Proposta de método para avaliação da erosão hídrica em taludes de pilhas de estéril e verificação da eficiência do uso de cal como revestimento de proteção

• Ano de defesa: 2025
• Autor(a) principal: Daniel Luiz Teixeira Ferreira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais
• Palavras-chave em Português: Engenharia sanitária; Recursos hídricos - Desenvolvimento; Taludes (Mecânica do solo); Cal; Chuvas; Métodos de simulação; Erosão
• Link de acesso: https://hdl.handle.net/1843/82480

Mining is an anthropogenic activity essential for Brazil’s economic development. However, in the pursuit of natural resources, mining activities cause alterations in landscapes and local biodiversity, potentially exceeding the resilience limit of natural systems. Mineral extraction is an activity that accelerates erosion processes, for example, through the removal of vegetation cover for the opening of mining pits and the deposition of unwanted materials, such as tailings and waste, which leave the soil exposed to erosive agents, increasing the risk of siltation, eutrophication of water bodies, among other impacts. It is common practice in mining enterprises to dispose of waste in piles dumps, whose slopes are subject to water erosion. Therefore, determining water erosion is relevant to ensure proper engineering planning for these structures, aiming for environmentally sustainable implementations. Additionally, seeking elements capable of reducing such erosion is necessary to minimize material transport and deposition. Thus, this work aimed to evaluate water erosion on waste dumps slopes in laboratory-scale experimental plots using the modified Inderbitzen experiment with a rainfall simulator and to verify the efficiency of using lime as a protective coating. The experiments were conducted at the Hydraulic Research Center (CPH) of UFMG, and the methodological procedures included: (i) determining the optimal lime concentration to be used as a protective coating for the slopes, based on immersion mass loss tests; (ii) calibrating the rainfall simulator to achieve representativeness for the predefined rainfall index; (iii) conducting the modified Inderbitzen experiment for the calibrated rainfall index from the previous step, simulating the typical slope gradient of waste dumps, both with and without lime application. As for the results, the optimal mass concentration obtained from the immersion mass loss tests for the tested material was 4%. The results regarding the average rainfall intensity, Christiansen's uniformity coefficient (CUC), D50 of the raindrops, and kinetic energy were satisfactory for the target rainfall intensity of 96 mm/h. For the modified Inderbitzen tests, the average total erosion rate for the samples without lime application was 0.2666 g/cm². When assessing the erodibility factor (k) using the Universal Soil Loss Equation (USLE), the result obtained was 0.4677 t h MJ⁻¹ mm⁻¹, indicating that the disposal of waste in piles dumps, with the configurations adopted in the present study, may lead to an increase in the erodibility of the material by approximately 10 times compared to what is expected for the local soil under natural conditions, when compared to values reported in the literature. The average total erosion rate for the samples with lime application was 0.3587 g/cm², indicating that the chosen application method was ineffective for the tested material, as the immersion mass loss tests showed that adding lime was effective, reducing mass loss by an average of 81%.