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原文传递 AN IMMEDIATE PAYOFF FROM FHWA'S NDE INITIATIVE.

题名：	AN IMMEDIATE PAYOFF FROM FHWA'S NDE INITIATIVE.
作者：	Ciolko-AT; Yen-WP
关键词：	ANCHORAGES-; CABLE-STAYED-BRIDGES; CABLES-; COCHRANE-BRIDGE; DAMPING-ENGINEERING; FLAW-DETECTION; FORCE-; HIGHWAY-BRIDGES; LASERS-; MAINTENANCE-; MOBILE-ALABAMA; NONDESTRUCTIVE-TESTS; RAIN-; RESEARCH-PROJECTS; RETROFITTING-; STATE-DEPARTMENTS-OF-TRANSPORTATION; STAYED-CABLE-BRIDGES; STRUCTURAL-ANALYSIS; TECHNOLOGY-TRANSFER; U.S.-FEDERAL-HIGHWAY-ADMINISTRATION; ULTRASONIC-TESTS; VIBRATION-; WIND-
摘要：	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.
总页数：	Public Roads. 1999/05. 62(6) pp10-17 (7 Phot., 5 Fig.)
报告类型：	科技报告