# The Impact of Fine-Layering of Tailings Dam on the Variation Pattern of Infiltration Lines
## 4 Conclusions  
In this study, three different strategies were simulated, including constant head, 9 days of rainfall, and 720 days of drainage, to not only analyze the impact of the three layered schemes on the infiltration line variation pattern in the tailings dam but also reveal the influence mechanism of compactness on the permeability coefficient and infiltration line variations. In addition, as the level of layer refinement increased, the compactness of scheme 1, scheme 2, and scheme 3 also gradually increased.  
Under the constant hydraulic head strategy, the inclination angles of the infiltration lines between measurement lines D and E for scheme 1, scheme 2, and scheme 3 are 4.972\({}^{\circ}\), 5.370\({}^{\circ}\), and 5.824\({}^{\circ}\), respectively. Compared to schemes 1 and 2, scheme 3 shows an increase of 17.14% and 8.45% in the inclination angle of the infiltration line, which reveals that as the compaction density of tailings increases, the permeability coefficient decreases, resulting in a deterioration in water permeability capacity and an increase in the slope of the seepage channel as well as the inclination angle of the infiltration line.  
After 9 days of continuous rainfall, the average increases in the infiltration line compared to the constant head strategy are 46.2%, 65.88%, and 83.52% for scheme 1, scheme 2, and scheme 3, respectively. Among these schemes, measurement lines B, C, and D show a higher increase in the proportion of the infiltration line compared to lines A and E, which reveals that as the compactness increases, there is a corresponding decrease in the permeability coefficient, resulting in a deterioration of the water permeability of the tailings. Furthermore, it indicates a heightened sensitivity to variations in the infiltration line under rainfall conditions.  
After 720 days of drainage, the fitting percentages of the infiltration line height at each point for scheme 1, scheme 2, and scheme 3 compared to the constant head strategy are 72.38%, 88.27%, and 93.61%, respectively. Among the three schemes, the elevation of the infiltration line is in the order of scheme 3, scheme 2, and scheme 1. In particular, scheme 3 is closer to the measured infiltration line elevation at the constant head stage, which confirms that as the compactness of the tailings increases and the permeability coefficient decreases, the water permeability decreases and the water retention capacity increases. Consequently, the seepage velocity decreases, and the position of the infiltration line rises. Scheme 3, with a higher stratification refinement, has the highest fitting percentage for the infiltration line and provides the best reflection of the real infiltration line, making it more consistent with the actual situation.  
Conceptualization, W.G.; Formal analysis, W.G. and X.D.; Funding acquisition, Z.S.; Investigation, X.D.; Methodology, W.G., Z.S. and C.H.; Project administration, Z.S.; Software, W.G. and C.H.; Supervision, Z.S.; Writing--original draft, W.G. and H.W.; Writing--review and editing, W.G. and Z.S. All authors have read and agreed to the published version of the manuscript. This research was funded by the National Natural Science Foundation of China (41202214), the National Natural Science Foundation of China (51774163), and the China Coal Technology and Industry Group Double Creation Funding Major Project (2022-ZD002).  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to its potential use as a master's thesis.