尾矿水侵蚀下不同浸水高度砂岩声发射特征研究

Studyon Acoustic Emission Characteristics of Sandstone with Different Immersion Heightsunder Water Erosion Conditions of Tailings

为了探索尾矿水浸水高度对砂岩的损伤演化规律的影响,利用单轴压力机和声发射系统,研究了干燥、0、50、100 mm浸水高度下砂岩的应力-应变特征与声发射活动规律。试验结果表明:从干燥状态到0 mm浸水高度,声发射累积能量上升,随着浸泡高度的进一步增加声发射累积能量呈现先快后慢的降低趋势。张拉裂纹是试样破坏的主要原因,随着浸水高度的增加拉伸裂纹所占比例上升。无论浸水高度如何变化,砂岩破坏阶段的质心频率在0~500 kHz均大量出现,低频质心频率的大量出现可以看作试样失稳破坏的前兆。

To investigate the damage evolution patterns in sandstone subjected to varying immersion heights of tailings water,for the stress-strain characteristics and acoustic emission activity under dry conditions,as well as at immersion heights of 0 mm,50 mm,and 100 mm were studied by utilizing uniaxial compression and acoustic emission tystem.The findings reveal that the cumulative acoustic emission energy exhibits an initial increase from the dry state to an immersion height of 0 mm,followed by a decrease that first accelerates and then slows as the immersion height increases.Notably,tensile cracks emerge as the primary factor leading to sample failure,with their proportion increasing alongside the rise in immersion height.Regardless of immersion height variations,the centroid frequency during the sandstone failure stage predominantly occurs within the 0~500 kHz range.The emergence of numerous low-frequency centroid frequencies can serve as an indicator of impending instability and failure in the specimens.