| As the complexity of coal mining conditions intensifies, the damage resultingfrom rock burst in the worldwide has become more and more severe, which is one ofmajor disasters that affect coal mine safety. To solve this problem, the author willstudy on the rock burst in mining roadways under an extremely thick ingenious rock.By means of theoretical analysis, numerical simulation, physical experiments andmeasurement on site, a systematic study has been undertaken on the stability of anextremely thick igneous rock, the rule of pressure presentation in bottom stratum, theevolution features of stress and influential factors in preparatory working, themechanism of rock burst in the roadway during coal excavation under an extremelythick igneous rock and control techniques of rock burst in the roadway under anextremely thick igneous rock. The main innovative research results are as follows:（1）Based on the present theory of rock burst tendency, the author has putforward an improved elastic energy indexWE T and impact energy indexKE as the newdetermining index for rock burst tendency, which combine the former indicatorstogether to improve the correctness of judgments and correspond to the exactcalculation of energy release after the actual destruction of coal, thus providing anaccurate method to calculate the energy when the roadway is damaged by rock burst.（2）The author used the method of stress relief to measure on-site stresses underan extremely thick igneous rock and got the sizes and directions of the stress and itschange rule under different depths. Combined with features of the stress, the authorused the method of numerical analysis to study the effect of stress on the rock burst inthe roadway and got the features of the stress, displacement and fracture under thecondition that the direction of the maximum principal stress and that of tunnel axisform different angles.（3）Using the method of theoretical analysis, numerical simulation and actualfield measurement, the author studied the rules of stratum migration and pressurepresentation of mine excavation under an extremely thick igneous rock, the roof stressof the igneous rock, breaking span and the energy accumulation of the coal rock.From the perspectives of stress concentration and energy, the effects of an extremelythick igneous rock on the generation of high stress environment in rock burst werealso studied.（4）The author used elastic mechanics and complex variable function to calculate the distribution and the destruction sphere of stress in the roadway. With thehelp of numerical simulation, the author also studied the influence of working facemovement on the stress concentration in the roadway under an extremely thickigneous rock, the effect of superimposed stresses in the roadway area and theevolution rule of stresses in the side roadway. The study is also on the differentfactors’ influence on the stability of surrounding rock system in the roadway such aselastic wave, stress environment and elasticity modulus of roof and floor.（5）According to the fact that the occurrence of rock burst is connected with thetime and specific roadway area, the study of rock burst was divided into four stagesand four areas, thus establishing rock burst models. Through the balance of strengthsand energies, the author established the criteria of strengths and energies in theroadway. Based on the systematic idea, the author studied the comprehensivedestruction effects of rock burst and the equilibrium condition of system stability. Theauthor also designed experimental facilities and tests to prove that the research on themechanism of rock burst in the coal roadway is correct.（6）Based on the site condition that the tenth coal in mining area II102under anextremely thick igneous rock tends to have rock burst, the author put forward thecontrol measures of continual monitoring and making the strong to weak and weak tostrong for rock burst. Through monitoring the movement of the extremely thickigneous rock and the displacement of the stress of the surrounding rock system, thestress environment of coal seam will be improved and rock burst tendency will bereduced from the strong to weak to ensure mechanical equilibrium of the system.Besides, the control measures of changing the weak to strong with enhanced roadwaysupporting and the supporting effect of broken coal, corresponding measures will betaken to guarantee the safe production of the tenth coal. |
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