Experimental and numerical investigation on seismic response of the soil-structure cluster interaction system

With the rapid advancement of urbanization in recent decades, a large number of surface dense buildings have appeared. Soil-structure cluster interaction (SSCI) has attracted widespread attention. However, most current research is based on numerical simulations, and studies using shaking table tests are rare. Here, a series of shaking table tests of soil-structure interaction and SSCI systems were designed and conducted to investigate the effect of SSCI on the response of the structure and site soil. The number of structures, seismic wave types, and amplitudes were considered. The numerical method was verified based on test data. The test data and numerical results indicate that (1) the presence of surface buildings does not always reduce the free-field soil motion. However, the soil vibration decreases as the number of surface structures increases. (2) The maximum influence of SSCI effects on the roof acceleration and displacement of the central building (CB) can be as high as -23% and-18%, respectively. (3) The relative deformation of the structure decreases with an increase in the number of structures, and the relative deformation of the middle layer is the largest. (4) Different evaluation indices can yield roughly the same results, although the focus of each evaluation index is different. (5) A denser layout enhances the SSCI effect and further reduces the response of the CB when the urban density of the structural cluster is the same.