含煤地层裂隙岩石声波速度特征试验研究

选取完整岩样、含裂隙岩样进行声波速度试验测定。统计分析试验结果得出：（1）裂隙的存在使岩石声波速度降低．声波速度降低的程度随裂隙张开度的增大而增大；（2）完整岩样纵横波速比的差小于0．1，含裂隙岩样纵横波速比的差大于0．1；（3）含裂隙岩样声波速度随围压的增大而增大，两横波速度差随围压的增大而减小。试验证明裂隙的存在降低声波在岩石中的传播速度，研究得出裂隙岩石声波速度特征，为煤田地震勘探研究的发展提供了基础性研究资料。

Experimental Study on Properties of Acoustic Velocity in Crack Rocks of Coal-bearing Strata

Acoustic speed features of intact and crack rock specimen are studied in this paper. Experimentalresults show that the crack reduced the speed of longitudinal and transverse waves. The degree of reductionincreases with the crack opening. The difference of speed ratio of longitudinal wave to transverse waveabout intact specimen is less than 0.1. The difference of speed ratio of longitudinal wave to transverse waveabout crack rock specimen is more than 0.1. Acoustic speed of crack rock increases with the confined pressure. Speed difference of two transverse waves reduces with the increase of confined pressure. Experimentsprove that the crack reduced the acoustic speed. The acoustic speed property of cracking rock has been got,offering the basic data of the development of coalfield seismic prospecting.