Three-Dimensional Laser Scanning as Applied to Subway Tunnel Inspections (05-1206) - MP-02
Charles Edward Rheault, Greenman-Pedersen, Inc.
Govind R. Sulibhavi, Maryland Transit Administration

As many mass transit agencies have found, increased operational hours have severely limited the time periods available for tunnel inspection teams. Add to that, the additional burdens of tighter budgets and reduced staff and you are just beginning to see the problems ahead. One mass transit agency has teamed with a consulting firm, to think outside the box and develop a viable solution to this situation. 3D Laser scanning was initially considered for its ability to recording the tunnel liner condition. The data from the scanner was combined with “off-the-shelf-software” (CAD, rail design software and a spreadsheet) to develop a system for documenting and managing tunnel inspection data. Current maintenance methods are manually intensive, involving numerous cross referencing of the data. The full process includes collection, documentation, analysis, prioritization, plan preparation, advertisement, award, repair, inspection and records upkeep. Coordinating the information of this very spatially oriented data in a manual methodology is a daunting task. The decision to incorporate the 3D scanner into the process, with its ability to record spatial data so completely seemed like a natural fit. And as the workflows developed, it became apparent that this process could be significantly streamlined with the application of this and other technologies. This paper will describe the evolution of this process as it currently stands, and look at the future and where we think these efforts will lead.