JК
11 сентября 2001 :: Мейссан Тьерри
Страница: 262 из 286The fires heated the structural systems and, over a period of time, resulted in additional stressing of the damaged structure, as well as sufficient additional damage and strength loss to initiate the third event, a progressive sequence of failures that culminated in total collapse of bothstructures. Of course, this does not even begin to explain the total collapse of WTC Seven.
2.2.1 WTC 1
2.2.1.1 Initial Damage From Aircraft Impact
American Airlines Flight 11 struck the north face of WTC 1 approximately between the 94th and 98th floors (Figures 2-13 and 2-14), causing massive damage to the north face of the building within the immediate area (Figure 2-15).
Figure 2-13 Zone of aircraft impact on the north face of WTC 1.
At the central zone of impact corresponding to the airplane fuselage and engines, at least five of the prefabricated, three-column sections that formed the exterior walls were broken loose of the structure, and some were pushed inside the building envelope.
Figure 2-15 Impact damage to the north face of WTC 1.
Locally, floors supported by these exterior wall sections appear to have partially collapsed, losing their support along the exterior wall. Away from this central zone, in areas impacted by the outer wing structures, the exterior columns were fractured by the force of the collision. Interpretation of photographic evidence suggests that from 31 to 36 columns on the north building face were destroyed over portions of a four-story range. Partial collapse of floors in this zone appear to have occurred over a horizontal length of wall of approximately 65 feet, while floors in other portions of the building appear to have remained intact. Figure 2-16 shows the damage to the exterior columns on the impacted face of WTC 1.
General notes:
(1) column damage captured from photographs and enchanced video,
(2) Damage to column lines 111-115 at level 96 is estimated.
Figure 2-16 Impact damage to exterior columns on the north face of WTC 1.
In addition to this damage at the building perimeter, a significant but undefined amount of damage also occurred to framing at the central core. For an estimate of the likely damage to the central core (by the University of California, Berkeley professor, Astaneh-Asl) see the article Microsoft Software Used To Simulate The Crash Of A Boeing 747 Into The World Trade Centre. This article claims that the damage caused by the much, much larger and heavier Boeing 747, in a collision with the World Trade Center, would be insufficient to bring the central core down. Interviews were conducted with persons who were present in offices on the 91st floor of the building at the north face of the structure, three floors below the approximate zone of impact.
2.2.1 WTC 1
2.2.1.1 Initial Damage From Aircraft Impact
American Airlines Flight 11 struck the north face of WTC 1 approximately between the 94th and 98th floors (Figures 2-13 and 2-14), causing massive damage to the north face of the building within the immediate area (Figure 2-15).
Figure 2-13 Zone of aircraft impact on the north face of WTC 1.
At the central zone of impact corresponding to the airplane fuselage and engines, at least five of the prefabricated, three-column sections that formed the exterior walls were broken loose of the structure, and some were pushed inside the building envelope.
Figure 2-15 Impact damage to the north face of WTC 1.
Locally, floors supported by these exterior wall sections appear to have partially collapsed, losing their support along the exterior wall. Away from this central zone, in areas impacted by the outer wing structures, the exterior columns were fractured by the force of the collision. Interpretation of photographic evidence suggests that from 31 to 36 columns on the north building face were destroyed over portions of a four-story range. Partial collapse of floors in this zone appear to have occurred over a horizontal length of wall of approximately 65 feet, while floors in other portions of the building appear to have remained intact. Figure 2-16 shows the damage to the exterior columns on the impacted face of WTC 1.
General notes:
(1) column damage captured from photographs and enchanced video,
(2) Damage to column lines 111-115 at level 96 is estimated.
Figure 2-16 Impact damage to exterior columns on the north face of WTC 1.
In addition to this damage at the building perimeter, a significant but undefined amount of damage also occurred to framing at the central core. For an estimate of the likely damage to the central core (by the University of California, Berkeley professor, Astaneh-Asl) see the article Microsoft Software Used To Simulate The Crash Of A Boeing 747 Into The World Trade Centre. This article claims that the damage caused by the much, much larger and heavier Boeing 747, in a collision with the World Trade Center, would be insufficient to bring the central core down. Interviews were conducted with persons who were present in offices on the 91st floor of the building at the north face of the structure, three floors below the approximate zone of impact.