Stress migration and strata pressure behavior law in transitional region of coal pillar

Basing on coal mining in coal pillar transition region of 250103 working face in Tuating colliery,the stress distribution and migration law in coal entities were investigated by numerical simulation,in-situ monitoring of microseism and stress.Characteristics of coal bump in the process of coal mining were revealed.The results showed that the stress migration path was from the dip side of returning air laneway to the rise side of equipment removing gateway,then to the dip side of returning air laneway and wide coal pillar.In the narrow coal pillar region,vibrations were mainly concentrated in adjacent goaf.While in the wide coal pillar region,vibrations were mainly concentrated in current working face and wide coal pillar.The probability of strong mine tremors became higher when the stress value of one measuring point increased and another one decreased at the same time.Effective preventing and controlling measures were demonstrated in order to guarantee the safety of producing at working faces.