Abstract: Based on the analytic solution of body-wave velocities and polarizations for arbitrary spatial orientation TI media (ATI), the characteristics of body-wave velocities with azimuth variation in ATI media can be obtained by using simulating calculation. The result shows that the body-wave propagation in ATI media is related to not only the five elastic constants of TI media, but also the dip angle of the symmetrical axis of TI and the azimuth between the symmetrical axis of TI and the survey line. That is, the spatial orientation of TI symmetry axis and surveying line azimuth have an effect on body-wave velocities. The patterns of body-wave group-velocities and phase-velocities are fixed relative to TI symmetry axis and exhibit certain symmetry and repetition of azimuth variation. For complex structural geology of ATI areas, this research can provide the patterns of body-wave group-velocities and phase-velocities to benefit the theoretical research. The result can also be used directly to analyze VSP and cross-well seismic data.

Key words: ATI media, Group-velocity, Phase-velocity, Azimuth variation

摘要： 基于任意空间取向TI介质(简称ATI)中体波速度和偏振解析解,通过模型数值计算给出ATI介质中体波群速度和相速度的变化特征,说明TI空间取向与测线方位对速度的影响。研究表明,体波群速度图案和相速度图案相对TI对称轴固定,随TI对称轴倾角及其相对测线方位角的变化呈现出一定的对称性和重复性;可以针对ATI地区的地质情况,给出体波群速度和相速度变化图案,为进一步的理论研究提供便捷。此结果也可以直接用于VSP(垂直地震剖面)和井间地震资料的分析研究。

关键词: ATI介质, 群速度, 相速度, 方位变化