# Study on Optimization of Downward Mining Schemes of Sanshandao Gold Mine
## 7 Conclusions  
1. According to the characteristics of the mining method of the deep ore body of the Sanshandao gold mine, three different downward mining schemes were designed, namely, the staggered downward mining from the horizontal wing to the other wing, the vertical interval six, and the oblique interval two; the horizontal center to the two wings separated by five mining one, the vertical interval six, and the oblique interval two; and the horizontal two wings to the center of the staggered downward mining scheme.
2. A numerical simulation analysis was conducted on three distinct mining phases, with the objective of elucidating the evolution rules governing the maximum principal stress, minimum principal stress, equivalent strain, vertical displacement, horizontal displacement, and the distribution of the plastic zone in different mining schemes across varying mining phases. The change in vertical displacement is between 4.42 and 22.73 mm, while the change in horizontal displacement is between 1.72 and 3.69 mm. These values demonstrate that vertical displacement has a more significant impact on the stability of the stope than horizontal displacement.
3. As the mining range is extended, the mechanical effect of the filling body is becoming increasingly pronounced. The downward mining scheme is conducive to the effective management of deep ground pressure at the Sanshandao gold mine. Scheme 2 is conducive to the control of stress concentration, the reduction in tensile stress in  
Figure 23: Blasting effect of the 2# stope cutting patio.  
Figure 24: Slope blasting effect.  
the mining area, the prevention of large plastic zones and large displacements in the mining area, and the realization of ground pressure control at the Sanshandao gold mine.
4. Based on the characteristics of three mining technology schemes, the evolution laws of stress-strain distribution and other data for three different schemes were analyzed. The AHP and FCE method was used to optimize different mining schemes in the deep deposit of Sanshandao gold mine. Six indicators (maximum compressive stress of surrounding rock, average vertical displacement of top pillar monitoring points, average vertical stress of top pillar monitoring points, maximum compressive stress in the mining area, maximum tensile stress in the mining area, and degree of plastic failure) were selected to establish an evaluation index system, and Scheme 2 was determined as the optimal scheme. Finally, the rationality and reliability of Scheme 2 were validated through on-site industrial trials.  
Conceptualization, W.L.; methodology, W.L. and Z.L. ([PERSON]); formal analysis, W.L. and Z.L. ([PERSON]); writing--original draft, W.L.; investigation, Z.L. ([PERSON]); writing--review, [PERSON] ([PERSON]); supervision, [PERSON] ([PERSON]); resources, Z.L. ([PERSON]); project administration, [PERSON] ([PERSON]); funding acquisition, Z.L. ([PERSON]); software, [PERSON] ([PERSON]); data curation, [PERSON] ([PERSON]); validation, [PERSON] ([PERSON]); visualization, [PERSON] ([PERSON]). All authors have read and agreed to the published version of the manuscript.  
This work was supported by the Fundamental Research Funds for the Central Universities of Central South University (No. 2024 zzts0421) and Liupanshui Innovation Technology Center for Disaster Prevention and Resilience Enhancement in Ecologically Fragile Areas (52020-2024-PT-06).  
Not applicable.  
The data will be made available on request.  
The authors would like to acknowledge the reviewers for improving the quality of the manuscript.  
The authors declare no conflicts of interest.