Reasons Analysis and Pressure Law of Gob-side Entry Driving of Extra Long Isolated Working Face

In order to study mine pressure behavior and roadway supporting of isolated working face,it taking transportation roadway of 120502 extra long isolated working face of Lianghuai mine district as engineering background,and then mine pressure law of gob-side entry driving of the isolated working face was studied by field test and FLAC^3D number simulation software.The results showed that roadway roof separation amount was large,and the largest separation amount was about 117mm,and most separation was shallow separation,roadway surrounding rock deformation was small during earlier period of roadway driving,and then roadway deformation increased with distance increased,deformation was fiercely as distance to roadway start point was 600~800m,deformation was the largest at gob side of 120503 working face,it’s average value was 180.41mm,the largest value was 780mm,successively were coal body side(an average was 138.23mm,the largest was 445mm),floor heave(an average was 124.29mm,the largest was 545mm), roof subsidence (an average value was 64.03mm,the largest was 430mm),elastic core formed within coal pillar as vertical stress,and vertical stress reached about 32.5MPa,vertical stress at working face side arrived 26.3MPa,it’s value increased about 6.2MPa,god side of transportation roadway deformation largely as 120502 working face mining, also gob area deformation increased, straight wall and three centers arch section was applied during roadway tunneled, vertical stress was converted to tangential stress,plastic zones showed that compressed stress appeared around roof but tension stress appeared at floor,as better characteristics of compress resistance, so roof subsidence less than floor heave, specific roadway enhancement supporting technology was put forward.The practical showed that based on original supporting design,roadway surrounding rock deformation could be effectively controlled by some combination supporting means of anchoring net cable,guniting and grouting and so on.