WANG S，LI K，WANG Y, et al．Investigation of the correlation mechanism between phreatic line and reservoir water level observations in upstream-style tailings dams［J］.Journal of Henan Polytechnic University( Natural Science)，doi:10.16186/j.cnki.1673-9787. 2025030069

doi: 10.16186/j.cnki.1673-9787.2023050069

Received：2025-03-30

Revised：2025-06-12

Online：2025-06-13

Investigation of the correlation mechanism between phreatic line and reservoir water level observations in upstream-style tailings dams

Wang Sha^1,2，Li Kun^1,2，Wang Yali^1,2，Chu Yifan^1,2，He Binbin^1,2

(1. Beijing General Research Institute of Mining & Metallurg Beijing 100160, China；2. National Centre for International Research on Green Metal Mining, Beijing 100160, China)

Abstract: [Objective] The spatial formation mechanism of the phreatic line results from the gradual decrease of the water head caused by the infiltration of the reservoir water level along the accumulation dam. Therefore, affected by the amplitude of the reservoir water level variation, there is a certain correlation between the phreatic line and the observed values of the reservoir water level. However, the relevant interaction mechanism remains not fully understood at present. [Methods] Based on the above key issues, this study collected the prototype observation data sequences of the phreatic line and the reservoir water level of a typical upstream tailings dam. A relevant statistical regression model was constructed to conduct an in-depth exploration of the relationships among the phreatic line, the absolute value of the reservoir water level, the water head, and the time effect. The goodness of fit was employed to evaluate the regression effect. Meanwhile, based on the established mathematical statistical prediction model, the grey correlation analysis theory was utilized to compare the importance of different factors. The grey correlation coefficient results between different factors and the observed values of the phreatic line were obtained, and then the importance ranking of different factors was determined, revealing the main influencing factors of the phreatic line. [Results] According to the results of grey correlation analysis, the spatial variation trends of various factors in the statistical model exhibit a strong dependence on the dependent variable. The statistical analysis results indicate that the measured values of the phreatic line are related to the measured water head value (H factor), the square of the water head (H⟡ factor), the cube of the water head (H³ factor), the average water head values of the previous 5, 10, 15, 20, 25, and 30 days, and the average water head rise rate factors of the previous 5, 10, 15, 20, 25, and 30 days. The statistical regression results demonstrate high precision. [Conclusion] The effects of the statistical regression models for the observed values of the phreatic line at different installation positions vary. Generally speaking, they are related to the measured values of the water head and its rate of change, and show a certain correlation with the time effect. As the time series lengthens, the correlation with the time effect gradually weakens.

Key words: phreatic line; reservoir water level; statistical regression model; grey correlation analysis; time effect

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