Experimental study on acoustic emission characteristics of consolidated filling body under cyclic loading

With the increase of mining depth, the ground pressure of stope is becoming more and more serious. As one of the important structural units in filling mining method, consolidated filling body plays an important role in maintaining the stability of stope, and therefore understanding the response characteristics of consolidated filling body has important significance. The studies on acoustic emission (AE) characteristics and fractal characteristics of AE quiet period were carried out by the uniaxial cyclic loading and unloading test on consolidated filling body. The results show that there is obvious compaction stage for consolidated filling body, which the AE energy value is high in the beginning. After that the AE energy will reduce gradually with increasing of the stress, finally maintains at a low level. In the elastic stage, the AE rate value and energy will increase with the stress growing. Moreover, the AE rate is greater than other loading stages. Before the loading stress getting to the peak, the AE will take on a quiet period in which the AE energy will fluctuate dramatically and the AE fractal will drop continuously. According to the test, the AE energy in subsequent loading is higher than previous loading, and also AE energy is more sensitive to the damage of consolidated filling body, compared with the AE rate.