Study on the symmetric bilinear initiating technique of deep-hole boulder blasting in the TBM tunnel excavation

The excavation of the deep-buried tunnel with tunnel boring machines (TBM) is often affected by boulder, which harm the cutter disc of the TBM. It is sometimes difficult to achieve the ideal blasting effect by the conventional blasting technology. In this study, a novel symmetric bilinear initiating (SBI) technique based on detonation wave collision was proposed to reduce the oversize boulders and improve the construction efficiency. The...