Journal of Geoscience and Environment Protection, 2021, 9, 121-131
https://www.scirp.org/journal/gep
ISSN Online: 2327-4344
ISSN Print: 2327-4336
DOI: 10.4236/gep.2021.91010 Jan. 29, 2021 121 Journal of Geoscience and Environment Protection
Effects of Sublevel Open Stope Underground
Mining on Surface and Open Pit Slopes
Tumelo K. M. Dintwe
1*
, Takashi Sasaoka
1
, Hideki Shimada
1
, Akihiro Hamanaka
1
, Dyson Moses
1
,
Sifei Liu
2
, Fanfei Meng
1
1
Department of Earth Resources Engineering, Kyushu University, Fukuoka, Japan
2
China University of Science and Technology, Xuzhou, China
Abstract
Underground mining is an economically viable option for exploiting ore re-
serves deemed uneconomic after open pit mining. However, underground
development can have adverse effects on the above existing open pit slope
walls. As a goal of this paper, identification and assessment of potential slope
instabilities prior to underground development is crucial for safe and sus-
tainable mining. Towards goal achieving, this paper gives a comprehensive
parametric study to investigate the influence of sublevel open stope (SLOS)
underground mining on the surface and open pit slope walls. By means of
numerical simulation, the SLOS design is tried against the existing open pit
followed by adjustments of important slope parameters which are overall
slope height (OSH) and overall slope angle (OSA). We found that under-
ground mining may induce slope failure, particularly on the hangingwall side
of the pit. Subsidence is prominent on the hanging wall and the surface, whe-
reas, the uplift dominates the footwall and pit bottom. Pit wall closure is ob-
served during underground mining. Although the assigned dimensions in the
parametric study show a negligible effect of OSH and OSA, the high OSH ex-
perience low subsidence in comparison with low OSH. Overall, the results
demonstrate that the slope walls on the hanging wall side are mostly affected
by the underground mining and high-stress concentration prevails near slope
toes and pit bottom. Additionally, slope deformation decrease from pit bot-
tom towards the slope crest and surface. The results of this study add know-
ledge to open pit and underground mining interaction.
Keywords
Open Pit-Underground Interaction, Slope Stability,
Underground Mining, Subsidence
How to cite this paper: Dintwe, T. K. M.,
Sasaoka, T., Shimada, H., Hamanaka, A.,
Moses, D., Liu, S. F., & Meng, F. F. (2021).
Effects of Sublevel Open Stope Under-
ground Mining on Surface and Open Pit
Slopes. Journal of Geoscience and Envi-
ronment Protection, 9, 121-131.
https://doi.org/10.4236/gep.2021.91010
Received: December 28, 2020
Accepted: January 26, 2021
Published: January 29, 2021
Copyright © 2021 by author(s) and
Scientific Research Publishing Inc.
This work is licensed under the Creative
Commons Attribution International
License (CC BY 4.0).
http://creativecommons.org/licenses/by/4.0/
Open Access