低速软弱夹层二维横波速度结构的OCCAM反演

Estimation of 2D s-wave velocity section with low velocity layers by OCCAM algorithm

高速公路路基中的低速软弱夹层若处理不当,将会给高速公路的后期正常运行留下安全隐患,甚至将会导致路基结构严重的下陷和变形。本文成功地将OCCAM算法引入到瑞雷波频散曲线反演中,并获得了某路基低速软弱夹层地质结构的二维横波速度剖面。在反演过程中,权重矩阵的应用,提高了解的纵向分辨率;拉格朗日乘子光滑参数的应用改善了迭代效果并提高了解的稳定性,使其可以在解的精度和模型分辨率中取最佳折中解。实例分析结果表明,OCCAM算法用于反演低速软弱夹层瞬态瑞雷波频散曲线不但具有稳定性好、精度高及分辨能力强的优点,而且能自动分层和反演地层参数。

The low velocity layers of pavement systems usually lead to serious subsidence and deformation of a roadbed. The OCCAM algorithm has been successfully used to invert transient Rayleigh wave dispersion curves for lower velocity layers. The new efficient algorithm can improve shear wave accuracy and resolution using thinned layers and weighted matrix, and can enhance iterative effect and adjust the relationship between resolution and solution by self-adaptive iterative smooth factor. Inversion results of field data indicate that the OCCAM algorithm is characterized by good stability, high accuracy and strong resolution, and can automatically invert shear wave velocity and thickness.