Abstract: In a strong earthquake, the liquefaction-induced lateral deformation of ground has induced severe damages to the ground structures and the underground lifeline engineering. It is foreseeable that the safety of subway underground structure is seriously threatened by the seismic liquefaction-induced lateral deformation of ground. For this reason, the earthquake response of a subway underground structure buried in a soil foundation with a slight inclined ground surface was investigated by shaking table tests. The results demonstrated that the soils beside the underground structure were not liquefied synchronously with the soils near the slope toe were easier to be liquefied than the soils near the slope top. When the soils in the slope was liquefied, they would flow down along the slope, which can induce the uplift of the ground surface near the slope toe. Meanwhile, it was found that the lateral deformation of soil in the slope was larger than that of soil near the slope toe, and the lateral deformation of soil near the slope top was smallest. The results also revealed that the underground subway station floated more severely than that of connected tunnel, which could induce seismic damage at the connection part between the tunnel and subway station.

Key words: slight inclined ground, sand liquefaction, lateral deformation of soil, subway underground structure, shaking table test