JOURNAL OF ROCK MECHANICS

JOURNAL OF ROCK MECHANICS

Slope stability analysis using a distinct element method considering the effects of fluid flow in open pit mines

Document Type : ٍAn English Original Article

Authors
Mohammad Shekari Nejad 1
Mohammad Fatehi Marji 2
Manouchehr Sanei 2
1 Department of Mining Engineering, Islamic Azad University, Sirjan Branch, Sirjan, Iran
2 Department of Mining and Metallurgical Engineering, Yazd University, Yazd, Iran
10.22034/irsrm.2024.466658.0411
Abstract
The groundwater and subsurface flows may cause instability in the open pit mines. The water in pores leads to applying pressure to the rocks, decreasing the effective stress and reducing the shear strength of rock slopes. It means that water pressure causes instability in the benches of open pits. In the present study, we used the versatile and sophisticated distinct element method to investigate the water flow influence on the stability of the pit wall of one of the Golgohar mines, in Kerman, Iran. Numerical results showed that the smaller the distance of the water level from the crest of the first bench of the mine, i.e. the ground level, the higher the amount of flow in the discontinuities. Also, the results showed that the slope's overall safety factor increases with the water level reduction, that is, drainage. For a water level with a height of 57 meters compared to the ground level (the crest of the first bench), the safety factor is estimated to be 0.78. The same issue for a water level with a height of 150 meters shows a safety factor of 1.1, which its safety factor has increased compared to the previous case. The safety factor obtained from the numerical method compared with the results obtained from the Janbu and Bishop analytical methods confirms the validity of the modeling. In addition, the failures in benches indicated, there are planar sliding and toppling occurrences in this mine slope. For this case, it is proposed to decrease the water table level to reach a stable state in this mine.
Keywords
Fluid flow
Slope stability analysis
Distinct element method
Effective stress
Golgohar mine
Subjects
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JOURNAL OF ROCK MECHANICS
Volume 7, Issue 4
Winter 2024
Pages 73-88