Mechanism and prevention technology of large inclined workface retracement inducing rock burst in deep tectonic zone

The risk of rock burst during the retracement of large inclined workface in the deep tectonic area is high, in order to study the mechanism of rock burst and prevention and control technology for the retracement of the workface, the research is carried out by theoretical analysis and numerical simulation with the background of 6199 workface of Panxi Coal Mine. It was concluded that: the workface is in a complex high static load environment under the influence of many factors, the shear stress concentration in upper basic top corner is obvious, the hydraulic support of the workface is retreated, the pressure of the overburden rock layer is transferred to the front of the workface, the high static load loading type rock burst may occur locally exceeding the limit load, and the activation of the basic roof broken and faults generates the dynamic load, and it may induce the dynamic and static load superposition type rock burst; the mine pressure data before the retracement indicate that the rock activity ahead is more intense, the resistance of the support increases before and after the occurrence of the working face micro-seismic warning event, there is a basic top break and fault activation may be, the risk of rock burst is high; based on the mechanism of rock burst during the retracement period, it is proposed to decompress-support cooperative prevention technology of rock burst, by weakening the influence of the high static load and decreasing the possibility of the dynamic load, and it assists in increasing the strength of the support of the tunnel of the workface, and controlling the roof of the workface to reduce the risk of rock burst during the retraction period. During the retracement of workface, there is no obvious increase in mine pressure monitoring data, and the effect of decompress-support cooperative prevention technology is good.