Experimental Study on Acoustic Emission Characteristics of Coal and Rock Under Horizontal Stress Loading

In order to study the acoustic emission laws of coal and rock under different horizontal stress, the true thiaxial compression failure test of different stress was carried out in the laboratory. The results show that the acoustic emission signal of coal and rock increases with the increase of stress level, and the effect of axial stress σ_v on acoustic emission signal is more great than that of horizontal stress σ_h. To compare the acoustic emission characteristics of coal and rock under complicated stress level, we defined “equivalent confining pressure” to describe the stress level. According to the acoustic emission energy characteristics of true triaxial compression test at different stress levels, the failure process of coal and rock samples is divided into three stages: elastic stage, yield stage and failure stage. With the increasing of “equivalent confining pressure”, the acoustic emission signal of specimen damage is significantly enhanced, the number of peak values of acoustic emission counting increased, and the peak intensity lag was more obvious. The acoustic emission characteristics of coal and rock samples under different stress conditions can prevent the occurrence of coal and rock dynamic disasters through theoretical and experimental studies.