STUDY ON REASONABLE POSITION OF AIR-RETURN ROADWAY NEAR THE EDGE OF GOAF

There are a few distinct difficulties in support of roadway by bolt-mesh near the edge of coal seam with thin roof strata under the gob.Five different positions of air-return roadway and support are proposed through analyzing the distribution of the abutment pressure near the edge of goaf.By using numerical simulation,the deformation and stress distribution of the surrounding rocks in different positions of air-return roadway are studied and the influence to the surrounding rocks of the air-return roadway excavation in different positions is discussed.The study indicates that the deformation of the air-return roadway induced by excavation was reduced in the low-stress coal stratum about 5 meters inner the edge of goaf.Moreover,the anchoring cables can be installed to bear the stress from upper strata with the roof,which is helpful for controlling the development of the plastic zones and the deformation,as well as increasing the stability of the air-return roadway.