Electrical Resistivity Imaging for Investigating Aquifer Properties

The paper presents the application of non-pervasive electrical resistance tomography (ERT) subsurface imaging surveys for the rehabilitation and strengthening of Abu Serga church in Cairo, Egypt. The use of several high-resolution geoelectrical methods derived from the field survey techniques proved to be very effective in the Non-Destructive Testing and survey of architectural heritage. In particular, the application of a tomographical approach allowed us to obtain subsurface images of the cross-sections of the bearing soil with complex layers and structures that clearly show the presence of eventual anomalies. Some experiments with geoelectrical tomographic techniques also gave very interesting results when working on historical buildings that seemed hostile to geoelectrics. This is very also interesting due to the velocity of the measurements and the data processing: this means short times and low costs.The use of micro-geophysical techniques offers many advantages with respect to some “classical” techniques under different angles: velocity of execution, non-pervasiveness and costs. The results of ERT are compared to ground penetrating radar (GPR) – they are just as detailed but are often easier to interpret at a lower cost.

Keywords: Abu Serga church, Cairo, Electrical Resistance Tomography (ERT), Architectural Heritage Preservation, Non-destructive Testing.