Overlying Strata Movement Law And Control Mechanism Of Fully Mechanised Longwall Mining Face In Thin And Medium Thickness Steeply Inclined Coal Seam

The large inclined angle, poor stability of the equipments and low coefficient of safety andsecurity issues for the miners exist in thin and medium thickness steeply inclined fullymechanised longwall mining working face. Thus, a combination of field research, theoreticalanalysis, similar simulation, numerical simulation, field measurement and other researchmethods is carried out to systematically analyse the steep coal seam mining similar experimentalplatform, the overlying strata movement law and the control mechanisms of surrounding rock ofworking face as well as the stability of equipment, the main conclusions are followed:(1) The steeply inclined rotatable similar simulation system and mobile hydraulic servoloading system are developed. This system has the intelligent control advantage of the rotatingparameters of the model, thus the difficult technical problem of similar model creation of thesteeply inclined coal seam is solved, and the reliability of the experimental data is improved. Thematerial ratio calculation software of similar simulation is developed, and the safe rotation of themodel and precise tracking under a certain rotation pressure load and even load distribution areachieved.(2) The coal and rock asymmetric force and asymmetric gangue filling and compactioncharacteristics of goaf in steeply inclined working face is revealed. The “ear” shaped bearingcase of the direct roof and inclined “voussoir beam structure” of the broken main roof areobtained. The instability type of overburden strata structure, the mutual influence relationshipbetween the overburden strata deformation and the mining parameters of the working face aswell as support-surrounding rock bearing characteristics are studied. The calculation methods ofsupport yield load and gangue filling width in the goaf in the steeply inclined working face aredetermined.(3) The force bearing model of the section pillar in the steeply inclined working face isestablished and the coal partially falling-whole sliding instability type of the section pillar isobtained. The section coal pillar size design method is determined, based on the stress failurecharacteristics of the section coal pillar in the steeply inclined coal seam mining. The instabilitymechanism of section pillar, coal rib in coal mining face, roadway deformation, overlying roofabove the working face are analysed.(4) The "three equipments" dynamic stability control technology system is created. Theoblique layout parameters of the working face in the steeply inclined coal seam are determined.Coal rib falling in the working face and roadway surrounding rock control method are developed.The equipment way in the working face, gangue blocking sideway, equipment road and sidewalkisolation arrangement methods are studied. These methods ensure the stability of the equipments and the safety of miners in the steeply inclined coal seam working face.118figures,5tables and166references are involved in this dissertation.