Bruce R. Ellingwood

Distinguished Professor & the Raymond Allen Jones Chair
Civil Engineering & Environmental Engineering
Georgia Institue of Technology

Abnormal Loads and Progressive Collapse - Assessment and Mitigation of Risk (click to view video)

Friday, April 17th, 2009
4:10 P.M.

Sinclair Laboratory Auditorium

Overview:

A progressive (or disproportionate) collapse is one that initiates from a local structural failure and propagates, by a chain reaction mechanism, into a failure that involves a major portion of the structural system and is disproportionate to the local initiating damage. Such collapses can initiate as a result of extreme environmental or abnormal loads or design/construction errors. Public awareness of building safety issues has increased markedly in recent years as a result of well-publicized natural and man-made disasters.

The presentation summarizes design strategies to minimize the likelihood of progressive collapse, and prospects for the0 implementation of general provisions in national standards such as ASCE Standard 7, Minimum design loads for buildings and other structures.

Bruce R. Ellingwood: The Raymond Allen Jones Chair in Civil Engineering, College of Engineering Distinguished Professor - Dr. Ellingwood received his undergraduate and graduate education at the University of Illinois at Urbana-Champaign. From 1975-1986, he held the position of Research Structural Engineer at the National Bureau of Standards (now the National Institute of Standards and Technology), and led the NBS Structural Engineering group from 1982 - 1986. He joined the Johns Hopkins University in 1986, was appointed Chairman of the Department of Civil Engineering in 1990, and was named the Willard and Lillian Hackerman Chair in 1997. He has served on the faculty of the School of Civil and Environmental Engineering at Georgia Tech since 2000, and was Chair of the School from 2000 - 2002.

Dr. Ellingwood's main research and professional interests involve the application of probability and statistics to structural engineering. Within the general field of structural reliability, his research has included structural load modeling, studies of performance of structures, development of safety and serviceability criteria for design, studies of abnormal loads, progressive collapse and the response of structures to fires, probabilistic risk analysis and stochastic mechanics. As Administrator of the Secretariat of the American National Standard Committee A58 (now ASCE Standard Committee 7) on Minimum Design Loads for Buildings and Other Structures from 1977 - 1984, he directed the development of the probability-based load criteria for limit states design that now appear in ASCE Standard 7 on Minimum Design Loads, the AISC Specification, ASCE Standard 16 on LRFD for Engineered Wood Construction, ACI Standard 318, and both national Model Building Codes.

Dr. Ellingwood is internationally recognized as an authority on structural load modeling, reliability and risk analysis of engineered facilities, and as a leader in the technical development and implementation of probability-based codified standards for structural design. He has authored over 300 papers and reports. He is Editor of Structural Safety, and serves on six other editorial boards. He has held numerous leadership positions in professional societies, and his research and professional service have garnered numerous awards from ASCE (where he has twice received the Norman Medal), AISC and other professional organizations. He is a member of the National Academy of Engineering.

Abnormal Loads and Progressive Collapse - Assessment and Mitigation of Risk:

A progressive (or disproportionate) collapse is one that initiates from a local structural failure and propagates, by a chain reaction mechanism, into a failure that involves a major portion of the structural system and is disproportionate to the local initiating damage. Such collapses can initiate as a result of extreme environmental or abnormal loads or design/construction errors. Public awareness of building safety issues has increased markedly in recent years as a result of well-publicized natural and man-made disasters. Improved building practices and design procedures to control the likelihood of such progressive failures are receiving heightened interest from standards organizations and structural engineers in the United States and elsewhere. Procedures for assessing the vulnerability of buildings to such occurrences and for designing structural systems to withstand local damage without subsequent development of a general structural collapse can be developed using concepts of risk and structural reliability analysis and probability-based limit states design. The presentation summarizes design strategies to minimize the likelihood of progressive collapse, and prospects for the implementation of general provisions in national standards such as ASCE Standard 7, Minimum design loads for buildings and other structures.

The Fazlur R. Khan Distinguished Lecture Series has been initiated and organized by Dan M. Frangopol, the first holder of Lehigh's Fazlur Rahman Khan Endowed Chair of Structural Engineering and Architecture.

The Dendrite and Graphite of a Grey Cast Iron Structure