石灰岩声发射特性及其演化规律试验研究

摘要

为定量描述不同应力条件下岩石材料声发射特性及其特性演变规律，分析不同应力条件下岩石声发射参数与应力、变形的量化关系，对广西高峰矿石灰岩进行了单轴压缩、拉伸和劈裂条件下的声发射特性试验，在此基础上将模糊自相似分维概念引入岩石的声发射试验分析中，就不同应力条件下岩石声发射所表现出的自相似规律进行了研究。研究表明：在压应力作用下石灰岩声发射出现短暂的“钝化期”，其声发射事件率及能量率模糊容量维记数曲线出现了“最小-回升”现象；在劈裂条件下石灰岩声发射事件频发且其声发射参数序列同样存在模糊自相似容量维特性，但其模糊容量参数的演化过程未能观测到“最小-回升”现象；在直接拉伸试验中，由于“胶结、引力”材料声发射活动具有瞬发性，不易监测，本次试验可测范围内无法计算其分维数，因此在拉伸条件下岩石试样是否具有自相似性演化规律还有待于进一步的研究。%In order to quantitatively describe the characteristics and evolution regularities of acoustic emission (AE) in different rocks under different stress conditions, the paper studied the quantitative relationship between AE pa-rameters of rocks, stress field and strain field based on laboratory tests. The paper firstly carried out the AE tests with conditions of axial compression, tension and splitting for limestone specimens of Gaofeng mine in Guangxi Provence, then introduced the fuzzy self-similarity fractal dimension concept and analyzed the self- similarity regularities of rock AE. It stated that the AE of limestone has a short deactivation period. The fussy dimension number curves of AE event ratio and energy ratio have the phenomena of “minimal rising”. In the condition of splitting, the AE event frequency and AE parameter series also have fuzzy self similar dimension characters, how-ever, there is not the“minimal rising”phenomena. In the direct tension test process, because the AE of“glue, grav-ity” material has sudden occurrence, it is not easy to be monitored, the fractal dimension can not be calculated in the monitoring scope. So, whether the rock with tension condition has the self similar character evolution is also to be studied in future.