School of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo　 454003,China

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。

Using the self-made testing device of coal seepage and spontaneous combustion of compacted broken coal, the evolution characteristics and mechanism of bulking coefficient of broken coal under different conditions of stress, stress-temperature,and stress-water were tested and analyzed. The results show that:① the bulking co-efficient of bro- ken coal has obvious stage with the increase of stress,and the change rule of bulking coefficient under the stress meets with the negative exponent. ② under the same axial compression,the bulking coefficient increases with the increase of temperature,and the thermal expansion effect is obvious,which indicates that the thermal effect of spontaneous com- bustion will increase the bulking coefficient and loose the accumulation of broken coal in gob. ③ when the water con- tent increases in vitro of the broken coal,under the same axial com-pression,the bulking coefficient increases with the increase of external moisture,which shows that the broken coal bulking coefficient will increase with the increase of water. ④ under the action of stress,thermal expansion and wet expansion,the internal particles occur relatively moving in the accumulation body, secondary crushed and granular self-accumulation, which cause the stress-strain curve change,and the bulking coefficient affected.

CHU Tingxiang,LI Pin,CHAO Jiangkun,et al. Bulking coefficient evolution characteristics and mechanism of compacted broken coal[J]. Journal of China Coal Society,2017,42(12):3182-3188.