Prediction of the rock properties ahead of the tunnel face in TBM tunnels by geostatistical simulation technique

The authors developed the TBM Excavation Control System (the TBM Navigator), in order to realize more advanced observational construction. During the excavation using this system, the rock strength value is immediately calculated from the TBM driving data as the index of rock properties, and the drill energy coefficient is also calculated from the drill logging data that is carried out using the exploration hole ahead of the tunnel face. In this study, a new, geostatistical simulation-based method is proposed for the automatic prediction of the rock properties ahead of the tunnel face with good precision, using both the drill logging data and the TBM driving. The applicability of this method is validated through the prediction at the actual tunnel excavation that passes through the faults