承压破碎煤体碎胀系数演变特征与机制

发布时间：2018-04-25 23:01

本文选题：采空区 + 破碎煤体　；参考：《煤炭学报》2017年12期

【摘要】：利用自制的承压破碎煤体渗流及自燃测试装置,实验测试及分析了破碎煤体在应力、应力-温度、应力-水分不同条件下的碎胀系数的演变特征与机制。研究结果表明:(1)煤样随着应力增加,碎胀系数变化具有明显的阶段性,且随应力变化服从负指数变化规律;(2)在相同的轴压下,碎胀系数随温度升高而增加,热膨胀效应明显,说明采空区煤自燃的热效应将造成破碎煤体的碎胀系数增大,堆积更为松散;(3)当破碎煤体外在水分含量增加,在相同的轴压情况下,碎胀系数随外在水分增加而增加。说明随着采空区破碎煤体外在水分的增加,破碎煤体的碎胀系数将增大;(4)破碎煤体在应力、热膨胀及湿膨胀作用下,堆积体内部颗粒发生相对移动、二次破碎、颗粒自组织再堆积,致使应力-应变曲线发生变化,进而影响其碎胀系数。
[Abstract]:The evolution characteristics and mechanism of dilatation coefficient of broken coal under different conditions such as stress, stress-temperature and stress-moisture were tested and analyzed by using the self-made self-made apparatus for seepage and spontaneous combustion of broken coal body under different conditions of stress, stress-temperature and stress-moisture. The results show that with the increase of stress, the dilatation coefficient of coal sample has obvious phase change, and the variation rule of the coefficient of dilatation is from negative exponent to that of stress. (2) under the same axial pressure, the coefficient of dilatation increases with the increase of temperature, and the thermal expansion effect is obvious. The results show that the thermal effect of spontaneous combustion in goaf will cause the breaking expansion coefficient of broken coal to increase, and the accumulation is looser. When the external moisture content of broken coal body increases, under the same axial pressure, the breaking expansion coefficient increases with the increase of external water content. It shows that with the increase of water content outside the broken coal body in goaf, the breaking expansion coefficient of the broken coal body will increase by 4) under the action of stress, thermal expansion and wet expansion, the internal particles of the crushed coal body will move relatively and the secondary crushing will take place. Self-organization and reaccumulation of particles lead to the change of stress-strain curve and then influence the coefficient of dilatation.
【作者单位】：河南理工大学安全科学与工程学院;
【基金】：国家自然科学基金资助项目(51404090,51774114,51574111)
【分类号】：TD752.2

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