An experimental study of Rayleigh waves based on seismoelectric measurements

Abstract

In laboratory acoustic experiments of Rayleigh waves, spatial resolution often suffers from the size effect of the acoustic receivers, which often cannot be scaled-down by the experimental wavelength used for model scaling due to the limitations of the acoustic technique. Based on scaled-down models with homogeneous and lateral inhomogeneous media, the laboratory experiments of Rayleigh waves are performed using acoustic and seismoelectric measurements, respectively. The measurements and resulting dispersion analysis indicate that the accompanying seismoelectric fields, which are measured by point-like electrodes, can represent the acoustic fields measured in the experiments by wide band acoustic receivers. Moreover, for the lateral inhomogeneous model, seismoelectric signals received by electrodes with a point-like size show more detail in the dispersion features of Rayleigh waves than do acoustic signals measured by acoustic receivers with a size close to that of the wavelength. This verifies that the receiver sizes have a great effect on the spatial resolution of the waves. The experimental results suggest a potential application of the seismoelectric conversion effect to the development of point-like and wide band receivers to improve spatial resolution as well as to meet the requirement of dispersion measurement in acoustic experiments of Rayleigh waves, for the size of electrodes with a broad bandwidth can easily be scaled down by using the same wavelength as that for the scaled-down model with little technical limitation.