TruthSeeker1234
Banned
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- Sep 9, 2006
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Estimated time frame of collapses
Time Collapse Situation 1:29 East face of the 21st floor collapsed 1:37 South middle section of several floors above the 21st floor gradually collapsed 1:50 Parts of floor slab with curtain walls collapsed 2:02 Parts of floor slab with curtain walls collapsed 2:11 Parts of floor slab with curtain walls collapsed 2:13 Floors above about 25th floor collapsed Large collapse of middle section at about 20th floor 2:17 Parts of floor slab with curtain walls collapsed 2:47 Southwest corner of 1 ~ 2 floors below about 20th floor collapsed 2:51 Southeast corner of about 18th ~ 20th floors collapsed 3:35 South middle section of about 17th ~ 20th floors collapsed Fire broke through the Upper Technical Floor 3:48 Fire flame spurted out below the Upper Technical Floor 4:17 Debris on the Upper Technical Floor fell down
The observation that the Windsor Building is the only skyscraper to have suffered even a partial collapse as a result of fire suggests that the use of steel-reinforced-concrete framing was responsible. A closer look at the incident shows reality to be more complex. The portion of the building that collapsed consisted of the outer portions of floor slabs and perimeter walls throughout the upper third of the building (the 21st through 32nd floors). The outer walls consisted of steel box columns arranged on 1.8 meter centers and connected by narrow spandrel plates. The columns had square cross-sections 120mm on a side, and were fabricated of C-sections 7mm thick welded together. (these were a fraction of the dimensions, and spaced about twice as far apart as the perimeter columns of the Twin Towers.) The perimeter columns lacked fireproofing throughout the upper third of the Windsor building. [SIZE=-1] 4 [/SIZE]
The Windsor Building fire engulfed the upper third of the building, but also spread downward as low as the fourth floor. A report by two fire safety experts in Japan highlighted three causes for the very wide extent of the fire:
Time Collapse Situation 1:29 East face of the 21st floor collapsed 1:37 South middle section of several floors above the 21st floor gradually collapsed 1:50 Parts of floor slab with curtain walls collapsed 2:02 Parts of floor slab with curtain walls collapsed 2:11 Parts of floor slab with curtain walls collapsed 2:13 Floors above about 25th floor collapsed Large collapse of middle section at about 20th floor 2:17 Parts of floor slab with curtain walls collapsed 2:47 Southwest corner of 1 ~ 2 floors below about 20th floor collapsed 2:51 Southeast corner of about 18th ~ 20th floors collapsed 3:35 South middle section of about 17th ~ 20th floors collapsed Fire broke through the Upper Technical Floor 3:48 Fire flame spurted out below the Upper Technical Floor 4:17 Debris on the Upper Technical Floor fell down
The observation that the Windsor Building is the only skyscraper to have suffered even a partial collapse as a result of fire suggests that the use of steel-reinforced-concrete framing was responsible. A closer look at the incident shows reality to be more complex. The portion of the building that collapsed consisted of the outer portions of floor slabs and perimeter walls throughout the upper third of the building (the 21st through 32nd floors). The outer walls consisted of steel box columns arranged on 1.8 meter centers and connected by narrow spandrel plates. The columns had square cross-sections 120mm on a side, and were fabricated of C-sections 7mm thick welded together. (these were a fraction of the dimensions, and spaced about twice as far apart as the perimeter columns of the Twin Towers.) The perimeter columns lacked fireproofing throughout the upper third of the Windsor building. [SIZE=-1] 4 [/SIZE]
The Windsor Building fire engulfed the upper third of the building, but also spread downward as low as the fourth floor. A report by two fire safety experts in Japan highlighted three causes for the very wide extent of the fire:
- The lack of a sprinkler system
- Incorrect installation of spandrels
- The lack of fire prevention regulations in Spain