Study of the impacts of intact rock properties and RQD on the performance of Raise Boring Machine (RBM) during pilot hole drilling

In the recent years, the continuing trends has been towards to mechanization of shaft excavation operations. Mechanization offers safer, faster, more efficient, and more environment friendly operations in mining and tunneling. Raise Boring Machine (RBM) is one of the mechanical excavation machines that commonly used in mine and tunnel projects for excavation of shafts. This study aimed to analyze the effect of intact rock properties (uniaxial compressive strength and indirect tensile strength) and RQD (rock quality designation), as well as fault zones on the performance of a RBM (daily advance rate, consumed tricone bit torque, net pushing force, instantaneous penetration rate, unit penetration, net cutting rate, consumed tricone bit power, and field specific energy) during pilot drilling of one of the ventilation shaft in the Balya lead-zinc underground mine, Turkey. The field investigation indicated that the instantaneous penetration rate, unit penetration, and net cutting rate were the highest in the fault zone compared to the other geological units. The statistical modeling studies indicated that RQD might be a predictor for estimation of field specific energy. Additional field and laboratory data is required to improve the reliability of the discussed models in this study.