## 4 Conclusions  
Based on the underground concealed excavation station project of Tianhe Road Station of Guangzhou Metro Line 10 in China, this paper designed and established a model test device for the arch cover method by using the existing model box in the laboratory, and carried out an indoor model box test study of the arch cover method for underground stations, and analyzed the influence of different excavation conditions on the stress patterns of the arch cover, ground settlement, arch haunch, arch foot, and central column. The main conclusions of the paper are as follows:  
(1) Better overtopping reduces the settlement of the arch, with the maximum settlement of the arch located near the top of the arch. The removal of the diaphragm wall primaries has a greater effect on the settlement of the arch compared to the other conditions. Among them, the removal of the initial support of the diaphragm wall is the single condition that leads to the largest settlement increment in the middle of the arch. The effect of the excavation of the middle guideway stage on the settlement of the arch haunch is not obvious, and the excavation of the lower body will still disturb the rock layer above, resulting in a larger amount of settlement.  
(2) The ground settlement generally occurs at the same location as the arch settlement, but in practice, the arch settlement will occur earlier than the ground settlement. If there are sandy strata above the tunnel, the ground settlement may be greater than the arch settlement due to the liquefaction of the strata caused by excavation vibration.  
(3) The influence of arch cover excavation on overburden pressure is small, and the supporting structure is more conducive to controlling the deformation of overburden. The central column bears most of the compressive stress over the arch cap, showing a trend of first decreasing and then increasing. The central column gradually bears the pressure above the arch since the removal of the diaphragm wall and increases to the maximum value after the excavation is completed. The upper region of the arch cover is mainly subjected to extrusion stress, and the maximum extrusion stress of the arch cover occurs near the middle of the arch cover. The left and right arch feet did not change significantly during the excavation of the central drift, and the stress in the arch feet decreased greatly during the excavation of the side drift. After excavating the lower rock body, the left and right arch feet began to bear the pressure of the soil body above, resulting in an increase in the arch foot stress.  
(4) The presence of the central column has a greater impact on the settlement of the arch and the ground settlement, and the closer to the middle of the arch the more pronounced the magnitude of deformation is after the removal of the central column.  
Conceptualization, W.Y.; Methodology, W.Y. and T.L.; Validation, W.P.; Formal analysis, W.Y. and M.X.; Investigation, M.X. and T.L.; Data curation, M.X. and W.P.; Writing--original draft, W.Y. and W.P.; Writing--review & editing, T.L.; Supervision, T.L. 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 grant number [No. 52374108].  
Not applicable.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to the subsequent paper writing also needs to use the paper data.  
Authors [PERSON], [PERSON], [PERSON] and [PERSON] was employed by the company China Railway 16 th Bureau Group Corporation. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.