干燥及饱和岩石循环加卸载过程中声发射特征试验研究

利用YAG-3000微机控制岩石刚性试验机和PCI-Ⅱ声发射监测系统,对中关铁矿深部闪长岩分别进行干燥、饱和2种条件下循环加卸载过程的声发射试验,以探讨这2种含水条件下岩石的力学特性、声发射特征、加卸载响应比的变化情况。结果表明:水对岩石的力学特性和声发射特征具有不同程度的影响。岩样从干燥状态到饱和状态,其抗压强度降低了6.96%;整个加卸载过程中,饱和岩样的声发射能量累积数为干燥岩样的17.94%,且试件发生宏观破坏之前,饱和岩样的声发射能量累积数为干燥岩样的4.6%;干燥岩样的加卸载响应比的最大值出现在峰值强度前的很短时间内,而饱和岩样的最大值出现在裂纹的非稳定扩展阶段。

Experimental study of acoustic emission characteristics of dry and saturated rocks during cyclic loading and unloading process

By using YAG-3000 microcomputer controlled rock stiffness testing machine and PCI-II acoustic emission monitoring system，the cyclic loading experiments for dry and water-saturated diorites obtained in Zhongguan iron mine were carried out for analyzing the variation of mechanical properties，acoustic emission properties and LURR.The results show that the water content has significant influence on rock strength as well as acoustic emission properties.The compressive strength of water-saturated samples is 6.96% lower than that of dry samples；and during the whole process，the accumulated AE events of the water-saturated are about 17.94% of the dry specimen，moreover before the peak value，the total AE events of water-saturated specimen are about 4.6% of the dry specimen.Furthermore the max LURR of the dry specimen occurs just before the strength value，while the max LURR of water-saturated specimen occurs in the process of unsteady extending of the fracture.