A Cost-effective 3D Electrical Resistivity Imaging Approach for Embankment Dike Assessment
C. Jodry, Y. Fargier, S. Palma Lopes, P. Côte and M. Sanchez
Event name: Near Surface Geoscience 2014 - 20th European Meeting of Environmental and Engineering Geophysics
Session: Modelling and Inversion
Publication date: 08 September 2014
Info: Extended abstract, PDF ( 1.04Mb )
Price: € 20
Although DC-electrical resistivity imaging techniques are efficient tools for embankment dike and levee investigation and monitoring, the complexity of such structures often leads to misinterpretation when conventional 2D procedures are implemented. Nevertheless, fully 3D procedures can be very slow and costly, and bring results and resolution that may exceed the needs. This paper introduces the ‘3D– inversion’ approach that allows a useful and reliable 3D vision of the investigated structure while maintaining an acceptable number of electrodes and data. To compensate the lack of dense 3D data, the approach is mainly based on i) designing data acquisition based on a reasonable number of electrodes and measurements, ii) designing a well-adapted model discretization and iii) inserting as much a priori information as possible. The building process of the numerical model requires attention, particularly on the model discretization. To exemplify this new approach, synthetic results are presented on a model that is a simplification of a real scale experimentation. Preliminary outcomes show the cost-effective potential of the 3D– approach which is to be tested on various case studies in the near future.