scholarly journals POSSIBLE CAUSE OF ABNORMAL COLLAPSE OF THE WORLD TRADE CENTER BULDING

Author(s):  
М. Н. Кокоев

Национальный институт стандартов и технологий (NIST) провел расследование о причинах обрушения Всемирного торгового центра (WTC). Однако до сих пор встречаются суждения о якобы специально подготовленном взрыве зданий WTC некими «заговорщиками». Действительно, для многих наблюдателей и экспертов картина обрушения башен WTC послужила поводом для сомнений - как могли высотные здания относительно ровно, практически вертикально, обрушиться? В связи с этим, в работе обсуждается гипотеза, на основе которой можно объяснить специфический характер обрушения зданий. Лифтовые шахты в зданиях занимали 25% площади на плане. Они были сгруппированы в центре здания. Внутренний объем шахт для лифтов на протяжении 200 метров по высоте равен 120000 м3. Разлившийся авиационный керосин пропитал поверхности стенок лифтовых шахт и создал внутри смесь из паров керосина и воздуха. У керосина в три раза ниже поверхностное натяжение, чем у воды. Поэтому он легко смачивает почти любые поверхности, быстро растекается и пропитывает всё. Для керосина концентрационные границы взрываемости в смеси с воздухом находятся от 0,8 до 5,2%. Энергия паров керосина в лифтовых шахтах, равная нижнему концентрационному пределу взрываемости, эквивалентна 13000 кг ТНТ. При случайной искре происходит объемный взрыв паров керосина в лифтовых шахтах. Энергии взрыва достаточно для разрушения и последующего почти вертикального обрушения здания. The National Institute of Standards and Technology (NIST) has conducted an investigation into the causes of the collapse of the World Trade Center (WTC). However, there are still opinions about the allegedly specially prepared explosion of the WTC buildings by some “conspirators”. For many observers and experts, the picture of the collapse of the WTC towers gave rise to doubts - how could high-rise buildings collapse relatively evenly, almost vertically? The paper discusses a hypothesis on the basis of which it is possible to explain the specific nature of the collapse of these buildings. The elevator shafts were grouped in the center of the building. They occupied 25% of the area on the plan. The internal volume of the elevator shafts over a length of 200 meters in height is equal to 120,000 m3. The spilled aviation kerosene soaked the surfaces of the walls of the elevator shafts and created a mixture of kerosene and air vapors inside. Kerosene has three times lower surface tension than water. Therefore, it easily wets almost any surface, spreads quickly and soaks everything. For kerosene, the concentration limits of explosiveness in a mixture with air are from 0.8 to 5.2%. The energy of kerosene vapors in lift shafts, equal to the lower concentration limit of explosiveness, is equivalent to 13000 kg of TNT. In case of an accidental spark, a volumetric explosion of kerosene vapors occurs in the elevator shafts. The energy of the explosion was enough to destroy the building causing subsequent almost vertical collapse.

2008 ◽  
Vol 2 (3) ◽  
pp. 142-149 ◽  
Author(s):  
Robyn R.M. Gershon ◽  
Marcie S. Rubin ◽  
Kristine A. Qureshi ◽  
Allison N. Canton ◽  
Frederick J. Matzner

ABSTRACTObjective: Participatory action research (PAR) methodology is an effective tool in identifying and implementing risk-reduction interventions. It has been used extensively in occupational health research, but not, to our knowledge, in disaster research. A PAR framework was incorporated into the World Trade Center evacuation study, which was designed to identify the individual, organizational, and structural (environmental) factors that affected evacuation from the World Trade Center Towers 1 and 2 on September 11, 2001. PAR teams—comprising World Trade Center evacuees, study investigators, and expert consultants—worked collaboratively to develop a set of recommendations designed to facilitate evacuation from high-rise office buildings and reduce risk of injury among evacuees.Methods: Two PAR teams worked first separately and then collectively to identify data-driven strategies for improvement of high-rise building evacuation.Results: The teams identified interventions targeting individual, organizational, and structural (environmental) barriers to safe and rapid evacuation.Conclusions: PAR teams were effective in identifying numerous feasible and cost-effective strategies for improvement of high-rise emergency preparedness and evacuation. This approach may have utility in other workplace disaster prevention planning and response programs. (Disaster Med Public Health Preparedness. 2008;2:142–149)


2007 ◽  
Vol 22 (3) ◽  
pp. 165-173 ◽  
Author(s):  
Robyn R.M. Gershon ◽  
Kristine A. Qureshi ◽  
Marcie S. Rubin ◽  
Victoria H. Raveis

AbstractIntroduction:Due to the fact that most high-rise structures (i.e., >75 feet high, or eight to ten stories) are constructed with extensive and redundant fire safety features, current fire safety procedures typically only involve limited evacuation during minor to moderate fire emergencies. Therefore, full-scale evacuation of high-rise buildings is highly unusual and consequently, little is known about how readily and rapidly high-rise structures can be evacuated fully. Factors that either facilitate or inhibit the evacuation process remain under-studied.Objective:This paper presents results from the qualitative phase of the World Trade Center Evacuation Study, a three-year, five-phase study designed to improve our understanding of the individual, organizational, and environmental factors that helped or hindered evacuation from the World Trade Center (WTC) Towers 1 and 2, on 11 September 2001.Methods:Qualitative data from semi-structured, in-depth interviews and focus groups involving WTC evacuees were collected and analyzed.Results:On the individual level, factors that affected evacuation included perception of risk (formed largely by sensory cues), preparedness training, degree of familiarity with the building, physical condition, health status, and footwear. Individual behavior also was affected by group behavior and leadership. At the organizational level, evacuation was affected by worksite preparedness planning, including the training and education of building occupants, and risk communication. The environmental conditions affecting evacuation included smoke, flames, debris, general condition and degree of crowdedness on staircases, and communication infrastructure systems (e.g., public address, landline, cellular and fire warden's telephones).Conclusions:Various factors at the individual, organizational, and environmental levels were identified that affected evacuation. Interventions that address the barriers to evacuation may improve the full-scale evacuation of other high-rise buildings under extreme conditions. Further studies should focus on the development and evaluation of targeted interventions, including model emergency preparedness planning for high-rise occupancies.


Disasters ◽  
1996 ◽  
Vol 20 (2) ◽  
pp. 125-132 ◽  
Author(s):  
LYNN E. QUENEMOEN ◽  
YVETTE M. DAVIS ◽  
JOSEPHINE MALILAY ◽  
THOMAS SINKS ◽  
ERIC K. NOJI ◽  
...  

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