Early warning signals of critical transitions in rock before its sudden failure are key for forecasting geological disasters in rock engineering. Here we examined the critical slowing down characteristics of acoustic emission (AE) and precursory signals preceding catastrophic rock failure. We conducted laboratory experiments on different types of rock specimens subjected to tension and compression, instrumented by real-time AE monitoring. Based on the critical slowing down theory, AE signals monitored over the deformation and failure of the rock specimens were parametrized statistically. The results show that the critical slowing down characteristics of AE signals exist for rocks under various experimental conditions. The sudden and significant increase in the variance and the autocorrelation coefficient of AE can be used as precursors for rock failure. The time intervals between the precursory signals and rock rupture for brittle rocks under tension are smaller than those under compression. These early warning time intervals are longer and the ratios of the early warning to peak states are lower during Brazilian tests than during direct tensile tests. Furthermore, relationships between multiple influencing factors and precursory signals were discussed. We found that the precursory signals are strongly related to the intrinsic properties of rock and the external experimental conditions. Finally, the applicability and reliability of precursory signals through the critical slowing down theory were verified for rock failure by statistically analysing the laboratory data from a wide range of rocks.

在岩石突然失效之前，关键过渡的预警信号是预测岩石工程中地质灾害的关键。在这里，我们检查了灾难性岩石破坏之前声发射（AE）和前兆信号的临界减速特性。我们通过实时AE监测对受拉和受压的不同类型岩石样品进行了实验室实验。基于临界减速理论，对岩石样品变形和破坏进行监测的声发射信号进行了统计参数化。结果表明，在各种实验条件下，岩石都存在声发射信号的临界减速特性。AE的方差和自相关系数的突然和显着增加可以用作岩石破坏的前兆。张力作用下脆性岩石的先兆信号与岩石破裂之间的时间间隔比受压条件下的时间间隔小。与直接拉伸试验相比，在巴西试验中，这些预警时间间隔更长，预警与峰值状态的比率更低。此外，讨论了多种影响因素与先兆信号之间的关系。我们发现，前兆信号与岩石的固有性质和外部实验条件密切相关。最后，