低速夹层上瑞雷波频散曲线快速稳定反演算法

Fast and Reliable Method for Inversion of Rayleigh Wave Dispersion Curves for Lower Velocity Layers

该文提出了TDWLSA反演算法 ,有效地解决了对初始模型的选取。等厚薄层的应用 ,提高了横波速度的反演精度 ,引入权重矩阵提高数据分辨率 ,采用自适应修改阻尼因子提高迭代效果并协调分辨率与解的关系。实测资料试算结果表明 ,用该算法对低速软弱夹层瞬态瑞雷波频散曲线进行反演 ,不但具有稳定性好、精度高、分辨能力强的特点 ,而且能自动分层和反演地层参数。

Thinned Damped Weighted Least Square Algorithm is used to invert transient Rayleigh wave dispersion curves for lower velocity layers. The new efficient algorithm can overcome such serious shortcomings as the strict dependence on initial model,improve shear wave accuracy and resolution using thinned layers and weighted matrix and enhance iterative effect and adjust the relationship between resolution and solution by self-adaptation iterative damped factor. Inversion results of field data indicate that TDWLSA is characterized by good stability, high accuracy and strong resolution, and also automatically invert shear wave velocity and thickness.