The integrated building-bridge structure system represents integrated railway stations in China and has emerged as a new structural approach in recent years. This paper presents a case study on large shaking table tests that explore various seismic responses of a pile group system based on the Kunming South Railway Station. The study focused on the dynamic characteristics of both the soil and the pile-superstructure interaction. Findings indicate that pile damage is concentrated on the side facing the direction of vibration, with the middle pile experiencing greater damage than the corner pile. Hysteresis is observed in the growth of the pore pressure ratio during soil liquefaction in saturated conditions. Both the bending moment and the ground pressure acting on the pile increase with the degree of liquefaction. The maximum pile bending moment occurs at the interface between liquefied and non-liquefied soil layers. During seismic events, the side piles facing the vibration direction experience increased seismic surcharge, while the central piles are subjected to lower loads due to the isolation effect of the side piles.