裂隙岩体声波传播特征数值模拟研究

Numerical Simulation of Acoustic Wave Propagation in Fractured Rock

以工程中常见的裂隙岩体为研究对象,采用显式动力有限元法研究了不同长度、宽度、倾角、密度、形态(连续与断续)的裂隙对岩体声波传播特性的影响,测试了声波在裂隙介质中的衰减规律。以ABAQUS为数值分析平台,对裂隙介质中的声波传播过程进行数值仿真分析。结果表明,波幅的衰减取决于垂直于波传播方向的裂隙水平投影长度,裂隙水平投影长度越大,波幅衰减量越大;波幅衰减几乎不受裂隙宽度的影响;随着裂隙密度的增加,波幅衰减速度明显加快;裂隙形态(连续与断续)对波幅影响不大。将模拟结果与相关试验进行对比,发现数值模拟和相关试验结果符合较好。

By taking the fractured rock mass as a research object,this paper researched the acoustic characteristics of the non-through crack specimen with different lengthes,widthes,angles,densities and shapes(continuous and discontinuous)by the explicit dynamic finite element method.The law of acoustic attenuation in fractured media was tested.By taking ABAQUS as the numerical analysis platform,the propagation process of sound wave in the fractured media was analyzed by numerical simulation.The results show that the attenuation of the amplitude depends on the horizontal projection length of the crack on the direction perpendicular to the wave propagation;the larger the length of the projection length is,the greater the amplitude attenuation is;amplitude attenuation is almost free from the impact of the width;with the density increasing,the amplitude decay is significantly faster;fracture patterns(continuous and discontinuous)have little effect on the amplitude.The results of numerical simulation are well agreement with experimental results.