厚煤层综放工作面煤壁稳定性分析及合理工艺参数研究
Study on coal wall stability and reasonable process parameter in fully mechanized caving face of thick coal seam
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摘要:
厚煤层综放工作面矿压显现剧烈,合理的工艺参数选择可以有效减少综放工作面煤壁片帮、顶板冒顶及支架压架等矿压现象,割煤高度、端面距及支架工作阻力是影响综放工作面矿压现象的主要工艺参数,本文采用理论分析及数值模拟等方法对煤壁稳定性及合理工艺参数展开研究。建立煤壁与支架间相互作用的力学模型,得到满足煤壁稳定的支护强度与割煤高度的关系表达式。采用FLAC3D数值模拟分析不同采放比和端面距对综放开采端面煤壁及顶煤稳定性影响,得出不同割煤高度及端面距时,端面煤壁及顶煤的垂直应力、水平位移、超前支承应力的变化规律曲线。综合考虑煤壁及顶煤的稳定性、支架支护强度对于割煤高度的限制,确定综放工作面合理的割煤高度为2.5~3.5 m。端面距对顶煤位移的影响程度大于煤壁位移,减小端面距,综放工作面煤体的稳定性加强,确定综放工作面合理端面距小于250 mm。研究结论可为类似条件综放工作面工艺参数优化提供参考。
Abstract:The mining pressure in the thick fully mechanized caving face is severe.Reasonable selection of technological parameters can effectively reduce the mining pressure phenomena such as coal wall slicing, roof falling and support pressing.The cutting height, end distance and support working resistance are the main technological parameters affecting the mining pressure phenomenon in the fully mechanized caving face.The stability of coal wall and reasonable technological parameters are studied by theoretical analysis and numerical simulation.The mechanical model of the interaction between the coal wall and the support is established, and the expression of the relationship between the support strength and the cutting height satisfying the stability of the coal wall is obtained.FLAC3D numerical simulation is used to analyze the influence of different mining and caving ratio and face distance on the stability of face coal wall and top coal in fully mechanized caving mining.The curve of variation of vertical stress, horizontal displacement and leading abutment stress of face coal wall and top coal under different cutting height and face distance is obtained.Comprehensive consideration of coal wall and the stability of the top-coal, bracket supporting strength for the limitation of coal cutting height, to determine the reasonable of fully mechanized caving mining face of coal cutting height is 2.5-3.5 m, end face on top-coal displacement is greater than the influence of coal wall, reduce the transverse distance, strengthened the stability of fully mechanized caving coal, determine reasonable fully mechanized caving face distance less than 250 mm.The research results can provide reference for the optimization of process parameters of fully mechanized caving face under similar conditions.