The researchers studied how PCC pile composite foundations behave under train vibrations. They created a computer model to analyze how the foundation, piles, and soil respond to dynamic loads. They found that PCC piles handle dynamic loads differently than solid piles, with the cushion layer affecting stress distribution. Increasing cushion stiffness shifts more load to the pile body. Higher cushion and pile stiffness increase stress at the pile top and speed up stress propagation. PCC piles can bear most of the dynamic load, reducing the impact on the soil. Dynamic stress decreases in side piles as distance from the center pile increases.