23-05-2011, 10:25 AM
Of course I am aware that the steel was sold for salvage. Some of it was held here and examined. It's true we only have the images of the fallen debris to work with and a few saved samples... some of which I am about to examine personally.
However, in the images there is no sign of explosive damage to the columns as far as I can tell and aside from the infamous diagonal cut column... which turned out to be from the clean up... as it was a remaining floor one column which was braced by the rubble and was cut for removal... to conclude that the columns were exploded is rather a stretch from what we DO have in the visual record.
However, there is some evidence of enormous load redistribution onto some very distorted columns such as "the horse shoe" column which we can interpret as one the the few columns remaining as others were "taken out" at that level and it was apparently bent like a pretzel when it carried loads of perhaps 40 or more times its yield strength. While it shows no signs of unnatural tampering... only unexpected loading... it seems to suggest that the columns near by might have likely been "taken out" intentionally and no naturally. However, the load redistribution did not have to take out all the other 46 columns leaving this one to bend like a pretzel. The load redistribution could have progressed through the array of columns as their safety factor was exceeded.
The FOS study reveals that with an FOS of 1.54 a column will fail if it is carries more than 1.54 of its design load. A column designed for 1,000 tons can safely support 1,540 tons. So if you had 47 columns carrying their design loads (let's make it equal for the example)... and each carried 1,000 tons and 18 columns were destroyed... the remain 29 would see an additional 18,000 tons distributed amongst them adding 620 tons to each column increasing its load to 1,620 tons. This load is now over the yield strength including the safety factor. Those 29 columns would then begin to buckle and fail. So you can see how destroying slightly more than 1/3 of the columns in the example led to failure of all the columns.
In the twin towers this situation was perhaps even worse since not all the columns were designed to carry the same loads. The 24 perimeter core columns did the vast majority of the "heavy lifting" with the central ones carrying much less as there were few floor loads in the center of the core. And the 4 corners in the core carried the most loads in the towers on any given floor (except the tree columns on floors 1-6). With all columns not being equal attacking even fewer of the "big guys" would lead to a rapid over lading condition and stress redistribution to the smaller columns and so you could take out as few as 12 perimeter core columns and see a load redistribution which exceed the yield strength of the remaining 35 columns! This would then rapidly progress through them leading to buckling and loss of support for the entire mass they carried.
However, in the images there is no sign of explosive damage to the columns as far as I can tell and aside from the infamous diagonal cut column... which turned out to be from the clean up... as it was a remaining floor one column which was braced by the rubble and was cut for removal... to conclude that the columns were exploded is rather a stretch from what we DO have in the visual record.
However, there is some evidence of enormous load redistribution onto some very distorted columns such as "the horse shoe" column which we can interpret as one the the few columns remaining as others were "taken out" at that level and it was apparently bent like a pretzel when it carried loads of perhaps 40 or more times its yield strength. While it shows no signs of unnatural tampering... only unexpected loading... it seems to suggest that the columns near by might have likely been "taken out" intentionally and no naturally. However, the load redistribution did not have to take out all the other 46 columns leaving this one to bend like a pretzel. The load redistribution could have progressed through the array of columns as their safety factor was exceeded.
The FOS study reveals that with an FOS of 1.54 a column will fail if it is carries more than 1.54 of its design load. A column designed for 1,000 tons can safely support 1,540 tons. So if you had 47 columns carrying their design loads (let's make it equal for the example)... and each carried 1,000 tons and 18 columns were destroyed... the remain 29 would see an additional 18,000 tons distributed amongst them adding 620 tons to each column increasing its load to 1,620 tons. This load is now over the yield strength including the safety factor. Those 29 columns would then begin to buckle and fail. So you can see how destroying slightly more than 1/3 of the columns in the example led to failure of all the columns.
In the twin towers this situation was perhaps even worse since not all the columns were designed to carry the same loads. The 24 perimeter core columns did the vast majority of the "heavy lifting" with the central ones carrying much less as there were few floor loads in the center of the core. And the 4 corners in the core carried the most loads in the towers on any given floor (except the tree columns on floors 1-6). With all columns not being equal attacking even fewer of the "big guys" would lead to a rapid over lading condition and stress redistribution to the smaller columns and so you could take out as few as 12 perimeter core columns and see a load redistribution which exceed the yield strength of the remaining 35 columns! This would then rapidly progress through them leading to buckling and loss of support for the entire mass they carried.