| Popis: |
As the deepening of an underground mine occurs, dynamic events (rockbursts) or high deformation ground conditions can occur. The Cuiaba underground gold mine (AngloGold Ashanti, Minas Gerais, Brazil) which is around 1300 m deep, started to experience some of these issues. High deformation associated with bulking and buckling was experienced in the main decline resulting in many rehabilitation stages. Aiming to better understand and reduce the impact of this behaviour, a damage mapping of the support and reinforcement were carried out in the Serrotinho decline. Field measurements of deformation were also undertaken. It was then possible to correlate the numerical modeling outputs with the observed damage and suggest design changes. Based on the observed mechanisms, as well as the reinforcement and support damage experienced in the decline, laboratory tests were necessary to adjust the rock bolt face plate capacity and redefine the most adequate rock bolt and surface support combination to guarantee the functionality of the whole support system. |
