EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
Navegar
2 resultados
Resultados da Pesquisa
Item Application of the HF, DRA and DCDA technologies for in situ stress determination in Iron Quadrangle rock masses.(2021) Penido, Henrique de Andrade; Funato, Akio; Metsugi, Hideya; Torres, Vidal Félix Navarro; Girao Sotomayor, Juan Manuel; Dight, Phil; Figueiredo, Rodrigo Peluci de; Assis, André Pacheco de; Guimarães, Alessandro JésusThis study presents an unprecedented campaign of measurements (magnitudes and orientations) of the in situ stresses in itabirite rocks of the Brazilian Iron Quadrangle region using the hydraulic fracturing (HF), deformation rate analysis (DRA) and diametrical core deformation analysis (DCDA) methods. The previous studies of this rock mass consider estimated values of k, and the practice of using in situ stress tests to support geotechnical analyses of the rock mass of this region has not been adopted. The study site is located at a depth of up to 400 m around a pit. The rock mass under study shows the presence of different geological structures, which made performing the tests difficult. The DRA results show a marked difference compared to the HF and DCDA results; the horizontal stresses were greater than the vertical stresses, which is a finding that may occur due to local geodynamic influences. The results contribute to the understanding of the strains and stresses induced by mining activities in the Brazilian Iron Quadrangle. For a better determination of the regional in situ stresses in the rock mass of the Brazilian Iron Quadrangle, new HF tests, as well as hydraulic testing of pre-existing fractures are recommended.Item Hydrofracturing in situ stress measurements of itabirite in the Brazilian Ferriferous Quadrangle and their limitations.(2022) Penido, Henrique de Andrade; Figueiredo, Rodrigo Peluci de; Assis, André Pacheco de; Torres, Vidal Félix Navarro; Girao Sotomayor, Juan Manuel; Guimarães, Alessandro JésusThis article presents a first attempt to carry out in situ stress measurements (magnitudes and orientations) of the itabirite in the Brazilian Ferrifer- ous Quadrangle by hydraulic fracture testing at a depth of 399 m. Previous studies on this rock have consid- ered estimated values of the k index (ratio between the horizontal effective stress Sh, generally controlled by tectonism, and the vertical effective stress Sv, gener- ally controlled by gravity), and it is not a common practice to carry out in situ stress tests in this region and rock type to support geotechnical analysis. The area of study was located at a depth of 500 m in a pit because the determination of the in situ stress distri- bution is very important to assess the stability of the open-pit mine. The planning, execution and results of the tests are presented. The studied rock mass exhibits different geological structures, such as banding and foliation, which resulted in difficulties with perform- ing the tests, and only 12.5% of the tests were successful. The results can help interpret the strains and stresses induced by mining activities in slopes in the Brazilian Ferriferous Quadrangle and their impacts on the surrounding structures. For a better determina- tion of the regional in situ stresses in the rock of the Brazilian Ferriferous Quadrangle, hydraulic tests on pre-existing fractures are recommended.