Dynamic evaluation technology of rock burst based on response energy and non-response time

The research on the evaluation of rock burst hazard has attracted extensive attention in the field of safe pro- duction in mines and many static evaluation methods have been proposed to guide the control of rock burst. On the one hand,the mechanism and influencing factors of rock burst are not yet fully understood;on the other hand,the hazard is dynamically changed along with mining activities,so the static evaluation methods are not enough to solve this prob- lem. The dynamic evaluation technology based on field monitoring has a stronger reference for safe production in mines. According to the principle of statistic damage mechanics,the energy evolution behavior of coal rock under load- ing conditions is analyzed. It is found that the cumulative energy release rate has a critical sensitivity to the response of time,that is,the cumulative energy release rate will increase sharply when coal rock is approaching catastrophe. In ad- dition,according to the statistical principle,the behavior of a complex system in a normal state (no hazard) should oc- cupy a large probability,and the behavior in an abnormal state (hazardous) should occupy a small probability,so the deviation from the normal state at a certain moment actually reflects the change of its dangerous state. Based on the above,a microseismic technology for the dynamic evaluation of rock burst hazard is preliminarily established,which takes the response energy anomaly coefficient and the non-response time anomaly coefficient as indicators. It is an at- tempt to carry out short-term or imminent shock early warning. Finally,on the basis of microseismic data of a typical rock burst mine,field verification is carried out. The results show that the microseismic cumulative energy release rate could directly reflect the dangerous state of coal rock. The frequency distribution law of microseism calm time satisfies positive skew distribution. The combination of two indicators constructed on this basis can realize the real-time and continuous evaluation of the rock burst hazard. With the development of mining activities,the threshold of indicators should be dynamically revised on the basis of statistical principle to ensure that the results of evaluation are more sen- sitive and accurate. This study can be applied to other dynamic evaluation methods.