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.
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Resultados da Pesquisa
Item Three‑dimensional stability analyses and sensitivity studies of the input parameters in a global failure of an open pit slope : a case study.(2023) Oliveira, Davidson Paulo Azevedo; Lana, Milene SabinoThis work aims to study the parameters afecting a global slope failure in an open pit mine. The event was a complex failure, formed by an upper layer of a weathered rock, which behaved like a soil mass, above two faults, which intersect to form a wedge. This upper soil layer has pressured the wedge leading to its failure. It occurred in the northern sector of the pit in 2013, causing the interruption of mining activity for about 1 year. The geomechanical parameters were defned from an extensive feld survey database; lab tests and Schmidt hammer tests were performed in the region of the failure. The HoekBrown criterion was adopted for the rock mass; Barton-Bandis for the discontinuities and Mohr-Coulomb for the weathered rocks. Three-dimensional limit equilibrium methods were applied using the average strength parameters. The factor of safety (F.S.) was 1.33, a situation which indicated relative stability. Thus, sensitivity analyses were performed to defne the parameters that conditioned the failure, by progressively reducing the discontinuity shear strength via percentage factors, until F.S reached 1.0. Failure surface geometry obtained in the analysis was close to the failure observed at the feld. The susceptibility condition of the wedge failure was evaluated through kinematic analyses in two scenarios; F.S = 1.33 and F.S. = 1. The results indicated a signifcant increase in the probability of kinematic feasibility when F.S. was 1. The reduction of the slope dip should ensure a stable condition. Moreover, the water level should be kept far from the slope face.Item Stress–strain analysis of buckling failure in phyllite slopes.(2013) Pereira, Luana Cláudia; Lana, Milene SabinoBuckling failure occurs in the open pit mines in the Quadrila´tero Ferrı´fero of the State of Minas Gerais, Brazil. In this study, this failure mechanism is evaluated through stress–strain analysis, using the finite element software named Phase2. Many representative hypothetical models of the slopes were created in order to reproduce the conditions in open pit mines, like their geometry and foliated joints with kinematic conditions for buckling failure. Elastic and plastic simulations have been done. Strength and deformability parameters, such as discontinuity stiffness and cohesion, as well as the in situ stress field, are analyzed in order to understand their influence in the buckling failure mechanism in the global open pit mine slopes excavated in phyllites. As studies about this problem are extremely rare, the present research brings important contributions to establish the basic conditions for this kind of failure.Item Estabilidade dos taludes da Cava Cachorro Bravo com base em modelagem numérica por elementos finitos.(2008) Silva, Carolina Helena Caldeira; Lana, Milene Sabino; Pereira, Luana Cláudia; Lopes, Manoel da ConceiçãoEsse trabalho apresenta a análise da estabilidade de um talude da Mina Córrego do Sítio, que pertence ao Grupo Anglo Gold Ashanti, e encontra-se inserida na porção nordeste do Quadrilátero Ferrífero. No local, ocorrem rochas metamórficas deformadas, com significativas descontinuidades que ocasionam problemas geotécnicos. Os objetivos do estudo foram analisar os fenômenos de ruptura observados na Cava Cachorro Bravo, em 2003, e avaliar a estabilidade dos taludes da cava, em 2006, a partir da simulação da evolução da lavra nesse período. Para tal, utilizou-se um modelo computacional, por meio do software Phase²6.0 da Rocsciense (Canadá), que permite a modelagem do maciço através do método dos elementos finitos. Os resultados mostraram-se satisfatórios, reproduzindo a situação observada em campo e indicando a necessidade de novos estudos para avaliação da estabilidade dos taludes a longo prazo.