Abstract:

In order to study the influences of the factors such as cutter width, cutter spacing and penetration on the rock breaking process, groups of rock breaking tests are conducted on a fullscale linear rock cutting machine. The experiments of granite cutting under different parameters are carried out with CCS (constant cross section) disc cutter. The rock with uniaxial compressive strength of about 140 MPa is cut straightly by disc cutters of 13 mm and 17 mm width under the conditions of 60 mm, 65 mm, 70 mm, 75 mm and 80 mm of cutter spacing and 0.5 mm, 1.0 mm, 2.0 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm and 6.0 mm of penetration. The load data of rock breaking such as normal force and rolling force are obtained, and rock cutting specific energy (SE) is calculated. The test results show that: (1) The average normal and rolling forces increase with the cutter width, but they increase differently. (2) The cutter width and penetration have stronger impacts than the cutter spacing on the average rock breaking forces. (3) The cutter width has stronger impact on the average normal force than the average rolling force. (4) The specific energy decreases with the penetration first and then increases under the conditions of different cutter widths and cutter spacings, while the specific energy increases with the cutter width.

Key words: tunnel boring machine (TBM), disc cutter, rock breaking mechanism, linear cutting test, rock cutting specific energy, granite