Experimental Study on Acoustic Emission of Weakly Cemented Sandstone considering Bedding Angle

Abstract

Uniaxial compression experiments and acoustic emission (AE) tests were conducted on weakly consolidated sandstone samples with bedding angle of 0°, 45°, and 90° collected from Xiaojihan coal mine in Shaanxi Province, China; the acoustic emission (AE) characteristics of bedding sandstone were investigated, including the influencing mechanism of bedding angle on characteristics, spatial distribution, and b value changes of AE activity. According to the research, AE ringing counting rate and energy rate are the highest and energy release is intense during the loading process when the bedding angle is 0°, and these values decrease and the energy release is gentle with rising of the angle. Based on spatial distribution, the number of AE events was the largest and cluster phenomenon occurs between the bedding plane when the bedding inclination was 0°, which decreased and sprouted along the plane of bedding plane at 45° and which was smaller and evenly distributed in the space at 90°. With the increase of bedding angle, the proportion of large-scale microcracks decreases and the variation range of microcracks narrows down. Therefore, under the same uniaxial compression conditions, the b value increases by the increase of bedding angle. The research results offer reliable reference to carry out monitoring work on acoustic emission and microseism of mine with layer rock (rock mass).