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| Quantitative evaluation of fracturing effect of coal-rock masses under high-voltage discharge actions in water#br# |
| BAO Xiankai1，LIU Yuan1，GUO Junyu1，CAO Jiaxing1，ZHAO Jinchang2，WU Jinwen3#br# |
| (1. School of Civil Engineering，Inner Mongolia University of Science and Technology，Baotou，Inner Mongolia 014010，China；2. School of Mining Technology，Taiyuan University of Technology，Taiyuan，Shanxi 030024，China；3. School of Science，North University of China，Taiyuan，Shanxi 030051，China) |
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Abstract To study the fracturing effect of high-voltage discharge in water on coal-rock masses with low permeability，the fracturing test of high-voltage pulse discharge in 3MPa drilling hydraulic water was designed, and the crack expansion law of coal-rock masses under different loading fracturing conditions was quantitatively analyzed by using computed tomography(CT) scanning system and the fracture characteristic analysis software to study the geometry parameters and fractal dimension of internal cracks and the variation of probability density function of crack width of coal samples. It is shown from the test results that under the same hydraulic pressure，the effect of hydraulic fracturing of high-voltage electrical pulse on coal-rock masses is superior to that of pure 3 MPa hydraulic pressure. The higher the discharge voltage，the more the number of cracks and nodes inside the coal sample，the longer the total length，the wider the average width and the higher the cracking rate. The higher the discharge voltage，the larger the fractal dimension and the logarithm of the crack distribution initial value，that is，the more complex the cracks and the greater the proportion of macro-cracks. The higher the discharge voltage，the wider the crack width and its distribution range. It can be seen that the high pressure pulse discharge in water has good fracturing effect on coal-rock masses.
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2020, Vol. 39 
