砂岩单轴破坏损伤时空演化规律及前兆特征声发射试验研究

    Experimental Study on Temporal and Spatial Evolution Law of Damage and Failure Precursory Characteristics of Sandstone Under Uniaxial Compression Based on Acoustic Emission

    • 摘要: 研究岩体损伤时空演化规律及破坏前兆特征对围岩灾害识别预警与防治具有重要意义,通过声发射试验,研究单轴加载下砂岩损伤时空演进过程。研究发现:砂岩损伤在时间-空间域有连续演进的行为特征,损伤发育速度在关键时刻有突变,主裂隙由“成核”区域发生并向四周扩散,最终贯通试件轴向与径向;高能声发射事件,空间上多分布在砂岩内部损伤集中的区域,时间上多发生于损伤快速扩展的时期,可作为损伤传导和加剧的重要参照;高频率出现的高能声发射信号可以作为砂岩破坏失稳时间域的前兆信息,高能声发射信号的空间密度可作为判断砂岩破坏起始区域的判定信息。

       

      Abstract: The temporal and spatial evolution laws of damage and failure precursory characteristics of rock mass are of great significance to the identification, prediction, prevention and control of rock disasters. Based on acoustic emission (AE) experiment, the damage temporal and spatial evolution law and failure characteristics were studied in this paper. The results are as following: the damage of sandstone evolves continuously in time and space, and there is a sudden change in the speed of damage development at the key moment. The main crack grows from the “gathering” region and extends to the periphery, ultimately penetrating the simplein axial and radial direction; the AE events with high energy usually appear in the period of rapid expansion of damage, and the location points of the AE events are mainly distributed in the internal damage concentration area, which could be used as an important reference for damage conduction and accumulation; the high frequency appearance of high-energy AE signals could be regarded as precursor information of sandstone failure and instability in temporal domain, while in spatial domain, the spatial density of high-energy AE events would be provided as reference to judge the initial area of sandstone failure.

       

    /

    返回文章
    返回