Investigation of the structure-soil-structure interaction between two structures in centrifuge test

Dynamic soil-structure interaction and structure-soil-structure interaction (SSSI) between two structures were investigated using the dynamic geo-centrifuge machine at KAIST, South Korea. A homogeneous ground silica sand with a relative density of 80% was prepared using air pluviation method. In-flight shear wave velocity profile of the soil was measured using an array of bender elements during the test. A Hachinohe earthquake (recorded at Tokachi Oki, Japan in 1968) was applied to the soil base as input excitation. Two single-degree-of-freedom structures were constructed with aluminum named B1 and B2. The results indicate that total power spectral density of B1, which is a more massive structure, decreased in series of test with the B2 structure compared to those in reference tests. However, SSSI effects increased response of the B2 structure, regardless of distance between the two structures. The mass ratio and distance between two structures were important parameters controlling SSSI effects.