Analysis of Roadheader for Breaking Rock Containing Holes under Confining Pressures

Deep underground mines have high energy consumption due to the need to overcome the confining pressure. This study investigates the characteristics of the roadheader used for breaking rock containing a different number and size of holes under different confining pressures. A series of simulations were conducted using the LS-DYNA software to study the cutting torque, thrust force, specific energy, and failure mode during the rock-breaking process. Following this, the results were further validated with experimental data. It was found that the decrease in energy rates of rock containing different numbers (1, 5, 9, and 13) of holes are 12.7%, 19.3%, 25.9%, and 38.4%, respectively. Meanwhile, the decrease in energy rates of rock with different hole diameters (35, 45, 55, and 65 mm) are 10.5%, 19.3%, 24.6%, and 28.1%, respectively. Under the confining pressure of 10 MPa, the increase in the torque of the rock without holes is 23.5%, while this increase in the rock with five holes is 7.9%. This indicates that the high torque and energy consumption caused by the confining pressure can be reduced by drilling holes in the rock.