Experimental study on acoustic and electrical response of double shear friction sliding of coal and rock

Abstract

In the process of underground mining, coal body friction is often accompanied. The coal-rock dynamic disaster caused by the friction and sliding of large-scale coal-rock mass will bring huge economic losses and casualties. Based on this, this paper takes Kuangou coal samples as the experimental object, and uses the friction device to carry out the coal sample friction experiments under the conditions of different loading rates(0.1, 0.2, 0.3, 0.4 mm/s), and obtain signal characteristics of acoustic emission and electromagnetic radiation at loading rates. The research shows that the sample is accompanied by obvious acoustic emission electromagnetic radiation signal in the process of sliding under loading, and the acoustoelectric signal changes periodically with the loading. The intensity of acoustic signal appears with the occurrence of load drop, and increases with the increase of load drop amplitude. There is a certain synergy between the two in time sequence; the change of the cumulative acoustic energy count is positively correlated with the degree of friction damage of the sample. Based on the cumulative acoustic energy count index, the judgment and early warning of the start and end of the friction of the sample can be realized.

Keywords

• coal rock
• double shear experiment
• friction sliding
• acoustic emission
• electromagnetic radiation
• monitoring and early warning