Tunnel Boring Machines

Tunneling in hard rock with tunnel boring machines is one of the most mechanized construction processes. Mechanization also applies to the installation of the temporary excavation support and the final lining. Computer-aided process systems have been developed, including: (1) sensor-supported gathering and computer-aided storage of all relevant tunnel operational and survey data; (2) computer-aided visualization and control of the most important boring machine systems; and (3) computer-aided, process-oriented control of all operational processes. Presented here are recent tunneling developments related to gripper and shielded boring machines. In the case of gripper boring machines, particular focus is directed to innovations such as the installation of ground stabilization directly behind the cutter head and adequate logistics to the excavation by engineered “back-up” systems. The back-up system requirements necessary to maintain the high performance of shielded boring machines are enumerated.