In order to explore the impact of fracture dip angle on the effect of high-voltage electric pulse induced fracturing of coal-rock mass in water,the fracturing tests of true triaxial high-voltage electric pulse induced fracturing in water were carried out by using similar specimens of coal-rock mass with prefabricated central hole and parallel prefabricated fracture,and the crack propagation characteristics were analyzed based on the test results.The influence of fracture dip angle on crack propagation characteristics was further studied by using particle flow program.The results show that under the action of confining pressure,the stress in the area between the parallel fractures is reduced,and stress concentration occurs at both ends of the fracture,and the cracks are more likely to occur in the stress reduction area and extend to the stress concentration area under the action of impact load.With the increase of fracture dip angle,the consumption of stress wave energy by fracture increases first and then decreases,and the length and width of crack increase first and then decrease.Under the action of high-voltage electrical pulse,the specimen generates microcracks at the central hole,both ends of the prefabricated fracture and the inside of the prefabricated fracture.With the reflection and diffraction of the stress wave at the fracture,the stress concentration area is transferred,and the microcrack develops into a macroscopic crack in this process,so that the fracture communicates with the central hole.The research results provide a basis for the engineering application of high-voltage pulse induced fracturing technology and the reasonable selection of drilling position.
关键词
高压电脉冲/预制裂隙/裂隙倾角/裂纹扩展/数值模拟
Key words
High-voltage electric pulse/Prefabricated fracture/Fracture dip angle/Crack propagation/Numerical simulation
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