大尺度冲击性煤体电阻率变化规律的实验研究The Experim ental .PDF

24 2 () Vol. 24 No. 2 2010 6 Journalof niversity of South China( Science and Technology) Jun. 2010 : 1673- 0062( 2010) 02- 0015- 04 大尺度冲击性煤体电阻率变化规律的实验研究 王云刚 ( , 454003) :在未加载条件下对大尺度煤样的电阻率测试结果表明,在自然状态下煤样的 电阻率较大; 过浸泡后其电阻率明显下降.在单轴压缩条件下的大尺度冲击性煤样 电阻率实验表明, 电阻率变化曲线整体上成不对称的/ 凹0型, 基本符合二次曲线; 煤 样电阻率随压力增加逐渐减少, 当达到一定的应力值时, 电阻率达到最小值; 继续加 载, 电阻率将升高, 直到完全失稳. 1#3#和 4#煤样单轴抗压强度与其受载过程中的 视电阻率变化存在一定的正相关性; 受载煤体的电阻率变化与其变形破裂过程中的 裂隙分叉发育汇合贯通密不可分; 兼有剪裂和拉裂特点的破坏类型可能是大尺度 煤样较常见的破坏形式. :大尺度煤体; 冲击倾向性;视电阻率;前兆信息 + : TQ531; TD324 . 2 : A TheExperimentalStudy on theApparentResistivity of Large- scale CoalSampleswith BurstTendency WAN Yun- ang ( School of Safety Science and Engineering,H enan Polytechnic niversity, Jiaozuo, Henan 454003, China) Abstract: In this paper, the characteristics and rules of the apparent resistivity of large- scale coalsampleswith burst tendency are studied. Expermi ent results show that the appar- ent resistivity of coalsamples are relatively large in natural state and decrease significantly afterwater mi mersion, and the apparent resistivity curves of coal samples in the uniaxial compression are like asymmetric concave type, which is basically in line w ith quadratic curve. The positive correlation between theuniaxial compressive strength and the apparent resistivity changes of 1#, 3#, 4# coal samples is studied and the apparent resistivity chan- ges of coal samples under load are closely associated w ith the bifurcation, expand, conflu- ence and connection of their cracks. The failure typew ith the characteristics of both shear : 2010- 05- 15