Estimation for seismic wave propagation property of soil structure based on seismic interferometry

Thursday, 18 December 2014
Seiichiro Kuroda, Susumu Masukawa and Hidekazu Tagashira, Natl. Inst. for Rural Eng., Tsukuba Ibaraki, Japan
Recently seismic interferometry was applied to estimation for seismic response of natural ground but also those of artificial structure like a building. We applied seismic interferometry concept for retrieval of seimic response of a model dike of soil structure like a fill dam. We employed deconvolution interferometry to estimate seismic response in time domain. From the waveforms obtained from deconvolution with the motion in the basement of a model dam, we estimate traveltimes of shear wave propagating through it and its mean velocity. Estimated velocity explain the dominant frequency of a model dike well. This approach can be applicable to monitor change in seismic response of a dike induced consolidation process after construction, or by shaking during strong‐motion earthquake.

In order to examine the applicability of this method to monitoring of a fill dam, we conducted the centrifuge tests with shaking table. We can retrieve the time-domain seismic response from not only acceleration waveforms at shaking but also ambient vibration induced by the centrifuge loading. By monitoring the change in the response estimated by the application of time-lapse deconvolution interferometry, we could find the temporal change in shear velocity while shaking and its recovery process after shakin.