Shaking table test on underground structure-soil-aboveground structure interaction

Abstract

Under seismic excitations, the large underground structure often changes the seismic wave propagation and affects the seismic response of adjacent aboveground structures. To understand the interactions between the underground structure, soil and aboveground structure, in this paper, three series of shaking table tests were carried out to investigate the soil-underground structure interaction (SUSI), the underground structure-soil-aboveground structure interaction (SSSI), and the soil-aboveground structure interaction (SSI). Each series of shaking table tests was excited by six different seismic waves with five different peak accelerations (PA). The test results show that as the increase of the PA, both the fundamental frequency of the aboveground structure and the phase difference between degrees of freedom of the modes increase. The mode displacement of the foundation rotation in the SSSI system is larger than that in the SSI system. The influence range of underground structure would be expanding to one-times of the underground structure width. The SSSI would enhance the kinematic interaction, resulting in larger rocking motion box foundation in the SSSI system than that in the SSI system. The peak moments of horizontal, rocking, and structural deformation acceleration of the SSSI system are not synchronous. Accordingly, it is necessary to consider the influence of the underground structure to improve the seismic safety of the aboveground structure due to the potential increase of the seismic response.