Hydro-chemo-mechanical processes in soil samples: monitoring through electrical resistivity tomography

The electrical conductivity of a soil can be related to the electrical conductivity of its solid and fluid constituents by means of theoretical and empirical relationships, taking into account the effect of porosity, saturation degree, fabric and clay content. Hence monitoring the evolution of the electrical conductivity inside a soil sample can provide useful information concerning the progress of hydro-chemomechanical processes and the subsequent effects on both soil skeleton and pore water. With this aim a laboratory apparatus for 3D electrical resistivity tomography has been recently developed. Some applications of this apparatus to the monitoring of different geotechnical processes in which the knowledge of the water content and of ionic concentration is particularly relevant are presented.