TY - JOUR
T1 - Reliability Analysis of Rock Supports in Underground Mine Drifts
T2 - A Case Study
AU - Adoko, Amoussou Coffi
AU - Yakubov, Khamit
AU - Kaunda, Rennie
N1 - Funding Information:
This study was supported by the Faculty Development Competitive Research Grant program of Nazarbayev University, Grant Nº 090118FD5338. The authors wish to acknowledge the contribution of the authorities of Ridder Mine for having provided the rock support design data. We appreciate the valuable contributions of the anonymous reviewers.
Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
PY - 2022/4
Y1 - 2022/4
N2 - Support failures in mine drifts represent potential hazards that threaten underground mine safety and productivity. The aim of this study is to determine the reliability index associated with the rock supporting elements used in Ridder-Sokolny mine, an underground mine located in East Kazakhstan. Numerical simulations of the drift support and the First Order Reliability Method (FORM) were employed to carry out the analysis. Several support cases were considered including: shotcrete, bolting, concrete, bolting combined with concrete and unsupported drift case. For each support case, the Factors of Safety (FS), the reliability index (β) and the Probability of Failure (PF) were determined in accordance with the corresponding rock mass quality and the excavation geometry. The results indicate a slight variation of the average FS values for the different support cases (except for shotcrete) while β and PF vary more significantly between 0.62–3.25 and 0.05–27 (× 103%) factor depending on the rock conditions and the installed support. The probability of failure of the rock support increases with a decrease in the rock mass quality. Similar trends are observed with an increase of the width/height ratio of the excavations for the same rock domain. These results illustrate that a single FS value obtained from a deterministic method may not always provide a sufficient indication of safety. This is in agreement with the field observations which have indicated a poor performance of the supports. Hence, on the basis of the reliability index of the supports, the requirement in terms of coefficient of variability of the rock mass quality to meet the target performance level is proposed. It is concluded that the results of this study could help improving the drift support design in Ridder-Sokolny mine.
AB - Support failures in mine drifts represent potential hazards that threaten underground mine safety and productivity. The aim of this study is to determine the reliability index associated with the rock supporting elements used in Ridder-Sokolny mine, an underground mine located in East Kazakhstan. Numerical simulations of the drift support and the First Order Reliability Method (FORM) were employed to carry out the analysis. Several support cases were considered including: shotcrete, bolting, concrete, bolting combined with concrete and unsupported drift case. For each support case, the Factors of Safety (FS), the reliability index (β) and the Probability of Failure (PF) were determined in accordance with the corresponding rock mass quality and the excavation geometry. The results indicate a slight variation of the average FS values for the different support cases (except for shotcrete) while β and PF vary more significantly between 0.62–3.25 and 0.05–27 (× 103%) factor depending on the rock conditions and the installed support. The probability of failure of the rock support increases with a decrease in the rock mass quality. Similar trends are observed with an increase of the width/height ratio of the excavations for the same rock domain. These results illustrate that a single FS value obtained from a deterministic method may not always provide a sufficient indication of safety. This is in agreement with the field observations which have indicated a poor performance of the supports. Hence, on the basis of the reliability index of the supports, the requirement in terms of coefficient of variability of the rock mass quality to meet the target performance level is proposed. It is concluded that the results of this study could help improving the drift support design in Ridder-Sokolny mine.
KW - Factor of safety
KW - First order reliability method
KW - Mine drift
KW - Numerical modelling
KW - Reliability index
KW - Rock support
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U2 - 10.1007/s10706-021-02014-4
DO - 10.1007/s10706-021-02014-4
M3 - Article
AN - SCOPUS:85119984732
SN - 0960-3182
VL - 40
SP - 2101
EP - 2116
JO - Geotechnical and Geological Engineering
JF - Geotechnical and Geological Engineering
IS - 4
ER -