Abstract: To study the influence of underground space structure on ground motion, a shaking table test of soil-underground structure dynamic interaction was designed and carried out with a three-story underground shopping mall structure as a prototype. Six seismic waves with different predominant frequencies and peak accelerations were regarded as input waves to test ground motion. The experimental results show that the amplification factor of horizontal acceleration of ground surface is symmetrically distributed along the axis of the underground structure. The underground structure significantly affects the horizontal acceleration of the ground surface above and adjacent to the sites. At the same time, due to the local site effect of underground space structure, vertical vibration will occur even under horizontal seismic excitations. The amplification factor of vertical acceleration of ground surface is distributed as M-shaped. The influence range of underground space structure can reach a distance equal to its own width on both sides. The amplification factor of acceleration of ground surface is obviously affected by the predominant frequency of input seismic wave, and decreases with the increase of peak ground acceleration (PGA), but the space amplification factor increases with the increase of PGA. The peak frequency of ground acceleration Fourier spectrum is influenced by the predominant frequency of seismic waves, natural frequencies in horizontal and vertical directions of soil site.

Key words: shaking table test, underground structure, soil-structure interaction, ground motion, seismic response