UB-MCEER-EERI Seminar Series at the University at Buffalo
The EERI student chapter of the University at Buffalo (UB-EERI), the MCEER Student Leadership Council, the Networking and Education Programs of MCEER, and the University at Buffalo's Department of Civil, Structural and Environmental Engineering jointly sponsor a series of seminars on a variety of topics related to earthquake hazard mitigation. The purpose of the seminar series is to widen accessibility to timely, technical presentations by students, researchers, visitors and affiliates of MCEER. The seminars are broadcast over the Internet in real-time, and can be viewed anytime at http://civil.eng.buffalo.edu/webcast . UB's Professor Andrei Reinhorn and undergraduate student Jason Hanley, from Computer Science and Engineering, arrange the webcasts.
Dr. Mete A. Sozen is shown with UB-EERI-SLC students (from left) Darren Vian, Prof. Sozen, Gordon Warn, and Benedikt Halldorsson following his seminar.
On April 5, 2002, Dr. Mete A. Sozen of Purdue University gave the 2002 EERI Distinguished Lecture entitled "A Way of Thinking," which was included as the ninth in the ongoing seminar series on earthquake engineering topics. However, at the request of Dr. Sozen, the seminar was not webcast.
Mr. Darren Vian, Ph.D. candidate in the Department of Civil, Structural and Environmental Engineering (CSEE), president of the UB-EERI Student Chapter, and member of the MCEER Student Leadership Council (SLC), opened the seminar by welcoming the standing-room-only audience of approximately sixty people, and introducing the speaker.
Prof. Sozen began his presentation by explaining how it would differ from most technical presentation on engineering topics. In his abstract for the presentation, he wrote: "Structural engineering is a profession. A profession is characterized by the need to exercise judgment within a domain defined by a set of canons. The structural engineering canons have developed sometimes as a result of and sometimes despite the interaction between science and experience. That structures were built successfully without science and, worse yet, even with the wrong science for hundreds of years and that science has, so far, been insufficient to guarantee predictability, emphasize the challenge in discriminating between the poles: "Science is all!" and "Experience is all!" The territory in between is vast and slippery. It is difficult to navigate a true course without giving in to the lure of one pole or the other. Today, ready access to versatile and powerful software enables the engineer to do more and think less. It is not often questioned whether the exact analysis of the approximate model qualifies as an approximate analysis of the structure itself. To contemplate once again the role of analysis in design is not a waste of time.
A way of thinking about structural design was developed in a series of iterations in the mid 20th century by three engineers. Their goals were not global. The whole was made up of specific solutions for specific problems. But when their contributions are viewed together, a complete way of thinking about structural design becomes discernible. The goal of this talk is to encourage engineers to review the works of Harald M. Westergaard, Hardy Cross, and Nathan M. Newmark as a whole not for the specific processes but for the general principles of their art of thinking about structural design.
Of the three, Harald M. Westergaard was the immaculate and painstaking scholar with a penchant for simple and direct expression. His vision of the relationship between theory and design is captured by his statement ".. a simple device can yield perhaps 80 percent of the truth whereas the next 10 percent would be difficult to obtain and the last 10 percent impossible...."
Hardy Cross was the creative genius more interested in the engineering artifact than its analysis. Though intensely interested and eminently successful in the development of analytical methods for structures, he kept his students' eyes on the prize by repeating that a building is to build and not to analyze. Perhaps he said it all about the role of analysis in design when he wrote "All analyses are based on some assumptions which are not quite in accordance with the facts. From this, however, it does not follow that the conclusions of the analysis are not very close to the facts."
As a graduate student in 1930's at Urbana, Illinois, Nathan M. Newmark worked with Professors Cross, the artist, and Westergaard, the analyst. In retrospect, he appears to have excelled them both in scholarship and creativity. It is difficult to capture Newmark's state of mind with a single quote. Things came easily to him and, in general, he did not take the time to write to be understood. But his flashes of genius in applied mechanics demonstrate his thinking was a perfect fusion of his gifted teachers. His quick grasp of the important and his ability to cut through seemingly complex problems using sophomore-level mechanics is at once astounding and delightful. He was a master of the synecdoche. A dam would be modeled as a rigid object with a single degree of freedom. A multidimensional ground motion became a pulse. His understated apology after having represented one component of an entire ground motion by one half of a square wave, "It would be possible to consider a sinusoidal pulse but this complicates the expressions unnecessarily," is enough to make one stop in one's tracks. Because of the pinnacles of his achievements in simplifying geotechnical and structural design, it is easy to miss that his strongest contribution was to expand and deepen the way of thinking set into motion by Cross and Westergaard.
The thinking of Cross, Westergaard and Newmark did not always intersect completely. But when it came to the relationship of structural mechanics to design (all three had design experience and remained active and interested in structural design throughout their careers), they were completely together. To them, structural mechanics was perfect as long as it was not applied. When it was applied, it had to be applied with judicious care to maximize return in relation to investment. As long as one was going to be wrong anyway, one might as well be wrong the easy way.
After Dr. Sozen's interesting and personal presentation, Mr. Vian moderated the discussions and finally, after thanking our guest with a generous applause, the seminar was closed.
--Submitted by Benedikt Halldorsson, UB-EERI secretary
World Trade Center Disaster
Emmanuel Velivasakis, LZA Technology, A Division of The Thornton-Tomasetti Group
Emmanuel Velivasakis described the role of structural engineers at ground zero in the aftermath of the World Trade Center attack.
On Friday, March 15, 2002, Emmanuel Velivasakis of LZA Technology gave a presentation entitled "World Trade Center Disaster." It was the eighth presentation in the ongoing seminar series on earthquake engineering topics held at the University at Buffalo.
Mr. Darren Vian, Ph.D. candidate at the Department of Civil, Structural and Environmental Engineering (CSEE), president of the UB-EERI Student Chapter, and member of the MCEER Student Leadership Council (SLC), opened the seminar by welcoming the audience and introducing the speaker.
Mr. Velivasakis described how in New York City, emergency response teams, including hundreds of police officers and firefighters, were immediately dispatched to the World Trade Center site by the Mayor's Office of Emergency Management. Simultaneously, the New York City Department of Design and Construction retained four major construction management firms to assist in the search and rescue operation, as well as LZA Technology, which was charged with responsibility for all structural engineering operations at the site.
He discussed and showed numerous examples of how the structural engineer played a crucial role in enabling the intense search and rescue effort to proceed without hindrance on a 24-hour basis, while maintaining safety in an environment fraught with the risk and danger posed by partially collapsed and severely damaged structures.
With many photographs to illustrate the situation facing the engineers, Mr. Velivasakis expanded on the services provided by LZA Technology at and around ground zero. These services included immediate damage assessment of buildings in the collapse area, assistance with demolition and temporary stabilization procedures, design of grillages and analysis of existing structures to support construction equipment, coordination of the survey monitoring of existing damaged structures, and inspection of hundreds of buildings in the area surrounding the collapse site.
Mr. Velivasakis' presentation was received by generous applause, after which Mr. Vian moderated the discussions. After Mr. Velivasakis answered numerous questions from the audience, the seminar was closed.
--Submitted by Benedikt Halldorsson, UB-EERI secretary
Using Synthetic Aperture Radar and Other Remote Sensing Technologies to Detect Earthquake Damage in the 1999 Marmara, Turkey Earthquake
Ronald T. Equchi, ImageCat, Inc.
Ronald T. Eguchi discussed the application of remote sensing technologies to post-earthquake damage detection.
Ronald T. Eguchi of ImageCat, Inc.gave a seminar entitled "Using Synthetic Aperture Radar and Other Remote Sensing Technologies to Detect Earthquake Damage in the 1999 Marmara, Turkey Earthquake" at the University at Buffalo on March 6, 2002. Mr. Eguchi's presentation was the seventh in the ongoing seminar series.
As with the other seminars held this semester, Darren Vian opened the event by welcoming the audience and introducing the speaker.
Mr. Eguchi described the activities of an MCEER research team, who for the past several years have been investigating the use of remote sensing technologies in post-earthquake damage detection. This research has focused on various aspects of damage detection including: 1) detection of damage or no damage, 2) quantification of various damage states, on a regional basis, and 3) quantification of damage to specific buildings. The research team has found that currently available remote sensing data (namely, SPOT, Landsat, and certain radar data, such ERS) can indeed detect major changes to cities caused by extensive damage from an earthquake. In certain situations, remotely sensed data can also verify particular damage states (such as collapsed buildings).
To test and validate the methodology, the research team applied specially developed change detection algorithms to two areas of Turkey. Both areas, Golcuk and Adapazari, were devastated in the 1999 Marmara, Turkey earthquake. In Golcuk, severe damage was observed to multi-story residential structures, in addition to some ground subsidence problems. To estimate change, a broad set of change detection algorithms was applied to the analysis. For the two areas above, Landsat and ERS data were used to assess major structural changes caused by the earthquake. These data were provided by the European Space Agency. For the Golcuk area, they also obtained SPOT data from researchers in Turkey who are also investigating the use of remotely sensed for damage detection.
The significance of these findings is far-reaching. As demonstrated in many prior disasters, delayed or impeded response can lead to further damage (as in the case of unchecked fires) and prolonged recovery. Ultimately, these impacts burden the local and regional infrastructures with higher recovery costs and additional social burdens. They concluded that by developing and implementing technologies that allow for more rapid evaluation of regional damage, a community's level of resilience can be increased. This research is sponsored by MCEER and by the National Science Foundation through a special grant on the Marmara, Turkey earthquake.
Mr. Eguchi's presentation was received by generous applause, after which Mr. Vian moderated the discussions. A number of interesting questions were posed from the active audience, and after the discussions, the seminar was closed.
--Submitted by Benedikt Halldorsson, UB-EERI secretary