AN IMMEDIATE PAYOFF FROM FHWA'S NDE INITIATIVE
Advanced nondestructive evaluation (NDE) and nondestructive flaw-detection technologies (NDT), developed partly through the assistance of a recent Federal Highway Administration (FHWA) applied research program, played a vital role in a successful emergency structural evaluation program undertaken by the Alabama Department of Transportation to assess potential wind-induced damage to a major cable-stayed span in Mobile. On February 26, 1998, a number of stay cables on the Cochrane Bridge unexpectedly began vibrating at high amplitudes during a period of light rain and high winds. This rain/wind vibration phenomenon has affected a large number of cable-stayed bridges worldwide. Such high-amplitude vibrations can affect the strength and useful life of the cables and the bridge. A stay-cable assessment team devised and implemented a comprehensive test program to assess the presence and extent of stay-cable damage. This field assessment program was the first of its kind in terms of scope, comprehensiveness, and speedy response to be conducted on any cable-stayed bridge span in the United States. The following technologies were adapted: laser-based stay-cable force measurements, ultrasonic testing, and detailed laser-based stay-cable damping measurements. Forces in all 96 cables were measured in 3 days. As an important complement to the stay-cable structural evaluation protocol, an ultrasonic flaw detection technique was adapted to conduct a complete examination of the stay anchorages. Based on test results, it was recommended that mechanical viscous dampers designed to eliminate rain/wind-induced vibration be installed during the Cochrane span's upcoming maintenance cycle.
- Record URL:
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/oclc/1586080
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Corporate Authors:
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC United States 20590 -
Authors:
- Ciolko, A T
- Yen, W P
- Publication Date: 1999-5
Language
- English
Media Info
- Features: Figures; Photos;
- Pagination: p. 10-17
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Serial:
- Public Roads
- Volume: 62
- Issue Number: 6
- Publisher: Federal Highway Administration
- ISSN: 0033-3735
- Serial URL: https://www.fhwa.dot.gov/publications/publicroads/
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Publication flags:
Open Access (libre)
Subject/Index Terms
- TRT Terms: Anchorages; Cable stayed bridges; Cables; Damping (Engineering); Flaw detection; Force; Highway bridges; Lasers; Maintenance; Nondestructive tests; Rain; Research projects; Retrofitting; State departments of transportation; Structural analysis; Technology transfer; Ultrasonic tests; Vibration; Wind
- Identifier Terms: Cochrane Bridge; U.S. Federal Highway Administration
- Geographic Terms: Mobile (Alabama)
- Subject Areas: Bridges and other structures; Design; Education and Training; Highways; Maintenance and Preservation; Research; I24: Design of Bridges and Retaining Walls; I61: Equipment and Maintenance Methods;
Filing Info
- Accession Number: 00765033
- Record Type: Publication
- Files: TRIS, USDOT
- Created Date: Jun 15 1999 12:00AM