有岩爆倾向岩石的声发射特征试验研究

Experiment Research on Acoustic Emission Characteristics of Burst-Prone Rocks

在一次循环加卸载条件下,通过对有岩爆倾向的石英闪长岩破坏过程的声发射试验,研究了声发射事件数(AE数)、能量、事件率、能率与应变、时间的关系以及AE信号的频谱特征。试验结果表明:岩石经历了初始压密段和非弹性塑性破坏段2个阶段。卸载条件比初始加载条件下的声发射活动要强烈,卸载作用进一步促进了岩石非稳定性破坏;岩石在发生破坏前,AE率与能率突然急剧增大;在加载-卸载-加载过程中,声发射活动的主频表现出了先低频再中频,最后到高频并伴随次高频出现的这样一个发展过程;这为此类岩体的岩爆预报提供了一定的依据。

Through the acoustic emission（AE）experiments on the failure process of burst-prone quartzitic diorites under one-cycle loading and unloading condition, the characteristics of spectrum of AE signal and the relations among AE counts, energy, AE rate, energy rate, strain and time were studied. The results show that the rock experiences an initial consolidation stage and a non-elastic stage. The acoustic activity is stronger under unloading than under initial loading condition and the unloading further promotes the instable deformation. Before the deformation, AE rate and energy rate sharply increase and in the loading-unloading-loading process, the main frequency of acoustic activity develops in a process of low frequency, medium frequency, high frequency and then sub-high frequency, which can be reference to the rock-burst pre- diction for this type of rockmass.