Study on the influence of coal-rock interface roughness on ultra-low friction effect
To reveal the influence mechanism of coal-rock interface roughness on ultra-low friction rock burst under dynamic load disturbance,a self-designed ultra-low friction test device for coal-rock interface is used.The coal rock block of 1 082 m mining depth in Shenyang Hongyang Three Mine is used as the research object.The coal block is used as the working block,different roughness characteristics of coal-rock interface is simulated by changing the surface roughness of coal blocks.The horizontal displacement of the working block is used to characterize the ultra-low friction effect strength during the impact process.The influence of different roughnesses of coal-rock interface on ultra-low friction effect of coal-rock block under stress wave disturbance is tested.The results show that:(1)under different coal-rock interface roughnesses,the ultra-low friction effect has a frequency sensitivity value.When the disturbance frequency is 2 Hz,the coal-rock interface is more prone to ultra-low friction effects.(2)The disturbance amplitude is linearly positively correlated with the ultra-low friction effect strength.The smaller the coal-rock interface roughness,the greater the horizontal displacement and horizontal acceleration of the working block,and the greater the ultra-low friction effect strength.The greater the coal-rock interface roughness,the greater the increase of the horizontal displacement and acceleration of the working block,and the greater the influence of the disturbance amplitude on the ultra-low friction effect.(3)The roughness only affects the ultra-low friction effect within a certain range,and JRC=3.81 is the critical value affecting the ultra-low friction effect.(4)The greater the horizontal impact force,the greater the horizontal displacement and horizontal acceleration of the working block,and the greater the ultra-low friction effect strength.
mining engineeringcoal-rock interfaceroughnessstress wave disturbancecoal rock blocksultra-low friction effect
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