Mining Pressure Distribution Law And Control Technology Of Mining Super-high Faces Under Shallow Coal Seam Of Complex Topography

For the mining super-high faces under shallow coal seam,strata behaviors of working surface is obviously influenced by topography.It often occurs abnormally pressure working face during production,even causes great air leakage of roof,hydraulic support pushes down,roof maintenance difficulties.As to Shendong shallow depth and thickness mining coal seam occurrence characteristics and mining conditions,the paper,using the field investigation,theoretical analysis,and numerical simulation,respectively studied the mine pressure regularities distribution and control technology of the shallow burial large mining height of face on the hill terrain,valleys terrain,and hills-valleys terrain.Baced on the engineering background of 12401 working face of Shendong Shangwan mine,it established strata behaviors mechanical model of shallow buried and large mining height of face,gave working face mining height for the analysis of the principle and method in strata behaviors.The higher,the recovery space is greater,the strata behaviors of working face are more dramatic.According to numerical simulation of 12401 face to determine the partition of the front abutment of face and original stress zone.It established the hill terrain stress concentration mechanics model and had the mechanism of hill terrain abnormal pressure.It builded "short voussoir beam" instability model of valleys terrain shallow buried large mining height strata on the face and gave the main key stratum deficiency mechanism which caused acute strata behaviors of face.Affected by the stress concentration of the hill terrain,face through the hills uphill section advanced abutment pressure and the area of the stress-concentrated are increased.Bearing stress is proportional to the hill slope angle.As working face through valleys uphill section is affected by acceptor missing key stratum,strata behavior was abnormal,face through valleys uphill section face abutment pressure was always great,the stress concentration coefficient was around 3.0.The hills-gully terrain was influenced by hills terrain stress concentration and the main key stratum of gully topography loss coupling,the stress concentration factor reached 3.5,the area of stress-concentrated area increased sharply.With Shangwan mining 12401 working face,influence area of Shangwan mining is confirmed and monitored by topography.Studied working face roof control technology under complicated topography,ensured the smooth advance of shallow buried large mining height.