Analysis on the mechanics and deformation of side pile structure in metro station with the PBA method

There are few researches on the interaction mechanism between the buckling load of the side pile top and the soil pressure behind pile (SPP) and the side pile structure. While the side pile structure is the key component of the lining structure of the metro with pile-beam-arch (PBA) method, which plays a very important role in the mechanical stability and deformation control of the lining system of station. Therefore, relying on the metro project about Guangzhou Metro Line 11, this paper investigates the influence law of mechanical characteristics and deformation of the side pile structure of the station with PBA method, taking into account the factors such as different buckling loads (including horizontal load of arch (HLA) and vertical load of arch (VLA)) and SPP, and puts forward corresponding construction suggestions. It is found that the lateral displacement and deformation of side pile structure are controlled by the HLA, and the optimal HLA is 1200kN. The influence of HLA on the bending moments about side pile are greater than that of the axial force. The VLA has more significant effect on vertical settlement of side pile, but little effect on lateral deformation about pile body. The SPP has significant impact on the stability of side pile structure, so it is recommended to take appropriate lining measures to ensure the stability of side pile structure when the SPP is too large.