深井厚煤层综放沿空掘巷煤柱合理尺寸研究

Study on Reasonable Size of Coal Pillar in Fully-mechanized Gob-side Entry Driving of Thick Coal Seam in Deep Mine

以山东新河煤矿为研究背景,采用理论分析与计算、数值模拟、现场监测等方法,对深井厚煤层综放面沿空掘巷小煤柱合理尺寸进行研究,建立了深井厚煤层综放面沿空巷道顶板(煤)破断结构模型,计算出上工作面侧向支承压力低应力区范围为13.3m,小煤柱合理尺寸为5~6m;利用FLAC3D模拟上工作面侧向支承压力分布特征及不同宽度煤柱下小煤柱应力分布特征。结果表明:上工作面侧向低应力区范围为14m;一方面,随煤柱宽度增加,具有承载能力的煤柱宽度增大,另一方面,煤柱上方高应力区范围也在增大,仅5m和6m煤柱顶板高应区的范围较小。现场工业实践选择留5~6m煤柱进行掘巷,由巷道表面位移监测结果知,巷道变形满足工作面回风、运输等生产要求。

In this paper,theoretical analysis and calculation,numerical simulation,and on-site monitoring were used to study the reasonable size of small coal pillar in fully mechanized top coal caving face of thick coal seam in Xinhe coal mine.The roof broken structure model of gob-side entry in the fully mechanized top coal caving face in deep coal seam was established.The range of the low stress zone of the vertical pressure was calculated to be 13.3mand the reasonable size of the small coal pillar was calculated to be 5-6m.The FLAC^3 D was used to simulate the lateral vertical pressure distribution of the upper working face and the stress distribution of the small coal pillar with different widths.The results indicate that the range of the lateral low stress zone in the upper working face is 14 m.On the one hand,with the increase of the width of the coal pillar,the width of the coal pillar with bearing capacity increases;On the other hand,the range of the high stress zone above the coal pillar also increases except for the 5mand6 mpillars.In site industrial practice,5-6mcoal pillar is chosen as the excavation roadway spacing.The roadway displacement monitoring results show that the pillar size meets the production requirements such as return air and transportation after roadway deformation.