【摘要】 利用MTS 815试验机和声发射监测系统对单体岩石、单体煤和煤岩组合体进行单轴试验下的声发射测试,找出三者之间破坏机制的差异,从而为现场微震监测提供指导。试验结果表明,随着荷载的增加,单体岩石、单体煤及煤岩组合体的累积声发射数都增加,并且煤及煤岩组合体单位体积的声发射数要比岩石的声发射数高1个数量级,这主要是煤的强度较低且内部结构松软破碎所致。通过区分不同时段的声发射特征,得出三者破坏存在本质差异:随着荷载的增加,岩石的时段声发射数逐渐增多,煤的时段声发射数逐渐减少,而煤岩组合体的时段声发射先逐渐增加后逐渐减少。岩石的抗拉强度最高,煤的最低,而煤岩组合体的位于单体岩石和煤之间。对于煤岩组合体,岩石内部的声发射数约占声发射总数的10%～30%,煤体占70%～90%;并且声发射的空间分布主要受煤体结构及原生裂隙的影响。更多还原

【Abstract】 Both of MTS 815 testing system and acoustic emission(AE) monitoring system are used to measure the AE activities of single rock,single coal and coal-rock combined body under uniaxial compression test.We focus on finding the discrepancies of failure mechanisms of the three;and then it can provide guidance for microseismic monitoring in the field.The experimental results indicate that with the increase of load,the cumulative AE numbers of single rock,single coal and coal-rock combined bodies are increasing.In addition,the AE numbers of unit volume of single coal or coal-rock combined body is about 1 order of magnitude more than those of single rock.It can be attributed to the low coal strength and its internal fractured structure.Through comparison of the AE numbers of different periods,we find the essential characteristics among the three kinds of samples.With the increase of load,the AE number in a time interval gradually increases in rock,decreases in coal,and increases initially and then decreases in coal-rock combined body.In the three kinds of samples,single rock and coal have the maximum and the minimum failure strength,respectively.However,the failure strength of coal-rock combined body lies in between the single rock and coal.For the coal-rock combined body,the AE number accounts for about 10%–30% in rock,and about 70%–90% in coal.In addition,the spatial distribution of AE activity is mainly affected by the coal initial internal micro structure and the primary micro cracks.更多还原