## 6 Conclusions  
The paper establishes a finite element model, verifies the accuracy of the finite element simulation values of the rise-span ratio based on the monitoring data collected at the site, and analyses the internal force trends of the steel pipe piles and the top arch structure and the ground settlement control under different rise-span ratios by setting different rise-span ratios of the vault. The main conclusions are:  
1. Different rise-span ratios have different responses to the ground settlement caused by the construction of cavity pile method metro stations. The ground settlement first decreases and then increases with increasing rise-span ratio, but the rate of increase becomes smaller and tends to converge. The rise-span ratio of 0.28 has the lowest settlement, which is 22 mm less than the maximum value and accounts for 27% of the maximum settlement. By setting a reasonable rise-span ratio, the amount of surface settlement caused by excavation of the section can be effectively controlled.
2. According to the field monitoring data and finite element model analysis, the surface settlement caused by the construction of the pilot tunnels accounted for at least 50% of the total settlement, and the excavation of the pilot tunnels was the main construction stage leading to the surface settlement. The cross-sectional settlement curve shows a symmetrical distribution on both sides of the station. The settlement caused by the main construction with a rise-span ratio of 0.28 is significantly reduced, increasing the stiffness and strength of the structure and facilitating the excavation of large sections during the main construction.
3. The different rise-span ratios of the pile-beam-arch method have a greater impact on the internal forces of the structure. The maximum axial force of steel pipe pile with different rise-span ratio is parabolically distributed, large on both sides and small in the middle, the axial force of the middle pile increases continuously with the construction, and the axial force of the middle pile is the smallest when the rise-span ratio is 0.31. The maximum axial force and the maximum bending moment of the vault are negatively correlated with the rise-span ratio.
4. Combined with the analysis of the internal force characteristics of the pile-beam-arch method structure and the ground settlement control, the arch structure and the pilot tunnels structure are located in the ground with weak foundation bearing capacity such as residual soil. If the rise-span ratio is too high, the shear force of the arch will be reduced and the horizontal shear force will be greater, resulting in difficulties in the construction at the foot of the arch; if the rise-span ratio is designed to be 0.28-0.31, the stability of the station structure and the deformation of the ground surface will be better ensured.  
Conceptualization, [PERSON] ([PERSON]) and [PERSON] ([PERSON]); methodology, [PERSON]; software, [PERSON] and [PERSON]. ([PERSON]); validation, [PERSON] and J.L. ([PERSON]); formal analysis, [PERSON] ([PERSON]); investigation, [PERSON] ([PERSON]); resources, [PERSON] ([PERSON]); data curation, [PERSON] ([PERSON]); writing--original draft preparation, [PERSON] ([PERSON]); writing--review and editing, [PERSON] ([PERSON]). All authors have read and agreed to the published version of the manuscript.  
Foundation of Outstanding Youth of Guangdong Province--Research on Bearing Mechanism and Stability of pile foundation in Karst Area based on static and dynamic loads and time-varying soil Characteristics, (Approval number: 2023B1515020061).  
Not applicable.  
The authors wish to express their gratitude to the reviewers and editors for their positive and constructive comments and suggestions on the manuscript.  
The authors declare no conflict of interest.