单轴多级加载下岩石声发射特性试验研究

Experimental Study on the Characteristics of Acoustic Emission of Rock Nuiaxial Multilevel Loading

对大理岩和花岗岩开展室内单轴多级加载试验,得到应力—应变,声发射参数、应力与时间关系。研究结果表明:在加载初期,两者没有明显的声发射现象,表明试件中原有张开性结构面或微裂隙逐渐闭合;在稳压阶段,大理岩声发射活动水平较低,岩石中有少量新生裂纹的产生或扩展;花岗岩声发射活动显著,岩石在载荷稳定时裂隙继续发展;临近破坏时,大理岩声发射活动水平较低,花岗岩声发射活动集聚增加。室内单轴多级加载试验在一定程度上反映工程岩体分级开挖时应力调整前后声发射的变化趋势。对高应力、多扰动的深部岩体,建议现场声发射监测岩体稳定性,岩爆等地质灾害时,应掌握合适的监测时机,对多中段同时开采的矿山深部岩体应加强顶底板、围岩、矿柱的声发射监测,为现场岩体稳定性监测与预报的判据提供了借鉴和思路。

This paper offers laboratory tests on uniaxial multilevel loading of marble and granite,including stress-strain,acoustic emission parameters and stress of the relationship between time.The results show that,at the beginning of loading,the two are not apparent acoustic emission phenomenon,indicating that the original opening of the specimen surface structure or micro-cracks gradually closed;the regulator stage,marble acoustic emission activity level is low.There are rocks in a small amount of crack initiation or expansion of newborn;granite acoustic emission activity significantly,and rock fractures continue to develop at a stable load.When approaching destruction,marble acoustic emission activity level is low,granite AE activity increases agglomeration;multistage uniaxial loading test to some extent,reflect the classification of engineering rock excavation stress before and after adjustment when the acoustic emission trends.High stress,deep rock more disturbing,the proposed site geological disaster monitoring acoustic emission rock steady,rock burst like,should have the right to monitor the time,more mines in the middle of deep rock while mining,should strengthen the roof and floor,surrounding rocks,acoustic emission monitoring pillar for the monitoring and forecasting of rock mass stability criterion site for reference and ideas.