本文以宁夏煤业的灵新矿的煤样为研究对象,设置煤样含水率、干湿循环次数、高盐矿井水矿化度3个变量,系统研究煤样无损吸水特性及不同浸水作用下煤样的力学性质损伤规律。并结合声发射试验获得的特征参数,量化抗压强度和弹性模量与不同含水率、不同干湿循环次数、不同矿化度间的定量关系,分析不同变量下的煤样破坏特征及裂隙发育演化过程。结果表明:含水煤样的抗压强度及弹性模量与含水率和矿化度呈线性递减关系,与干湿循环次数呈指数递减关系;随煤样含水状态(含水率、干湿循环次数)的提高,煤样内部剪切裂隙的占比逐渐增加,之后增加幅度较小;三者对煤岩介质的力学性质都存在劣化作用。煤岩介质的浸水试验有效揭示了不同浸水条件的“水-岩”耦合作用下煤岩介质的损伤破坏机理,为确保地下水库煤柱坝体稳定性研究提供有效的参考,同时可以为解决煤炭开采过程中所产生矿井水难以有效储存和利用以及大量水资源损失等问题提供有效思路。
In this paper, the water content, the number of wet and dry cycles and the mineralization degree of high-salt mine water of coal samples were set as the research objects to systematically study the nondestructive water absorption characteristics of coal samples and the damage law of coal samples under different water immersion effects. The damage characteristics and fracture development evolution of coal samples under different variables were analyzed by combining the characteristic parameters obtained from acoustic emission tests and quantifying the quantitative relationships between compressive strength and elastic modulus with different water content, different number of wet and dry cycles and different mineralization degrees. The test results show that: the compressive strength and elastic modulus of water-bearing coal samples have linearly decreasing relationships with water content and mineralization, and exponentially decreasing relationships with the number of wet and dry cycles; the percentage of shear fractures inside the coal samples gradually increases with the increase of water content (water content, number of wet and dry cycles), and then the increase is smaller; all three have degradation effects on the mechanical properties of coal rock media. The water immersion test effectively reveals the damage mechanism of coal-rock media under the coupling effect of "water-rock" under different water immersion conditions, which can provide an effective reference for ensuring the stability of coal pillar dams in underground reservoirs, and at the same time, it can provide an effective solution to the problems such as the difficulty of effective storage and utilization of mine water generated in the coal mining process and the loss of large amount of water resources. It can also provide a solution to the problems such as the difficulty of effective storage and utilization of mine water and the loss of large amount of water resources during coal mining.
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