Abstract
Investigating analytical solutions to determine stresses for mine stopes with inclined walls is essential for the design of stopes in the mining industry, contributing to the prevention of serious accidents. Two variables in the analytical formula used for computing the vertical stresses in mine stopes with inclined walls play a vital role in the design. The two variables are the coefficient of lateral earth pressure, Kα, and the ratio η. Here, Kα is the ratio of the normal earth pressure on the inclined wall at some level to the vertical stress at the same point and η is the ratio of the normal lateral earth pressure on the hanging wall to the normal lateral earth pressure on the footwall. The difficulty of using the analytical formula is to choose the correct values of both parameters. Hence, calibrating the formula involves selecting appropriate values of Kα and η in order to predict the actual results of the vertical stress, and consequently provide the designer with appropriate values that can be used in the design of mine stopes with inclined walls. Accordingly, in this study, the coefficient of lateral earth pressure in inclined mine stopes is numerically evaluated for various backfill friction angles; 30°, 35° and 40° with and without reference to the surrounding rock. The ratio η is also investigated at different depths ranging from 25 to 275 m. Moreover, Kα was formulated as a function of the ratio of the height to the breadth for different angles of the inclined stope, i.e., 60°, 70° and 80°. The considered cases in this analysis differ considerably from the commonly considered case in previous research, which completely overlooks the wall inclination effect. Furthermore, the considered cases better represent the actual in-situ conditions because they model the interaction between the sidewalls and the backfilling in the stope. The results have shown that the use of η = 0.6–0.8 and Kα ≤ Ka for the different angles of inclination in the analytical formula resulted in vertical stress being compatible with the numerical analysis results.
Article highlights
-
Different researchers considered several aspects of mine stopes; however, none of them considered the effect of the stope wall inclination explicitly.
-
Choosing appropriate values of the coefficient of lateral earth pressure, K, and the ratio of the normal lateral earth pressure on the hanging wall to the normal lateral pressure on the footwall, η, is crucial to predict the actual vertical stress.
-
In this paper the ratio η is investigated at different depths ranging from 25 to 275 m. Moreover, K was formulated as a function of the ratio of the height to the breadth for different angles of the inclined stope.
Similar content being viewed by others
Data availability
All data, models, and code generated or used during the study appear in the submitted article.
References
Aubertin M, Li LSTBM, Arnoldi S, Belem T, Bussière B, Benzaazoua M, Simon R (2003) Interaction between backfill and rock mass in narrow stopes. Soil Rock Am 1:1157–1164
Blight GE (1986a) Pressures exerted by materials stored in silos: part I, coarse materials. Géotechnique 36(1):33–46
Blight GE (1986b) Pressures exerted by materials stored in silos: part II, fine powders. Géotechnique 36(1):47–56
Caceres DCA (2005) Effect of delayed backfill on open stope mining methods (doctoral dissertation, University of British Columbia)
Handy RL (1985) The arch in soil arching. J Geotech Eng 111(3):302–318
He Z, Xie H, Gao M, Deng G, Peng G, Li C (2021) The fracturing models of hard roofs and spatiotemporal law of mining-induced stress in a top coal caving face with an extra-thick coal seam. Geomech Geophys Geo-Energy Geo-Resour 7(1):1–15
Itasca (2011) FLAC version 7.0. Itasca Consult. Gr. Inc.
Jiang F, Zhou H, Sheng J, Li X, Hu Y, Zhou Y (2020) Evaluation of safety and deformation characteristics of cemented tailings backfill mining disturbed area near shafts: a case study in China. Geomech Geophys Geo-Energy Geo-Resour 6(3):1–22
Knutsson S (1981) Stresses in the hydraulic backfill from analytical calculations and in-situ measurements. In: Conference on the application of rock mechanics to cut and fill mining: 01/06/1980–03/06/1980. The Institution of Mining and Metallurgy, pp 261–268
Li L, Aubertin M (2008) An improved analytical solution to estimate the stress state in subvertical backfilled stopes. Can Geotech J 45(10):1487–1496
Li L, Aubertin M (2009a) Numerical investigation of the stress state in inclined backfilled stopes. Int J Geomech 9(2):52–62
Li L, Aubertin M (2009b) Horizontal pressure on barricades for backfilled stopes. Part I: fully drained conditions. Can Geotech J 46(1):37–46
Li L, Aubertin M, Simon R, Bussière B, Belem T (2003) Modeling arching effects in narrow backfilled stopes with FLAC. In: FLAC and numerical modelling in geomechanics-2003, pp 211–219
Li L, Aubertin M, Belem T (2005) Formulation of a three dimensional analytical solution to evaluate stresses in backfilled vertical narrow openings. Can Geotech J 42(6):1705–1717
Li L, Dubé JS, Aubertin M (2013) An extension of Marston’s solution for the stresses in backfilled trenches with inclined walls. Geotech Geol Eng 31(4):1027–1039
Mitchell RJ, Olsen RS, Smith JD (1982) Model studies on cemented tailings used in mine backfill. Can Geotech J 19(1):14–28
Pirapakaran K, Sivakugan N (2006) Numerical and experimental studies of arching effects within mine fill slopes
Pirapakaran K, Sivakugan N (2007) Arching within hydraulic fill stopes. Geotechn Geol Eng 25(1):25–35
Shukla SK, Gupta SK, Sivakugan N (2009) Active earth pressure on retaining wall for c–ϕ soil backfill under seismic loading condition. J Geotech Geoenviron Eng 135(5):690–696
Singh S, Sivakugan N, Shukla SK (2010) Can soil arching be insensitive to ϕ? Int J Geomech 10(3):124–128
Sivakugan N, Widisinghe S (2013) Stresses within granular materials contained between vertical walls. Indian Geotech J 43(1):30–38
Ting CH, Shukla SK, Sivakugan N (2011) Arching in soils applied to inclined mine stopes. Int J Geomech 11(1):29–35
Ting CH, Sivakugan N, Shukla SK (2012) Laboratory simulation of the stresses within inclined stopes. Geotech Test J 35(2):280–294
Zhigang T, Chun Z, Manchao H, Kuiming L (2020) Research on the safe mining depth of anti-dip bedding slope in Changshanhao Mine. Geomech Geophys Geo-Energy Geo-Resour 6(2):1–20
Author information
Authors and Affiliations
Contributions
Dr. El Kamash contributed to this paper by performing the numerical analysis and extracting results and the discussion. Moreover, he initially wrote the whole of the initial draft of the paper including the discussion and figures. Dr. El Naggar contributed to this paper by introducing comprehensive editing to the manuscript to improve the technical presentation of the results including the figures and the associated discussions and enhancing the readability of the paper. Dr. Sivakugan contributed to this paper as he suggested the topic idea and the fast final revision.
Corresponding author
Ethics declarations
Conflict of interest
On behalf of all authors, the corresponding author states that there is no conflict of interest.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
El Kamash, W., El Naggar, H. & Nagaratnam, S. Numerical analysis of lateral earth pressure coefficient in inclined mine stopes. Geomech. Geophys. Geo-energ. Geo-resour. 7, 61 (2021). https://doi.org/10.1007/s40948-021-00255-4
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s40948-021-00255-4