| In Rayleigh wave exploration, the digital processing of data plays a very important position.
This directly affects the interpretation of ground effect. Therefore, the use of accurate
processing software and effective method in the Rayleigh wave exploration has important
theoretical and practical significance.
Previously, Rayleigh wave dispersion curve obtained by the one-dimensional phase
analysis. This method requires channel spacing should be less than the effective wavelength.
And minimal phase error will cause great changes in the phase velocity of Rayleigh wave.
Damped least square method is a local linear model. It is easy to cause that inversion
objective function cannot find the global optimal solution. Therefore, the method and the
technology used in the past are difficult to apply the requirements of the current Rayleigh
wave exploration.
This study focused on the related technologies and algorithms of F-K domain dispersion
curve extraction and GA global non-linear inversion, and combined with the impact of
Rayleigh wave data acquisition parameters and the characteristics. Rayleigh wave
exploration data processing software design and process technology research is
completed.
Firstly, the article describes the theoretical basis of Rayleigh wave method. This is also
part of the theoretical basis of following treatment. The theoretical proof of existence of
Rayleigh wave Dispersive in layered strata.
Secondly, F-K domain dispersion curve extraction tests showed that the method
can overcome the one-dimensional digital processing technology deficiencies, and
make full use of multi-channel Rayleigh wave data record information. GA global
non-linear inversion indicated that the inversion is not easy getting into local optimal
solution.
Thirdly, some examples illustrate each mode Rayleigh wave dispersion curve
characteristics in the X-T domain. Tests demonstrated the impact on their extraction of
dispersion curves. Parameters change example (including the X-T removal window,
collection order, and channel interval) shows the impact on the F-K domain energy spectrum.
The shape of the H-V domain dispersion curve shows the initial inversion model setting
method. Some example presented GA inversion parameter settings.
Finally, Rayleigh wave exploration data digital processing examples presented software
and processing techniques, including data browsing, array parameter, dispersion curves
picking, S-wave velocity inversion and profile. The results show that the software is very
user-friendly, human-computer interaction and graphical capabilities. F-K domain dispersion
curves extraction and the GA global non-linear inversion is very accurate. Wish to make
further use of the FV domain frequency dispersion curves extracted, as well as other
non-linear inversion method. |