the column will become unstable and fall over.
Applying the developed equations to core column members, 36 feet long, we can obtain an estimate of the sudden load required to reach the critical point. As the linear spring is supposed to represent the weld at the bottom of the member, I placed it 1/4 foot above the pin. Using a loading time of 0.1 seconds and an eccentricity of 1 foot, we find that about one million lbf is the required load!
Even accounting for the self-load due to gravity on the column lowers this figure only a little. However, another approach is possible. First, the critical point is reached for this highly idealized system when the angle reaches 45 degrees. But it seems obvious that the weld would fracture at a much smaller angle, say a.
Then multiply the one million lbf by sin a to find the force required. Using a = 5.75 degrees, the sine is 0.10. Is one hundred thousand lbf too much to expect?
Seems too big for the situation in the towers to me... 36 feet without support?
The large beams braced the columns every 12 feet.
You really don’t understand the core construction do you?
QUOTE (Chainsaw+,Feb 10 2007, 04:24 PM)
http://www.livingsteel.org/structural-safety-9
http://www.nsf.gov/pubs/1998/nsf9836/nsf9836.htm
Earthquake studies on steel buildings.
Thanks Chainsaw
http://www.nsf.gov/pubs/1998/nsf9836/nsf9836.htm
Earthquake studies on steel buildings.
QUOTE
However, in the 1994 Northridge earthquake, more than 200 buildings of this structural type suffered brittle fractures at connections. None of these steel frame buildings collapsed...
Thanks Chainsaw
QUOTE (reasonwhy+Feb 11 2007, 12:49 AM)
The large beams braced the columns every 12 feet.
What about 'shear connections are unable to transfer lateral loads' do you fail to understand?
Until I have a better understanding of just what around 100,000 lbf implies, I'm going to conclude that eccentric sudden loads of short duration do not provide a reasonable model for weld failures of the column splices.
What about 'shear connections are unable to transfer lateral loads' do you fail to understand?
Until I have a better understanding of just what around 100,000 lbf implies, I'm going to conclude that eccentric sudden loads of short duration do not provide a reasonable model for weld failures of the column splices.
QUOTE (David B. Benson+Feb 10 2007, 03:58 PM)
NIST ignored the shear connected beams in the core when doing their final FEA to determine tower degradation. When the core columns in their analysis began to deform, this would develop lateral loads. They only considered lateral load transfer via the moment connections (which I think are only along column lines and not between them).
Since these shear connections cannot transfer (much) lateral load, this seems a good approximation to me.
Another reason the NIST report is a Joke!
Since these shear connections cannot transfer (much) lateral load, this seems a good approximation to me.
Another reason the NIST report is a Joke!
QUOTE (David B. Benson+Feb 10 2007, 04:58 PM)
What about 'shear connections are unable to transfer lateral loads' do you fail to understand?
Until I have a better understanding of just what around 100,000 lbf implies, I'm going to conclude that eccentric sudden loads of short duration do not provide a reasonable model for weld failures of the column splices.
WHAT ARE THE LATERAL LOADS YOU KEEP REFERRING TO?
Until I have a better understanding of just what around 100,000 lbf implies, I'm going to conclude that eccentric sudden loads of short duration do not provide a reasonable model for weld failures of the column splices.
WHAT ARE THE LATERAL LOADS YOU KEEP REFERRING TO?
reasonwhy --- Since this column swings like a inverted pendulum, there is the vertical component and a horizontal component to displacements and velocities. Hence there are horizontal forces, which the engineers like to call lateral loads. Got it now?
Everybody --- turns out that 100,000 lbf is not much, once the potent force of gravity is taken into account. Assuming a drop of 12 feet, accelerated at 32 ft/s^2, a mere 2600 lb with a 0.1 foot displacement suffices to produce the required 100,000 lbf, close enough.
Fine! Eccentric sudden loads then appear to suffice to destroy column splices. Indeed, I could do the same again each 12 feet for the moment connections in the core floors. Since the length L only appears linearly in the equations, only 3 times as much mass is required.
Now, reasonwhy, just what were you saying about heavy beams? So once started, the collapse progresses easily in the core, smashing through everything by its own mass under the potent force of gravity...
Everybody --- turns out that 100,000 lbf is not much, once the potent force of gravity is taken into account. Assuming a drop of 12 feet, accelerated at 32 ft/s^2, a mere 2600 lb with a 0.1 foot displacement suffices to produce the required 100,000 lbf, close enough.
Fine!
Eccentric sudden loads then appear to suffice to destroy column splices. Indeed, I could do the same again each 12 feet for the moment connections in the core floors. Since the length L only appears linearly in the equations, only 3 times as much mass is required.Now, reasonwhy, just what were you saying about heavy beams? So once started, the collapse progresses easily in the core, smashing through everything by its own mass under the potent force of gravity...
QUOTE (David B. Benson+Feb 10 2007, 05:19 PM)
reasonwhy --- Since this column swings like a inverted pendulum, there is the vertical component and a horizontal component to displacements and velocities. Hence there are horizontal forces, which the engineers like to call lateral loads. Got it now?
Everybody --- turns out that 100,000 lbf is not much, once the potent force of gravity is taken into account. Assuming a drop of 12 feet, accelerated at 32 ft/s^2, a mere 260 lb suffices to produce the required 100,000 lbf, close enough.
Fine! Eccentric sudden loads then appear to suffice to destroy column splices. Indeed, I could do the same again each 12 feet for the moment connections in the core floors. Since the length L only appears linearly in the equations, only 3 times as much mass is required.
Now, reasonwhy, just what were you saying about heavy beams? So once started, the collapse progresses easily in the core, smashing through everything by its own mass under the potent force of gravity...
Only problem is the column is supported at the top and bottom by the heavy beams even in your imaginary 12 foot fall (the undamaged lower core).
No inverted pendulum, small lateral forces.
Everybody --- turns out that 100,000 lbf is not much, once the potent force of gravity is taken into account. Assuming a drop of 12 feet, accelerated at 32 ft/s^2, a mere 260 lb suffices to produce the required 100,000 lbf, close enough.
Fine!
Eccentric sudden loads then appear to suffice to destroy column splices. Indeed, I could do the same again each 12 feet for the moment connections in the core floors. Since the length L only appears linearly in the equations, only 3 times as much mass is required.Now, reasonwhy, just what were you saying about heavy beams? So once started, the collapse progresses easily in the core, smashing through everything by its own mass under the potent force of gravity...
Only problem is the column is supported at the top and bottom by the heavy beams even in your imaginary 12 foot fall (the undamaged lower core).
No inverted pendulum, small lateral forces.
reasonwhy --- The towers broke into two parts. The top part falls onto the bottom part. So there is no connection between those two parts. Next, the top part hits the beams, etc., at the very top of the bottom part, brutally destroying those. Continued eccentric strikes fracture all welds as the collapse progresses.
Everybody --- Note that I edited my previous post to 2600 lb for an assumed force action distance of 0.1 foot. This is still a rather small mass given all the falling heavy beams and columns.
Everybody should understand this calculation is only approximate for a simplified, idealized model. But using imperfect columns (ones that lean a little) lowers the energy requirements quite a bit. On the other hand, using a nonlinear spring and allowing for linear buckling will up the energy requirements. Lets just say that the model of eccentric, sudden loading of short duration provides a plausible means of fracturing welds without inelastic buckling of core column members...
Everybody --- Note that I edited my previous post to 2600 lb for an assumed force action distance of 0.1 foot. This is still a rather small mass given all the falling heavy beams and columns.
Everybody should understand this calculation is only approximate for a simplified, idealized model. But using imperfect columns (ones that lean a little) lowers the energy requirements quite a bit. On the other hand, using a nonlinear spring and allowing for linear buckling will up the energy requirements. Lets just say that the model of eccentric, sudden loading of short duration provides a plausible means of fracturing welds without inelastic buckling of core column members...
QUOTE (David B. Benson+Feb 10 2007, 05:39 PM)
reasonwhy --- The towers broke into two parts. The top part falls onto the bottom part. So there is no connection between those two parts. Next, the top part hits the beams, etc., at the very top of the bottom part, brutally destroying those. Continued eccentric strikes fracture all welds as the collapse progresses.
Everybody --- Note that I edited my previous post to 2600 lb for an assumed force action distance of 0.1 foot. This is still a rather small mass given all the falling heavy beams and columns.
Everybody should understand this calculation is only approximate for a simplified, idealized model. But using imperfect columns (ones that lean a little) lowers the energy requirements quite a bit. On the other hand, using a nonlinear spring and allowing for linear buckling will up the energy requirements. Lets just say that the model of eccentric, sudden loading of short duration provides a plausible means of fracturing welds without inelastic buckling of core column members...
Buckling does not sever the columns.
Explosives sever the columns.
The towers DID NOT brake into two parts unless explosives were used.
Now at least you are looking in the right direction. You are coming up with a CD model!
Everybody --- Note that I edited my previous post to 2600 lb for an assumed force action distance of 0.1 foot. This is still a rather small mass given all the falling heavy beams and columns.
Everybody should understand this calculation is only approximate for a simplified, idealized model. But using imperfect columns (ones that lean a little) lowers the energy requirements quite a bit. On the other hand, using a nonlinear spring and allowing for linear buckling will up the energy requirements. Lets just say that the model of eccentric, sudden loading of short duration provides a plausible means of fracturing welds without inelastic buckling of core column members...
Buckling does not sever the columns.
Explosives sever the columns.
The towers DID NOT brake into two parts unless explosives were used.
Now at least you are looking in the right direction. You are coming up with a CD model!
Lozenge 124:
You have said: "OK, but I am asking for your (or someone's) calculations that give the 2/3g result for this simplified model we are postulating of a tower core and perimeter minus floors when a block falls on it."
I am afraid that you will have to DO YOUR OWN calculations on any "new (simplified) model" instead of asking someone else to do it! It is YOU that is supposedly postulating something new, not WE....
It is very easy to find fault with somebody else's model. It is not so easy to come up with a better one!
NF
You have said: "OK, but I am asking for your (or someone's) calculations that give the 2/3g result for this simplified model we are postulating of a tower core and perimeter minus floors when a block falls on it."
I am afraid that you will have to DO YOUR OWN calculations on any "new (simplified) model" instead of asking someone else to do it! It is YOU that is supposedly postulating something new, not WE....
It is very easy to find fault with somebody else's model. It is not so easy to come up with a better one!
NF
QUOTE (reasonwhy+Feb 11 2007, 01:47 AM)
Buckling does not sever the columns.
Nonsense. Since the core columns were constructed out of members, each 36 feet long, sufficient buckling of a member will destroy all of its welded connections.
The eccentric sudden loads of short duration that I worked up today is not intended to explain collapse initiation, only the observed progression in which, largely, only welds failed with little damage to the core column members.
For collapse initiation we have to turn to two things. Consider just WTC 1. The top part of the tower was tilted to the south. Then the south, east and west walls broke, wedging in. At this point the surviving core columns had an average DCR of about 2, a sure sign of inelastic behavior. Indeed, what is observed is further tipping, up to 8 degrees of arc. What is not yet completely clear is which mode of inelastic behavior accounts for this further tipping followed by descent.
That's all for today...
Nonsense. Since the core columns were constructed out of members, each 36 feet long, sufficient buckling of a member will destroy all of its welded connections.
The eccentric sudden loads of short duration that I worked up today is not intended to explain collapse initiation, only the observed progression in which, largely, only welds failed with little damage to the core column members.
For collapse initiation we have to turn to two things. Consider just WTC 1. The top part of the tower was tilted to the south. Then the south, east and west walls broke, wedging in. At this point the surviving core columns had an average DCR of about 2, a sure sign of inelastic behavior. Indeed, what is observed is further tipping, up to 8 degrees of arc. What is not yet completely clear is which mode of inelastic behavior accounts for this further tipping followed by descent.
That's all for today...
reasonwhy
You just don't know anything, do you??? The lateral forces are transmitted between the core tubes, not stopped by them. Without the bracing of the floors the core would be as whippy as a reed EVEN IF THEY ALL WHIPPED IN THE SAME DIRECTION BECAUSE OF THE TRANSFER OF FORCES. This means the whole core would be stressed and would snap. The core was not designed to stand on it's own, nor was the frame. Once the floors were gone it was inevitable the rest would fall.
Grumpy
QUOTE
Only problem is the column is supported at the top and bottom by the heavy beams even in your imaginary 12 foot fall (the undamaged lower core).
No inverted pendulum, small lateral forces.
No inverted pendulum, small lateral forces.
You just don't know anything, do you??? The lateral forces are transmitted between the core tubes, not stopped by them. Without the bracing of the floors the core would be as whippy as a reed EVEN IF THEY ALL WHIPPED IN THE SAME DIRECTION BECAUSE OF THE TRANSFER OF FORCES. This means the whole core would be stressed and would snap. The core was not designed to stand on it's own, nor was the frame. Once the floors were gone it was inevitable the rest would fall.
Grumpy
QUOTE (David B. Benson+Feb 10 2007, 06:00 PM)
Nonsense. Since the core columns were constructed out of members, each 36 feet long, sufficient buckling of a member will destroy all of its welded connections.
Please show the photographic evidence of this?
Please show the photographic evidence of this?
QUOTE (Grumpy+Feb 10 2007, 06:00 PM)
reasonwhy
You just don't know anything, do you??? The lateral forces are transmitted between the core tubes, not stopped by them. Without the bracing of the floors the core would be as whippy as a reed EVEN IF THEY ALL WHIPPED IN THE SAME DIRECTION BECAUSE OF THE TRANSFER OF FORCES. This means the whole core would be stressed and would snap. The core was not designed to stand on it's own, nor was the frame. Once the floors were gone it was inevitable the rest would fall.
Grumpy
Grumpster, were are you getting your mythical lateral forces?
We are referring to collapse initiation so why are the floors already removed?
What is a “core tube”?
Someone that doesn’t “know anything” is sure making the OCT look foolish.
You just don't know anything, do you??? The lateral forces are transmitted between the core tubes, not stopped by them. Without the bracing of the floors the core would be as whippy as a reed EVEN IF THEY ALL WHIPPED IN THE SAME DIRECTION BECAUSE OF THE TRANSFER OF FORCES. This means the whole core would be stressed and would snap. The core was not designed to stand on it's own, nor was the frame. Once the floors were gone it was inevitable the rest would fall.
Grumpy
Grumpster, were are you getting your mythical lateral forces?
We are referring to collapse initiation so why are the floors already removed?
What is a “core tube”?
Someone that doesn’t “know anything” is sure making the OCT look foolish.
QUOTE (NEU-FONZE+Feb 11 2007, 01:48 AM)
Lozenge 124:
You have said: "OK, but I am asking for your (or someone's) calculations that give the 2/3g result for this simplified model we are postulating of a tower core and perimeter minus floors when a block falls on it."
I am afraid that you will have to DO YOUR OWN calculations on any "new (simplified) model" instead of asking someone else to do it! It is YOU that is supposedly postulating something new, not WE....
It is very easy to find fault with somebody else's model. It is not so easy to come up with a better one!
NF
Grumpy proposed a model (based on what I had said, yes):
I then asked him where the 2/3g came from.
I would ask you to please read my posts more carefully before posting.
You have said: "OK, but I am asking for your (or someone's) calculations that give the 2/3g result for this simplified model we are postulating of a tower core and perimeter minus floors when a block falls on it."
I am afraid that you will have to DO YOUR OWN calculations on any "new (simplified) model" instead of asking someone else to do it! It is YOU that is supposedly postulating something new, not WE....
It is very easy to find fault with somebody else's model. It is not so easy to come up with a better one!
NF
Grumpy proposed a model (based on what I had said, yes):
QUOTE
Actually, if you take off the top ten floors and then suspend a sandbag with ten times the weight of sand necessary to collapse one floor diaphram, one floor height above the first exposed floor(and core and frame). Release all the sand at one time.
The frame will still be standing, as will the core, but all of the floors of the building will be in the basement.
Now drop the ten stories, tilted, so it will wedge into the bottom sections. The outer frame will peel away and the top block will accelerate into the ground at roughly 2/3G.
Grumpy cool.gif
The frame will still be standing, as will the core, but all of the floors of the building will be in the basement.
Now drop the ten stories, tilted, so it will wedge into the bottom sections. The outer frame will peel away and the top block will accelerate into the ground at roughly 2/3G.
Grumpy cool.gif
I then asked him where the 2/3g came from.
I would ask you to please read my posts more carefully before posting.
QUOTE (reasonwhy+Feb 11 2007, 02:08 AM)
Grumpster, were are you getting your mythical lateral forces?
We are referring to collapse initiation so why are the floors already removed?
What is a “core tube”?
Someone that doesn’t “know anything” is sure making the OCT look foolish.
No just yourself a core tube is a hollow steel Column, the rectangular Column at the Base of the towers that support the core.
Grumpy was refering to continuation of the collapse past initiation, that is clear, and no we are actually refering to both here.
Again your only proving the statement that you know nothing to be 100% accurate.
Can you post some of you math formulas so we can have a look at them please?
We are referring to collapse initiation so why are the floors already removed?
What is a “core tube”?
Someone that doesn’t “know anything” is sure making the OCT look foolish.
No just yourself a core tube is a hollow steel Column, the rectangular Column at the Base of the towers that support the core.
Grumpy was refering to continuation of the collapse past initiation, that is clear, and no we are actually refering to both here.
Again your only proving the statement that you know nothing to be 100% accurate.
Can you post some of you math formulas so we can have a look at them please?
QUOTE (David B. Benson+Feb 11 2007, 01:19 AM)
reasonwhy --- Since this column swings like a inverted pendulum, there is the vertical component and a horizontal component to displacements and velocities. Hence there are horizontal forces, which the engineers like to call lateral loads. Got it now?
Everybody --- turns out that 100,000 lbf is not much, once the potent force of gravity is taken into account. Assuming a drop of 12 feet, accelerated at 32 ft/s^2, a mere 2600 lb with a 0.1 foot displacement suffices to produce the required 100,000 lbf, close enough.
Fine! Eccentric sudden loads then appear to suffice to destroy column splices. Indeed, I could do the same again each 12 feet for the moment connections in the core floors. Since the length L only appears linearly in the equations, only 3 times as much mass is required.
Now, reasonwhy, just what were you saying about heavy beams? So once started, the collapse progresses easily in the core, smashing through everything by its own mass under the potent force of gravity...
Do you think that if I played in my back yard enough, I would discover the key to solving the riddle of how to combine general relativity, with quantum mechanics the grand unified theory?
Hearing your resent results makes me want to go beat on some more beams.
Everybody --- turns out that 100,000 lbf is not much, once the potent force of gravity is taken into account. Assuming a drop of 12 feet, accelerated at 32 ft/s^2, a mere 2600 lb with a 0.1 foot displacement suffices to produce the required 100,000 lbf, close enough.
Fine!
Eccentric sudden loads then appear to suffice to destroy column splices. Indeed, I could do the same again each 12 feet for the moment connections in the core floors. Since the length L only appears linearly in the equations, only 3 times as much mass is required.Now, reasonwhy, just what were you saying about heavy beams? So once started, the collapse progresses easily in the core, smashing through everything by its own mass under the potent force of gravity...
Do you think that if I played in my back yard enough, I would discover the key to solving the riddle of how to combine general relativity, with quantum mechanics the grand unified theory?
Hearing your resent results makes me want to go beat on some more beams.
QUOTE (Chainsaw+,Feb 10 2007, 06:47 PM)
Can you post some of you math formulas so we can have a look at them please?
If I had the time and resources (to get the model from EAI), I would start by asking ENGINEERING ANALYSIS INC. for the model of the WTC and take a HEXDAM, VEXDAM, VASDIP, HEXFRAG TRAINING COURSE.
http://jmcleland.home.mindspring.com/EAIprs83.html
http://eai.home.mindspring.com/5WTCanim.gif
Notice the vapor cloud explosion does not go down the elevator shafts.
QUOTE
October 29, 2001, As part of a company-funded study, based on its earlier analysis of the 1993 World Trade Center bombing, Engineering Analysis Inc. has produced a preliminary three-dimensional graphical representation of the September 11 World Trade Center attack. The view presented is looking from west to east with the North Tower on the left and the South Tower on the right. Also included are World Trade Center Buildings #3, 4, 5, 6, and 7. This representation was generated by means of the VEXDAM 5.2 software, utilizing the concept of distributed vapor cloud explosions.
Then I could experiment with all the different explosives until the model matched what we saw on 9/11.
For some reason their are models of most everything al qaida and domestic terrorist have blown up.
http://eai.home.mindspring.com/
I could also use the model of WTC7 and show how CD could bring the building down.
QUOTE (reasonwhy+Feb 11 2007, 03:25 AM)
If I had the time and resources (to get the model from EAI), I would start by asking ENGINEERING ANALYSIS INC. for the model of the WTC and take a HEXDAM, VEXDAM, VASDIP, HEXFRAG TRAINING COURSE.
http://jmcleland.home.mindspring.com/EAIprs83.html
http://eai.home.mindspring.com/5WTCanim.gif
Notice the vapor cloud explosion does not go down the elevator shafts.
Then I could experiment with all the different explosives until the model matched what we saw on 9/11.
I have a feeling this was done by someone prior to 9/11.
Then you have to rely on others models and not your own, shame, I was expecting more from you, you really are a disappointment.
You constantly criticize, but can offer nothing actually to the discussion, you have a closed narrow train of thought.
http://jmcleland.home.mindspring.com/EAIprs83.html
http://eai.home.mindspring.com/5WTCanim.gif
Notice the vapor cloud explosion does not go down the elevator shafts.
Then I could experiment with all the different explosives until the model matched what we saw on 9/11.
I have a feeling this was done by someone prior to 9/11.
Then you have to rely on others models and not your own, shame, I was expecting more from you, you really are a disappointment.
You constantly criticize, but can offer nothing actually to the discussion, you have a closed narrow train of thought.
QUOTE (Chainsaw+,Feb 10 2007, 07:36 PM)
Then you have to rely on others models and not your own, shame, I was expecting more from you, you really are a disappointment.
You constantly criticize, but can offer nothing actually to the discussion, you have a closed narrow train of thought.
Sorry to disappoint you.
I am perfectly capable of modeling the towers if the drawings are supplied.
I would much rather use my own model to make sure EAI did not pull a NIST and model the floors and columns wrong .
The training course really looks interesting:
http://jmcleland.home.mindspring.com/EAIprs83.html
You constantly criticize, but can offer nothing actually to the discussion, you have a closed narrow train of thought.
Sorry to disappoint you.
I am perfectly capable of modeling the towers if the drawings are supplied.
I would much rather use my own model to make sure EAI did not pull a NIST and model the floors and columns wrong .
The training course really looks interesting:
QUOTE
The HVV training course will involve detailed, hands-on training concerning the proper operation of the following Trinity software:
High Explosive Damage Assessment Model (HEXDAM)
Vapor Cloud Explosion Damage Assessment Model (VEXDAM)
Vulnerability Assessment of Structurally Damaging Impulses and Pressures (VASDIP)
The course duration would be 2 ½ days. Each student would be provided with a desk-top computer with all three software programs installed. Copies of the Training Course notes would be provided each student as follows:
High Explosive Damage Assessment Model, 7th Industrial Version (HEXDAM 7.0) Training Course Notes (268 pages)
Vapor Cloud Explosion Damage Assessment Model, 7th Industrial Version (VEXDAM 7.0) Training Course Notes (275 pages)
Vulnerability Assessment of Structurally Damaging Impulses and Pressures, 4th Industrial Version (VASDIP 4.0) Training Course Notes (133 pages)
High Explosive Damage Assessment Model (HEXDAM)
Vapor Cloud Explosion Damage Assessment Model (VEXDAM)
Vulnerability Assessment of Structurally Damaging Impulses and Pressures (VASDIP)
The course duration would be 2 ½ days. Each student would be provided with a desk-top computer with all three software programs installed. Copies of the Training Course notes would be provided each student as follows:
High Explosive Damage Assessment Model, 7th Industrial Version (HEXDAM 7.0) Training Course Notes (268 pages)
Vapor Cloud Explosion Damage Assessment Model, 7th Industrial Version (VEXDAM 7.0) Training Course Notes (275 pages)
Vulnerability Assessment of Structurally Damaging Impulses and Pressures, 4th Industrial Version (VASDIP 4.0) Training Course Notes (133 pages)
http://jmcleland.home.mindspring.com/EAIprs83.html
reasonwhy
Notice how that simulation does not conform to reality, we already know that water(or fuel) will always go downhill, no matter how convoluted the path. It's not magic, it's just physics.
We already know that people were burned. Explosives don't burn people, they just blast them apart.
We already know fuel reached the basement level, Rodreguez himself said he smelled"kerosene". Jet fuel is basically high grade kerosene.
We already know this fuel was at least in part vaporized and being pushed by a high speed flame front, and under those circumstances WILL detonate in the confined space of the bottom of a shaft. And that such an explosion is capable of doing great damage, again, as described by Rodreguez.
We already know such explosions occured in several of those shafts ranging from the express elevators and those on the ground floors to those on the 78th floor. Many people were burned or killed by that burning fuel.
And we already know that the energy required to cause gravitational collapse was well within the amount of energy available, and that thermite fairies(ninja or invisible) do not exist.
We already know that no explosives were used anywhere on the WTC complex on 9/11. The FBI, BATF and their bomb sniffing dogs found no residue and the seismic record is clear, NO EXPLOSIVES WHATSOEVER.
We already know that not one CREDIBLE report of explosives cut beams, explosive device debris, timing devices, detcord residue or heavy thermite channels was found by anyone and all the real experts think you guys are a few bales short of a haystack.
In short, it is you who is being made the fool by every post you write.
Grumpy
QUOTE
Notice the vapor cloud explosion does not go down the elevator shafts.
Notice how that simulation does not conform to reality, we already know that water(or fuel) will always go downhill, no matter how convoluted the path. It's not magic, it's just physics.
We already know that people were burned. Explosives don't burn people, they just blast them apart.
We already know fuel reached the basement level, Rodreguez himself said he smelled"kerosene". Jet fuel is basically high grade kerosene.
We already know this fuel was at least in part vaporized and being pushed by a high speed flame front, and under those circumstances WILL detonate in the confined space of the bottom of a shaft. And that such an explosion is capable of doing great damage, again, as described by Rodreguez.
We already know such explosions occured in several of those shafts ranging from the express elevators and those on the ground floors to those on the 78th floor. Many people were burned or killed by that burning fuel.
And we already know that the energy required to cause gravitational collapse was well within the amount of energy available, and that thermite fairies(ninja or invisible) do not exist.
We already know that no explosives were used anywhere on the WTC complex on 9/11. The FBI, BATF and their bomb sniffing dogs found no residue and the seismic record is clear, NO EXPLOSIVES WHATSOEVER.
We already know that not one CREDIBLE report of explosives cut beams, explosive device debris, timing devices, detcord residue or heavy thermite channels was found by anyone and all the real experts think you guys are a few bales short of a haystack.
In short, it is you who is being made the fool by every post you write.
Grumpy
QUOTE (Grumpy+Feb 10 2007, 07:54 PM)
reasonwhy
Notice how that simulation does not conform to reality, we already know that water(or fuel) will always go downhill, no matter how convoluted the path. It's not magic, it's just physics.
We already know that people were burned. Explosives don't burn people, they just blast them apart.
More BS from the Grumpster:
http://www.columbia.edu/cu/ccnmtl/projects.../exp/print.html
We need a Grumpster BS meter to warn lurkers.
http://www.columbia.edu/cu/ccnmtl/projects.../exp/print.html
We need a Grumpster BS meter to warn lurkers.
We already know that no explosives were used anywhere on the WTC complex on 9/11. The FBI, BATF and their bomb sniffing dogs found no residue and the seismic record is clear, NO EXPLOSIVES WHATSOEVER.
In short, it is you who is being made the fool by every post you write.
Grumpy
Show me one residue test result from the FBI, BATF or anyone else .
Like I have mentioned in my post about Greening's paper I do not think E1 considerations are valid. The core and perimeters are interconnected you can not look at them on a floor by floor basis. You have to consider them as a whole.
When I said "mentally add into the model the supporting strength of 47 core columns and the perimeter walls (again, because up to now we have just considered the inertia of the floor mass in slowing down the collapse)". I mean just that, the supporting strength, not the mass.
So what happens to the columns in the lower portion that aren't subject to axial strikes? I don't see how this is favorable to your model.
Some of the columns were impacted laterally by the debris pile and failed by buckling or splices breaking. Some were bypassed by the front and stood for a few seconds and then toppled. That's seen in the videos where parts of perimeter wall and the core are seen still standing by themselves but topple in a few seconds. Little energy was expended on those sections and no momentum was transferred to them by the front. They were essentially stagnant shed mass. The core had a greater strength axially than the long span floors, but the front didn't have to destroy the core completely in order to propagate the collapse. It bypassed some of the core and perimeter by breaking floor connections.
The main floors were about 71 % of the tower area and had a rating of about 70 lb/ft2. They couldn't support a majority of the mass of 14 or 29 stories falling on them or even resting on them statically. The floor connections had little load bearing and energy absorbing ability compared with the columns. In the upper levels, the floors represented most the mass and inertia of story. It wasn't possible to transfer much energy from them to the columns through the floor connections during an impact. That's one mechanism by which the front stayed localized.
It's actually more difficult to account for how the front moved as slow as it did, especially after the first few seconds, considering the short-cut failure mechanisms and E1 values of about 0.5 GJ per story needed to fully buckle every core and perimeter column each story height. I'm considering shedding more carefully as an explanation for the observed front speed later in the collapse.
And we have just been through discovering that vibrations could have fractured the welds and also eccentric sudden loads of short duration could have done the same.
We have also been told beam weapons from space caused the towers to collapse, does that make it true?
Your mythical lateral forces do not exist because the columns are pinned at the top and bottom.
Notice how that simulation does not conform to reality, we already know that water(or fuel) will always go downhill, no matter how convoluted the path. It's not magic, it's just physics.
We already know that people were burned. Explosives don't burn people, they just blast them apart.
More BS from the Grumpster:
QUOTE
Explosive Properties
The larger the explosive shock, the greater the shock wave will be.
Mechanisms of injury resulting from explosions include:
• Direct exposure to the blast wave
• Reflective blast waves
• Acceleration-deceleration forces
• Penetrating and non-penetrating wounds
• Burns and inhalation of toxic gases
• Building collapse
The larger the explosive shock, the greater the shock wave will be.
Mechanisms of injury resulting from explosions include:
• Direct exposure to the blast wave
• Reflective blast waves
• Acceleration-deceleration forces
• Penetrating and non-penetrating wounds
• Burns and inhalation of toxic gases
• Building collapse
http://www.columbia.edu/cu/ccnmtl/projects.../exp/print.html
We need a Grumpster BS meter to warn lurkers.
QUOTE (->
| QUOTE |
| Explosive Properties The larger the explosive shock, the greater the shock wave will be. Mechanisms of injury resulting from explosions include: • Direct exposure to the blast wave • Reflective blast waves • Acceleration-deceleration forces • Penetrating and non-penetrating wounds • Burns and inhalation of toxic gases • Building collapse |
http://www.columbia.edu/cu/ccnmtl/projects.../exp/print.html
We need a Grumpster BS meter to warn lurkers.
We already know that no explosives were used anywhere on the WTC complex on 9/11. The FBI, BATF and their bomb sniffing dogs found no residue and the seismic record is clear, NO EXPLOSIVES WHATSOEVER.
In short, it is you who is being made the fool by every post you write.
Grumpy
Show me one residue test result from the FBI, BATF or anyone else .
Hey reasonwhy, an interview at UT with NIST engineer John Gross showed up today. I'm not able to post images or links for some reason(Arthur says I need to post x amount before?) Anyway found it off of PNACitizens or Google video. RS
QUOTE (roves shill+Feb 10 2007, 09:11 PM)
Hey reasonwhy, an interview at UT with NIST engineer John Gross showed up today. I'm not able to post images or links for some reason(Arthur says I need to post x amount before?) Anyway found it off of PNACitizens or Google video. RS
Thanks RS. Good video. Good to see you posting again. Hope you aren’t suffering any health problems for living close to ground zero on 9/11.
He confirms what I have speculated. NIST stopped at collapse initiation then just used the video to prove global collapse ensued.
http://video.google.com/videoplay?docid=-7...01&q=John+Gross
Thanks RS. Good video. Good to see you posting again. Hope you aren’t suffering any health problems for living close to ground zero on 9/11.
QUOTE
John Gross, one of the lead engineers of the NIST report is quesitoned about the existance of molten steel at the WTC building, the collapse of Building 7, and also explains how the NIST report did not do any analysis of the collapse of all three buidlings.
He confirms what I have speculated. NIST stopped at collapse initiation then just used the video to prove global collapse ensued.
http://video.google.com/videoplay?docid=-7...01&q=John+Gross
QUOTE (lozenge124+Feb 10 2007, 04:43 PM)
@shagster:
thanks for taking a look at Hoffman's model.
Hoffman's model is similar to mine. He's removing mass from the front just after impact. I've been using a constant mass per story for the tower which gives a slightly shorter duration compared with an increasing mass toward the ground. However, I'm also considering the slowing effect of E1 which Hoffman's model doesn't include, which increases the duration. I'm getting comparable values for the duration.
The towers were top heavy in the upper levels which means that a large amount of mass in the upper block was striking floors of relatively low mass. A decreasing mass all the way to the tower top isn't a proper way to model the mass distribution, even though in general the mass increased toward the ground level. What DBB has done is a good approach for the first few seconds of collapse.
911-research uses the phase 'just 6%', but 6% the mass of the upper block shed per impact is large amount and doesn't agree with the amount of debris observed in the pit. It needs to be much less than that, on the order of 2% or less. Even with an unreasonable amount of shedding such as 6%, the stage 1 duration is still in the neighborhood of 13 to 16 s, close to what was observed. The duration is relatively insensitive to shedding.
The front of WTC2 was seen in videos at or above the top of WTC3 at the 12 second mark which was about 100m above ground. WTC2 wasn't near freefall rate (WTC1 wasn't either). I've run a shedding model that takes into account losing part of the upper block, 0.32 of a story mass per impact, and an E1 of 0.8 GJ that increases to 3.2 GJ at the ground level. The model predicts a stage 1 duration of 14.7 seconds and predicts the position of the front at about 100 m above ground at the 12 second mark, which agrees with what was seen in the video.
One has to be careful with shedding models, as the upper block can be consumed if the shedding is more than one story mass per impact, such as the case for WTC2 and 6% the mass of the upper block shedding per impact. The upper block may be gone or partly consumed by the end of stage 1 which can effect stage 2 and the overall duration. It depends on the amount of shedding and how much the mass of the tower is increasing toward the ground level.
thanks for taking a look at Hoffman's model.
Hoffman's model is similar to mine. He's removing mass from the front just after impact. I've been using a constant mass per story for the tower which gives a slightly shorter duration compared with an increasing mass toward the ground. However, I'm also considering the slowing effect of E1 which Hoffman's model doesn't include, which increases the duration. I'm getting comparable values for the duration.
The towers were top heavy in the upper levels which means that a large amount of mass in the upper block was striking floors of relatively low mass. A decreasing mass all the way to the tower top isn't a proper way to model the mass distribution, even though in general the mass increased toward the ground level. What DBB has done is a good approach for the first few seconds of collapse.
911-research uses the phase 'just 6%', but 6% the mass of the upper block shed per impact is large amount and doesn't agree with the amount of debris observed in the pit. It needs to be much less than that, on the order of 2% or less. Even with an unreasonable amount of shedding such as 6%, the stage 1 duration is still in the neighborhood of 13 to 16 s, close to what was observed. The duration is relatively insensitive to shedding.
The front of WTC2 was seen in videos at or above the top of WTC3 at the 12 second mark which was about 100m above ground. WTC2 wasn't near freefall rate (WTC1 wasn't either). I've run a shedding model that takes into account losing part of the upper block, 0.32 of a story mass per impact, and an E1 of 0.8 GJ that increases to 3.2 GJ at the ground level. The model predicts a stage 1 duration of 14.7 seconds and predicts the position of the front at about 100 m above ground at the 12 second mark, which agrees with what was seen in the video.
One has to be careful with shedding models, as the upper block can be consumed if the shedding is more than one story mass per impact, such as the case for WTC2 and 6% the mass of the upper block shedding per impact. The upper block may be gone or partly consumed by the end of stage 1 which can effect stage 2 and the overall duration. It depends on the amount of shedding and how much the mass of the tower is increasing toward the ground level.
Hey RW, thanks man. So i didnt see a date. Is that current? Was the interview today?
QUOTE (lozenge124+Feb 10 2007, 04:43 PM)
Like I have mentioned in my post about Greening's paper I do not think E1 considerations are valid. The core and perimeters are interconnected you can not look at them on a floor by floor basis. You have to consider them as a whole.
When I said "mentally add into the model the supporting strength of 47 core columns and the perimeter walls (again, because up to now we have just considered the inertia of the floor mass in slowing down the collapse)". I mean just that, the supporting strength, not the mass.
So what happens to the columns in the lower portion that aren't subject to axial strikes? I don't see how this is favorable to your model.
Some of the columns were impacted laterally by the debris pile and failed by buckling or splices breaking. Some were bypassed by the front and stood for a few seconds and then toppled. That's seen in the videos where parts of perimeter wall and the core are seen still standing by themselves but topple in a few seconds. Little energy was expended on those sections and no momentum was transferred to them by the front. They were essentially stagnant shed mass. The core had a greater strength axially than the long span floors, but the front didn't have to destroy the core completely in order to propagate the collapse. It bypassed some of the core and perimeter by breaking floor connections.
The main floors were about 71 % of the tower area and had a rating of about 70 lb/ft2. They couldn't support a majority of the mass of 14 or 29 stories falling on them or even resting on them statically. The floor connections had little load bearing and energy absorbing ability compared with the columns. In the upper levels, the floors represented most the mass and inertia of story. It wasn't possible to transfer much energy from them to the columns through the floor connections during an impact. That's one mechanism by which the front stayed localized.
It's actually more difficult to account for how the front moved as slow as it did, especially after the first few seconds, considering the short-cut failure mechanisms and E1 values of about 0.5 GJ per story needed to fully buckle every core and perimeter column each story height. I'm considering shedding more carefully as an explanation for the observed front speed later in the collapse.
QUOTE (lozenge124+Feb 10 2007, 04:43 PM)
Again, I think you are comparing upper block kinetic energy with E1 do determine this. (correct me if I'm wrong). The core is a single large structure. I like the model Grumpy proposed where all the floors are removed, and you drop a block onto the remaining steel core and perimeter. I would like to know what you think happens next.
A portion of the core about half the height of WTC2 was seen standing briefly at the end of the collapse. It wasn't able to stand on its own for more than a few seconds. It didn't even need to have a block dropped on it. Part of the core of WTC1 was also seen still standing then wavering and falling within a few seconds. Same for sections of perimeter wall during the collapse which wavered on their own for a few seconds and then toppled due to splices failing from the bending.
A portion of the core about half the height of WTC2 was seen standing briefly at the end of the collapse. It wasn't able to stand on its own for more than a few seconds. It didn't even need to have a block dropped on it. Part of the core of WTC1 was also seen still standing then wavering and falling within a few seconds. Same for sections of perimeter wall during the collapse which wavered on their own for a few seconds and then toppled due to splices failing from the bending.
QUOTE (shagster+Feb 11 2007, 12:14 AM)
It bypassed some of the core and perimeter by breaking floor connections.
I just thought for Lozenge's sake, a repost of the floor connections were warranted... from Common Sense's web site.
http://www.debunking911.com/trussschem.jpg
And maybe this one too, from the same page...
http://www.debunking911.com/construction.jpg
I just thought for Lozenge's sake, a repost of the floor connections were warranted... from Common Sense's web site.
http://www.debunking911.com/trussschem.jpg
And maybe this one too, from the same page...
http://www.debunking911.com/construction.jpg
QUOTE (reasonwhy+Feb 11 2007, 03:49 AM)
Sorry to disappoint you.
I am perfectly capable of modeling the towers if the drawings are supplied.
I would much rather use my own model to make sure EAI did not pull a NIST and model the floors and columns wrong .
The training course really looks interesting:
http://jmcleland.home.mindspring.com/EAIprs83.html
From the NIST Small Business Innovation Research Awards for FY1997 (SBIR).
reasonwhy, you were fortunate not to attend the HEXDAM, VEXDAM, VASDIP, HEXFRAG TRAINING COURSE offered by Engineering Analysis Inc., because in the past they have been awarded contracts by the Great Satan, NIST.
Their software would have been bugged to give erroneous WTC blast analysis, and they would have informed the FBI of your attendance, and you would have been put on another enemy of the state watch list.
You're going to have rely on the brain trust within the Truth movement to model any demolition theories.
All of the mainstream engineering firms are in the pocket of the Bush administration and cannot be trusted.
Be careful, and good luck.
I am perfectly capable of modeling the towers if the drawings are supplied.
I would much rather use my own model to make sure EAI did not pull a NIST and model the floors and columns wrong .
The training course really looks interesting:
http://jmcleland.home.mindspring.com/EAIprs83.html
From the NIST Small Business Innovation Research Awards for FY1997 (SBIR).
QUOTE
FY1997 Phase 2 Award Winner
TOPIC: 8.1 Atmospheric and Hydrological Sciences
SUBTOPIC: 8.1.4A Seismic Tornado Detection System
TITLE: Seismic Detection of Tornadoes
FIRM: Engineering Analysis, Inc.
715 Arcadia Circle
Huntsville, Alabama 35801
PRINCIPAL INVESTIGATOR: Frank B. Tatom
205-533-9391
AWARD AMOUNT: $199,998ABSTRACT:
The Phase 1 study results provide strong confirmation that tornadoes on the ground produce significant seismic signals which a properly designed Seismic Tornado Detector (STD) can detect. The proposed Phase 2 effort should result in an operational STD system design, with considerable potential application by government agencies for the protection of the general populace, as well as by the individual homeowner for personal safety. The technical approach involves: 1) applying the Phase 1 results to the Phase 2 effort; 2) using the experience of the University of Memphis Center for Earthquake Research and Information (CERI), the Soil dynamics Laboratory of Michigan and the National Severe Strom Laboratory (NSSL); 3) maintaining good communications between research team members; 4) modifying the existing short-Period STD instrument packages to include Long-Period capability; and 5) using (where possible) existing designs for key STD components. The specific technical objectives are: 1) continued collection and analysis of chance TSS measurements; 2) detailed design of STD instrument package; 3) development of STD instrument package software;4) STD instrument package fabrication and assembly; 5) testing of STD instrument package; 6) development of deployment plan; 7) deployment of STD instrument packages; 8) recovery of STD instrument packages; 9) data retrieval and analysis; 10) development of detection algorithm; 11) design of STD prototype; and 12) complete documentation.
COMMERCIAL APPLICATIONS:
Two applications of the research are envisioned, both dealing with the detection of tornadoes. First, from the standpoint of both state and federal government agencies involved in the detection of tornadoes, an STD network, when used in conjunction with Doppler radar, should provide an accurate, efficient method to determine when a tornado is actually on the ground. Second, in addition to the development of STD networks another STD version could be developed for warning the individual homeowner.
TOPIC: 8.1 Atmospheric and Hydrological Sciences
SUBTOPIC: 8.1.4A Seismic Tornado Detection System
TITLE: Seismic Detection of Tornadoes
FIRM: Engineering Analysis, Inc.
715 Arcadia Circle
Huntsville, Alabama 35801
PRINCIPAL INVESTIGATOR: Frank B. Tatom
205-533-9391
AWARD AMOUNT: $199,998ABSTRACT:
The Phase 1 study results provide strong confirmation that tornadoes on the ground produce significant seismic signals which a properly designed Seismic Tornado Detector (STD) can detect. The proposed Phase 2 effort should result in an operational STD system design, with considerable potential application by government agencies for the protection of the general populace, as well as by the individual homeowner for personal safety. The technical approach involves: 1) applying the Phase 1 results to the Phase 2 effort; 2) using the experience of the University of Memphis Center for Earthquake Research and Information (CERI), the Soil dynamics Laboratory of Michigan and the National Severe Strom Laboratory (NSSL); 3) maintaining good communications between research team members; 4) modifying the existing short-Period STD instrument packages to include Long-Period capability; and 5) using (where possible) existing designs for key STD components. The specific technical objectives are: 1) continued collection and analysis of chance TSS measurements; 2) detailed design of STD instrument package; 3) development of STD instrument package software;4) STD instrument package fabrication and assembly; 5) testing of STD instrument package; 6) development of deployment plan; 7) deployment of STD instrument packages; 8) recovery of STD instrument packages; 9) data retrieval and analysis; 10) development of detection algorithm; 11) design of STD prototype; and 12) complete documentation.
COMMERCIAL APPLICATIONS:
Two applications of the research are envisioned, both dealing with the detection of tornadoes. First, from the standpoint of both state and federal government agencies involved in the detection of tornadoes, an STD network, when used in conjunction with Doppler radar, should provide an accurate, efficient method to determine when a tornado is actually on the ground. Second, in addition to the development of STD networks another STD version could be developed for warning the individual homeowner.
reasonwhy, you were fortunate not to attend the HEXDAM, VEXDAM, VASDIP, HEXFRAG TRAINING COURSE offered by Engineering Analysis Inc., because in the past they have been awarded contracts by the Great Satan, NIST.
Their software would have been bugged to give erroneous WTC blast analysis, and they would have informed the FBI of your attendance, and you would have been put on another enemy of the state watch list.
You're going to have rely on the brain trust within the Truth movement to model any demolition theories.
All of the mainstream engineering firms are in the pocket of the Bush administration and cannot be trusted.
Be careful, and good luck.
reasonwhy
Talk to the FBI or BATF. They are the ones who told FEMA and, indirectly, NIST that no explosives were found. Or talk to the professional siesmologists. They are the ones saying no trace of an explosive signal was found. Or talk to the guys at Implosion World, they are the experts on CD and they say you are full of misinformation(among other stuff).
Grumpy
QUOTE
Show me one residue test result from the FBI, BATF or anyone else . laugh.gif
Talk to the FBI or BATF. They are the ones who told FEMA and, indirectly, NIST that no explosives were found. Or talk to the professional siesmologists. They are the ones saying no trace of an explosive signal was found. Or talk to the guys at Implosion World, they are the experts on CD and they say you are full of misinformation(among other stuff).
Grumpy
QUOTE (reasonwhy+Feb 10 2007, 06:57 PM)
What conspiracy story? The official conspiracy or not sure how it happened?
You can't argue with the logic so you make a an attemp at dry CT humor. Heh!
The conspiracy story you and your CT nutbars continue to regurgitate. That conspiracy story.
You can't argue with the logic so you make a an attemp at dry CT humor. Heh!
The conspiracy story you and your CT nutbars continue to regurgitate. That conspiracy story.
Yeah Lozeng, this always seemed odd to me also. These connections:
see alans post
According to NIST, were strong enough to initiate the collapse by "pulling" in the robust exterior columns:
see alans post
Yet they are not a factor for many when calculating resistance (time) in the collapse.
RS
Sorry, still not able to post links or images.
see alans post
According to NIST, were strong enough to initiate the collapse by "pulling" in the robust exterior columns:
see alans post
Yet they are not a factor for many when calculating resistance (time) in the collapse.
RS
Sorry, still not able to post links or images.
QUOTE (roves shill+Feb 11 2007, 05:04 PM)
Yeah Lozeng, this always seemed odd to me also. These connections:
see alans post
According to NIST, were strong enough to initiate the collapse by "pulling" in the robust exterior columns:
see alans post
Yet they are not a factor for many when calculating resistance (time) in the collapse.
RS
Sorry, still not able to post links or images.
YOU might want to check on the design then , it is actually the bowing out of the outer perimeter Columns in conjunction with the falling accumulating mass that breaks the connections the bolts, on the trusses.
That plus the buckling beams putting stress on them. These are non redundant bolted beams you know with the bolts being the weakest link.
see alans post
According to NIST, were strong enough to initiate the collapse by "pulling" in the robust exterior columns:
see alans post
Yet they are not a factor for many when calculating resistance (time) in the collapse.
RS
Sorry, still not able to post links or images.
YOU might want to check on the design then , it is actually the bowing out of the outer perimeter Columns in conjunction with the falling accumulating mass that breaks the connections the bolts, on the trusses.
That plus the buckling beams putting stress on them. These are non redundant bolted beams you know with the bolts being the weakest link.
QUOTE (Alan (ex elevator man)+Feb 11 2007, 06:46 AM)
I just thought for Lozenge's sake, a repost of the floor connections were warranted... from Common Sense's web site.
debunking911.com/trussschem.jpg
And maybe this one too, from the same page...
debunking911.com/construction.jpg
I find it very telling that you did not post an image of the core.
Let me suggest some:
homepage.mac.com/dansound/.Public/Pix/SteelOnFire/WTC_Core_03s.jpg
www.lescarney.com/Pictures/wtc_9_63.jpg
911research.wtc7.net/wtc/arch/docs/mage6.jpg
As I still cannot post images/links, perhaps someone would be so kind as to quote this post and add the IMG tags?
thanks
debunking911.com/trussschem.jpg
And maybe this one too, from the same page...
debunking911.com/construction.jpg
I find it very telling that you did not post an image of the core.
Let me suggest some:
homepage.mac.com/dansound/.Public/Pix/SteelOnFire/WTC_Core_03s.jpg
www.lescarney.com/Pictures/wtc_9_63.jpg
911research.wtc7.net/wtc/arch/docs/mage6.jpg
As I still cannot post images/links, perhaps someone would be so kind as to quote this post and add the IMG tags?
thanks
QUOTE (lozenge124+Feb 11 2007, 06:05 PM)
I find it very telling that you did not post an image of the core.
Let me suggest some:
homepage.mac.com/dansound/.Public/Pix/SteelOnFire/WTC_Core_03s.jpg
www.lescarney.com/Pictures/wtc_9_63.jpg
911research.wtc7.net/wtc/arch/docs/mage6.jpg
As I still cannot post images/links, perhaps someone would be so kind as to quote this post and add the IMG tags?
thanks
http://www.lescarney.com/Pictures/wtc_9_63.jpg
http://homepage.mac.com/dansound/.Public/P...TC_Core_03s.jpg
http://911research.wtc7.net/wtc/arch/docs/mage6.jpg
I posted your pictures as links so that anyone who wanted to can see them.
Since we have all seen them I do not quite know what the point of posting them was, but I did it anyway.
For the sake of honesty.
Let me suggest some:
homepage.mac.com/dansound/.Public/Pix/SteelOnFire/WTC_Core_03s.jpg
www.lescarney.com/Pictures/wtc_9_63.jpg
911research.wtc7.net/wtc/arch/docs/mage6.jpg
As I still cannot post images/links, perhaps someone would be so kind as to quote this post and add the IMG tags?
thanks
http://www.lescarney.com/Pictures/wtc_9_63.jpg
http://homepage.mac.com/dansound/.Public/P...TC_Core_03s.jpg
http://911research.wtc7.net/wtc/arch/docs/mage6.jpg
I posted your pictures as links so that anyone who wanted to can see them.
Since we have all seen them I do not quite know what the point of posting them was, but I did it anyway.
For the sake of honesty.
reasonwhy --- See photos of B-1011 in NIST's steel inventory. The main portion is stored in Hanger 17 and photos of it are plenty on the web. It is bent into a U shape.
roves shill --- The truss seats were about 2.2 times stronger in the horizontal direction than in the vertical. The pull-in force that NIST used was about 5 kip, vastly less than the 100+ kip required to rip apart the truss seat in the horizontal direction. In any case, every sensible model of the progressive collapse of the towers includes, one way or another, the trussed floors.
Everybody --- In the case of WTC 1, NIST's final FEA is timed at 2 minutes before collapse initiation. Looking into NCSTAR1-6D will graphically illustrate the extensive damage to, for example, the core at this time. Hence NIST concludes that "global collapse ensued".
roves shill --- The truss seats were about 2.2 times stronger in the horizontal direction than in the vertical. The pull-in force that NIST used was about 5 kip, vastly less than the 100+ kip required to rip apart the truss seat in the horizontal direction. In any case, every sensible model of the progressive collapse of the towers includes, one way or another, the trussed floors.
Everybody --- In the case of WTC 1, NIST's final FEA is timed at 2 minutes before collapse initiation. Looking into NCSTAR1-6D will graphically illustrate the extensive damage to, for example, the core at this time. Hence NIST concludes that "global collapse ensued".
QUOTE (lozenge124+Feb 11 2007, 10:05 AM)
I find it very telling that you did not post an image of the core.
Let me suggest some:
homepage.mac.com/dansound/.Public/Pix/SteelOnFire/WTC_Core_03s.jpg
www.lescarney.com/Pictures/wtc_9_63.jpg
911research.wtc7.net/wtc/arch/docs/mage6.jpg
As I still cannot post images/links, perhaps someone would be so kind as to quote this post and add the IMG tags?
thanks
No problem.
Let me suggest some:
homepage.mac.com/dansound/.Public/Pix/SteelOnFire/WTC_Core_03s.jpg
www.lescarney.com/Pictures/wtc_9_63.jpg
911research.wtc7.net/wtc/arch/docs/mage6.jpg
As I still cannot post images/links, perhaps someone would be so kind as to quote this post and add the IMG tags?
thanks
No problem.
Lozenge124,
What does it say when you try to post links or images? I get an error message myself, but I think it's my own browser settings. Right below the address bar, I can click on "temorparily allow..." , or however it's worded... and the link and image tags work then.
Also, I hope you realize alot of what you're seeing on those 3 pictures is the cranes' own towers that are temporary and come down after the building is topped out.
What does it say when you try to post links or images? I get an error message myself, but I think it's my own browser settings. Right below the address bar, I can click on "temorparily allow..." , or however it's worded... and the link and image tags work then.
Also, I hope you realize alot of what you're seeing on those 3 pictures is the cranes' own towers that are temporary and come down after the building is topped out.
QUOTE (David B. Benson+Feb 11 2007, 10:33 AM)
reasonwhy --- See photos of B-1011 in NIST's steel inventory. The main portion is stored in Hanger 17 and photos of it are plenty on the web. It is bent into a U shape.
Sorry DBB, bent into a U-shape does not equal broke into two pieces!
If the core was bypassed as Shagster suggests, I would doubt the floors would even pancake as one unit.
http://i111.photobucket.com/albums/n122/xzvgpz/wtc_9_63.jpg
Even if it were possible to pancake on one side the other would act independently with the core standing.
On the edge of the short truss side (33 feet) there are double truses or beams.
Sorry DBB, bent into a U-shape does not equal broke into two pieces!
If the core was bypassed as Shagster suggests, I would doubt the floors would even pancake as one unit.
http://i111.photobucket.com/albums/n122/xzvgpz/wtc_9_63.jpg
Even if it were possible to pancake on one side the other would act independently with the core standing.
On the edge of the short truss side (33 feet) there are double truses or beams.
That third picture must be trouble. I see it didn't link right for Chainsaw, then for Reason, it just repeated the first picture. When I tried to post pictures of all three(with links), it told me the images were a problem. I supposed I could've posted just the links, but when I hit "back" on the browser to erase the image tags, I lost the whole post. Oh well...
That third picture wasn't as good as the middle one anyway, and it had a weird blue tint to it.
That third picture wasn't as good as the middle one anyway, and it had a weird blue tint to it.
QUOTE (shagster+Feb 11 2007, 05:45 AM)
Hoffman's model is similar to mine. He's removing mass from the front just after impact. I've been using a constant mass per story for the tower which gives a slightly shorter duration compared with an increasing mass toward the ground. However, I'm also considering the slowing effect of E1 which Hoffman's model doesn't include, which increases the duration. I'm getting comparable values for the duration.
The towers were top heavy in the upper levels which means that a large amount of mass in the upper block was striking floors of relatively low mass. A decreasing mass all the way to the tower top isn't a proper way to model the mass distribution, even though in general the mass increased toward the ground level. What DBB has done is a good approach for the first few seconds of collapse.
911-research uses the phase 'just 6%', but 6% the mass of the upper block shed per impact is large amount and doesn't agree with the amount of debris observed in the pit. It needs to be much less than that, on the order of 2% or less. Even with an unreasonable amount of shedding such as 6%, the stage 1 duration is still in the neighborhood of 13 to 16 s, close to what was observed. The duration is relatively insensitive to shedding.
The front of WTC2 was seen in videos at or above the top of WTC3 at the 12 second mark which was about 100m above ground. WTC2 wasn't near freefall rate (WTC1 wasn't either). I've run a shedding model that takes into account losing part of the upper block, 0.32 of a story mass per impact, and an E1 of 0.8 GJ that increases to 3.2 GJ at the ground level. The model predicts a stage 1 duration of 14.7 seconds and predicts the position of the front at about 100 m above ground at the 12 second mark, which agrees with what was seen in the video.
One has to be careful with shedding models, as the upper block can be consumed if the shedding is more than one story mass per impact, such as the case for WTC2 and 6% the mass of the upper block shedding per impact. The upper block may be gone or partly consumed by the end of stage 1 which can effect stage 2 and the overall duration. It depends on the amount of shedding and how much the mass of the tower is increasing toward the ground level.
Shagster,
If you are interested in seeing Hoffman discussing his model, there is an excellent lecture he gave as part of the "Lifting the Fog" conference available here:
www.archive.org/details/liftingthefog_2006_11_11_session3
He starts discussing his model at about the 56-57 minute mark.
But again, as you will see if you watch it, the model is only intended to obtain a lower bound for the time of collapse. I agree with your point about the top of the tower having some extra weight, I don't think Hoffman modelled this.
The towers were top heavy in the upper levels which means that a large amount of mass in the upper block was striking floors of relatively low mass. A decreasing mass all the way to the tower top isn't a proper way to model the mass distribution, even though in general the mass increased toward the ground level. What DBB has done is a good approach for the first few seconds of collapse.
911-research uses the phase 'just 6%', but 6% the mass of the upper block shed per impact is large amount and doesn't agree with the amount of debris observed in the pit. It needs to be much less than that, on the order of 2% or less. Even with an unreasonable amount of shedding such as 6%, the stage 1 duration is still in the neighborhood of 13 to 16 s, close to what was observed. The duration is relatively insensitive to shedding.
The front of WTC2 was seen in videos at or above the top of WTC3 at the 12 second mark which was about 100m above ground. WTC2 wasn't near freefall rate (WTC1 wasn't either). I've run a shedding model that takes into account losing part of the upper block, 0.32 of a story mass per impact, and an E1 of 0.8 GJ that increases to 3.2 GJ at the ground level. The model predicts a stage 1 duration of 14.7 seconds and predicts the position of the front at about 100 m above ground at the 12 second mark, which agrees with what was seen in the video.
One has to be careful with shedding models, as the upper block can be consumed if the shedding is more than one story mass per impact, such as the case for WTC2 and 6% the mass of the upper block shedding per impact. The upper block may be gone or partly consumed by the end of stage 1 which can effect stage 2 and the overall duration. It depends on the amount of shedding and how much the mass of the tower is increasing toward the ground level.
Shagster,
If you are interested in seeing Hoffman discussing his model, there is an excellent lecture he gave as part of the "Lifting the Fog" conference available here:
www.archive.org/details/liftingthefog_2006_11_11_session3
He starts discussing his model at about the 56-57 minute mark.
But again, as you will see if you watch it, the model is only intended to obtain a lower bound for the time of collapse. I agree with your point about the top of the tower having some extra weight, I don't think Hoffman modelled this.
QUOTE (Capracus+Feb 11 2007, 04:36 AM)
From the NIST Small Business Innovation Research Awards for FY1997 (SBIR).
reasonwhy, you were fortunate not to attend the HEXDAM, VEXDAM, VASDIP, HEXFRAG TRAINING COURSE offered by Engineering Analysis Inc., because in the past they have been awarded contracts by the Great Satan, NIST.
Their software would have been bugged to give erroneous WTC blast analysis, and they would have informed the FBI of your attendance, and you would have been put on another enemy of the state watch list.
You're going to have rely on the brain trust within the Truth movement to model any demolition theories.
All of the mainstream engineering firms are in the pocket of the Bush administration and cannot be trusted.
Be careful, and good luck.
How many watch lists do you clowns have?
Does that mean I would be on the Double Triple threat to expose the states lies, watch list?
reasonwhy, you were fortunate not to attend the HEXDAM, VEXDAM, VASDIP, HEXFRAG TRAINING COURSE offered by Engineering Analysis Inc., because in the past they have been awarded contracts by the Great Satan, NIST.
Their software would have been bugged to give erroneous WTC blast analysis, and they would have informed the FBI of your attendance, and you would have been put on another enemy of the state watch list.
You're going to have rely on the brain trust within the Truth movement to model any demolition theories.
All of the mainstream engineering firms are in the pocket of the Bush administration and cannot be trusted.
Be careful, and good luck.
How many watch lists do you clowns have?
Does that mean I would be on the Double Triple threat to expose the states lies, watch list?
QUOTE (reasonwhy+Feb 11 2007, 06:43 PM)
... bent into a U-shape does not equal broke into two pieces!
If the core was bypassed as Shagster suggests, I would doubt the floors would even pancake as one unit.
Not the column members, but the tower core is thusly broken into two pieces at the buckled members. Gosh, as the quote goes, its good to be open minded, but not so much so that your brains fall out.
Trussed floors are not required to bagel as one unit. But ripping apart the connections between segments of the trussed floor might have required more energy. The seems to have happened before the trusses came to rest at Ground Zero.
If the core was bypassed as Shagster suggests, I would doubt the floors would even pancake as one unit.
Not the column members, but the tower core is thusly broken into two pieces at the buckled members. Gosh, as the quote goes, its good to be open minded, but not so much so that your brains fall out.
Trussed floors are not required to bagel as one unit. But ripping apart the connections between segments of the trussed floor might have required more energy. The seems to have happened before the trusses came to rest at Ground Zero.
QUOTE (reasonwhy+Feb 11 2007, 06:43 PM)
Sorry DBB, bent into a U-shape does not equal broke into two pieces!
If the core was bypassed as Shagster suggests, I would doubt the floors would even pancake as one unit.
http://i111.photobucket.com/albums/n122/xzvgpz/wtc_9_63.jpg
Even if it were possible to pancake on one side the other would act independently with the core standing.
On the edge of the short truss side (33 feet) there are double truses or beams.
Then you agree the mass acumulated on the way down because of the funnel effect, as that is what everyone here has been saying, and that is what you are describing!
If the core was bypassed as Shagster suggests, I would doubt the floors would even pancake as one unit.
http://i111.photobucket.com/albums/n122/xzvgpz/wtc_9_63.jpg
Even if it were possible to pancake on one side the other would act independently with the core standing.
On the edge of the short truss side (33 feet) there are double truses or beams.
Then you agree the mass acumulated on the way down because of the funnel effect, as that is what everyone here has been saying, and that is what you are describing!
@reasonwhy:
thanks!
@Alan:
I think you should be OK with posting links and images as you have more than 50 posts. I get this error:
I believe this is because of my one square "Newbie" rating.
thanks!
@Alan:
I think you should be OK with posting links and images as you have more than 50 posts. I get this error:
QUOTE
Sorry, your post contains link(s), which are not allowed. New members are not allowed to make a post here linking elsewhere. Please remove all links from you post.
I believe this is because of my one square "Newbie" rating.
QUOTE (lozenge124+Feb 11 2007, 01:06 PM)
@Alan:
I think you should be OK with posting links and images as you have more than 50 posts. I get this error:
I believe this is because of my one square "Newbie" rating.
hmmm! *scratches chin*
Maybe that's a new rule, cause I don't think it took me 50. Either way, you're getting up there close to that number.
I think you should be OK with posting links and images as you have more than 50 posts. I get this error:
I believe this is because of my one square "Newbie" rating.
hmmm! *scratches chin*
Maybe that's a new rule, cause I don't think it took me 50. Either way, you're getting up there close to that number.
QUOTE (Alan (ex elevator man)+Feb 11 2007, 06:38 PM)
Lozenge124,
Also, I hope you realize alot of what you're seeing on those 3 pictures is the cranes' own towers that are temporary and come down after the building is topped out.
Do you really believe once the construction was done, they dismantled those structures the cranes are on all the way down to the bottom? I can't prove otherwise, but common sense would seem to indicate that they were left in as a part of the core.
In any case, even without them, you still have this massive core made off 44-47 steel core columns cross braced together. It is very hard to even imagine how it could come apart entirely as a result of potential energy hitting from above, or some kind of lateral pull by the floors - let alone how this could happen floor by floor at the speeds observed.
Also, I hope you realize alot of what you're seeing on those 3 pictures is the cranes' own towers that are temporary and come down after the building is topped out.
Do you really believe once the construction was done, they dismantled those structures the cranes are on all the way down to the bottom? I can't prove otherwise, but common sense would seem to indicate that they were left in as a part of the core.
In any case, even without them, you still have this massive core made off 44-47 steel core columns cross braced together. It is very hard to even imagine how it could come apart entirely as a result of potential energy hitting from above, or some kind of lateral pull by the floors - let alone how this could happen floor by floor at the speeds observed.
QUOTE (Chainsaw+,Feb 11 2007, 11:04 AM)
Then you agree the mass acumulated on the way down because of the funnel effect, as that is what everyone here has been saying, and that is what you are describing!
Only the Pseudoscience pancake theory promoters agree that is how the towers collapsed.
I am sure DBB, Greening and Shagster can come up with a mathematical perpetual motion machine!
NIST does not even claim that is how it happened.
You need to take a class in how to design funnels, it is not supposed to be the same shape top and bottom.
OCT promoters are certainly not everyone.
I am sure the SHILL budget is getting bigger as more people question the OCT!
Only the Pseudoscience pancake theory promoters agree that is how the towers collapsed.
I am sure DBB, Greening and Shagster can come up with a mathematical perpetual motion machine!
NIST does not even claim that is how it happened.
You need to take a class in how to design funnels, it is not supposed to be the same shape top and bottom.
OCT promoters are certainly not everyone.
I am sure the SHILL budget is getting bigger as more people question the OCT!
QUOTE (lozenge124+Feb 11 2007, 07:22 PM)
Do you really believe once the construction was done, they dismantled those structures the cranes are on all the way down to the bottom? I can't prove otherwise, but common sense would seem to indicate that they were left in as a part of the core.
In any case, even without them, you still have this massive core made off 44-47 steel core columns cross braced together. It is very hard to even imagine how it could come apart entirely as a result of potential energy hitting from above, or some kind of lateral pull by the floors - let alone how this could happen floor by floor at the speeds observed.
No, those cranes would have been in the way. Read "Men of Steel" for a good, but not completely correct, account of the construction of the towers.
There were 47 columns in the core, before aircraft impact damage. However, other than on the mechanical floors and the bottom 11 or so floors, there was no cross bracing.
And we have just been through discovering that vibrations could have fractured the welds and also eccentric sudden loads of short duration could have done the same.
The core was designed to stand up and flex every so slightly in the wind. That is all.
Finally, potential energy is the energy of position. Kinetic energy is the energy of motion.
In any case, even without them, you still have this massive core made off 44-47 steel core columns cross braced together. It is very hard to even imagine how it could come apart entirely as a result of potential energy hitting from above, or some kind of lateral pull by the floors - let alone how this could happen floor by floor at the speeds observed.
No, those cranes would have been in the way. Read "Men of Steel" for a good, but not completely correct, account of the construction of the towers.
There were 47 columns in the core, before aircraft impact damage. However, other than on the mechanical floors and the bottom 11 or so floors, there was no cross bracing.
And we have just been through discovering that vibrations could have fractured the welds and also eccentric sudden loads of short duration could have done the same.
The core was designed to stand up and flex every so slightly in the wind. That is all.
Finally, potential energy is the energy of position. Kinetic energy is the energy of motion.
QUOTE (David B. Benson+Feb 11 2007, 11:35 AM)
And we have just been through discovering that vibrations could have fractured the welds and also eccentric sudden loads of short duration could have done the same.
We have also been told beam weapons from space caused the towers to collapse, does that make it true?
Your mythical lateral forces do not exist because the columns are pinned at the top and bottom.
QUOTE (lozenge124+Feb 11 2007, 01:22 PM)
Do you really believe once the construction was done, they dismantled those structures the cranes are on all the way down to the bottom? I can't prove otherwise, but common sense would seem to indicate that they were left in as a part of the core.
Well, first off... the towers the cranes are on don't go "all the way down to the bottom". I can't say exactly how tall they are, but I'm guessing a 100 ft or so. They jack theirself up when the construction catches up with their height. They will then 'climb' up another full length and start building again in a repeated process until they reach the top, then they take 'em down. That's one of the most interesting times on a construction job... to see how they get the huge cranes down from the top. They lower theirself, actually.
Well, first off... the towers the cranes are on don't go "all the way down to the bottom". I can't say exactly how tall they are, but I'm guessing a 100 ft or so. They jack theirself up when the construction catches up with their height. They will then 'climb' up another full length and start building again in a repeated process until they reach the top, then they take 'em down. That's one of the most interesting times on a construction job... to see how they get the huge cranes down from the top. They lower theirself, actually.
reasonwhy --- Columns pinned at top and bottom undergo buckling at sufficiently high loads. So I could go through the same exercise again for model A. But I won't bother because the general sense of Ground Zero and NIST steel collection photos is that most columns failed at the connections. Few appear to have actually buckled.
But I keep telling you it was GR with the G-ray in the basement. But nobody seems to believe me...
But I keep telling you it was GR with the G-ray in the basement.
But nobody seems to believe me...
QUOTE (Alan (ex elevator man)+Feb 11 2007, 07:47 PM)
Well, first off... the towers the cranes are on don't go "all the way down to the bottom". I can't say exactly how tall they are, but I'm guessing a 100 ft or so. They jack theirself up when the construction catches up with their height. They will then 'climb' up another full length and start building again in a repeated process until they reach the top, then they take 'em down. That's one of the most interesting times on a construction job... to see how they get the huge cranes down from the top. They lower theirself, actually.
OK, fair enough.
OK, fair enough.
i asked a tower crane operator about the "pulling itself up by the bootstraps". he said that they ALWAYS pour CONCRETE underneath to fill the space(and add structural support for both the crane and the building). i re-emphasized the question, "ALWAYS!?"
he said, 'YES'.
so, it would seem to be rare indeed for there to be zero (vertical walls of) concrete in the core.
and yes, i know the propoganda line about drywall being used for walls in the core, but the official propadanda has NO PROBLEM lying their arses off.
(*cough, ...asbestos....., *cough*, ....safe, *cough* *keel*)
he said, 'YES'.
so, it would seem to be rare indeed for there to be zero (vertical walls of) concrete in the core.
and yes, i know the propoganda line about drywall being used for walls in the core, but the official propadanda has NO PROBLEM lying their arses off.
(*cough, ...asbestos....., *cough*, ....safe, *cough* *keel*)
QUOTE (lozenge124+Feb 11 2007, 07:22 PM)
Do you really believe once the construction was done, they dismantled those structures the cranes are on all the way down to the bottom? I can't prove otherwise, but common sense would seem to indicate that they were left in as a part of the core.
In any case, even without them, you still have this massive core made off 44-47 steel core columns cross braced together. It is very hard to even imagine how it could come apart entirely as a result of potential energy hitting from above, or some kind of lateral pull by the floors - let alone how this could happen floor by floor at the speeds observed.
If you check the design drawings you will see that I believe an elevator shaft goes though where one of the crane towers is in the photo.
The cranes structures were not needed to support the buildings and they were removed to gain added space inside for mechanical, and people.
You build a building for the area of open space that it contains not for the structure.
In any case, even without them, you still have this massive core made off 44-47 steel core columns cross braced together. It is very hard to even imagine how it could come apart entirely as a result of potential energy hitting from above, or some kind of lateral pull by the floors - let alone how this could happen floor by floor at the speeds observed.
If you check the design drawings you will see that I believe an elevator shaft goes though where one of the crane towers is in the photo.
The cranes structures were not needed to support the buildings and they were removed to gain added space inside for mechanical, and people.
You build a building for the area of open space that it contains not for the structure.
QUOTE (newton+Feb 11 2007, 09:11 PM)
i asked a tower crane operator about the "pulling itself up by the bootstraps". he said that they ALWAYS pour CONCRETE underneath to fill the space(and add structural support for both the crane and the building). i re-emphasized the question, "ALWAYS!?"
he said, 'YES'.
so, it would seem to be rare indeed for there to be zero (vertical walls of) concrete in the core.
and yes, i know the propoganda line about drywall being used for walls in the core, but the official propadanda has NO PROBLEM lying their arses off.
(*cough, ...asbestos....., *cough*, ....safe, *cough* *keel*)
IN normal building construction that is true, there is always a concrete floor under the cranes to stabilize them, but not in tube frame construction, there is good photo and video evidence of another tube frame going up on an Asian site that actually shows the kangaroo cranes jacking themselves up and then the steel cross beams going in under to spread the loading.
The technique was designed specifically for tube frame design.
Also remember the concrete floor goes in after the crane is jacked to the next level, because the cranes actually lift the concrete up.
I think I am looking for the promotional film of the towers with the walk way in between them. I can not remember there name.
he said, 'YES'.
so, it would seem to be rare indeed for there to be zero (vertical walls of) concrete in the core.
and yes, i know the propoganda line about drywall being used for walls in the core, but the official propadanda has NO PROBLEM lying their arses off.
(*cough, ...asbestos....., *cough*, ....safe, *cough* *keel*)
IN normal building construction that is true, there is always a concrete floor under the cranes to stabilize them, but not in tube frame construction, there is good photo and video evidence of another tube frame going up on an Asian site that actually shows the kangaroo cranes jacking themselves up and then the steel cross beams going in under to spread the loading.
The technique was designed specifically for tube frame design.
Also remember the concrete floor goes in after the crane is jacked to the next level, because the cranes actually lift the concrete up.
I think I am looking for the promotional film of the towers with the walk way in between them. I can not remember there name.
QUOTE (newton+Feb 11 2007, 03:11 PM)
i asked a tower crane operator about the "pulling itself up by the bootstraps". he said that they ALWAYS pour CONCRETE underneath to fill the space(and add structural support for both the crane and the building).
If he's saying they don't go but a few floors of steel structure before decking it and pouring concrete floors, then yes. If you mean some kind of concrete support for the crane itself... then you better ask your friend again.
It's usually like Chainsaw said... they lower the cranes' towers in sections right back down through the 'tunnel' they made going up.
If he's saying they don't go but a few floors of steel structure before decking it and pouring concrete floors, then yes. If you mean some kind of concrete support for the crane itself... then you better ask your friend again.
It's usually like Chainsaw said... they lower the cranes' towers in sections right back down through the 'tunnel' they made going up.
newton
A tower crane and a kangaroo crane are two very different things. As others have explained, the kangaroo crane climbs the steel as assembly advances. A tower crane is a tall tower outside of the building it is constructing.
A tower crane and a kangaroo crane are two very different things. As others have explained, the kangaroo crane climbs the steel as assembly advances. A tower crane is a tall tower outside of the building it is constructing.
and yes, i know the propoganda line about drywall being used for walls in the core, but the official propadanda has NO PROBLEM lying their arses off
It is not propoganda, it is fact. Drywall was the only fireproofing in the core and the only thing seperating the various elevator shafts. And you have yet to provide evidence for any of your lies.
Grumpy
QUOTE
i asked a tower crane operator about the "pulling itself up by the bootstraps". he said that they ALWAYS pour CONCRETE underneath to fill the space(and add structural support for both the crane and the building).
A tower crane and a kangaroo crane are two very different things. As others have explained, the kangaroo crane climbs the steel as assembly advances. A tower crane is a tall tower outside of the building it is constructing.
QUOTE (->
| QUOTE |
| i asked a tower crane operator about the "pulling itself up by the bootstraps". he said that they ALWAYS pour CONCRETE underneath to fill the space(and add structural support for both the crane and the building). |
A tower crane and a kangaroo crane are two very different things. As others have explained, the kangaroo crane climbs the steel as assembly advances. A tower crane is a tall tower outside of the building it is constructing.
and yes, i know the propoganda line about drywall being used for walls in the core, but the official propadanda has NO PROBLEM lying their arses off
It is not propoganda, it is fact. Drywall was the only fireproofing in the core and the only thing seperating the various elevator shafts. And you have yet to provide evidence for any of your lies.
Grumpy
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