The land terminal of Chongqing Donggang project phase I needs excavation and backfill, with the biggest backfilling thickness of 32 m. According to local complex ground conditions, cast-in-situ U rail board foundations were used for the rail base in the backfilling area, by adjusting the sleeper to meet the demands after settlement. In the excavation area, slag free rail board foundations were used in order to make the operation of cranes stable and save investment as well.