二维随机介质对声波传播影响

Effects of 2-D random media to acoustic wave propagation

地层的形成是随机性和不确定性,用基于随机理论的方法来描述更为适合。利用随机介质建模的方法来描述地下介质中的小尺度非均匀性。为了考察小尺度非均匀性介质中声波的传播特性,建立了不同尺度的二维随机介质模型,利用有限差分法模拟随机介质中的声波场。分别对比不同自相关长度条件下地震记录及其波形与振幅谱,研究这些特征量与随机介质模型的自相关长度的关系。结果表明,自相关长度作为描述小尺度非均匀性尺度的参量,对声波在随机介质中传播影响很大。

The formation of stratum is uncertain and random, so it is more appropriate to model based on the random theory. The authors describe the small scale inhomogeneity in the underground medium by random media modeling. And in order to study the propagation characteristics of acoustic wave in the small scale inhomogeneous media, the authors build different scales 2-D random media models and use the finite differential method to model the acoustic field in the random media. Then compare the seismic record and its waveform and amplitude in differ- ent correlation lengths to study the relationship between these characteristic quantity with correlation lengths. The result shows that as the parameter described the small scale inhomogeneity, the correlation lengths have a great in- fluence on the acoustic wave propagation in random media.