The relation between district raise in the multiple coal seams and its pillars

Based on the multiple coal seams mining geological condition in No 8 colliery of Pingdingshan Coal Group, the behaviors of front abutment pressure in the multiple coal seams and fixed abutment pressure are observed. The main reason to result in deformation and damage of galleries is that surround rock valid load coefficient of gallery under the coal seam becomes higher. The reasonable pillar width of district raise is studied, when its two side seams have been mined, and the layout question of district raise in the different set of seams is also studied. The conclusions are guided to district raise layout in the multiple deep coal seams mining.