| China is rich in coal reserves, Thick coal seam reserves account for about 44% of the total reserves in China, Therefore, the thick seam mining technology to a great extent determines the level elevation of technology research and the exertion of economic efficiency of the entire coal industry of China. Over the last decade, The research and production of Large mining height hydraulic support, shearer and the scraper conveyor and other ancillary equipment have made a major breakthrough, contributed to great advances in technology of great mining height fully mechanized mining. As the great mining height fully mechanized mining has the advantage of high recovery rate, the low rate of coal gangue-containing, less coal dust production, small amount of gas emission, etc. , it rapidly developed into a new technology in the thick seam mining technology. However, through years of field observations and a lot of theoretical study many experts and scholars discover that, in similar geological conditions, With the wall of working face and the height of hydraulic support increase, the stability of hydraulic support - rock system will reduce and the accident rate will increase. If subject to impact of faults, fissures, joints, fold, collapse columns of complicated geological conditions and soft seam and the seam itself joints fractured, most likely that the stability of hydraulic support - rock system of the great mining height fully mechanized working face will be worse, the accident rate even higher, bringing serious risks to safety in production of the coal mine. In-depth and systematic study on the surrounding rock control theory and technology of soft seam great mining height fully mechanized stope, Not only provides a scientific basis for designing, mining, production safety management and decision-making of similar coal mine, at the same time is able to enrich and develop the mine pressure and strata control theory, Therefore, the study of this subject has important theoretical significance and practical significance.As the initial stage of study on the surrounding rock control theory and technology of soft seam great mining height fully mechanized stope, In this paper, the coal seam and the roof and floor of lowerpermian Shanxi formation seam 3 of Zhao zhuang coal mine in Jin cheng coal industry group were studied, Using methods such as on-site measurement, theoretical analysis, numerical simulation, and industrial test, etc., Exploratory study was done on six aspects, i. e., the regularity of mine pressure of soft seam great mining height fully mechanized stope, the structure and movement breakage regularity of roof rock, the rib fall mechanism and control techniques, the floor damage, the relationship of hydraulic support-surrounding rock and mining technology security system. The key results are as follows:(1)By on-site measurement method, the basic features and laws of the regularity of mine pressure of soft seam great mining height fully mechanized stope are revealed.(2)On the basis of the "lining beam" theory, aspects of morphology, movement breakage regularity of overlying strata of soft seam great mining height fully mechanized stope were systematically studied. A balanced structure model of main roof rock of soft seam great mining height fully mechanized stope was constructed; Two kinds of deformation instability and slip instability with the possibility of main roof "lining beam" structure,under soft seam great mining height conditions,were proposed. And these two conditions for instability occurs were also given; using the elasticity problem variational method, the mechanical model of immediate roof was solved, the relationship between the amount of immediate roof strata subsidence and therotation angle of main roof, elastic modulus and hydraulic support resistance was obtained.(3)By the numerical simulation and theoretical calculation of width of the plastic zone of coal front of the 3305 soft seam great mining height fully mechanized working face of Zhao zhuang coal mine, The mechanism of the rib fall of soft seam great mining height fully mechanized working face was obtained; the main factors of the rib fall of soft seam great mining height fully mechanized working face were analyzed, Control measures for the rib fall was proposed.(4)The set of degrees of support pressure rock bottom in front of working face and within goaf were calculated using elastic-plastic theory; rock stress calculation model for soft seam great mining height fully mechanized stope was established, Using Westergard stress function, by analyzing the model, the stope surrounding rock stress formula in the three boundary conditions was obtained; According to the Coulomb-Mohr criterion, Through the analysis of the edge of the destroyed areas of soft seam great mining height fully mechanized stope in the plane stress state and plane strain condition, the formula for calculating the depth of the greatest damage of soft seam great mining height fully mechanized stope was obtained; Using revised stope floor rock limit load calculation formula and slip-line field theory, the depth of yield damage calculation model of abutment pressure of soft seam great mining height fully mechanized stope was established, By calculation of the model, the formula of greatest damage depth of seam floor strata, the horizontal distance from the depth of the greatest damage to the face end and the length of the greatest damage of floor strata within goaf on horizontal direction were obtained.(5)Through the study of the relationship of hydraulic support working resistance and roof subsidence of soft seam great mining height fully mechanized working face, under the conditions of main roof given deformation, Hydraulic support of soft seam great mining height undertaken by a given percentage of given deformation was less than normal hydraulic support, principles were given to determine the setting load and working resistance of hydraulic support. The leakage "block" structure model of the end roof was constructed, Revealed the mechanism of the end roof leakage of soft seam great mining height fully mechanized working face, and proposed control measures. Proceeding from the relationship between the top beam length of hydraulic support and limit collapse gauge the length of immediate roof, carried out an analysis of the top beam length, pillar location of hydraulic support and roof applicability. The force model of shield-beam of hydraulic support was constructed, by granular media mechanics theory, the calculation formulas of the level of thrust and vertical pressure of shield-beam of hydraulic support were obtained.(6)In complex geological conditions, for the existence of roof strata broken severely, easy to form roof fall, severe leakage, upper corner gas easily overrun and the other hidden dangers of soft seam great mining height fully mechanized working face, With the actual situation of the 3305 soft seam great mining height fully mechanized working face of Zhao zhuang coal mine, On-site practical method was adopted to determine the support and reinforcement techniques of the roof and two side coal-walls of open-off cut and gateway, injection Malisan N material reinforcement technology advance soft seam great mining height fully mechanized working face, security measures to prevent the rib and roof fall, integrated management of working face safety measures, upper corner gas easily overrun measures. A set of perfect aid technology for soft seam great mining height fully mechanized was achieved, providing a reliable and efficient technical support for safe extraction in soft seam great mining height fully mechanized working face.In short, the thesis researches deeply and systematically into the theory and technology of surrounding rock control in soft seam great mining height fully mechanized stope, solves the practical problems existing in soft seam great mining height fully mechanized and has reference value to the future similar coal mine design, mining, product safety.
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