Bridge Assessment Using Forced-Vibration Testing
Publication: Journal of Structural Engineering
Volume 121, Issue 2
Abstract
Full-scale forced-vibration tests conducted before and after structural repairs on a multispan reinforced-concrete highway bridge are described in the paper. The tests were conducted to investigate any correlation that may exist between the repair works and changes in the dynamic characteristics of the bridge. The approach adopted is suitable for assessing the structural condition of a bridge using vibration data. A purpose-built hydraulic vibrator was used to artificially excite the bridge, and the dynamic response was measured by accelerometers placed on the bridge deck. A single-degree-of-freedom model was fitted to the response functions in order to extract natural frequencies, modal damping ratios, and mode shapes. It was found that the repair works caused a slight reduction in the natural frequencies but there was no definite trend in the changes to the modal damping ratios. Comparison of the mode shapes before and after repairs using modal analysis procedures was found to give an indication of the location of the repairs.
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Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 121 • Issue 2 • February 1995
Pages: 161 - 173
Copyright
Copyright © 1995 American Society of Civil Engineers.
History
Published online: Feb 1, 1995
Published in print: Feb 1995
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