A carregar...
Publicação
Caracterização geomecânica de maciços rochosos na exploração subterrânea de mármores
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 19.3 MB | Adobe PDF |
Orientador(es)
Resumo(s)
A exploração subterrânea de mármores exige uma análise detalhada das características
geomecânicas do maciço rochoso de modo a garantir o sucesso da exploração e a segurança e
eficiência do processo de escavação. O principal desafio deste estudo reside na variabilidade
das descontinuidades geológicas e no seu impacto na estabilidade dos taludes e das galerias
projetadas. A necessidade de compreender os modos de rotura e os fatores de segurança torna
esta análise essencial para a definição de medidas de suporte e acompanhamento da escava-
ção. Para abordar esta problemática, foram caracterizadas as descontinuidades do maciço atra-
vés de levantamentos de campo, complementados por ensaios com o martelo de Schmidt para
aferição da resistência da rocha à compressão. Identificaram-se quatro famílias de desconti-
nuidades, uma das quais se revelou a mais crítica para a estabilidade. A análise cinemática foi
realizada através do teste de Markland, utilizando o software DIPS, para avaliar a suscetibili-
dade a mecanismos de rotura. Foram aplicadas as classificações geomecânicas RMR, SMR e Q,
bem como o índice GSI, para avaliar a qualidade do maciço rochoso e propor medidas de
prevenção e estabilização das frentes de escavação e dos eixos das galerias.
Os resultados indicam que o modo de rotura por cunha é predominante, especialmente
nos taludes da frente de escavação Este, entretanto intervencionada com pregagens, carecendo
de monitorização contínua ao longo da escavação. Já os fatores de segurança estimados para
as frentes localizadas a oeste demonstram uma condição de estabilidade geral favorável. Estes
resultados fornecem informações fundamentais para o dimensionamento e acompanhamento
da exploração subterrânea, contribuindo para a segurança das operações e para a otimização
dos métodos de escavação.
The underground exploration of marble in carbonate rock masses requires a detailed analysis of their geomechanical characteristics to ensure the safety and efficiency of the exca- vation process. The main challenge of this study lies in the variability of geological disconti- nuities and their impact on the stability of both slopes and planned underground galleries. Understanding the failure mechanisms and associated safety factors is essential for defining appropriate support measures and for monitoring the excavation process. To address this is- sue, the discontinuities of the rock mass were characterised through field surveys, comple- mented by Schmidt hammer tests to assess the compressive strength of the rock mass. Four discontinuity sets were identified, one of them proved to be the most critical in terms of sta- bility. Kinematic analysis was performed using the Markland test with the DIPS software to evaluate the susceptibility to failure mechanisms. Additionally, geomechanical classification systems such as RMR, SMR, and Q, along with the GSI index, were applied to assess the qual- ity of the rock mass and propose prevention and stabilization measures of the excavation fronts and gallery alignments. The results indicate that the predominant failure mode is wedge failure, particularly on the slopes of the eastern excavation front, which has since been stabilised through rock bolting, for which continuous monitoring was recommended throughout the excavation process. In contrast, the estimated safety factors for the western excavation fronts indicates generally fa- vourable stability conditions. These results provide essential information for the design and management of underground operations, contributing to both the safety of the works and the optimisation of excavation methods.
The underground exploration of marble in carbonate rock masses requires a detailed analysis of their geomechanical characteristics to ensure the safety and efficiency of the exca- vation process. The main challenge of this study lies in the variability of geological disconti- nuities and their impact on the stability of both slopes and planned underground galleries. Understanding the failure mechanisms and associated safety factors is essential for defining appropriate support measures and for monitoring the excavation process. To address this is- sue, the discontinuities of the rock mass were characterised through field surveys, comple- mented by Schmidt hammer tests to assess the compressive strength of the rock mass. Four discontinuity sets were identified, one of them proved to be the most critical in terms of sta- bility. Kinematic analysis was performed using the Markland test with the DIPS software to evaluate the susceptibility to failure mechanisms. Additionally, geomechanical classification systems such as RMR, SMR, and Q, along with the GSI index, were applied to assess the qual- ity of the rock mass and propose prevention and stabilization measures of the excavation fronts and gallery alignments. The results indicate that the predominant failure mode is wedge failure, particularly on the slopes of the eastern excavation front, which has since been stabilised through rock bolting, for which continuous monitoring was recommended throughout the excavation process. In contrast, the estimated safety factors for the western excavation fronts indicates generally fa- vourable stability conditions. These results provide essential information for the design and management of underground operations, contributing to both the safety of the works and the optimisation of excavation methods.
Descrição
Palavras-chave
Mármores Exploração Subterrânea Caracterização Geomecânica Classificação de Maciços Rochosos Estabilidade Mecanismos de Rotura