【摘要】 超声波测试技术广泛应用材料内部缺陷与表面裂缝检测和描述,然而其声学参数同煤岩物理特性与结构特征的关系,成为该技术在地下采矿工程中应用的瓶颈问题之一。在大同煤矿集团塔山矿8212工作面采集煤块及顶板岩芯,采用美国Tektronix公司生产的超声波仪,开展不同层理方向煤岩及不同岩性岩石的超声波室内测试试验,并结合CT扫描、磨片分析等微观测试手段和覆压渗透试验获得煤岩内部物质含量组成形态及渗透特性,系统研究密度、层理方向、孔隙度、渗透率、矿物颗粒成分及大小等因素对超声波传播速度的影响。试验表明:纵波与横波波速均表现出随密度增大而增大的趋势;煤岩的超声波速有明显的层理效应,试验发现轴向与层理的夹角由小变大,其纵波和横波波速呈减小趋势,轴向平行层理煤岩的纵波、横波波速分别约为轴向垂直层理的1.22,1.23倍;纵波波速随孔隙率与渗透率的增大而减小,且煤的渗透率亦呈现明显的层理效应,轴向平行层理煤岩的渗透率约为轴向垂直层理的57.1倍;岩石矿物颗粒越细纵波波速越大,岩样纵波波速依次以细砂岩、中粗粒砂岩、含粗砂细砾岩和粗粒砂岩由大到小排列。更多还原

【Abstract】 Ultrasonic testing technology is widely used to describe and detect material internal defects and surface crack. However,the relationship between the acoustic parameters,physical properties and structural characteristics of coal rocks,has become one of the bottlenecks on the application of Ultrasonic testing technology in underground mining engineering. Based on the coal rock and roof core collected from No. 8212 working face of Tashan Mine,with the ultrasonic instrument produced by Tektronix company,an ultrasonic wave velocity test on the coal rock with different directions and different kind of rocks had been conducted. Combining with CT scanning,grinding testing and confining pressure permeability test for the grains of internal matter content and the permeability characteristics of the coal and rock,the impact of density stratification direction,porosity,permeability,mineral composition and particle size on ultrasonic propagation velocity had been studied. The results show that:longitudinal wave and shear wave velocities exhibited increase with the increase of density;the ultrasonic velocity of coal has an obvious bedding effect,with the ultrasonic ve-locity test in which the angle between axial direction and bedding direction varies from small to big,the longitudinal and shear wave velocity presents a decreasing trend,and the longitudinal and shear wave of coal rock with axial parallel to the bedding plane are respectively 1. 22,1. 23 times of the perpendicular to the bedding plane,longitudinal wave velocity increases with the decrease of porosity and permeability,and the permeability of axial parallel bedding coal rock is approximately 57. 1 times of the axial vertical stratification ones;the rock ultrasonic velocity has close relationship with internal composition and particle size,the lager mineral particle is,the greater longitudinal wave velocity is.The longitudinal wave velocity of rock sample is arranged from big to small as the order of fine sandstone,medium sandstone,containing fine grit conglomerate to coarse-grained sandstone.更多还原