Otimização da geometria de um solo reforçado a partir de investigações geotécnicas do solo e seu impacto no custo e fator de segurança: estudo de caso

Abstract

With city growth, lots with the most varied topographies start to be adapted to receive constructions. The presence of an unstable slope near constructions can result in loss of human lives and in material or environmental damage. There are many Brazilian regulated standards that determine minimum factors of safety, looking after the security of human life and patrimony. In a construction, when there is need of stabilizing a slope with a retaining structure, certain construction companies dismiss the stage of characterization tests with the soils from the lot and the landfill. Such companies use standard penetration tests and visual analysis to estimate relevant data of the retaining structure design. Such measure, while reducing the time and cost from the design stage, may result in: construction of a structure that is unable to withstand the requiring loads, or execution of an oversized retaining structure, which delays the project delivery and makes it more expensive. This case of study analyses one retaining structure of reinforced soil with the sides of gabion, located in the back of a residential venture in which the foundation and landfill soils were not tested, in order to know if the constructed structure offers risks, or it is stable but over-dimensioned, or it is stable with the best cost-benefit relation. In this study, from the landfill soil characterization tests, it was obtained less conservative parameters than the ones considered in the original design. When analyzing the standard penetration test report to determine the foundation soil parameters, the same happened. From the parameters found, this study redimensioned the retaining structure design in order to reach the determined factors of safety, while staying close to them. The results of this study indicate that the cost of this case study’s structure could have been reduced up to 13.94%, which justifies the necessity to perform a profound investigation of the soils in the design stage.