Geotechnical characterization of coastal lagoon deposits in Rio Grande/RS/Brazil

This study conducted a geotechnical characterization and geobehavior assessment of two coastal lagoon deposits in Rio Grande, a port city located in the southernmost region of Brazil. These deposits belong to the Porto Velho area, the oldest port structure in the city. The tests aimed to understand the geotechnical behavior of these deposits and support future interventions and management efforts. Standard Penetration Test (SPT) surveys were interpreted, and undisturbed samples were collected using Shelby tubes. These samples were subjected to geotechnical characterization tests, free-fall cone tests, triaxial tests, mini vane tests, and oedometer consolidation tests. In summary, the results revealed the presence of fill layers overlying soft, slightly sandy clays, and at greater depths, fine to medium sand deposits with higher resistance. The geotechnical behavior of the soft clay layer was carefully analyzed and exhibited significant variability. The integration of the applied methods demonstrated their effectiveness for geotechnical analyses in coastal areas, providing valuable data for planning sustainable interventions and preserving port infrastructure. This work significantly contributes to advancing technical knowledge about soils in coastal regions and serves as a reference for future projects in similar geotechnical contexts.