Cluster Analysis for Cavity Detection Using Seismic Refraction and Electrical Resistivity Tomography

Geophysical methods (in particular ERT technique) constitute an excellent tool for the detection of buriedcavities. However the integration approach of e different geophysical methods could minimize the ambiguity ofgeophysical interpretation of the buried cavity. The technique of electrical tomography has been joined to thetechnique of seismic refraction tomography in order to obtain more robust interpretations. Many tests have beencarried out using synthetic data and experimental ones. It was finally used a statistical approach based on clusteranalysis of the P-wave velocity, the density of the seismic rays and the electrical resistivity of the synthetic andexperimental models. Distribution maps of the cluster in multi-space were built, allowing to better define andinterpret the anomalies of the subsoil.