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为获得含水率对松软煤体力学特征的影响规律,以淮南矿业集团新庄孜煤矿66207工作面松软煤体为研究对象,开展不同含水率条件下松软煤体的单轴和三轴压缩试验研究。研究结果表明:松软煤体的强度和变形特征呈现明显的含水率效应。随含水率的增大,其强度、弹性模量和内聚力均呈先增后减的变化趋势,且极高点含水率均在3.072%左右,而内摩擦角变化不大;煤体泊松比与含水率正相关;随围压、含水率的增大,煤体偏应力-应变曲线由软化型向硬化型过渡,破坏类型由脆性逐渐转变为延性。与坚硬煤体遇水弱化的水理性不同,松软煤体合理注水后呈现出强化的特性,其力学本质为:松软煤体块度极小,含有大量的细微颗粒,水能促使煤颗粒团聚、胶结,提高煤体强度,强化煤体。研究成果对实施松软煤层的安全高效开采具有重要的理论意义和实用价值。
In order to obtain the law of moisture content affecting the mechanics characteristics of soft coal, a study was conducted on the uniaxial and triaxial compression tests of soft coal with different moisture contents under the condition of soft coal in 66207 working face of Xinzhuangzi Mine of Huainan Mining Group. The results show that the strength and deformation characteristics of soft coal show obvious moisture content effect. With the increase of water content, the strength, elastic modulus and cohesion all showed the trend of increasing firstly and then decreasing, and the water content of the highest point was about 3.072%, while the internal friction angle did not change much. The Poisson’s ratio And the water content is positively correlated. With the increase of confining pressure and water content, the deviatoric stress-strain curve changes from softening to hardening, and the type of failure gradually changes from brittleness to ductility. Different from hard water weakened by water, soft coal is characterized by its enhanced properties after reasonable water injection. The mechanical properties are as follows: the lumpiness of soft coal is very small and contains a large number of fine particles. Water can promote coal particles to agglomerate, Cement, improve the strength of coal, strengthen the coal. The research results have important theoretical significance and practical value for the safe and efficient mining of soft coal seam.