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Physical Simulation Study To Dispersion Characteristics Of Reyleigh Surface Wave

Posted on:2015-03-19Degree:MasterType:Thesis
Country:ChinaCandidate:K ZhangFull Text:PDF
GTID:2250330428477304Subject:Earth Exploration and Information Technology
Abstract/Summary:PDF Full Text Request
Currently, research to Rayleigh surface wave theory by scholars is relatively mature, The main direction of the research is the dispersion characteristics and elliptic polarization of surface waves. The research approach are generally physical simulation and numerical simulations experiments, and basically in the sound field conditions. In recent years, acoustic-electric effect has been widely concerned and researched deeply by a large number of scholars,and it has been applied in oil exploration industry. As an objective phenomenon, acoustic-electric effect, what the advantages and disadvantages to the ordinary seismic exploration is an issue of concern.So,it is very meaningful to research the application of acoustic-electric effect in geophysical exploration.This paper describes the theory and Rayleigh wave, it’s dispersion characteristics,and the physical basis of ultrasonic physical modeling and seismoelectric effect. Using reasonable material to make different models, conducted multi-channel surface wave test on two different homogeneous half-space models and a two-layer half space model by acoustic-acoustic methods of observation,and conducted multi-channel surface wave test on a homogeneous half-space model by acoustic-electric methods of observation. The test results processed and analyzed by using time-domain analysis and spectral analysis methods verifys the correctness of this test method technology. At the same time,it not only verify the possibility of the application of acoustic-electric effect in surface acoustic wave exploration but also summed up the advantages of acoustic-electric effect.The experimental results show that the spectrum of acoustic-electric conversions signal is widely broadened comparing with the spectrum of acoustic-acoustic signal, since the receive electrode has little free frequency limitation. As a direct result, the depth of surface wave exploration has increased significantly. Moreover, as the size of the receive electrode which is ued in the acoustic-electric experiment can be made in very tiny scale,whose diameter usually is about2-3mm, is much smaller than that of a acoustic transducer, the problems caused by large size of acoustic transducer in the experiment can be effectively overcomed,and it can enhance the observation precision of physical simulation of Rayleigh wave dispersion characteristic.
Keywords/Search Tags:Acoustic-electric effect, ultrasonic seismic physical modeling, multi-channelsurface wave exploration, Rayleigh wave dispersion
PDF Full Text Request
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