Mechanism of strong pressure reveal under the influence of mining dual system of coal pillar in Datong mining area

In Datong mining area,carboniferous seam of 8105 working face under the Jurassic gob pillar leaving was characterized by strong pressure,with the theoretical analysis and field testing applied,the Jurassic minedout area of pillar stress influence law and carboniferous seam roof collapse of crack zone was analyzed,and obtained a dual-line seam mining face under strong influence column of the strata coal pillar-overburden movement joint mechanism. It shows that the Jurassic gob pillar leaving in the horizontal and vertical stress is higher, up to 10. 5-13. 5 MPa,and stress concentration zone depth of 40-70 m,the shear stress spread range up 180 m;The roof of 8105 working face collapse crack zone height range is 150-170 m;face appeared a strong pressure of pillar is made up of the pillar and seam roof collapse result of combined effects of crack movement.