关键词: 在深埋地下岩石工程开挖过程中, 岩爆是多发的工程灾害, 且大多表现出明显的时滞性, 即大部分岩爆并不是随开挖而即时发生, 而是会滞后开挖一段时间。针对深埋地下岩石工程围岩发生时滞性岩爆的实际应力特征, 开展了锦屏二级水电站大理岩单轴压缩时滞性破坏试验研究。试验结果表明：在应力峰值前的长时间单轴压缩作用下, 硬脆性大理岩的破坏表现出明显的时滞性, 大理岩岩样在时滞性压缩破坏过程中会产生大量的竖向裂纹, 破坏时会产生大量的片状破裂碎屑, 岩样发生时滞性破坏时的环向应变不仅大于自身的轴向应变, 而且也大于其常规单轴压缩破坏时的环向应变, 当环向应变接近或超过轴向应变时, 大理岩发生剧烈脆性破坏的可能性将明显提高。研究结论对于深入认识岩爆的时滞性机制以及建立时滞性岩爆的预测方法具有重要的意义和启示。

Abstract: Rock bursts are often observed during the excavation of deep rock engineering; and most of them occur some time after the excavation. The time-lagged uniaxial compressive test for the marble from Jinping II Hydropower Station was conducted to study the time-lag properties of rock burst. The test results show that: the hard brittle marble obviously performs time-lagged destruction under long time of pre-peak stress uniaxial compression. Many vertical cracks occur during test process; and lots of sheet debris are created when the marble failure. The circumferential strain of marble sample is larger not only than its axial strain but also larger than its circumferential strain by conventional uniaxial compression test. The dramatic brittle failure of marble may happen more frequently if the circumferential strain approaches or exceeds the axial strain. The research results will play a great role in understanding the mechanism of time lag of rock burst and establishing the prediction method of rock burst.

Key words: rock burst, uniaxial compressive test, time-lag property, circumferential strain, axial strain