Data fusion of in situ geophysical and geotechnical information for levee characterization

Due to the lack of knowledge concerning their construction and their history (breaks and repairs, extensions horizontal ellipsis ), fluvial levees are often badly characterized. Breaks of work are likely to lead to disastrous consequences such as loss of lives and economic disasters. In order to prevent the risk of breakage, special supervision of the protection levee is required. Recognized methodologies for the assessment of hydraulic structures include complementary geotechnical and geophysical reconnaissance methods. This work presents a new way of mathematically combining data from these two types of information sources, taking into account the specificities of each kind of method (level of imperfection associated with the data, spatial distribution of the information). This new methodology considers the framework fixed by the theory of belief masses and improves the characterization of lithological sets within levees. It provides information on the level of conflict between information sources while proposing a confidence index associated with the results. The methodology is implemented through a subsoil section characterized by a real earthen levee investigation campaign. This campaign involves electrical resistivity tomography as well as particle size distribution from laboratory testing and on-site cone penetrometer test. The results highlight the ability of this fusion methodology to characterize the considered materials as well as to specify the positions of the interfaces and the associated levels of confidence.

Automated summary

This study introduces a new method that combines data from geotechnical and geophysical reconnaissance methods to improve the characterization and evaluation of fluvial levees, enhancing the representation of lithological sets and providing a confidence index for the results. This fusion methodology proved effective in characterizing materials and determining interface positions with associated levels of confidence during a real earthen levee investigation campaign.