Assessment of Physical Properties of a Sea Dike Using Multichannel Analysis of Surface Waves and 3D Forward Modeling
D.P. Pageot, M. Le Feuvre, D. Leparoux, Y. Capdeville and P. Côte
Event name: 23rd European Meeting of Environmental and Engineering Geophysics
Session: Geophysics for Engineering Geology and Geotechnical Investigations
Publication date: 03 September 2017
Info: Extended abstract, PDF ( 669.13Kb )
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Seismic surface waves analysis methods (SWM) have been widely developed and tested in the context of subsurface characterization and have demonstrated their effectivness for sounding and monitoring purposes. Given their efficiency, SWM have been transfered to several scale of which civil engineering structures. However, at this scale, many structures may often exhibit 3D surface variations which drastically limit the efficiency of SWM application which are are mostly developed under the assumption of semi-infinite 1D layered medium without topography. Taking advantages of high-performance computing center accessibility and wave propagation modeling algorithm development, it is now possible to consider the use of a 3D elastic forward modeling algorithm in the SWM inversion process. We use a parallelized 3D elastic modeling code based on the spectral element method which allows to obtain accurate synthetic data with very low numerical dispersion and a reasonable numerical cost. In this study, we choose a sea dike as a case example. We first show that their longitudinal geometry and structure may have a significant effect on dispersion diagrams of Rayleigh waves. Then, we demonstrate the necessity of 3D elastic modeling as a forward problem for the inversion of dispersion diagrams.