Damage evaluation of railway structures by using train-induced AE

For efficient maintenance of railway structures, nondestructive inspection for bridge substructures is developed by applying acoustic emission (AE) technique. As a newly proposed method, characteristics of secondary AE induced by a train in service are investigated. Based on AE experiments with model piles, in situ AE monitoring of railway bridges are conducted under railroad traffic. It is demonstrated that the proposed method is practical enough to detect the invisible defects in railway structures. Furthermore, a new index named RTRI (ratio of Repeated Train load at the onset of AE activity to Relative maximum load for Inspection period) is proposed for the evaluation of structural integrity. It is confirmed that RTRI is effective for in situ AE monitoring. (C) 2003 Elsevier Ltd. All rights reserved.