Mapeamento geotécnico na região nordeste da área urbana de Caçapava do Sul/RS

Abstract

The urban growth has intensified over the years, succeeding a disorderly territorial occupation by the citizens, leading to the installation of communities in risk areas, from the geotechnical and environmental points of view. Representing a significant amount in natural disasters, the landslides desolate many places, and the lack of geologicalgeotechnical studies is still high. In this context, this work has the purpose of investigating and identifying areas in the urban perimeter of Caçapava do Sul/RS with potential risk of natural disasters. Through material knowledge (rocks, unconsolidated materials, water and relief) it was possible to verify the slope stability. The work used as methodology the densification of analyzes in favorable regions of landslides to verify the stability of these areas. Among the field data collected, soil samples were carried out for classification, rock collection, for resistance tests, and survey of geophysical profiles for soil contact characterization, altered rock and healthy rock, and to quantify the thickness of each layer. The use of aerophotogrammetry, by Remotely Piloted Aircraft System (RPAS) and satellite image data, helped in the development of the work for mapping and locating the greatest variations areas, enabling the generation of a digital elevation model (DEM). With the collected data integration (DEM, geophysical profiles, and geotechnical tests) were created a critical model of stability. The method used was the limit equilibrium, considering a circular rupture profile, with the safety factor verification. Sensitivity analyzes was created to verify the impacts determined by input parameters variation on the model's result. With the found result, was possible to identify a local situation, generating a zoning map and directing the land occupation cares.