WTC 2 Collapse Initiation Model
The 5 stages of collapse initiation
1) 81, 82nd fl spandrels pull in sharply (along green and blue lines)......................inward bowing
2) 78th fl ejections.....................east wall separates into upper and lower parts
this allows tilting to begin
3) Tilting
whole upper part drops with this action
4) 75th fl east face row of ejections
5) 75th fl west wall north and south quarter of
MER panels ejected from building with flooring. NW and SW MER corners are destroyed.
The first 2 stages allow tilting to begin. Stages 4 and 5 finish the tilt and begin the fall.
The first 2 stages initiate tilt. The final 2 stages terminate tilt.
Stage 1: Sharp pull-in of 81st and 82nd floor spandrels along the green lines and the blue line. The pull-in will break the east wall into upper and lower part along the purple lines.
The pull-in along the blue line, on the north face, is shown below:
Stages 2, 3 and 4:
78th and 75th floor ejection locations
The
78th row ejections came out of the 7 areas marked in red along the 78th spandrel.
Emergence of the 78th fl row of ejections signifies the initiation of tilt.
Emergence of the 75th fl row of ejections signifies the beginning of global falling of the upper portion, or "release".
Stage 5: The 75th floor MER beam flooring, southwest corner, is shown as a yellow sheet. The attached west face MER perimeter panels are shown as a red sheet. During the final release of the upper tilting portion, the NW and SW corners of the 75th fl MER beam flooring was forcefully ejected from the building with MER west face perimeter panels still attached.
Created on 04/19/2011 03:33 PM by admin
Updated on 08/01/2011 05:40 PM by admin
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