EDA介质中地震波的传播特征

对Christoffel公式进行Bond变换得到EDA介质的Christoffel方程，并由其非零解推导出EDA介质中视横波(qSV)、横波(SH)、视纵波(qP)的相速度、群速度、偏振向量(质点的振动方向)的三维计算公式.通过模型计算分析了具有水平对称轴的各向异性(HTI)介质和EDA介质中介质对称轴的极角和方位角对相速度、群速度及偏振向量的影响，对其随极角、方位角的变化特征进行了分析，并采用Matlab进行了数值计算，对其特征采用三维显示.通过取极角或方位角为零简化得到HTI介质和具有垂直对称轴的各向异性(VTI)介质中地震波的相速度、群速度，对EDA介质中的三维计算结果进行退化验证. 通过数值计算进一步验证了地震波相速度与EDA介质对称轴的相互关系. 结果表明，通过广角地震勘探可探明地下介质的裂隙走向及密度，从而确定灾害体产状. 

The exact propagation characteristics of seismic wave in EDA media

Based on the Christoffel equation， the Christoffel equation of EDA (extensive dilatancy anisotropy) medium is derived by Bond transformation. The exact formulas for 3-D phase velocity, group velocity and polarization vector are derived from the nonzero solutions of the Christoffel equation. The influences of polar and azimuth of symmetry axis of HTI (horizontal transverse isotropy) and EDA media on phase velocity, group velocity and polarization vector are studied through numerical calculation and the results are displayed by 3D graph using Matlab, which makes the results more colorful and intuitive. By setting the polar and azimuth to zero, the phase velocity, group velocity of HTI and VTI (vertical transverse isotropy) media are derived, the 3D phase velocity, group velocity of EDA media are verified by degeneration. The result proves that it is possible to explore the azimuth of cracks, crack density, the occurrence of hazard body by azimuth seismic exploration.