Abstract:

Using an abrasive water jet and a tunnel boring machine(TBM), hard rock crushing can minimize tool wear and enhance excavation efficiency. However, the efficiency and energy consumption of abrasive water jet cutting are influenced by various factors, and the optimal matching relationship between the moving speed of the abrasive water jet and the cutting times under different operating conditions remains to be determined. Consequently, experiments on the repetitive cutting of granite using an abrasive water jet are conducted under different operating parameters, such as jet pressures and movement speed/cutting time. The influence patterns of these parameters on cutting width, depth, and specific energy consumption are determined. Furthermore, a comparison is made between the cutting efficiency and energy utilization of the two methods: onetime cutting at a low speed and repetitive cutting at a high speed. The matching relationship between the movement speed of the abrasive water jet and the cutting times is established. The results reveal the following findings: (1) Repetitive cutting at high speed can increase the cutting width and reduce width fluctuation, with the cutting width gradually increasing with rising jet pressure and movement speed/cutting time. (2) When the jet pressure is not high and within a certain range, the cutting depth and volume exhibit a linearpositive relationship with jet pressure. In contrast, movement speed/cutting time decreases sharply and gradually increases. (3) An optimal movement speed/cutting time exists for repetitive cutting. Under the experimental conditions, when jet pressures are 20~25 MPa and 30~40 MPa, the optimal movement speed/cutting time are 15 (mm/s)/3 (times) and 20 (mm/s)/4 (times), respectively.

Key words: abrasive water jet, hard rock, cutting efficiency, energy consumption, influencing factor