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Sasani Selected as ACI Fellow
Civil and Environmental Engineering Professor Mehrdad Sasani has been elected a Fellow of the American Concrete Institute (ACI) for his contributions to the institute and the concrete industry. Less than 5% of ACI members earn this recognition. The formal presentation of Sasani's election is during the ACI Spring 2019 Concrete Convention and Exposition during the Opening Session and Keynote Presentation, Sunday, March 24, 2019. To be named, a Fellow “shall have made outstanding contributions to the production or use of concrete materials, products, and structures in the areas of education, research, development, design, construction, or management.” Mehrdad Sasani has pioneered the field investigation of collapse resistance of reinforced concrete and prestressed structures. The story of this new field of study begins in an unlikely manner, more than two decades ago.
In the morning hours of April 19, 1995, a truck bomb was detonated beneath the Murrah Federal Building in Oklahoma City, killing 168 people and injuring many hundreds others. Until the events of 9/11, it was the deadliest terrorist attack in American history at the time. The attack raised challenging questions of security and counterterrorism, and it was clear that engineering would be integral to building resilience to such devastating events in the future. Analysis revealed that progressive collapse of the structure, not the initial effects of the explosion, caused the vast majority of the deaths. Progressive collapse is a process by which an initial failure in part of a system cascades into a further collapse of the structure. In the aftermath of the Oklahoma City Bombing, the General Services Administration (GSA), charged with the administration of all federal buildings, released new guidelines for the structural integrity of government buildings, requiring progressive resistance. In 2001, hijacked airplanes brought down the Twin Towers in New York City, with progressive collapse playing an important role.
The new GSA guidelines created a need for better research into progressive collapse. At the time, individual building materials could be tested for strength and durability, but computer simulation was the primary method for assessing a building’s ability to withstand blast forces. However, computer simulation alone is not ideal. Innovative research was needed into the ways in which structures respond to catastrophic events.
As the GSA was implementing new security guidelines, Prof. Sasani was beginning to rethink the ways in which we study progressive collapse of buildings as a complete structural system. A trained earthquake engineer, he wanted to continue exploring the effect of catastrophic events on structures and materials. He began to develop a novel means of testing system-level structural integrity by proposing to conduct tests in buildings slated for demolition.
In 2006, he found a company preparing to demolish a building that would let him conduct his first test. Controlled Demolition, Inc. was preparing to implode the 10-story University of Arkansas Medical Center dormitory in Little Rock, AR. Working through the night to install 10,000 feet of cables and remote sensors throughout the structure, Sasani and his students had CDI detonate a charge in a single column of the building in the early hours of the morning before the scheduled demolition. The ensuing shifting of the building, captured by the vast array of sensors, was an invaluable ocean of data Sasani’s team could mine to understand how the entire system would react to stress.
Since that first implosion, Sasani’s research team has carried our field tests of collapse resistance of seven reinforced concrete and post-tension structures slated for demolition by implosion. These field experiments could not have been completed without significant effort and contribution of two of Sasani’s former PhD students, Marlon Bazan and Serkan Sagiroglu. Sasani’s field tests represented a new approach for understanding progressive collapse. His understanding of structural behavior under stress was reinforced by data collected in the field, providing a far more accurate picture than previous work. His pioneering work has helped inform the design and construction of sturdier, more resilient buildings that resist progressive collapse. His tests included one building with a transfer-girder design, the same method used in construction of the Oklahoma City federal building. The lessons learned from his research help architects and engineers design safer buildings that are more resilient in the face of terrorist attacks and natural disasters.
Mehrdad Sasani has served as chair of ACI Committee 377, Performance-Based Structural Integrity and Resilience of Concrete Structures, since its formation in 2013, and is a member of ACI Committee 374, Performance-Based Seismic Design of Concrete Buildings. He has served on the ACI Committee on Awards for Papers and ACI certification committee for concrete licensing program. Additionally, he serves on the editorial board of the ASCE Journal of Structural Engineering. Sasani is an editor of ACI SP-309 Structural Integrity and Resilience. He is a member of the Subcommittee for General Structural Requirements of ASCE/SEI-7 Standard on Minimum Design Loads and Associated Criteria for Buildings and Other Structures, the SEI Disproportionate Collapse Mitigation of Building Structures Standard Committee, and the Risk and Resilience Measurements Committee (RRMC) of Infrastructure Resilience Division (IRD) of ASCE.
Congratulations to Prof. Mehrdad Sasani for this distinctive recognition of his significant contributions to the field of concrete structures.