公开(公告)号：US20250138209A1

公开(公告)日：2025-05-01

申请号：US18641019

申请日：2024-04-19

Applicant: DALIAN UNIVERSITY OF TECHNOLOGY

Inventor： Yaohui XUE ,  Zhiqian DONG ,  Gang LI ,  Dinghao YU ,  Yaozhong CUI ,  Hongnan LI

IPC: G01V1/30 ,  G01V1/28

Abstract: A multi-mode surface-wave free-field inversion method based on dispersion properties of layered media addresses the inaccuracy in existing methods that ignore higher modes. A novel approach for characterizing the participation quantity of each mode is proposed based on an energy flux density, which is applied to calculate a modal participation factor through dispersion curves and the frequency-domain dynamic stiffness matrix. Next, the ground surface-wave components with dispersion properties are transferred from the time domain to the frequency domain and decomposed into harmonic components composed of individual frequencies by the Fast Fourier Transform technology. These harmonic components continue to be decoupled as multiple modes by the modal participation factors, with each single-mode component being inverted to construct single-mode surface-wave free fields. Finally, all single-mode surface-wave free fields are superimposed following the mode superposition principle to form the multi-mode surface-wave free fields.

公开(公告)号：US20240264322A1

公开(公告)日：2024-08-08

申请号：US18641022

申请日：2024-04-19

Applicant: DALIAN UNIVERSITY OF TECHNOLOGY

Inventor： Gang LI ,  Yaohui XUE ,  Zhiqian DONG ,  Dinghao YU ,  Hongnan LI

IPC: G01V1/28 ,  G01V1/32

CPC classification number: G01V1/284 ,  G01V1/32

Abstract: The present invention provides a multi-phase wavefield inversion method considering both body waves and surface waves in half-space of rock media to address the deficiency in existing methods that neglect surface wavefields. In the present invention, Rayleigh components that strictly satisfy standard elliptic polarization characteristics in a half-space are extracted with Snell's Law of complex angles and the forward modeling and inversion theory of body waves. Then, the phase separation is executed to separate the body and Rayleigh waves. The pre-arrival components of S-waves are truncated to solve optimal incident angles of body waves. Thus, a Rayleigh wavefield inversion is implemented with ground Rayleigh components, and a body wavefield inversion is implemented with ground body components and their incident angles. Finally, based on linear elastic characteristics of the half-space of rock media, single-phase body wavefields and Rayleigh wavefields are superposed to form total multi-phase wavefields with the linear superposition principle.