## 7 Conclusions  
In this study, a method for surrounding rock stability analysis based on refined geological and mechanical parameter modeling was proposed. This method was successfully applied to the Jiangfeng Iron Mine, a case study involving multiple faults and joint mining in two levels. The stability of the mine rock mass was analyzed from three perspectives: plastic zone distribution, deformation evolution, and stress evolution. The method utilizes RQD intelligent identification technology, significantly improving the speed and accuracy of core data processing, which facilitates the calculation of rock mass parameters. Moreover, the analytical results of this method provide guidance for optimizing mining structures and offer reference value for ensuring mine safety. The main conclusions of this paper are as follows:  
(1) This method establishes a 3D refined calculation model, integrating rock mechanics parameters, borehole data, and structural plane orientation information. It provides a refined evaluation and zoning of rock mass quality using RQD and GSI. By employing the modified Hoek-Brown strength criterion to calculate the strength parameters of heterogeneous rock masses, it achieves refined characterization of the mechanical parameters of the surrounding rock, forming a data foundation for stability analysis.  
(2) Using the proposed method, rock quality grade zoning was performed for different levels of the Jiangfeng Iron Mine. For levels 115, 135, and 220, the rock mass quality grade between exploration lines 31 and 36 was evaluated as Grade IV, indicating that the mining structure parameters in these areas should be appropriately reduced.  
(3) Simulation results indicate that as the thickness of the isolation pillars increases, the stability of the Phase I and Phase II isolation pillars gradually improves. When a 20 m isolation pillar thickness is maintained, overall stability is optimized. However, stress concentration zones are likely to form at the junctions of the isolation pillars and fault zones, leading to potential rock instability. Mining structure adjustments in these areas should be carried out.  
Field research, Y.Z., G.C. and Q.Z.; manuscript writing, G.C.; numerical simulation, G.C., Q.Z., S.J. and J.L.; writing--review and correction, Y.Z. and T.Y. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the National Natural Science Foundation of China (Grant number 52374157), the Young Elite Scientists Sponsorship Program by CAST (Grant number 2023 QNRC001), Fundamental Research Funds for the Central Universities (Grant number 2023 GFYD17), and the Key Science and Technology Project of the Ministry of Emergency Management of the People's Republic of China (Grant number 2024 EMST080802).  
The original contributions presented in the study are included in the article; further inquiries can be directed to the corresponding author.  
The authors declare no conflicts of interest.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Isolation** **Pillar Thickness (m)** & **Range of Minimum Principal Stress (Pa)** & **Range of Maximum Principal Stress (Pa)** \\ \hline
0 & \(-1.5899\times 10^{5}\)\(-5.3325\times 10^{7}\) & \(-2.0863\times 10^{7}\)\(-8.7776\times 10^{5}\) \\
10 & \(-1.4940\times 10^{5}\)\(-5.1028\times 10^{7}\) & \(-2.1413\times 10^{7}\)\(-8.6008\times 10^{5}\) \\
20 & \(-1.4426\times 10^{5}\)\(-4.8914\times 10^{7}\) & \(-2.1055\times 10^{7}\)\(-8.9003\times 10^{5}\) \\ \hline \hline \end{tabular}
\end{table}
Table 7: Range of maximum and minimum principal stresses for different isolation pillar thicknesses in profile KH1.