ABSTRACT
Tunnel Boring Machine (TBM) performance in sedimentary rocks is negatively impacted by a variety of geotechnical problems. Even after extensive investigation, sedimentary rock masses can surprise the tunneling team with ground-related problems that had not been foreseen. The impacts of such problems might have been simply mitigated on the drawing board, but typically prove difficult to mitigate through methods and means change initiated during the course of construction.
