This paper investigates the fracture evolution during rockbursts of granodiorite and basalt that appeared to be representatives of two different rockburst modes under true-triaxial loading using acoustic emission (AE) analysis. In the experiments, with the macroscale ejection and failure features captured and presented by the high-speed video imaging and failed specimens, the inside micro- or meso-scale fracturing was detected and analyzed in detail by AE in terms of intensity, temporal-spatial distribution, and mechanism. The experimental results and AE analyses show that the fracture evolution during rockburst (particularly in granodiorite) exhibits hierarchical characteristics: during early loading, small local microfractures developed progressively and stably mainly by tension and clustered preliminarily; around and after the point of the crack damage stress, large-scale fractures developed and coalesced rapidly and unstably with increasing shear mechanism, and nucleation zones significantly developed; upon rockburst failure, rocks near the free face buckled or fractured and ejected rapidly, and shear ruptures suddenly ran through. The findings help facilitate the rockburst prediction and control.

本文利用声发射（AE）分析方法研究了真三轴载荷下花岗闪长岩和玄武岩岩爆在两种不同岩爆模式下的断裂演化。在实验中，利用高速视频成像捕获和呈现的宏观喷射和破坏特征以及失败的标本，通过AE在强度，时空方面对内部的微尺度或中尺度破裂进行了详细检测和分析。分布和机制。实验结果和声发射分析表明，岩爆（尤其是花岗闪长岩）中的裂缝演化具有分层特征：在早期加载过程中，局部细小裂缝主要是通过拉力逐渐稳定地发展，并初步聚集。在裂纹破坏应力附近和之后，随着剪切机制的增加，大范围的裂缝迅速发展并不稳定地聚结，成核区显着发展。岩爆失败后，自由面附近的岩石弯曲或破裂并迅速弹出，剪切断裂突然通过。这些发现有助于促进岩爆的预测和控制。