A portable linear rock cutting machine (PLCM)™ using mini discs is developed by the members of Mining Engineering Department, ITU.A groove is cut on the surface of a rock sample with a small disc cutter with constant depth of cut. Tool forces and specific energy values are recorded in 14 different rock samples having compressive strength values changing between 30 and 170MPa. The results are compared with the results obtained from full scale rock cutting tests using 13 inch disc cutter with 1.2 cm cutter tip width and full size conical cutters. It is found that there is close correlation between test results obtained from both cutting tests. Using PLCM some graphs are given to estimate cutting forces of full size disc cutters used in TBMs and to predict the performance of roadheaders for tunnel excavation.
Rock cuttability is an important parameter in rock cutting mechanics discipline for selection of a proper excavation machine and performance determination in mechanized tunneling. Different tests were used in the past for this purpose including core cutting tests, full scale rock cutting tests, index tests etc. Some of these tests are time consuming and expensive, and some others are not precise enough, Balci & Bilgin (2007), Bilgin a (2006), Çopur et al. (1997, 2001) McFeat- Smith&Fowell (1979), Rostami et al. (1994).Thuro& Plinninger (1999). This paper summarizes the research results of a project sponsored by Turkish Scientific and Research Council (TUBITAK) Bilgin at al. (2006) and Feridunoglu (2009) aimed to develop a rock cuttability index and to estimate the forces acting on real life disc cutters and to predict the performance of roadheaders.
A groove is cut on the surface of a rock sample with a small disc cutter with 5mm depth of cut.