Rungroj Arjwech and Mark E. Everett

pp. 675 - 681

Abstract

Electrical resistivity tomography (ERT) is a non-invasive geophysical method of primary interest for addressing subsurface engineering problems. The method is based on the assumption that subsurface geological materials have significant
resistivity contrasts that can be identified based on measurements on the surface. This paper presents three different case
studies that have been carried out at different sites. The first case study visualizes the contrast between high resistivity zones
of hard bedrocks and low resistivity zones of weathered rocks. Similar to the first case study, the second case study shows high
resistivity contrasts that clearly distinguishes the shape of a footing located within the surrounding materials. The third case
study shows no clear low resistivity zone that can be identified as a leaking zone. The 2D ERT survey method used in these
three investigations has been shown to be useful as a cost-effective and rapid method to obtain wide area subsurface information that is relevant for subsurface engineering problems.

Keywords

• non-invasive geophysical methods
• electrical resistivity tomography (ERT)
• unknown bridge foundation determination
• seepage