American Society of Civil Engineering, Journal of Engineering Mechanics

Over decade of proudly misrepresenting the collapse progression modes of the twin towers.


ASCE library linked here

In one of the best examples of the validity of the thesis of my "book", anyone who wishes can go to the library, run a search for "world trade center" and see not a single correct representation of the collapse progression modes of the twin towers. Not a single contributing author to the journals was able to positively identify anything like what we now know as ROOSD in more than a decade of publications.

As late as 2011 the journals published peer reviewed papers by Dr Grabbe and Dr Bazant, Mr Block himself, that misrepresent the collapse progression modes of the twin towers. A.S Usmani is also included in the journals, whose representation of sagging floors was examined by enik.

Dr Bazant leads the way with 4 papers which misrepresent the collapse progression processes literally in terms of "crush down, then crush up" from 2007 to 2011. Dr Seffen is also included in the journals.



Therefore, a special place in part 2 of the book, WTC collapse misrepresentations, will be made for the ASCE and the Journal of Engineering Mechanics to demonstrate how they repeatedly misrepresented the collapse progression modes. Another section will be made for Steven Jones.

In the follow-up experiments I'll contact the editors of the journal to record their explanation for why they allow these cartoon representations to the collapses into their journals. Actually, I'll visit them in person and make a video of their responses as to how they were unable to identify the ROOSD process in even a single paper in over a decade, while publishing the block representations they did.

Nothing can demonstrate the cluelessness and lack of integration between behavior and awareness among the highly educated wrt to the WTC towers better than ASCE and the NIST.

Over a decade of publications within ASCE serve as a confessional of how little they understood the collapse progression processes of the towers and how poorly they served the public interest during that time. In that time not a single author was able to spot the largest chain of cascading floor collapses in engineering history for what it was.


Note that nobody forced them to insert their feet so deeply into their own mouths. They did so willingly and through the peer review process. Nobody tricked the people reviewing these papers or the people publishing these papers to insert their feet into their mouths so deeply. Nobody tricked the authors to write so poorly.

If such extreme gullibility exists at that level of education and on that scale, isn't it prudent that you, too, approach the subjects of collapse and demolition with more caution and awareness in your own observations? With more awareness of your own vulnerability to false technical claims?

If they can be fooled so easily, you can too.



Ayhan Irfanoglu1 and Christoph M. Hoffmann2

1Assistant Professor of Civil Engineering, School of Civil Engineering, Purdue Univ., West Lafayette, IN 47907. E-mail: ayhan@purdue.edu

2Professor of Computer Science and Director of Rosen Center for Advanced Computing, Dept. of Computer Science, Purdue University, West Lafayette, IN 47907. E-mail: cmh@cs.purdue.edu

The writers report on a simulation study of the performance of the North Tower (WTC-I) of the World Trade Center complex during the impact of American Airlines Flight 11 on September 11, 2001. We discuss impact damage that the structural core might have sustained and its possible behavior under structural and thermal loading. Our simulations indicate that the worst damage to the core structure was in stories 95 through 97 of the tower. We estimate that a core collapse mechanism could be initiated if the tower core column temperatures were elevated to about 700°C .

This paper presents an experimental investigation of the World Trade Center Tower 1 (WTC1) collapse using a 1∕20 -scale model. The WTC1 fire on the 96th floor is reconstructed on a small scale, and structural members including the floor trusses and the exterior wall subsystem are built and tested under scaled fire load. Scaling rules are used to determine the values of the insulating material on the structural systems. This experimental study demonstrates the use of scaled models to investigate a real-world fire disaster. Results from the experimental investigation are compared to analytical results and visual evidence compiled in the National Institute of Standards and Technology report on the investigation of the collapse of WTC towers. This study helps engineers and researchers better understand the fire behavior and the associated structural response in WTC1, and a more solidly grounded collapse hypothesis can therefore pursued.

This paper reports on an investigation of the effects of fire on long span truss floor systems in a tall building environment. The effects of fire spread over multiple floors of a building are the focus of this research, especially where this may lead to progressive collapse. The results from an investigation of a two-dimensional model of a multistory office building analysis are presented. The model is representative of the type of construction used in the World Trade Center Towers 1 and 2. The local and global response of the model is described over the course of a concurrent fire on three floors reaching a peak compartment temperature of 800°C . The results of the analysis show that large displacements may occur in long span structural floor systems without failure, however, the interaction of the highly deflected floors with the exterior or perimeter columns can lead to structural collapse. Additional structural members, such as hat trusses, that allow redistribution of loads away from the exterior columns to the core columns have a significant beneficial impact on the robustness of the structure.

Progressive collapse is one of the most under-researched areas in structural engineering due to the relative scarcity of the circumstances leading to progressive collapse. The current design standards and building codes provide limited prescriptive or performance-based guidance on analysis or design to guard against progressive collapse. The collapse of the World Trade Center on September 11, 2001, led to demands by the public to amend current building codes and provide protection against collapse caused by extreme events. Following September 11, the literature on progressive collapse mitigation has expanded significantly. Important issues examined by investigators include events leading to progressive collapse, assessment of loads, analysis methods, and design philosophy. This paper seeks to explore aspects of the current state of knowledge on progressive collapse in the technical literature. The paper also discusses loads, structural analysis requirements, and design approaches in United States standards and guides as well as selected international building codes and standards.

This paper follows a companion paper “Progressive Collapse and Earthquake Resistance” (Gurley 2008) dealing with structural design against progressive collapse caused by accidental explosion, terrorist attack, or earthquake. The present paper focuses on those findings/recommendations/implications of the NIST 2005 Final Report on the Collapse of the World Trade Center Towers that relate particularly to proposed changes in structural design practice for fire in tall buildings such as: (1) A new role for, perhaps, a new breed of “fire engineer” as members of building project design teams alongside the established disciplines: architects/structural engineers/HVAC engineers/hydraulic engineers/electrical engineers; (2) a wider role for structural engineers working with fire engineers to carry out structural analysis including fire as a load condition so as to ensure burnout without progressive collapse even if a column is lost and sprinklers fail; (3) more research on sprayed fire resistant materials and better quality control during and after construction “over the life of the building”; and (4) the merits of nonstructural gypsum core walls as opposed to load-bearing concrete cores.

The behavior of the World Trade Center Tower 1 on September 11, 2001 is studied in light of experimental data on the effect of elevated temperature on mechanical properties of structural steel. It is concluded that the damage inflicted by aircraft impact on the insulation of the core framing was the dominant factor in the collapse of the structure.

Following the collapse of the World Trade Center towers in September 2001, there has been heightened interest among building owners and government entities in evaluating the progressive collapse potential of existing buildings and in designing new buildings to resist this type of collapse. The General Services Administration and Department of Defense have issued general guidelines for evaluating a building’s progressive collapse potential. However, little detailed information is available to enable engineers to confidently perform a systematic progressive collapse analysis satisfying these guidelines. In this paper, we present four successively more sophisticated analysis procedures for evaluating the progressive collapse hazard: linear-elastic static; nonlinear static; linear-elastic dynamic; and nonlinear dynamic. We discuss the advantages and disadvantages of each method. We conclude that the most effective analysis procedure for progressive collapse evaluation incorporates the advantageous parts of all four procedures by systematically applying increasingly comprehensive analysis procedures to confirm that the possibility of progressive collapse is high.

Progressive collapse is an increasing concern in the structural engineering community, especially after the collapse of the World Trade Centre Towers. While numerous papers have been published on the subject, the effects of random imperfections on failure paths have not yet been studied. The presented simulation study investigated the effects of random geometric imperfections on the formation of alternative paths after the removal of the first story column(s). Eccentricities and curvatures were introduced as independent random variables for each structural element. Gaussian distributions with means and standard deviations selected on the basis of a handbook of construction tolerances were applied to represent the real life imperfections. The selected, representative seismic building was repeatedly simulated under the same column(s) removal scenario with different imperfections randomly introduced in each simulation. The presented design exhibited competing failure modes. The dominant failure mode was observed in 80% of the simulations, while the secondary failure mode manifested itself in the remaining 20% of the simulations (the same column(s) removal scenario). The presented probabilistic study revealed that real-life imperfections may result in the alternate failure paths. Monte Carlo simulations shall be employed to detect such secondary load redistribution paths and/or collapse modes.

• Editorial: Engineering and Homeland Defense by George Bugliarello
• World Trade Center „Bathtub": From Genesis to Armageddon by George J. Tamaro The engineer who oversaw the construction of the World Trade Center „bathtub" describes the recovery efforts.
• A 911 Call to the Engineering Profession by Robert Prieto The events of September 11 challenged the future of our heavily engineered environment and the future of the engineering profession.

• 7,000+ FBI Agents who conducted a three-year 911 investigation
• 1,500 people who worked the flight 93 crash scene
• 40,000 people who worked the piles at Ground Zero
• 55 FBI Evidence Response Teams at Fresh Kills in New York
• 8,000+ people who worked the scene at the Pentagon