There is limited research on the interaction mechanism between the buckling load of the side pile top and the soil pressure behind pile (SPP) with the side pile. As the side pile serves as a crucial component of the lining structure in the metro, using the pile -beam -arch (PBA) method, it plays a vital role in maintaining the mechanical stability and deformation control of the station's lining system. Based on the Guangzhou Metro Line 11 project, this paper delves into the impact of mechanical characteristics and deformation of the side pile using the PBA method. It considers various factors such as different buckling loads, including horizontal load of arch (HLA), vertical load of arch (VLA) and SPP and offers corresponding construction suggestions. Our findings indicate that the lateral displacement and deformation of the side pile are primarily influenced by the HLA. The optimal HLA value stands at 1200kN. As the HLA increases, the side pile undergoes a transformation from a forward -inclined deformation mode to a belly distension deformation mode when moving towards the station's interior. The influence of HLA on bending moments about the side pile surpasses that of axial force. The VLA exerts a more significant effect on vertical settlement of the side pile, yet its impact on lateral pile body deformation is minimal. An increase in HLA significantly impacts the axial force of the side pile, but has minimal effects on bending moments. The SPP holds significant influence on the stability of the side pile; hence, it is recommended to implement appropriate lining measures to guarantee stability when dealing with exceptionally high SPP values.

The side pile is a crucial mechanical component in station construction using the PBA (pile -beam -arch) method, and its stability during the construction process cannot be overstated. The mechanical differences between single -row and double -row side piles in this construction method have garnered significant attention, yet few studies have been conducted on this matter. Therefore, this paper employs numerical simulation to compare the deformation and mechanical properties of single -row and double -row side piles (the adopted pile type is micro steel pipe pile, abbreviated as MSPP) in a metro station using the PBA method. The findings are validated through the model experiment. It is found that the soil arch effect created by the front -row pile of the double -row piles serves as the primary lining, offering a certain shielding effect to the soil stress behind the back -row pile. Notably, the soil stress values in double -row pile conditions are slightly higher compared to single -row pile condition, leading to a noticeably smaller final deformation of the pile top. The combined bending moments and axial forces of the front -row and back -row piles in double -row piles exceed those of a single -row pile. Specifically, bending moments are highest in single -row piles, followed by front -row piles and then back -row piles, while axial forces are highest in single -row piles, followed by back -row piles and then front -row piles. This suggests that the bending moments and axial forces of double -row piles are smaller than those of a single -row pile. The internal force distribution within the double -row pile is more balanced, thereby enhancing the lining strength and improving the station's safety through the PBA method. The findings in this paper can serve as valuable references for the design and construction of similar projects.