Responsible: Mathieu Le Feuvre (IFSTTAR)

The aim of the axis 4 is to develop a method of passive correlation, which takes advantage of the vibrations created by the swell and the backwash to obtain a more precise image of the mechanical properties of the seawalls. The objective is also to develop in the long term the automation of a remotely monitoring of the variations of these properties. Different sites will be tested to compare several types of structure geometry concerning the direction and the intensity of the swell, and thus to define a suitable site for perennial measurements.

Feasibility study of noise correlation on the seawall at high tide (Moutiers-en-Retz, 44-Fr) ; A) Typical example of recorded noise signal. B) Example of cross-correlations after application of diverse treatments, for 8 min of recording. C) Spatial distribution of noise sources, obtained by beamforming. D) Picture of the site taken in the direction indicated by the symbol of the apparatus.