Research on rational width of entry protection coal-pillar in large mining height workface

For the study on the problem of rational width of entry protection coal-pillar,according to the gateway of 6103 mining face with large mining heitht in Kanghe mine,through theoretical calculation and numerical simulation,rational width of entry protection coal-pillar was educed,and its feasibility was demonstrated through engineering practice,which provided some theoretical references for preserving reasonable coal-pillar for the similar coalface with large mining heitht.