2.3.2. Soil
Dry soil conditions were tested in the centrifuge, given that the effectiveness of TMDs in reducing the peak structural response during seismic loading relies on the absence of drastic changes in soil (e.g. liquefaction). The soil under consideration was finegrained siliceous Hostun sand (HN31). The properties of this sand are outlined in Table 2 [19].
The two soil profiles that were tested consisted of a loose (Dr ¼ 50%) homogeneous bed and a dense–loose–dense (Dr ¼ 85%; Dr ¼ 50%; Dr ¼ 85% ) layered bed of varying layer depths. The structure's footing was rested on the soil surface in each case. The total soil depth was consistently modelled to resemble 18.5 m in prototype scale. The relative density of the
loose bed was designed to be sufficiently low in order to investigate damping effects on structural response when soil damping is significant. In comparison, the layered bed was designed to better resemble the natural variability of soil conditions with depth