Research on the hole bottom installation method of acoustic emission monitoring sensor for coal and rock dynamic disasters in mine

The installation of acoustic emission sensor is an important step to ensure the effective monitoring of acoustic emission signals. Based on the comparison and analysis of different installation methods, it was pointed out that the hole bottom installation of sensor should be selected preferentially when the acoustic emission was used to monitor coal and rock dynamic disasters in coal mine. A fast and convenient hole bottom installation method of acoustic emission sensor named claw fixation method was designed and the field test was carried out. The test results show that this method can simplify the installation process, and solve the problem that the coupling of the sensor and the coal and rock by cement grouting in the upward hole is not close, which leads to the incomplete monitoring signals, and improve the timeliness and stability of the coupling between the sensors and the coal and rock, and ensure the signals can be received continuously and effectively. According to the angle of the field installation drill holes, the two kinds of the hole bottom installation methods of acoustic emission sensors have been formed, namely the installation method by cement grouting and the claw fixation. When the sensors are installed in large angle upward holes or horizontal holes, it is advisable to choose the claw fixation method; when the sensors are installed in downward holes, the installation method by cement grouting should be used.