【作者】 杨吉平；

【导师】 李学华；

【作者基本信息】 中国矿业大学 ， 采矿工程， 2013， 博士

【摘要】 当巷道顶板是由多层薄层状煤岩互层组成，且该互层顶板具有整体稳定性较差、强度较低、层间易于离层甚至发生冒顶等特征，由顶板的变形破坏引起的巷道失稳已成为该类巷道亟待解决的关键问题之一。根据薄层状煤岩互层顶板工程地质及巷道失稳破坏特征，提出了薄层状煤岩互层顶板的概念。通过对互层顶板中夹矸组分分析及微结构特征研究，揭示了水作用下薄层状互层顶板强度弱化的内在机制。建立了薄层状互层顶板组合梁弹塑性力学分析模型，掌握了互层顶板岩梁应力分布规律；并结合薄层板状力学模型，研究了固支与简支情况下，弯曲最大变形及顶板屈服破坏时水平应力的临界值，得到了基于跨厚比判断顶板破坏的计算公式；基于夹矸的位置、层数、厚度对顶板稳定影响，提出了以极限跨度为依据的判别顶板离层的准则。采用相似材料物理模拟试验研究了无支护条件下，切顶斜矩形断面、破顶半圆拱形断面以及煤层倾角对薄层状互层顶板稳定性的影响作用，结果表明半圆拱形巷道整体稳定性较好，而斜矩形巷道易于产生顶板岩体结构的滑移错动引起的非对称性而导致变形失稳。应用FLAC^3D研究了巷道断面对薄层状巷道顶板的影响规律，对比分析了有水、无水状态下薄层状顶板变形破坏特征。基于钻孔探测方法的巷道围岩动态破坏过程监测技术，提出了以巷道内部裂隙发展发育与巷道掘出时间、空间关系为核心的薄层状顶板长期稳定性监测技术体系。研究成果在乌海能源老石旦煤矿进行了应用研究，取得了良好的技术经济效果。更多还原

【Abstract】 When roadway roof is composed of lamellar coal-rock interbedded layers, and theinterbedded roof not only possesses the characteristics of relatively poor stability andlow strength, but also is apt to separate and fall, roadway instability resulted from thedeformation and failure of the roof is already one of the key problems that need to besolved urgently.The present paper puts forward the conception of lamellar coal-rock interbeddedroof according to its engineering geology and instable failure features of roadway. Thepaper also uncovers the internal mechanism of intensity weakening of lamellarcoal-rock interbedded roof under the effect of water through the study of the dirt bandcomponents in interbedded roof and its micro-structural characteristics.This paper not only establishes combined beam elastic-plastic mechanicalanalysis model of lamellar interbedded roof, grasps the stress distribution regularity ofinterbedded roof, but also combines the thin-tabular mechanical model with it toresearch the maximum bending deformation and the critical value of horizontal stresswhen roof’s yielding failure happens in two different boundary conditions, acquires thecalculating formula based on span to depth ratio to judge whether the roof fails or not.The paper proposes the criteria to distinguish roof separation determined by limit spanon the basis of the effects the position, number of layers, and thickness of dirt band hason the roof stability.Physical simulation test of similar material is adopted to research the impacts thatoblique rectangle section, round arch section and angle of coal seam have on thestability of lamellar coal-rock interbedded roof. The consequences indicate that integralroadway stability of round arch section is relatively well, and deformation failure is aptto take place in the oblique rectangle section roadway resulted from asymmetry ofsliding of roof rock structure.This paper studies the influence the roadway section has on the lamellar roadwayroof with the application of FLAC3D, contrasts and analyzes deformation failurecharacteristics of lamellar roadway roof in the condition of water and non-water. Basedon the technology of monitoring surrounding rock’s dynamic failure process in themethod of drilling detection, this paper presents technical system of long-term stabilitymonitoring of lamellar roof which treats relation between the excavating time, spatial ofroadway and internal fracture development as a core. The research results are applied in the Laoshidan mining, and earn favorable technical and economic effects.更多还原