Abstract:
In view of the current situation that the prediction means on the composite dynamic disasters of rockburst-coal and gas outburst are limited and the monitoring method of precursory information is not sufficient,the deformation and failure monitoring test of coal and gas complex under loading was carried out by using a high-frequency micro-seismic full waveform real-time monitoring system and a charge induction monitoring system with independent research and de- velopment. The relationship between the deformation and failure characteristics of coal and gas complex and the rules of micro-seismic signals and charge induction signals under different gas pressures was analyzed. Also,the influence of gas pressure on them was analyzed. The results show that the deformation and failure of coal and gas complex can be divided into three stages:elasticity stage,yield and strengthening stage,and failure stage. With the increase of gas pressure in coal and gas complex,the compressive strength,elastic modulus and softening modulus of coal and gas complex de- crease,the bursting tendency reduces,the duration of elastic and yield strengthening stage shortens. There are microseis- mic signals and charge induction signals generated in the deformation and failure process of coal and gas complex,and the peak amplitudes of two signals both appear in the failure stage of coal and gas complex. With the increase of gas pressure,the number of microseismic signals and charge induction signals increases,the signals become more and more dispersed,the amplitudes increase,the stress drop rate corresponding to peak amplitude increases. At the same time,the initial amplitude of microseismic signal waveform containing peak amplitude increases,the peak amplitude moves for- ward,and more and more closes to the initial amplitude. The higher the gas pressure in coal and gas complex is,the easi- er the rockburst-coal and gas outburst composite dynamic disaster is to occur. The deformation and failure stage of com- plex can be estimated through monitoring of microseismic signals and charge induction signals to a certain extent,and in combination with the gas pressure,the type and hazard of composite dynamic disasters can be estimated.