The 4th International Symposium on Mine Safety Science and Engineering (ISMSSE2018)

362 / 2018-05-31 08:50:35

Acoustic emission and fractal characteristics of coal samples with different rockburst tendency under load

rockburst; acoustic emission; fractal; rockburst tendency; precursor information

Mine Dynamics Disaster > Rock burst impact

In order to evaluate coal’s bursting liability scientifically and accurately, the Mahalanobis distance discriminant analysis method was introduced on the basis of establishing a measured database with 120 samples of the coal’s bursting liability. And the distance discriminant analysis (DDA) model of the classification of coal’s bursting liability was established. Then, this DDA model was used to evaluate three coal samples with strong, weak and none rockburst tendency. To study the acoustic emission (AE) and fractal characteristics of coal samples with different rockburst tendency under uniaxial compression, an experimental study was carried out to investigate the AE characteristics of coal samples with strong, weak and none rockburst tendency, by using YAW4306 rock mechanics servo testing system and CTA-1 AE signals acquisition system, and the fractal characteristics of AE signals was further analyzed. The results show that the AE energy precursor information of coal samples was sudden increase-calm-sudden increase, and AE energy ratio active point of coal samples with strong, weak and none rockburst tendency was 85%~90%, 75%~78% and 51%~55% of peak stress, respectively. The stronger the rockburst tendency of the coal sample, the shorter the duration of the main fracture and the duration after the peak, the greater the energy released during the failure. All of the coal samples with strong, weak and none rockburst tendency have the fractal characteristics, and the fractal dimension value of AE presents the phenomenon of abrupt increase, dump and continuous decline, which can be used as the failure precursor information of dynamic disaster prediction.