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基于真三轴试验条件的岩爆模拟声发射特征研究

Study on acoustic emission characteristics of rockburst simulation under true triaxial test conditions

  • 摘要: 为研究矿山高应力环境下深埋硐室开挖后因应力集中引发岩爆显现的声发射特征,采用TRW-3000型岩石真三轴电液伺服试验系统配合PCI-II型声发射监测系统,对大理岩试件模拟深埋硐室围岩体单面临空三向-五面应力环境开展三向独立加载和单面突然卸载试验研究。研究结果表明:声发射特征的振铃计数和b值能|反映岩石内部裂隙孔洞的发育、发展及贯通情况,临爆阶段振铃计数密集出现并达到峰值,同时声发射b值骤降,岩样内部孔洞裂隙迅速扩展发育形成大尺度裂纹,随后试件出现强烈的整体失稳破坏。因此,声发射振铃计数密集增长现象可作为判断矿山深埋硐室围岩体存在岩爆发生可能的关键阶段,声发射b值的突然降低现象可作为岩爆即将发生的前兆特征,为深部矿区开采实践提供理论指导。

     

    Abstract:  To investigate the acoustic emission characteristics of rockburst caused by stress concentration during excavation in deep-buried chambers under high-stress mining environments, true triaxial tests were performed using the TRW-3000 true triaxial apparatus coupled with the PCI-II acoustic emission monitoring system. Three-way and five-face stress environments with one side of the deep-buried chamber surrounding rocks facing air are simulated by carry -ing out triaxial independent loading and sudden single-sided unloading on marble specimens. The results show that the ringing count and b-value of acoustic emissions effectively reflect the initiation, propagation, and coalescence of inter-nal cracks and voids in the rock. During the pre-failure stage, the ringing count rapidly increases and reaches its peak. while the b-value sharply drops, indicating the rapid expansion of internal voids and cracks into large-scale fractures, leading to severe instability and failure of the specimen. The dense growth of ringing counts can serve as a key indicator of the likelihood of rockburst occurrence in the deep-buried chamber surrounding rocks, while the sudden decrease in the b-value is a precursor to imminent rockburst. These findings provide theoretical guidance for mining practices in deep underground areas.

     

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