Oscillating disc cutting technique for hard rock excavation
The technology for the mechanical excavation of low to medium strength rock has been substantially well developed, and therefore it has been used in most cases as an alternative technology to drill and blast excavation (Gertsch, 1994). However, in the case of hard rock excavation, especially for mining excavations, such advancement in the development of an efficient and effective cutting system has not yet been achieved. This is partly because of inadequate understanding of the basic mechanism of rock cutting and partly because of a lack of understanding in the fundamental processes involved in the rock cutting machines. This paper describes one of the advanced cutting technologies called the oscillating disc cutting for hard rock cutting and its advantages over other cutting systems are highlighted by comparing the results with that of conventional disc cutting technique employed in most tunnel-boring machines. The parameters such as oscillating frequency and the rock brittleness on the mean cutting forces are examined and their results are discussed. The experimental results clearly indicated the advantages of the cutting technology in the construction of a lightweight flexible machine for hard rock excavation. Copyright 2013 ARMA, American Rock Mechanics Association.