Underground mining is a set of methods that allows the extraction of ore in depth, ensuring sustainability and economic viability. One of the problems that arise in underground mine operations is open stope stability. The method for assessing stability of open stopes is the stability graph proposed by Mathews et al. (1981). It is possible to estimate and provide information about this stability and assist in the decision making about its viability. With the data obtained from 35 open stopes from a Zinc mine, the present study aims to use artificial intelligence techniques, specifically artificial neural networks, to process the data and classify the open stopes according to the stability regions of the graph. As a result, the applied methodology presented good assertiveness for the classification of two classes, stable and unstable open stopes, resulting in a global probability success of 82% overall hit probability and 18% apparent error rate. For the classification into three classes, adding the transitional open stopes, the internal validation presented a global probability success of 91% and apparent error rate of 9%. In external validation, the network evaluation measures presented values of global probability success of 42% and apparent error rate of 58%.

A avaliação geológico-geotécnica de taludes rodoviários são de extrema importância para a segurança da via, pois a partir destes estudos é possível elaborar programas de prevenção e de alerta e a implantação de obras para redução dos danos nestes empreendimentos. Assim, este trabalho teve como objetivo a caracterização geológico-geotécnica e avaliação do perigo à queda de blocos dos taludes localizados às margens da rodovia BR-262, entre as cidades de Betim e Nova Serrana, em Minas Gerais. Em relação a classificação dos maciços foram aplicados os sistemas RMR, Sistema-Q e GSI. Posteriormente, foram realizadas, análise cinemática, análise de estabilidade e por fim taludes foram hierarquizados conforme o perigo à queda de blocos. Em nenhum dos taludes o RMR foi inferior à regular. Os resultados das demais classificações foram concordantes com o RMR. Os fatores de segurança indicaram que os taludes estão estáveis. O talude com maior grau de perigo foi o Talude P4 - A e o de menor perigo foi o Talude PM1.

This work aims to investigate the influence of induced stresses by sublevel stopes in development excavations, which are excavated to access these stopes. Parametric studies changing the position of development openings in relation to stopes were performed in order to evaluate the stability conditions of these openings. Numerical modeling using finite element method was applied to the simulations. An elastic behavior of the rock mass was assumed to allow the simulation of a lot of different opening locations. The results have showed distinct scenarios. Some cases of global collapse were found as well as some situations where the integrity of the openings could be kept. Therefore, the most favorable situations were chosen to perform a plastic analysis in order to have a better knowledge of opening stability conditions. The geometry of the excavations from Caraiba Mining Company, which extracts copper from an underground mine in Brazil, was used in these analyses to illustrate a real situation where many failure problems in these development openings were observed.

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