DEMIN - Departamento de Engenharia de Minas

URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/510

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2017 - 20182

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Autor: search.filters.author.Silva, Denise de Fátima Santos da

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    Evaluation of rock slope stability conditions through discriminant analysis.
    (2018) Santos, Allan Erlikhman Medeiros; Lana, Milene Sabino; Cabral, Ivo Eyer; Pereira, Tiago Martins; Naghadehi, Masoud Zare; Silva, Denise de Fátima Santos da; Santos, Tatiana Barreto dos
    A methodology to predict the stability status of mine rock slopes is proposed. Two techniques of multivariate statistics are used: principal component analysis and discriminant analysis. Firstly, principal component analysis was applied in order to change the original qualitative variables into quantitative ones, as well as to reduce data dimensionality. Then, a boosting procedure was used to optimize the resulting function by the application of discriminant analysis in the principal components. In this research two analyses were performed. In the first analysis two conditions of slope stability were considered: stable and unstable. In the second analysis three conditions of slope stability were considered: stable, overall failure and failure in set of benches. A comprehensive geotechnical database consisting of 18 variables measured in 84 pit-walls all over the world was used to validate the methodology. The discriminant function was validated by two different procedures, internal and external validations. Internal validation presented an overall probability of success of 94.73% in the first analysis and 68.42% in the second analysis. In the second analysis the main source of errors was due to failure in set of benches. In external validation, the discriminant function was able to classify all slopes correctly, in analysis with two conditions of slope stability. In the external validation in the analysis with three conditions of slope stability, the discriminant function was able to classify six slopes correctly of a total of nine slopes. The proposed methodology provides a powerful tool for rock slope hazard assessment in open-pit mines.
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    Cluster analysis for slope geotechnical prioritization of intervention for the Estrada de Ferro Vitória-Minas.
    (2017) Silva, Denise de Fátima Santos da; Santos, Allan Erlikhman Medeiros; Ferreira, Bruno Trindade; Pereira, Tiago Martins; Corteletti, Rosyelle Cristina
    This article proposes the geotechnical prioritization of intervention of slopes with landslide scars for the Estrada de Ferro Vitória-Minas by cluster analysis and also the proposition of a relationship between area and volume in landslide scars. Cluster definition helps the decision-making associated to containment measures, mapping and study of landslides for the Estrada de Ferro Vitória-Minas. The database is composed of the variables: slope’s height, inclination, scar area and scar volume. The distance measure used was Gower’s index, with Ward’s methods to build the clusters. Eight characteristic groups were identified. It was possible to identify stretches that need attention in relation to the propensity of landslides, such as Group 7, stretches 362+600, 093+xxxE and 419+000. Group 7 presented high values for the scarred area and volume, such as maximum area 9.75 x 104 m² and minimum area 7.49 x 104 m², and maximum volume 9.20 x 105 m³ and minimum volume 4.08 x105 m³. Group 7 presented high ranges for slope height and inclination. The set of results about Group 7 can be interpreted as stretches with a predisposition for landslides. In relation to intervention measures, Group 7 presents the sections with priority. The relationship between area and volume of landslide scars obtained by the research was compared with the relationships established in literature.