岩石孔隙性质对电脉冲破岩的影响规律

为研究岩石孔隙对电脉冲破岩的影响规律,以电脉冲作用下岩石电场强度为评价指标,推导了岩石孔隙电场强度数学模型,建立了电脉冲作用下岩石电场强度二维模拟方法,开展了电脉冲破岩影响规律的数值模拟及实验研究。结果表明:孔隙的存在会引起岩石电场畸变,孔隙与岩石基质交界处的电场强度最大,电脉冲击穿将首先发生在孔隙边缘处;岩石孔隙数量越多、间距越小,电场强度越大;孔径、孔隙形态及方位对岩石电场强度具有重要影响,孔隙与电场线的有效作用面越大,电场强度越大,岩石越容易发生击穿破坏。高孔隙度的砂岩比低孔隙度的大理岩更容易被电击穿,砂岩样本的击穿概率同样随孔隙度的增大而升高。研究成果明确了孔隙对电脉冲破岩的重要影响,对于认识电脉冲破岩机理具有重要意义。

Study on the Law of the Effect of Rock Pore Properties on the Electric Pulse Rock Breaking

In order to study on the law of the effect of rock pore properties on the electric pulse rock breaking,by taking the electric field intensity of rock under the action of electric pulse as the evaluation index,a mathematical model of the electric field intensity of rock pores was derived,a two-dimensional simulation method of the electric field intensity of rocks under the action of electric pulses was established,and a numerical simulation study and an experimental study of the law of the effect on electric pulse rock breaking were carried out.The results show that:the existence of pores will cause the electric field distortion of rocks,the electric field intensity at the junction of pores and rock matrix is the largest,and the electric pulse breakdown will occur first at the edge of the pores; the more the number of pores is,and the smaller the spacing is,the greater the electric field intensity is; the pore diameter,pore morphology and orientation have an important impact on the electric field intensity of rocks,and the larger the effective action surface between the pores and the electric field lines is,the greater the electric field intensity is,and the more likely the rock will be broken down.The high-porosity sandstone is more likely to be electrically broken down than the low-porosity marble,and the breakdown probability of sandstone samples also increases with the increase of porosity.The results of the study clarify the important effect of pores on electric pulse rock breaking,which is of great significance for understanding the mechanism of the electric pulse rock breaking.