3D Modelling of Destress Slots at a Scandinavian Mine.
Saved in:
| Title: | 3D Modelling of Destress Slots at a Scandinavian Mine. |
|---|---|
| Authors: | Shnorhokian, Shahé1 (AUTHOR) shahe.shnorhokian@mcgill.ca, Ahmed, Samar2 (AUTHOR) samar__sayed@cu.edu.eg |
| Source: | Rock Mechanics & Rock Engineering. Mar2025, Vol. 58 Issue 3, p2877-2900. 24p. |
| Subjects: | Mines & mineral resources, Shearing force, Copper, Pyrites, Blasting |
| Abstract: | Destressing in underground hard-rock mines has been practiced for at least 70 years. It is conducted by specialized blasting in areas under high-stress regimes (destressing), or where these conditions are expected to occur in the future (preconditioning). Excavations such as horizontal cuts and vertical slots are also used to create stress shadows. Destress slotting was used at the Pyhäsalmi mine in Finland—an operation producing copper, zinc, and pyrite—where stopes in a parallel deposit were mined ahead of the ones in the main orebody, or where it was excavated within the latter at further depth. In this study, a simplified model of the mine is constructed in FLAC3D to examine the extent and impact of stress shadows created due to destress slotting. Two sequences are examined with the technique being implemented first in the parallel deposit, and then within the main orebody at further depth. Results indicate that the major principal (σ1) and minor principal (σ3) stress redistributions in the main orebody and adjacent alteration zones are very different for the two approaches. The σ1 and σ3 stress shadows are observed to be responsible for destressing but extend in different directions, which change between the parallel deposit and in-stope slotting techniques. Furthermore, σ1 concentration zones are identified where stresses are transferred during the slot excavation process. Maximum shear stresses are also observed to increase at several locations, but remain below the threshold for major rockbursting potential. Finally, the interaction of stress shadows with weak alteration zones is assessed, and valuable insights are obtained with respect to design. Highlights: 3D numerical modelling was conducted for two types of destress excavations (slots) used at the Pyhäsalmi mine (Finland). Increases and reductions in the major and minor principal stresses were observed to have variable extents of influence in the horizontal and vertical directions. The generated stress shadows were influenced by the presence of weak alteration zones around the main orebody. Excavations in a parallel pyrite deposit and in the main orebody resulted in different modes of reducing and concentrating stresses. The findings of this study agreed with those reported at the mine where high horizontal stresses – and not rockbursting – were identified as the main ground control challenge. [ABSTRACT FROM AUTHOR] |
| Copyright of Rock Mechanics & Rock Engineering is the property of Springer Nature and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
|
Full text is not displayed to guests.
Login for full access.
|
|
Be the first to leave a comment!
