Rayleigh Wave Testing Of Soil Shear Wave Velocity

Because shallow stratum information can be reversed without drilling a hole, Rayleigh wave is widely used in earthquake engineering and geotechnical engineering testing in recent years. In this paper theory shear wave velocity(SWV) of subsoil based on Rayleigh wave, testing and data processing methods are systematically studied; the development and state-of-the-art of Rayleigh wave theory and its applications are summarized, fundamental principle and equipment are introduced; the data processing method of adopting Gabor transform to extract Rayleigh wave dispersion curve and reversing subsoil SWV are studied; corresponding software are developed; SWVs of two grinder foundations of Rizhao Steel Holding Group Co.,Ltd. are tested and compared with the single hole method,. The results show that the errors between Rayleigh wave and single hole method are within 28%, which satisfies the requirements of field in-situ testing can be met.Theoretical analysis method of Rayleigh wave dispersion curve is studied for the horizontal layered-model in this paper. Relation of dispersion curve and SWV is discussed. When extracting dispersion curve based on traditional phase spectrum method, it needs to restrict the phase-difference from -πtoπof two sensors. The distance of two sensors has strict requirement. Dispersion curve extraction of transient Rayleigh wave is analyzed using time-frequency analysis method, which avoids the restriction of phase-difference. Numerical experiments show that the method has high precision. It builds up a solid foundation for calculating subsoil SWV.Fortran Program is written and verified by the two grinder foundations testing data. The efficiency and precision of data processing are improved.