This study focuses on the use of strong motion data recorded during earthquakes and aftershocks to provide a preliminary assessment of the structural integrity and possible damage in bridges. A system identification technique is used to determine dynamical characteristics and high-fidelity first-order linear models of a bridge from low level earthquake excitations. A finite element model is developed and updated using a genetic algorithm optimization scheme to match the frequencies identified and to simulate data from a damaging earthquake for the bridge. Here, two criteria are used to determine the state of the structure. The first criteria uses the error between the data recorded or simulated by the calibrated nonlinear finite element model and the data predicted by the linear model. The second criteria compares relative displacements of the structure with displacement thresholds identified using a pushover analysis. The use of this technique can provide an almost immediate, yet reliable, assessment of the structural health of an instrumented bridge after a seismic event. Copyright © 2011 John Wiley & Sons, Ltd.
Andrew Smyth is a professor of civil engineering and engineering mechanics at Columbia Engineering. He specializes in structural health monitoring, using sensor information to determine the condition of critical infrastructure. Smyth has been involved with the sensor instrumentation and vibration analysis and remote monitoring of a large number of iconic long-span bridges and landmark buildings and museums.
Professor Raimondo Betti received his Laurea degree magna cum laude in Civil Engineering from the University of Rome “La Sapienza” in 1985 and his Master of Science in Structural Mechanics (1988) and PhD in Civil Engineering (1991) from the University of Southern California. In the fall of 1991, Dr. Betti joined the Department of Civil Engineering and Engineering Mechanics at Columbia University as an Assistant Professor and has been there since, being promoted to Associate Professor (1998) and to Full Professor (2002). He is currently the Chair of the Department.