基于矢量波数变换法(VWTM)的多道Rayleigh波分析方法

In the last two decades, the Multi-channel Analysis of Surface Waves (MASW) have increasingly been used in shallow seismic exploration because of its convenience and high-efficiency. In this paper, a new multi-channel surface wave analysis based on the Vector Wavenumber Transformation Method (VWTM) is proposed. By approximating the source, we derive the empirical Green's function between the station and the source on a horizontally layered model, and then perform vector wavenumber transformation to obtain a frequency-phase velocity dispersion energy image for Rayleigh waves. We first evaluate the performance of VWTM by using synthetic data, and compare it with theoretical dispersion curves. Comparing with typical MASW methods such as the phase shift method, we find that VWTM has higher resolution and better imaging quality for fundamental and higher modes in the dispersion energy image. Next, we apply the VWTM to the multi-channel transient surface wave exploration. Comparative analysis with the phase shift method shows that VWTM is convenient, practical and effective to reveal features of multi-mode Rayleigh wave dispersion, and provides useful information for the joint inversion of Rayleigh wave dispersion of fundamental- and higher-modes.