Experimental Research on the Specific Energy Consumption of Rock Breakage Using Different Waterjet‐Assisted Cutting Heads

Abstract

To investigate the specific energy consumption (SE) of rock breakage by cutting heads assisted by different types of waterjet and to identify optimal waterjet parameters and assistance types, rock cutting with and without waterjets was carried on a rock fragmentation test bed. SE is a comprehensive evaluation index and was developed according to the applied load on cutting head, and the SE under different cutting conditions was compared and analyzed. e results show that the SE of rock breakage without waterjet assistance increased with the increasing of rock compressive strength (R CS ) but that the limited drilling depth decreased.e effect of the waterjet pressure on the SE of rock breakage by the cutting head I was marked, and SE decreased by 30∼40% when the ratio between R CS and waterjet pressure was less than 1. However, the function of the waterjet assistance was poor; therefore, a ratio of 1 could be used to distinguish the rock breakage effect of cutting head I. For cutting head II, the rock damage from the waterjet impact was limited due to the large waterjet standoff distance; thus the rock breakage performance of cutting head II was also limited. e waterjet impacting at the tip of the conical pick using cutting head III could enter into the cracks caused by the mechanical pick and fracture the rock. erefore, the rock breakage performance of cutting head III was better than that of cutting head II.

Study conical pick cutting performance and fatigue life in breaking rock plate process with numerical simulation

“…Wang et al 12 pointed out that the rock breaking performance of conical pick is affected by the confining pressure, and proved that the brittleness under biaxial confining pressure is different from that under uniaxial confining pressure through experiments and regression analysis. Jiang et al 13 studied the different water jet of cutting head influence on specific cutting energy, compared impact of the water jet on rock breaking performance and determined the best parameters of the water jet assisted rock breaking to improve the rock breaking efficiency. Zeng et al 14 studied the cutting force and rock damage with different cutting parameters and investigated the rock breaking performance and fatigue life of conical pick in the process of conical pick cutting rock 15 .…”

Research on cutting performance and fatigue life of conical pick in cutting rock process

“…The rock is more fragile under uniaxial confining pressure, while the rock is more fragile when the confining pressure stress is released. In 2018, Jiang and Meng 4 studied the influence of different water jet rock breaking cutting heads on the specific energy consumption, comparing the influence of water jet on rock breaking performance to determine the best parameters of water jet assisted rock breaking. In 2018, Liu et al 5 established conical pick cutting rock numerical simulation model with discrete element method of conical pick cutting rock, studies the influence of traction speed, angular velocity, and installation angle of conical pick on the cutting performance.…”

Rock Breaking Performance of TBM Disc Cutter Assisted by High-Pressure Water Jet

“…In geothermal exploitation, a new drilling technology, a mechanical driller assisted by a high-pressure water jet, has been developed for the challenging downhole environment [27]. The high-pressure water jet has been also used in underground mining, in which rock is broken by mechanical tools assisted with the water jet, reducing the cutting pick force and increasing the rock crushing efficiency [28][29][30][31].…”