矿井水库煤柱坝体力学性能分析
Analysis of Mechanical Properties of Coal Pillar Dam in Mine Goaf
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摘要: 为研究矿井采空区地下水库煤柱坝体在井下作业环境中的力学性能变化以及变形情况,以李家壕煤矿为研究背景,采用实验室相似模拟和FLAC3D数值模拟的方法,首先,将取自李家壕煤矿3-1煤层的煤样按照ISRM加工成标准试样,试样按照一定时间周期浸水处理,对其进行力学性能分析实验;随后,采用数值模拟技术模拟煤柱坝体的实际作业环境,分析煤柱坝体力学性能和变形情况。研究得出:水对煤样有软化作用,随着浸水时间的增加煤样单向抗压强度、单向抗拉强度均有所下降,但并未出现规律性递减趋势;在软化作用和上覆岩层的压力的共同作用下,煤柱浸水面容易发生水平变形,变形随着时间的增长逐渐增大,靠近底板处的变形量最大,从而现场煤柱更容易遭到破坏。Abstract: To study the mechanical properties changes and deformation of the underground coal pillar dam body in the mine goaf in the underground working environment, the Lijiatun Coal Mine is taken as the research background, and the laboratory similar simulation and FLAC3D numerical simulation method are adopted. The coal samples from 3-1 coal seam of Lijiatun Coal Mine were processed into standard samples according to ISRM. The samples were subjected to water immersion treatment for a certain period of time, and the mechanical properties analysis experiments were carried out. Subsequently, numerical simulation technology was used to simulate the actual working environment of the coal pillar dam and analyze the mechanical properties and deformation of the coal pillar dam. The study shows that water has a softening effect on coal samples. With the increase of water immersion time, the unidirectional compressive strength and unidirectional tensile strength of coal samples have decreased, but there is no regular decreasing trend; under the combined action of the overburden pressure, the coal pillar immersed surface is prone to horizontal deformation, the deformation gradually increases with time, and the deformation near the bottom plate is the largest, so that the on-site coal pillar is more vulnerable to damage.