在刚性压力机上对岩石进行单轴全过程加载和加卸载试验,测试岩石材料在不同加载条件下受力变形过程的应力–应变、应力–时间–声发射事件累计值、应力–时间–声发射事件率关系曲线。在试验结果的基础上,分析了加载时岩石全过程声发射特性、加卸载时岩石在卸载和重复加载时的声发射特性。试验表明:在不同的应力水平进行人为卸载时在卸载过程中岩石都会产生明显的声发射;在应力水平低于峰值强度的50%时卸载后的重复加载过程中,在未达到前次加载应力水平之前时岩样的声发射事件数很少(事件率很小)或不产生声发射,即出现典型的Kaiser效应现象;而在超过60%峰值强度的应力水平卸载后的重复加载过程中则出现明显的声发射现象,即出现所谓的Felicity现象;在加载和加卸载试验中,岩石峰后破坏过程中都产生大量的声发射事件。试验还表明,对于具有中压突增型声发射特性的岩样,都有峰值前出现声发射相对平静期现象的特点。 The uniaxial loading and unloading tests were carried out on the rigid press to test the stress-strain, stress-time-acoustic emission event cumulative value, stress-time-acoustic emission of the rock material under different loading conditions Event rate relationship curve. Based on the experimental results, the acoustic emission characteristics of rock during loading are analyzed, and the acoustic emission characteristics of rock during unloading and repeated loading are analyzed. The results show that the rock will have obvious acoustic emission during the unloading process at different stress levels. During the repeated loading process after unloading when the stress level is lower than 50% of the peak intensity, A typical sample of Kaiser effect was observed with a small number of acoustic emission events (event rate is very small) or no acoustic emission before level, while in the repeated loading process after unloading at stress level exceeding 60% of peak intensity The obvious phenomenon of acoustic emission appeared, that is, the so-called Felicity phenomenon occurred. During the loading and unloading tests, a large number of acoustic emission events were generated during the post-peak rock failure process. The experiment also shows that for the rock samples with medium-pressure sudden increase type acoustic emission characteristics, there is the phenomenon that the phenomenon of relative quiet period of acoustic emission occurs before the peak value.