The geological-geotechnical investigation campaign plays a fundamental role in dam safety by providing essential information for assessing and managing the risks associated with these structures. It also allows potential problems to be identified, such as the presence of geological faults or unstable soils. This information allows preventive actions to be taken to avoid catastrophic collapses, through additional containment measures or the revision of the dam's design. The aim of this article is therefore to present the interpretation of the geological-geotechnical data (geophysical tests, Vane Test, triaxial tests, CPTu and mixed borehole) obtained from a robust campaign to investigate the structure of a sediment containment earth dam, raised downstream, located in the state of Minas Gerais. The use of these results meant that the structure could be evaluated with the real conditions of the terrain in different situations such as seismic or hydrostatic overloads, guaranteeing the stability of the structure. In addition, it was possible to determine the soil's capacity to withstand the loads exerted by the dammed water and identify possible points of fragility. From the results obtained in the analysis and interpretation of the structure's sections, it was possible to measure the influence of the discretization of the earth dam massif through the structure's stability analysis, which also made it possible to make a comparison with the analysis sections before and after the geological-geotechnical campaign. In addition, it was possible to discuss the importance and demonstrate that it is essential to carry out comprehensive and up-to-date geological-geotechnical investigation campaigns to ensure that dams are built and operated safely.