Study On Control Mechanism In Surrounding Rock Of Stope In Large Inclined Angle Coal Thick Seam Under Complex Engineering Geology Conditions

With the application of the research methods of theoretical analysis, computer numerical simulation, field measurement, this paper makes a systematic research on the floor failure characteristics of fully mechanized mining in large inclined angle coal ceam of No.12125, mechanical characteristics of surrounding rock and the pressures behaviors at the trend segment and the rotation segment of No.12124under gob area coal with close distance.In the aspect of theoretical analysis, we analysised and calculated the depth of failure rock along tilted and striked direction, and ensured the plastic zone width of upper coal pillar of goaf in No.12125, and then we got the division characteristics of abutment pressure in coal wall along the tilted direction in large inclined angle coal ceam under gob area coal with close distance.In the aspect of computer numerical simulation, the numerical simulation model of fully mechanized mining in large inclined angle coal ceam was established with FLAC3D, the Vertical stress and shear stress distribution in different depth in the process of fully mechanized mining in large inclined angle coal ceam, and we get the floor failure characteristics in large inclined angle coal ceam of No.12125, and then we got the distribution of vertical stress,vertical displacement and horizontal displacement field at the trend segment and the rotation segment of No.12124under gob area coal with close distance.In the aspect of field measurement, the support working resistance and ground pressure feature were observed by KJ345on-line monitoring system, and we compared and analyzed the ground pressure behavior of trend segment and rotation segment in fully mechanized rotation mining face with large inclined angle coal seam, with the Installation of the multipoint displacement meter in the upper airway and lower roadway,we got the deformation law of rock roadway in large inclined angle coal ceam under gob area coal with close distance.Aiming at the pressure behavior of side and roof falling of broken roof and surrounding rock deformation in upper gateway in large inclined angle coal ceam mining of No.12124, designing the support method for side and roof falling of broken roof, using composite supporting with anchorcable, I-beam and u-shaped shed to support the stress concentration area in upper gateway, and using combined support with anchor to control rock deformation in the rotary area, which effectively ensured the safe and efficient mining.The research results have good guidances for the stope surrounding rock control and safe and efficient mining of longwall mining and rotation mining in large inclined angle coal ceam under gob area coal with close distance.