Research On Strata Movement And Control Of Continuous Mining And Continuous Charging In Shallow Deep And Extra-Thick Coal Seams

The strip filling mining technology has a good control effect on the migration of roof overburden while solving the problem of coal gangue treatment.At home and abroad,layered filling mining method is mostly used in extra-thick coal seams,while there are few studies on one-time full-height cemented filling mining in shallow buried extra-thick coal seams.Based on the background of roadway filling mining in 51106 working face of Guojiawan Coal Mine,this thesis adopts the methods of field investigation,theoretical analysis,numerical simulation and similar material model test to study the gradual bearing characteristics of filling body,the influencing factors of rock stability control,the stress and strain characteristics of filling body,coal pillar and overlying rock in the process of continuous mining and filling.The main research results are as follows:(1)The P coefficient method is used to evaluate the lithological characteristics of the overlying rock,and the rock property is medium hard.the supporting mechanism of the filling body is reflected in the lateral reinforcement effect of the filling body on the coal pillar and the vertical support effect of the filling body on the bearing rock layer.The bearing process of the filling body on the overlying rock layer can be divided into the isolation body bearing period,the filling body playing a role period and the stope stress balance period.(2)According to the characteristics of continuous mining and filling process,the mechanical model of overburden bearing structure is established,and the variation law of surface subsidence with mining and filling rounds is obtained by calculation.The stress model of continuous mining and filling coal pillar is established by using the theory of elastic-plastic mechanics,and the relevant parameters of 51106 working face are substituted.The engineering size of filling branch roadway should be between 3.95 m and 6.54 m.(3)The sensitivity of rock movement and deformation affected by filling body strength,elastic modulus of filling body,filling rate and mining and filling rounds is :filling rate > elastic modulus of filling body > mining and filling rounds > filling body strength.(4)When the three-wheel continuous mining and filling method is used to mine the coal seam,there is no obvious subsidence deformation and crack evolution characteristics of the overlying strata before the last round of coal seam mining.After the completion of the last round of mining,due to the setting of the filling rate according to 95 %,a small range of coal in the immediate roof of the working face collapsed,and the overlying strata showed the evolution of the fracture zone and the characteristics of the overall bending and sinking deformation,but the more the overlying rock fracture zone development and the overall sinking deformation characteristics are less significant.(5)According to the set surface movement and deformation control index,combined with the numerical simulation results,it is suggested that the filling rate of51106 working face in the first mining face of continuous mining and filling should not be less than 95 %,the elastic modulus of filling body should not be less than 1 GPa,the mining and filling rounds should be 3,and the uniaxial compressive strength of filling body should not be less than 5 MPa.The thesis has 64 figures,8 tables and 71 references.