Shaking table test on ground liquefaction effect of soil-metro station structure under near-and-far field ground motions

Based on a metro station structure of three stories and three spans at a liquefiable ground, a series of shaking table tests is conducted, in which the acceleration response, strain response and horizontal displacement of the station structure itself are tested. And the pore water pressure, acceleration and seismic subsidence of the foundation soil are also measured. This paper mainly analyzes the dynamic response rules of the foundation soils under the influence of liquefaction effect and it also summarizes the development law of pore water pressure for liquefaction ground around station. Moreover, seismic subsidence characteristics as well as the dynamic soil pressure on the side walls are concluded. The results indicate that the structure has an obvious effect on the distribution of the pore water pressure field. At the same depth of soil, the peak of the pore water pressure of each measured point near the structure is less than that far from the structure. The dissipation rate of the pore water pressure is gradually slowed down from bottom to top. The structure has a movement upward relative to the foundation in the process of earthquake; and the floating phenomenon is obvious under strong ground motion. The dynamic earth pressure of the side walls is decreasing with increased depth; and the earthquake characteristics have a significant influence on the dynamic earth pressure.