煤矸石侧限加载-浸水-卸载实验研究

Experimental study on confined loading-water immersion-unloading of coal gangue

采用不同含水状态破碎矸石分别进行侧限压密、蠕变观测、慢速浸水、卸载实验。实验发现,矸石轴向压缩时,应力-压缩率曲线是一条非线性曲线,可用指数函数拟合;矸石在经过实验后,发生明显的颗粒破碎,不均匀系数增大,有效粒度减小,并且浸水试样破碎程度明显大于干燥及天然状态矸石;矸石在经过浸水后,发生明显的轴向附加压缩,浸水过程中压缩率增长了9.68%,占试样压缩过程变形的37%,产生"湿陷"现象。分析认为,矸石发生浸水湿陷的机制为水对矸石颗粒的软化及水的润滑作用使得颗粒重新破碎及位置再次调整,导致矸石整体被再次压密。

Confined loading, creep observations, water immersion, unloading experiments about bro-ken coal gangue which has different water content were performed. The results showed that during the compression process, the stress-compression ratio relation can be fitted as a non-linear curve by expo-nential function; after the test, the significant particle breakage phenomenon occurred, the non-uniform coefficient increased and the effective particle size decreased and the fragmentation degree of water immersion specimens was greater than that of dry and natural state of waste rock; the axial additional compression occurred to coal gangue after water immersion, the compression rate of this process in- creased by 9.68%, accounting for 37% of the whole process, ＂collapsibility＂ phenomenon occurred; through the analysis, the mechanism of water immersion collapsibility of coal gangue is that, water sof-tening and water lubrication on the coal gangne particles made the particles re-broken and further ad-justment of the position, resulting in the coal gangue compact once again.