Detection and targeted control of regional stress field for coal burst prevention

As coal burst normally occurs in the area of high stress concentration, it is of significance to study the features of regional stress field in coal mines. Primitive stress field, mining-induced stress field and their coupling effect are investigated through the methods of theoretical analysis, field measurement, numerical simulation and wave velocity CT inversion, and the relationship among regional stress field, high-energy seismic events and coal bursts are analyzed. Investigation of the 3# mining district in Xingcun coal mine shows that: (1) Though stress concentration changes in the mining process, several special areas witnesses stress concentration in the whole mining process, such as the rise pillar area, several syncline axis areas and large fault areas; (2) Coal burst occurrence and high-energy seismic events have a close relationship with regional stress field. Coal bursts and high-energy seismic events tend to occur in areas of stable stress concentration, such as the rise area, several syncline axis areas and large fault areas. Targeted control of stress field for coal burst prevention is developed based on stress field detection. The process of targeted control of stress field for coal burst prevention is: detection of regional stress field based mainly on wave velocity CT, identification of stress concentration, implementation of destress measures to control the identified stress concentration. This method of stress field control was applied to LW3306 working face in Xingcun coal mine and coal burst hazards were effectively controlled in LW3306.