Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4920464 | Engineering Structures | 2017 | 12 Pages |
Abstract
Ikitsuki Bridge is a three span continuous truss bridge with a length of 800Â m, which was completed in July 1991. In December 2009, a crack which seriously damages the safety of the bridge was found in a diagonal member near an intermediate pier during an inspection for determining points to be annually inspected. In order to identify its cause, some tests on the material used for the cracked member were conducted, and a long-term monitoring of wind and vibration of some diagonal members with similar structural characteristics to the cracked member had been carried out since December 2011. In this article, the outline of the crack is presented and the main causes of the crack are discussed based on the results of the tests and monitoring. The conclusions can be summarized as follows: (i) The crack initiated and propagated to become approximately 200Â mm long as a fatigue crack. The quality of material and weld satisfies the requirement for them. (ii) The vibration of the diagonal members is induced by the wind with the velocity of 6-8Â m/s and higher than 15Â m/s in the direction approximately normal to the bridge longitudinal axis. The maximum stress range induced by the vibration due to 6-8Â m/s wind is approximately 30-40Â MPa, while that due to the wind blowing at the velocity of over 15Â m/s can be 195Â MPa. (iii) These wind-induced vibrations are thought to be the main cause of the fatigue crack.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geotechnical Engineering and Engineering Geology
Authors
Q. Wang, S. Nakamura, T. Okumatsu, T. Nishikawa,