近距离煤层群开采底板巷道围岩失稳及应力控制机理

Aiming at the instability of the floor roadway when the closed coal seams extracted, lots of closed coal seams mining in Guizhou would be taken as the research object to conduct systematic research on the instable mechanism of the roadway, which could provide theory basis for surrounding rock control. The main research contents are as follows:(1) stress evolution and distribution characteristics of surrounding rock could be obtained by analysing transmission rule of abutment pressure in floor. Combined with the typical closed coal seam mining, numerical model would be established, which could be used to analyse stress evolution path and the variation characteristics in surrounding rock and pillar during multi seams extraction. The numeric model also could reveal the damage mechanism of roadway floor including the slip, turn back, turn over induced by multi closed seams extracted. (2) A cross-mining mechanical model in which working face intersects floor at an angle, would be established considering stress control. Elastic theory of thin plate will be used for the analytical solution of roof deformation and failure, and the criterion of shear failure instability and tensile failure instability in the key strata. (3) Researching the damage mechanism of floor and the regeneration mechanism of surrounding rock bearing capacity under the condition of working face cross-mining. Finally, the comprehensive stress control mechanism of roadway would be obtained.

针对近距离煤层群开采底板巷道失稳问题，以贵州大量近距离煤层群开采为研究背景，对近距离煤层群开采底板巷道失稳机理进行深入、系统的研究，为该条件下煤矿开采的巷道围岩控制提供理论基础。主要研究内容有：（1）通过分析工作面开采过程中采动支承压力在底板中的传导规律，得到煤层群开采复合煤柱下底板围岩应力演化及分布特征。结合典型煤层群开采实际建立数值模型，分析不同层位多工作面开采过程中煤柱及底板巷道围岩应力演化路径及变异特征，揭示近距离煤层群开采复合煤柱下岩层发生滑移、折返、翻转的破坏机理。（2）从应力控制角度建立回采工作面与底板巷道相交的跨采力学模型，应用弹性力学中薄板理论研究工作面顶板变形的解析解和破断形式、关键层发生剪切破断失稳和拉伸破断失稳的判据。（3）研究工作面跨巷开采对底板的破坏机制及围岩承载能力重生机制，得出工作面跨巷调斜护巷开采的系统应力控制机理。

针对近距离煤层群开采底板巷道失稳问题，以贵州大量近距离煤层群开采为研究背景，对近距离煤层群开采底板巷道失稳机理进行深入、系统的研究，为该条件下煤矿开采的巷道围岩控制提供理论基础。主要研究内容有：(1)通过分析工作面开采过程中采动支承压力在底板中的传导规律，得到煤层群开采复合煤柱下底板围岩应力演化及分布特征。结合典型煤层群开采实际建立数值模型，分析不同层位多工作面开采过程中煤柱及底板巷道围岩应力演化路径及变异特征，揭示近距离煤层群开采复合煤柱下岩层发生滑移、折返、翻转的破坏机理。(2)从应力控制角度建立回采工作面与底板巷道相交的跨采力学模型，应用弹性力学中薄板理论研究工作面顶板变形的解析解和破断形式、关键层发生剪切破断失稳和拉伸破断失稳的判据。(3)研究工作面跨巷开采对底板的破坏机制及围岩承载能力重生机制，得出工作面跨巷调斜护巷开采的系统应力控制机理。