Challenges in the Seismic Modelling of Soil-Structure Systems with Unsaturated Soils Using Geotechnical Centrifuge

Steady-state infiltration technique can be used to develop a uniform degree of saturation profile in centrifuge physical models. This enables researchers to study different characteristics of partially-saturated soils. Although large-scale suction-controlled experiments have been conducted successfully, they involved inevitable challenges. Infiltrating water through soil-structure systems in the centrifuge could lead to non-uniform flow paths. Use of miniature pore pressure transducers (PPT) to capture changes of suction requires careful attention to avoid desaturation of the sensors. Suction scaling factor were proven to be unity for larger centrifuges (i.e. when the ratio between centrifuge arm and specimen height is greater than 10), but this issue has not been explored for smaller centrifuges. Seismic settlement of unsaturated soil layers in a geotechnical centrifuge contains limitations that should be considered when the results are interpreted.