1. Xinji No.2 Mine, China Coal Xinji Energy Co., Ltd., Huainan 232001, China; 2. State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221116, China
Abstract：Two methods were used to install microseismic sensors in roadway of Xinji No.2 Mine, namely the rigid connection installation of fully anchored anchor rods and the installation of drilling grouting adhesive rock walls. A week long microseismic test was conducted, and a total of 553 microseismic events were collected to compare and analyze the time-domain characteristics of microseismic signals. Research had found that the maximum amplitude of microseismic signals received by sensors installed using anchor rods was significantly greater than that of sensors installed using drilling methods, with the average maximum amplitude being about 2.86 times that of sensors installed using drilling methods. The effective signal duration received by sensors installed with anchor rods was longer than that of sensors installed with drilling, and the average effective signal segment length was about 4.41 times that of sensors installed with drilling, indicating that the coupling effect between anchor rods and sensors was better than that of sensors installed with drilling, which was more conducive to data processing and analysis. The peak value, root mean square value, margin factor, and pulse factor of the signal captured by the sensor installed on the anchor rod were all greater than those of the sensor installed on the drill hole, indicating that the sensor installed on the anchor rod had a higher degree of extreme change and energy intensity in capturing the signal, which could provide more basis for identifying microseismic signals. Therefore, the signals obtained from sensors installed with anchor rods had the characteristics of large effective signal amplitude, long duration, and obvious eigenvalues, and the signal quality was higher than that of drilling installation.
