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Title: Development of Flexural Vibration Inspection Techniques to Rapidly Assess the Structural Health of Rural Bridge Systems

Source: Brashaw, Brian K.; Vatalaro, Robert; Wang, Xiping; Sarvela, Kevin. 2008. Development of flexural vibration inspection tec1miques to rapidly assess the structural health of rural bridge systems. Publisher: Intelligent Transportation Systems Institute, Center for Transportation Studies, University of Minnesota, Minneapolis, MN. Final report. CTS 08-22. 66 p.

Author(s)Brashaw, Brian K.; Vatalaro, Robert; Wang, Xiping; Sarvela, Kevin; Wacker, James P.

Publication Year: 2009  View PDF »

Category: Journal Articles
Associated Research Project(s):   FPL-4714-3A

Abstract: Approximately 4,000 vehicle bridges in the State of Minnesota contain structural timber members. Recent research at the University of Minnesota Duluth Natural Resources Research Institute (UMD NRRI) has been conducted on vibration testing of timber bridges as a means of developing rapid in-place testing techniques for assessing the structural health of bridges. The technique involves measuring the frequency characteristics of the bridge superstructure under forced flexural vibration. The peak frequency of vibration was measured and compared to a set of load testing data for each of 9 bridges. Each bridge was also inspected using commercially available advanced inspection equipment to identify any major structural problems with individual bridge components such as timber pilings, pile caps, and girders. Two bridges were identified that needed immediate maintenance attention. The relationship between the load deflection data and the vibration characteristics showed a useful relationship and the results indicate that forced-vibration methods have potential for quickly assessing timber bridge superstructure stiffness. However, improvements must be made to the measurement system to correctly identify the 1st bending mode frequency of the field bridges. This global vibration technique has potential benefits for routine inspections and long-term health monitoring of timber bridge superstructures.

Keywords: Elasticity, bridges, inspection, nondestructive testing, deterioration, service life, design, construction, testing, loads, dynamic testing, performance testing, flexibility, stiffness, bending strength, timber bridges, structural timbers, vibration tests, wooden bridges, maintenance, repair, Minnesota, wood decay

Publication Review Process: Informally Refereed (Peer-Reviewed)

File size: 2,530 kb(s)

Date posted: 05/17/2010

This publication is also viewable on Treesearch:  view
RITS Product ID: 31072
Current FPL Scientists associated with this product (listed alphabetically)
Wacker, James P.
Research General Engineer
Wang, Xiping
Research Forest Products Technologist

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