ABSTRACT
Within the frame of the concepts given above, different rock-cutting theories will be summarized first and some numerical examples will be given later in order to make the understanding of rock-cutting theories easier. Radial cutters (wedge or chisel cutters) and conical cutters are used in medium-strength rocks in machines such as roadheaders, continuous miners, coal ploughs, and shearers. However, disk cutters are mainly used in tunnel-boring machines (TBMs) from medium-strength to very hard rocks. The main types of these cutters are seen in Figures 4.1 and 4.2.
