不同层理方向煤岩单轴压缩声发射特征试验

    Experimental Research on Acoustic Emission Characteristics of Coal Rock with Different Bedding Directions Under Uniaxial Compression

    • 摘要: 为了研究不同层理方向的煤岩体变形破坏规律及声发射特性,选取同忻煤矿3-5# 煤作为研究对象,对垂直层理和平行层理2种煤样进行单轴压缩下的声发射监测试验,分析二者在强度、变形特性、声发射计数、累计计数,能量以及累计能量特征方面的差异。结果表明:二者的破坏类型不同,垂直层理煤样呈现出崩解破坏的特性,而平行层理煤样以塑性破坏为主;平行层理煤样相较垂直层理煤样,其单轴抗压强度、弹性模量、变形模量以及极限应变均呈一定程度的降低;二者的应力-应变曲线很好地与声发射计数-时间曲线、能量-时间曲线相对应,瞬时计数峰值或瞬时能量峰值可作为煤岩破坏的前兆;2种煤样声发射特征值虽具有一定的离散性,但可以认为平行层理煤样累积能量更大,计数、累计计数和能量相对更低。

       

      Abstract: In order to research the deformation and acoustic emission characteristic of coal rock mass with different bedding directions, 3-5# coal of Tongxin Coal Mine was chosen as the research object to test two kinds of coal samples with vertical bedding and horizontal bedding under uniaxial compression. We compare the strength and deformation characteristics, acoustic emission count, cumulative count, energy and cumulative energy count characteristics of two kinds of coal samples. The results show that the failure types of the two kinds of bedding coal rock samples are different, the vertical bedding coal samples show the characteristics of disintegration and destruction, and the horizontal bedding coal samples are destroyed by plastic failure. Compared with the vertical bedding coal samples, the uniaxial compressive strength, elastic modulus, deformation modulus and ultimate strain of horizontal bedding coal samples decreased to a certain degree. The stress-strain curves of the two coal samples under uniaxial compression correspond well with the acoustic emission count-time curve and the energy-time curve, and the instantaneous peak count or instantaneous energy peak can be used as precursor of coal rock failure. Although the acoustic emission parameters of different bedding coal samples have a certain degree of dispersion, it can be considered that the horizontal bedding coal samples have larger cumulative energy, lower count, lower cumulative count and lower energy.

       

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