Study On The Control Theory And Technology Of Three Roadway Surrounding Rock In Longwall Mining

Coal is China's major energy, recently, as the depth of coal mining increases, the support of surrounding rock is more and more important. Working surface roadway experience the excavation, mining on the section and under section, in the whole process, surrounding rock shows special nonlinear mechanical behavior, so the nonlinear traditional rock mass (rock) mechanics theory and analysis method will confront with new challenges. In addition, the deterioration of surrounding rock mechanics properties, the superposition secondary stress field, the superimposition and the instability of surrounding rock bolting structural are the important reasons leading to the instability and destruction of roadway. Therefore, understanding the physical properties and mechanical properties of the surrounding rock correctly, establishing the rational mechanical structure model of roadway and constitutive relation of rock mass, and finding the superposition situation of secondary stress and the interaction mechanism of rock and support are very important.In order to meet the requirements of mine construction and safety production and promote science and technology application in practice, under the engineering background of the three roadway of working surface of 104 and 105# mining face in Yamei Daning coal mining, on the basis of research achievements of the existing surrounding rock control theory and support technology, this thesis focuses on three roadway of longwall mining face, formed a complete control method of the three roadway rock stability analysis in longwall mining, from five aspects such as:the surrounding rock mass deformation and failure modes, constitutive model, the mechanical structure of three roadway, the mechanism of rock and support, and the rock pressure characteristics of the roadway systematically, In sum, the main work and conclusion including:1. The deformation, failure form and mechanism of the surrounding rock are different under the different geological conditions and engineering background. This thesis discussed on the instability forms of rock destruction during roadway in the mining face driving, and makes special analysis on the damage form and mechanism.2. Aimed at the problem of surrounding rock loose, crushing, rock burst when elastic-plastic constitutive model simulating the excavation space, the thesis proposed the opinion that the yield surface contracts when the coal rock enter the plastic zone under low confining pressure and the yield surface expands when the coal rock enter the plastic zone under high confining pressure, and applying the theory that rock strength parameter after peak changed with strain to realize reasonable description of the loose, crushing, ruptured surrounding rock, and applied in numerical calculation.3. This thesis established three roadway surrounding rock mechanics structure model of different stages in longwall mining applying key strata theory, voussoir beam theory and classical mechanics theory, deduced the relations of supporting force, coal pillar width, and coal rock mechanics properties during the different stages, and put forward the conditions to maintain roadway structure stability.4. Applying the established rock mechanics structure model to analyses the pillar stress and physical-mechanical condition, and the stress distribution of the roadway sides and coal pillar is got.5. This thesis analyzed the relationship of roadway support structure deformation and supporting force by the theory of fluctuant equilibrium of in teraction between surrounding rock and support of roadway, and gives supporting principle in the process of extraction.6. The results are applied in three roadway 501,502 and 503# of the Yamei Daning coal mine 104 and 105 mine face, supporting force at different mining stage is calculated by theory formula, the stress distribution of roadway and the depth of the surrounding rock destruction are analyzed by numerical calculation method, and the feasibility can be verified through the field observation.There are 187 figures,10 tables and 91 references...