Study On Surrounding Rock Control Technology Of Abandoned Roadway In Fully Mechanized Top Coal Caving Face 1213-1 In Nancha Coal Mine

On the basis of the engineering research background of passing through the abandoned roadway in the gently inclined coal seam and fully mechanized top coal caving face of Shanxi Xinzhou Shenda Nancha Coal Industry Co.,Ltd.,this thesis employs the combined methods of theoretical analysis,mechanical calculation,numerical simulation and industrial test to study the failure mechanism of the surrounding rock passing through the abandoned roadway in the fully mechanized top coal caving face of gently inclined thick coal seam,the deformation and stress distribution characteristics of the surrounding rock passing through the abandoned roadway in the fully mechanized top coal caving face,and the simulation comparisons of the deformation characteristics of the surrounding rock after the abandoned roadway is filled with wood pile support and ultra-high water material,the main research results are as follows:(1)By establishing two groups of mechanical models of fully mechanized top coal caving face passing through abandoned roadway,including the model reflecting the support load and the pressure between the basic roof and the calculation model of the basic roof bending moment at different positions of the working face and the abandoned roadway,it is clarified that the coal pillar between the working face and the abandoned roadway has a significant impact on the abandoned roadway at a certain width,and the stress of the surrounding rock of the abandoned roadway before passing through the abandoned roadway is significant.(2)The three-dimensional numerical calculation model of fully mechanized top coal caving face 1213-1 passing through the abandoned roadway in gently inclined coal seam is established.It is obtained that the variation of vertical stress in different positions of the inclined direction of the working face varies greatly with the mining of the working face,and the farther it is from the abandoned roadway,the lower the variation degree of vertical stress near the abandoned roadway under mining conditions,and the more intense the variation degree of vertical stress is when the fully mechanized top coal caving face is close to the abandoned roadway.(3)Depending on the numerical simulation method,the deformation characteristics of surrounding rock after wood pile support and ultra-high-water material filling the abandoned roadway are comprehensively compared.It is obtained that after filling the abandoned roadway with ultra-high-water material,the overall strength of surrounding rock of the abandoned roadway is effectively improved,the stress concentration within the abandoned roadway area is reduced,and the roof deformation of the abandoned roadway is greatly reduced.However,the effect of wood pile support is not obvious,and the deformation and vertical stress have little change with the abandoned roadway without wood pile support.(4)The wood pile support and ultra-high-water material filling methods are tested and compared in the two sections of abandoned roadway in the fully mechanized top coal caving face 1213-1 of Nancha coal industry,and the test comparison and ground pressure monitoring schemes are designed respectively.It is obtained that the construction period of the wood pile support scheme is short,but the support effect is poor,the abandoned roadway deformation is serious,and the wood pile is dumped in the area with large local inclination angle,the roof rock and coal leakage,while the construction time of the ultra-high-water material filling abandoned roadway scheme is long.The working environment is good,which effectively ensures the safety and stability of fully mechanized top coal caving face passing through the abandoned roadway,and comprehensively verifies the good effect of filling the abandoned roadway with ultra-high-water material.This paper has 76 figures,4 tables and 76 references.