Difficult rock comminution and associated geological conditions

Conditions encountered by the authors on several projects (tunnel boring, blast hole drilling, and large diameter pile socket drilling) were unanticipated, undetectable, and even difficult to identify even after they had been encountered. These conditions have caused failure of mechanical components, low penetration rates, and remarkably high cutter wear . Coincidentally, all projects had one or more geotechnical conditions in common . The...