砂岩岩爆声发射特征及b值动态特性试验研究

在单轴加载条件下，对砂岩进行全程加载声发射试验，得到砂岩岩爆破坏过程中的应力-应变曲线、声发射参数与时间关系曲线。根据需要选择声发射累计数、震级-频度关系中的b值变化规律，研究了砂岩岩爆的前兆信息。研究表明，在砂岩弹性变形阶段后期和塑性变形阶段，声发射累计数快速增加，b值持续下降；在砂岩发生岩爆前，b值下降到最低值。对声发射累计数和b值进行联合分析，能更加准确地预知岩爆的发生。

Experiment Research on AE Characteristics and b-value Dynamic Characteristics of Sandstone Rock Burst

Under the uniaxial loading，the whole loading experiment of the acoustic emission (AE) for sandstones were made，and the stress-strain curve and the relation curve of AE characteristics change with time were obtained in failure process of rock burst.By choosing the times of cumulative AE events and based on the b-value variation in the relation between magnitude and frequency，the precursor information of rock burst was studied.The results show that the cumulative AE events increase rapidly and b-value continued to decline in the late stage of sandstone elastic deformation and the plastic deformation stage.Before the sandstone rock burst occurred，b-value decreased to be the lowest.The joint analysis of the time with cumulative AE events and b-value can more accurately predict the occurrence of rock burst.