Research On Bolting Mechanism Of Compound-Roofed Coal Roadway

In compound-roofed coal roadway, controling of Surrounding rock is invariably one of the difficulties in coal mining. First, compound roof is adpt to collapse ;second, deformation of surrounding rock is rather large, which affects safe production of mine. By means of theoretic analysis, numerical simulation, field observations and etc, bolt support mechanism is systematically researched. The achievements are as following:1.Through sumarizing the conceptions of compound roof on literatures, the definition of compound roof is given, the deformation traits and failure process are analysed; Based on plastoelasticity, by applying elastic and thin board theory, Mechanical model of mono-layered compound roof is established, and failure machanism of compound roof rock is analysed. As to plastic width and horizontal displacement of coal sides, based on the theories of elastic foundamental beam theory and limit equilibrium, expressions are deduced, then, it indicates that stability of coal sides can be enhanced with roof enforcement and sides suppport.2. By applying combination beam model, mechanism of bolt support for coal sides is analysed; Influences of active function and pre-stressed force on stability of surrounding rock in compound-roofed coal roadway are explored.3. On stability of surrounding rock in compound-roofed coal roadway, with numerical calculation soft FLAC, influences of factors ,comprising thickness of layers, dynamic pressure, horizontal stress and etc, are analysed and influences of parameters, including bolt length, bolt intervaland etc are explored.4 The research results of thesis are applied to engineering practices.