Control Mechanism And Engineering Application Of Ground Gangue Grouting And Filling In Rock Strata After Coal Mine Mining

The disposal and utilization of solid waste in mines is one of the main problems facing coal mining in China,which seriously restricts the coordinated development of coal resource development and environmental protection.Underground filling is one of the important technical approaches for green and efficient disposal of solid waste in mines.However,the existing underground filling technology faces the problem of spatiotemporal interference between solid waste filling and coal mining,which reduces the efficiency of mining and filling and limits the development and application of filling technology.The technology of injecting and filling gangue into the subsequent space of coal mining is a new way to achieve the disposal of solid waste in mines and control the movement of rock layers,which helps to solve the problem of the impact of underground disposal of gangue on coal production efficiency.However,the spatiotemporal evolution of subsequent space voids,the migration and diffusion rules of gangue slurry,and the theory of controlling rock layers by injecting and filling gangue are not yet clear.Therefore,this thesis revolves around the theme of the movement control mechanism and engineering application of ground gangue grouting filling rock layers after coal mining,and focuses on two scientific issues: the spatiotemporal evolution of subsequent space gaps,the migration and diffusion law of gangue slurry,and the control mechanism of gangue grouting filling rock layers.Comprehensive research methods such as on-site investigation,theoretical analysis,numerical simulation,physical simulation,and laboratory experiments are used,We conducted research on the connotation of subsequent space gangue grouting and filling technology,the characteristics of subsequent space structure and the spatiotemporal evolution law of porosity,the simulation system and diffusion morphology of heterogeneous gangue slurry grouting,the equivalent filling rate model and key rock deformation control of subsequent space gangue grouting,and the movement law of subsequent space gangue grouting and filling rock layers.Industrial experiments were conducted in a Coal Mine in Ordos,Inner Mongolia,The innovative achievements achieved are as follows:(1)A spatial layout method for the multi-source gangue slurry injection system in the subsequent space of coal mining was proposed,and a calculation model for the void ratio in the subsequent space collapse zone,fracture zone,and separation zone was constructed.The influence of mining parameters on the spatiotemporal evolution law of the void ratio in the subsequent space was studied,and the distribution morphology and quantitative distribution characteristics of the void ratio in the subsequent space were revealed.A method for optimizing the layout of gangue grouting filling boreholes and grouting timing was established.(2)A simulation test platform for fluidized grouting and filling of gangue was developed,and a visualization simulation method for heterogeneous gangue slurry was established to characterize the fractured rock mass in the subsequent space using transparent crystal stones.The influence of parameters such as void ratio,injection pressure,and slurry properties on the migration and diffusion of slurry particles in the subsequent space voids was revealed,and the distribution and diffusion characteristics of the "circular cone" shape of gangue slurry in the subsequent space were characterized.(3)We studied the bearing performance of heterogeneous gangue slurry under instantaneous compression and creep compression,and proposed an equivalent enrichment rate characterization method and theoretical model for the subsequent control effect of space gangue grouting on rock layers;We studied the overlying rock transport characteristics of collapse mining and subsequent space equivalent grouting filling,revealed the rock control mechanism of subsequent space gangue grouting filling,and conducted industrial experiments on subsequent space gangue grouting filling in a Coal Mine.The thesis mainly consists of 141 figures,21 tables,and 201 references.