Statistical comparative analysis between strength parameters of a bauxite mining tailing through laboratory tests and numerical simulation

Abstract

Tailings dams are the primary global way to solve the problem of low storage availability for tailings resulting from mining. However, the recent ruptures of this reservoir in Brazil, such Mariana and Brumadinho dams, draw attention to the importance of studies determining the geomechanical characteristics and behavior of mining tailings. With the implementation of Law nº 14066/2020, which establishes the National Dam Safety Policy, there was an increase in demands for the monitoring and inspecting dams and the imposition of bills. Given this, triaxial tests were carried out to characterize the mechanical behavior of bauxite mining tailing from a Brazilian deposit. Confining pressure of 25, 50, 100, and 200 kPa was applied. Moreover, data were obtained for applying numerical simulation modeling based on the parameters determined for this material. Therefore, this paper describes a comparison using exploratory data analysis between the results obtained in the laboratory by the triaxial test and the results obtained by the finite element method (FEM) analysis with the aid of the Abaqus software. Statistical analysis showed a greater discrepancy between laboratory and numerical simulation results. The most significant differences observed between laboratory and numerical simulation results occurred for the lowest stress levels. The greatest differences observed between laboratory and numerical simulation results occurred for the lowest stress levels. The difference was significant also in terms of behavior. This fact highlights the need for extensive geotechnical investigation to characterize the material adequately and obtain parameters to simulate the correct tailing behavior and develop a safe design for storage structures.