The Research On Section Pillar Parameter Optimization With Fully Mechanized Caving Mining In Thick Coal Seam

With the development of science and technology, the fully mechanized coal caving mining has been widely used in the thick seam mining. For thick coal seam fully mechanized coal caving mining, it will be still a difficult problem to be tackled in the coal industry that how to improve the recovery rate, reduce waste of coal resources and realize high yield and efficiency of mine. This paper takes Shanxi Yitang mine as the engineering research background, by means of theoretical analysis, numerical simulation and field measurement, the reasonable coal pillar parameters of the fully mechanized top coal face in No.10 coal seam will be optimized, finally, some achievements have been put out, which will be expected to provide some reference and guiding for the study of coal pillar width in fully mechanized caving mining section of thick coal seam.1.Based on the correlation theories, the rock mass structure of coal pillar and its mechanical characteristics, the failure mechanism and the failure modes as well as the failure deformation process will be analyzed in detail; and then the displacements of surrounding rock under the original width of coal pillar will be observed, which will draws the conclusion that the original width of coal pillar is larger, so as to provide foundation and basis for the following research work;2.Through the analysis of the strength and stability of coal pillar, the basic condition of coal pillar stability will be obtained, and with the help of relevant dataes, the paper summarizes the basic laws of the coal pillar width changed along with the depth of the coal seam, the thickness of the coal seam, the strength of the coal seam and the stress concentration coefficient, finally, based on the specific geological conditions of Yitang coal mine, it will be concluded that the reasonable width of coal pillar of the mine is 19.6m by means of empirical estimation method, load estimation method and the elastic kernel theory calculation method;3.By means of FLAC3 D numerical simulation software, the reasonable width of section coal pillar will be studied. Firstly, based on the specific geological conditions of Yitang coal mine, the numerical model will be established and the numerical simulation program will be determined; secondly, the yield failure and stress distribution of coal pillar under different schemes will be simulated and the curve of the support pressure above the coal pillar will be drawn, finally, through the analysis of the simulation results and the distribution characteristics of the supporting pressure, it will be concluded that the reasonable coal pillar width of Yitang mine’s No. 10 fully mechanized working face should be greater than or equal to 20.0m;4.The rationality of section coal pillar width will be analyzed and verified by means of field observation. First of all, according to the different research object, the paper will discuss the index of evaluating the stability of coal pillar; secondly, the observation scheme of supporting pressure and the using instruments will be introduced, finally, the 20 m width of coal pillar can be kept stable by analyzing the observation dataes.