Shaking table tests on a near-valley subway station

A large number of subway stations close to valley topography have been built in coastal and riverine cities in recent years, and the seismic safety of near-valley structures is threatened due to the seismic amplification effects of valley topography during earthquakes. However, the influence mechanism of valley topography on the adjacent structures has not been well understood. In this study, a 1g shaking table test model method for a near-valley subway station is proposed. Three sets of circular valley topography with depth-to-width ratios of 1/8, 1/4 and 1/3 are designed, the tests on a near-valley subway station under different topography and ground motion input conditions are performed, and a subway station test without valley site is used as a benchmark to investigate the seismic response of the valley topography on the adjacent structures. The results show that the dynamic response of the near-valley structures is greater under horizontal transverse motion compared to the response of the station structures without valley, particularly the acceleration amplification effects are up to 1.27 times at the structural top slab. The bending moment of the structural column increases due to the valley topography, and the amplification of the bending moment in the sidewall adjacent to the valley is more pronounced, i.e., up to 2.3 times compared to the tests without valley site. Additionally, the peak dynamic earth pressure at the top of the side wall is higher. The local seismic amplification effects of valley are more pronounced as the depth-to-width ratio of the valley topography increases, which leads to a greater seismic response of the near-valley station structures. The research results can provide a scientific basis for the seismic design and safety assessment of station structures around valley topography.