Ambient Vibration Monitoring
Civil Engineering Applications
Published Online: 15 SEP 2009
Copyright © 2009 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Structural Health Monitoring
How to Cite
Wenzel, H. 2009. Ambient Vibration Monitoring. Encyclopedia of Structural Health Monitoring. .
- Published Online: 15 SEP 2009
Structural health monitoring has become widely accepted in bridge management. The methodologies have become considerably developed over the past 10 years and reached a certain maturity. Many lessons have been learned from the monitoring activities. This article highlights the lessons learned over time that have relevance to bridge design.
Our transportation infrastructure is aging. Bridges are an essential asset of our economy. Reference is made to the situation in the United States, where within the network of the Federal Highway Agency (FHWA) 590 000 bridges are serving, out of which 160 000 are rated deficient when the traditional methodology is applied. It is estimated that replacement costs of seven billion US$ annually over 20 years may be required to achieve a perfect upgrade. In order to avoid such costs, the lessons learned with relevance to design should be considered in bridge design processes at the present time. Another drastic example is a bridge built in Austria in 1978, following the minimization principle of construction costs, at €8.5 million. Within 25 years, a total of €19.5 million had to be invested into retrofit measures. Considering the life-cycle costs, such situations have to be avoided in future.
The following is a collection of lessons learned from ambient vibration monitoring of over 400 bridge structures since 1997. The structures monitored are mainly situated in central Europe and represent the typical design for this region. Nevertheless, most of these lessons can be extended to structures worldwide. The terms and detailed explanations can be found in the book “Ambient Vibration Monitoring”, John Wiley, ISBN 0470024305, which is the standard literature on this subject.
- ambient vibrations;
- system identification;
- pattern recognition;
- feedback to design;
- damping factors;
- intensity calculation