Potential of drive-by inspection for railway bridges

Drive-by bridge inspection (DBBI) is a promising indirect monitoring approach due to its potential advantages over direct bridge monitoring. These advantages include economy and accessibility: one moving vehicle can monitor many bridges, with just a few sensors; and it is easier to instrument a vehicle than a bridge. As a result of these attractive features, it is gaining increased attention from researchers. However, most of the research done on DBBI has been conducted on highway bridges only. The application of the approach to railway bridges is not yet known. This paper will identify the challenges that are unique to the drive-by inspection of railway bridges. Firstly, the physics of vehicle-bridge interaction (VBI) and train-track-bridge interaction (TTBI) is described, as these are fundamental to DBBI. Then, a review of the research already done for DBBI on highway bridges is presented. From this, the problems facing DBBI are identified. Some of these problems may not exist for railway bridges, while there may be some further complicating issues not present for highway bridges. Therefore, these issues are assessed using the different physics of VBI and TTBI. From this, the potential of DBBI for railway bridges is considered, and the relevant research challenges identified.