不同硬岩破裂失稳声发射及b值动态特征实验研究

Experimental investigation on the acoustic emission and the b-value dynamic characteristics of different hard-rock failure

为了研究不同硬岩破坏过程中声发射及b值演化特征差异,在单轴加载条件下对不同种类硬岩进行声发射实验,得到不同种类硬岩破裂失稳过程中的力学特征,分析了不同种类的硬岩声发射能量率变化特征。并基于振幅与震级之间幂律关系定义声发射b值,对比了不同硬岩破裂失稳过程声发射b值演化特征,并分析了应力水平与声发射b值演化关系。研究表明:高强度、高脆性系数的岩石,从本构关系来看,没有明显屈服点,声发射能量率量级也越大;各试件在临近破坏时的声发射b值均大幅度下降,但花岗岩下降幅度最大。

In order to investigate the difference of acoustic emission and b-value dynamic characteristics in different hard-rock failure process,the acoustic emission experiments of different hard-rock were carried out under uniaxial loading,and the stress-strain curves in the process of failure were obtained,and the dynamic characteristics of acoustic emission energy rate were analyzed and compared.The b-value was calculated based on the power law relation between amplitude and magnitude;the evolution characteristics of b-value during different failure processes were compared.The relational about stress level and b-value was analyzed.The results show that the yield points of rock with high strength and brittleness are not obvious,and the magnitude of the AE energy rate is bigger;the b-values of all rock samples began to decrease when they were fracture,but the decline of granites were greatest.