ABSTRACT
This paper investigates the machine performance and cutter life in a mixed ground Tunnel Boring Machine (TBM) project. The paper studies correlations between TBM operating parameters and the corresponding cutter life. The research involves a 2.2 km long tunnel stretch, with extremely complex geological conditions, changing between basalt (UCS up to 95 MPa), soft ground (silt and clay) and mixed face. The length of the zones are varying from less than a hundred meters to about 900 meters making the boring process very varying. The cutter changes reports have been used to back-calculate the instantaneous cutter life along the different geological zones, making this the basis for a machine parameter study. The main machine operating parameters focused on in this study are the thrust, torque, RPM and performance parameter penetration rate, which together with the geological pre-investigation and laboratory-testing, provide a wide range of aspects connected to the boring process and ground conditions.
