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针对岩爆试验及监测研究的不足,开展了直墙半圆拱形巷(隧)道岩爆单轴压缩试验、声波监测及岩爆破裂的劈裂与剪切分析。结果表明,巷(隧)道围岩呈现起伏粗糙破裂面和劈裂后的薄块体,试样整体也呈现出明显的劈裂岩爆现象;波速可以很好地反映围岩内部损伤演化进程,将围岩波速由持续不变到开始变小点作为临界损伤点,可以通过监测波速变化进行围岩岩爆的预测预报;通过监测声波波形尤其是对波形稀疏、周期变长的监测,可以很好地掌握围岩内部的全程发展变化情况;通过综合监测声波的波速、波形稀疏、周期变长,达到定性、定量相结合,及时、准确地预测、预报岩爆,以保障人员、设备安全;得出了由应力强度比和压拉比来判定劈裂岩爆发生的综合表达式以及与应力强度比岩爆烈度分级标准相对应的压拉比数值;劈裂岩爆发生的应力强度比即应力判据在0.27~0.80之间(R为10~30时);随着满足劈裂岩爆发生的应力强度比的增大,其越接近满足剪切破坏条件,破坏主要形式将向剪切破坏方向发展。
Aiming at the shortcomings of rockburst test and monitoring research, uniaxial compression test, acoustic monitoring and rock burst fracture splitting and shearing analysis of straight semi-circular arch tunnel are carried out. The results show that the surrounding rock of the laneway (Tunnel) shows undulating rough rupture surface and thin slab body after splitting, and the whole specimen also shows obvious phenomenon of splitting rock burst; the wave velocity can well reflect the damage evolution process in the surrounding rock , The wave velocity of the surrounding rock will change from the point of invariability to the point of beginning decrease as the critical damage point. The rock burst can be predicted and predicted by monitoring the wave velocity variation. By monitoring the acoustic waveform, especially for the monitoring of sparse waveform and long period, It can well grasp the whole development and change of the interior of the surrounding rock. By comprehensively monitoring the wave speed of the acoustic wave, the waveform is sparse and the period is longer, the combination of qualitative and quantitative analysis is achieved. The rockburst is predicted and predicted in time and accurately to ensure the safety of personnel and equipment ; Derived from the stress intensity ratio and the ratio of tension and pressure to determine the occurrence of split rock burst comprehensive expression and stress intensity ratio of rockburst intensity grading standards corresponding to the value of tension and compression ratio; That is, the stress criterion is between 0.27 and 0.80 (R is between 10 and 30). With the increase of stress intensity ratio to meet the occurrence of splitting rock burst, the closer it is to the condition of shear failure, the main form of failure will be to shear Cut Development.