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The execution of interventions in the road network for its expansion or improvement implies interference in several types of reliefs, including undulated and mountainous. Considering the great variety of physical and anthropic factors coexisting along the routes of interest and emphasizing the occurrence of extreme rainfall events, the need to previously evaluate the susceptibility to mass movement on the hillsides bordering the roads becomes increasingly higher. The existence of studies to identify unstable areas aims to prevent the occurrence of inconvenience to users due to traffic interruption, damage to infrastructure and even fatalities. In the present research, shallow translational and rotational landslides were analyzed for a stretch of the BR-280 highway, located in Corupá and São Bento south, in the north of Santa Catarina. For this, maps of the physical environment identification were surveyed, and laboratory tests were performed to obtain the soil resistance parameters. With the data obtained, the interpretation of translational and rotational landslides was made, through the SHALSTAB and Bishop models, respectively, which were spatially applied in a Geographic Information System (GIS). Thus, a semaphore pattern was adopted for the union of translational and rotational landslide results, which indicates, on the map, the areas of greater instability, which require more attention, leading to the application of preventive measures, such as containment and drainage works.

This paper presents the results of a laboratory study of three expansive soil samples collected on the SC-112, an unpaved state road that connects the city of Rio Negrinho to Vila Volta Grande in Santa Catarina State, Brazil. The road's lack of pavement inhibits the development of the region by obstructing traffic during the rainy season. The study estimated the percentage of lime that would need to be added to the soil to minimize expansion of the soil and evaluated changes in the physical and mechanical characteristics of the soil. The study used the miniature, compacted, tropical (MCT) classification, which was developed in Brazil to study the properties and behavior of tropical soils. The following tests were used to study the physical and mechanical characteristics of the soil samples, soil–lime mixtures, and lime: Atterberg limits, grain size, compaction, California bearing ratio, MCT soil disk method, and chemical analysis of the lime. Lime requirements were estimated with the lime fixation point, pH, and MCT soil disk methods. The results of plasticity limit tests showed that the base exchange reactions of lime with the soil occur immediately after the addition of water to the soil–lime mixture. Use of the MCT methodology tests showed that the natural soil samples with the addition of lime changed their behavior from nonlateritic to lateritic. The addition of 3% lime to two soils and 2% to the third soil caused physical and mechanical changes in the soils that allow their use as subgrade of low-volume road pavement.