ABSTRACT
A vertical shaft, so-called Ciurug Raise Boring II (CURB II), at the underground cut and fill Pongkor Gold Mine, West Java was developed for ventilation, waste pass, and ore pass purposes by means of a raise boring 73RM-DC. Assessment on the performance of the raise boring related to the geomechanical parameters of the rock mass being excavated is described. The geomechanical parameters of intact rock, such as, density, Brazilian tensile strength, unconfined compressive strength, and Young’s Modulus were determined from core rock samples obtained from depths of 40 m, 70 m, and 100 m below the shaft collar. The machine performance parameters included, load per cutter, and reaming production. The raise boring performance was analysed using Rock Excavatability Index.
