Parâmetros de resistência de RSU: abordagem probabilística para análises de estabilidade de taludes de aterros de resíduos

Abstract

For landfill designs, the practice of adopting Municipal Solid Waste (MSW) shear strength parameters is often realized based on the values available in the literature, due to the difficulties associated with sampling and testing procedure, especially in the design phase. The high dispersion of these data, due to different methods and samples used, makes it difficult to carry out geotechnical analyzes with confidence, generating uncertainties for designers. In this scenario, the probabilistic slope stability analyzes appear as an alternative to traditional methodologies, enabling the evaluation of uncertainties in the process of obtaining MSW strength parameters and in during project. These analyzes demand knowledge and understanding of the statistical behavior of the variables involved in MSW shear strength parameters. Although compilations and recommendations for MSW shear strength parameters are available in the literature, none of these studies concentrated a large volume of data by the type of test and sample characteristics to analyze variability. This research aimed to evaluate and characterize the statistical behavior of MSW shear strength parameters regarding probabilistic analyzes of landfill stability. For this purpose, a statistical meta-analysis of an extensive bibliographic survey of available data on MSW geotechnical parameters was conducted. Adjustments of distribution, descriptive statistics, position and dispersion of these data were analyzed, according to methodologies for classifying these properties. As general results, it was found that the classification of MSW data helped in the lower dispersion of data, through the collection of data with similar mechanical-morphological characteristics. This process made it possible to propose recommendations for the adoption of parameters for each type of MSW. These results were applied in the failure analysis of the Sítio São João Landfill, in Sao Paulo State, Brazil. The probabilistic stability analyzes conducted showed that the results obtained here can be used in analysis and as decision-making tools to mitigate the risks of geotechnical designs, also assisting in the evaluation of tests and researches with MSW.