煤系岩石声波速度及其影响因素实验分析

Experimental Research on Acoustic Wave Velocity of Coal Measures Rocks and Its Influencing Factors

岩石声波速度是岩体质量评价的重要指标,通过超声-时间动态测试方法系统地研究了煤系岩石声波速度特征,探讨了影响沉积岩石声波速度的主要因素,建立了沉积岩石纵、横波速度之间及其与沉积岩石密度、围压和含水量之间的定性定量关系.研究结果表明,砂岩和石灰岩的纵、横波速度一般要高于砂质泥岩、泥岩和煤.沉积岩石的横波速度与纵波速度之间呈现出很好的线性相关性,反映出横波速度大约为纵波速度的3/5.沉积岩石的声波速度受沉积岩石密度、围压和含水量等因素所控制,且随着岩石密度、围压和含水量的增大而增大,但由于岩性不同,岩石的声波速度增高的速率则不完全相同.

Acoustic wave velocity of rock is the most important index in quality estimation of rocks. Using the ultrasonic-time dynamic test method, we studied the characteristics of rock＇s acoustic wave velocity in coal measures, discussed the key factors affecting acoustic wave velocity of sedimentary rock, and established the qualitative and quantitative relationships between longitudinal wave and transverse wave velocity of sedimentary rock, between the rock＇s acoustic wave velocity and its density, and between confining pressure and moisture content. The resuits show that both longitudinal wave and transverse wave velocities of sandstone and limestone are higher than that of sandy mudstone, mudstone, and coal. The transverse wave veloc- ity （Vs） and longitudinal wave velocity （Vp） of sedimentary rock shows a good linear correlation and that transverse wave velocity （Vs） is about three-fifth as much as longitudinal wave velocity （Vp）. Acoustic wave velocity of rock is controlled by some factors such as rock density and confining pressure. In addition, it increases with the increase of rock density and confining pressure. But because of the difference in lithology, the increasing speeds of acoustic wave velocity of the rocks are not always the same.