Uso de cartografia histórica como ferramenta para a interpretação do comportamento geotécnico dos depósitos tecnogênicos em regiões portuárias de Rio Grande/RS/Brasil

Abstract

The Rio Grande city corresponds to the first Portuguese landmark in Rio Grande do Sul state. The location was chosen to the possibility of building a port at the exit of water from Laguna dos Patos to the Atlantic Ocean, in the context of vast extension of the straight coast of southern Brazil. The physiographic difficulties imposed by the region, which is part of the coastal plain active resting, throughout the evolution of the municipality, technogenic deposits were made. Thus, this paper presents the use of historical cartography geodetically referenced with field control points to determine the location and temporal evolution of these deposits. In summary, the results indicate that the territorial advances occur in three regions. Of these, two correspond to the city’s two oldest port regions: Old Port and New Port. From this, the geotechnical investigation of these two regions of technogenic deposits is interpreted through SPT and CPTu tests. Therefore, it is clear that the evaluated technogenic deposits have a predominant granulometric composition of clays and sands. However, the thin soils, due to the heterogeneity of material, caused by the constitutional and temporal variation of anthropogenic deposits, present draining behavior, unlike the natural soils of the region.