Mechanisms of Destruction and Collapse of the World Trade Center (WTC) Buildings on 9/11
Monday, May 6, 2013 10:18
% of readers think this story is Fact. Add your two cents.
The importance of understanding the mechanisms of collapse for the three World Trade Center buildings on September 11, 2001 cannot be over-estimated, for these unusual collapses and their disputed causes raise questions regarding all future steel-frame building design. A literature review was conducted to identify the evolving trend in research results in this area, which have become increasingly diverse over time. Recommendations for further research are presented.
Introduction
Over the past decade there have emerged two primary hypotheses regarding the mechanism of destruction for World Trade Center (WTC) buildings 1, 2 and 7, namely, the official fire-induced Progressive Collapse (PC) versus the alternate Controlled Demolition (CD). The question of which of these two hypotheses is correct is singularly important because its current lack of resolution leaves unmet the following critical needs (assuming PC):
(1) Thousands of other structures may also be subject to such catastrophic destruction by office fires, and inspections and upgrades based on determination of what caused the WTC buildings to collapse may be needed to ensure public safety;
(2) Significant structural design analysis tools and computer models need upgrades to account for the potential of such catastrophic destruction;
(3) Major revisions to building codes for high-rise steel-frame buildings are critically needed (Bement, 2002).
Our goals here are to fully document the available peer-reviewed literature on this important question, and to promote more open and in-depth research by a broader community of scholars.
Although much relevant evidence from portions of the events of 9/11 remains unavailable to researchers as well as the general public, substantial evidence is available concerning the destruction of WTC 1, 2 and 7 that is relevant to resolving the key question of PC versus CD. Nevertheless, the diversity and complexity of the 9/11 events make it very difficult for most citizens, and even many researchers, to obtain the quality information needed to address and resolve the above questions.
In particular, information provided officially is notoriously incomplete; e.g., the official 9/11 Commission Report (2004) makes no mention of destruction of the third high-rise steel-frame building, WTC 7. Further, relevant official reports produced by the National Institute of Standards and Technology (NIST) for the Twin Towers are incomplete in that they stopped their efforts at “collapse initiation” and could not explain total destruction. Finally, the same NIST reports have been surrounded by controversy that remains mostly unreported in mainstream media sources (see peer-reviewed papers referenced herein).
