Study On Dispersion Characteristics Of The Rayleigh Surface Wave And It's Application

In the near-surface geophysical investigation and engineering testing, we adopt generally drilling, refraction or reflection seismic methods. Drilling is credible, but it is costly and destructive; Refraction and reflection need a big velocity difference between two layers. Specially, the refract wave exist a precondition, that is the bottom medium velocity is bigger than upper, then medium interface produces the refractive wave. If the medium exists the speed turn in reverse, and low speed in false bottom, the medium interface can not calculate. At present, we provides transient surface wave technique for this difficult. This paper just researches how to use the characteristics of transient surface wave, and apply it to the near-surface geophysical investigation and engineering testing.The exploratory technique by multichannel transient surface wave collects the seismic information by multichannel cymoscopes. It is good for our research and application of the surface wave. By it we can research the multimode dispersion characteristics of the surface wave in X-T field & in F-K field. And we can get serial dispersion curves by using Two Adjacent Channel Cross-Correlation Function. From analyzing these dispersion curves we can find the changes of the medium's structure in landscape. In my paper, all the original data for research is collected by this multichannel transient surface wave technique.Rayleigh wave is a sort of the sub-wave that travels along the surface of medium. It's energy rapidly decline along with the bigger distance to the medium surface and only get to about a wavelength depth. Frequency dispersion is a very important character of Rayleigh wave. We can get geology information by analyzing it. The article analyses multimode frequency dispersion characteristics of the surface wave which travel through three sorts of mediums, and then, research the according surface wave exploratory technique.Applying this transient surface wave technique to the road-bed quality inspection and landslide prospecting settle the matters the common method can't overcome, and get favorable application effect.