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采用双轴刚性伺服控制系统进行花岗岩岩爆模拟试验,采用美国物理声学公司生产的PCI-2型声发射系统同步采集岩爆过程中的声发射数据,研究了不同水平构造应力对巷道岩爆的影响。研究结果表明:随着侧压的升高,花岗岩峰值强度随之增加,并且孔洞内壁初次弹射岩屑的时间提前;轴向载荷达到峰值荷载的80%~88%时,声发射进入平静期。随着侧压的增大,峰值载荷前的声发射平静期延长,振铃计数率突增点出现的时间提前;随着侧压的增大,岩样出现初始损伤的时间相对滞后。花岗岩孔洞内出现碎片弹射时,声发射b值下降到最低值,这一现象可作为发生岩爆的前兆特征。
The biaxial rigid servo control system was used to simulate the granite rockburst. The acoustic emission data of the rockburst was acquired synchronously by the PCI-2 acoustic emission system manufactured by American Physical Acoustics Company. The effects of different levels of tectonic stress on the rockburst of the roadway influences. The results show that with the increase of lateral pressure, the peak intensity of granite increases, and the timing of the initial ejection of cuttings on the inner wall of the hole is advanced. When the axial load reaches 80% ~ 88% of the peak load, the acoustic emission enters the quiet period. With the increase of lateral pressure, the acoustic emission calm period before the peak load prolongs and the emergence time of the ringing counting rate rises ahead of time. With the increase of lateral pressure, the initial damage time of the rock sample lags behind. The occurrence of debris ejection in the granite hole decreases the b value of acoustic emission to its lowest value, which can be used as a precursor to rock burst.