ABSTRACT
Soil liquefaction is the complete or partial loss of the strength of soil, the transition of sand into the state of very low stiffness followed by a period of reconsolidation as temporarily elevated excess pore pressures dissipate. The phenomenon appears mostly during strong earthquakes with high shaking duration, in loose soil profiles. Thus, soil liquefaction mitigation methods are required for constructions projects founded on soils with high liquefiability. Compared to other liquefaction mitigation methods, stone columns offer three basic advantages. The column installation leads to the densification of the surrounding soil, the potential for dissipation of excess pore water pressure is enhanced by the presence of the higher permeability column and the overall soil stiffness increases. However, the relative contribution of each of these benefits is unclear. The purpose of this work is to separate out the relative contribution of drainage capacity via centrifuge modelling. Appropriate modelling considerations for a small-scale stone column system are addressed, especially particle size. Centrifuge tests are carried out to record the excess pore pressures in a stone column reinforced liquefiable loose soil during different earthquake motions. Further testing is taken place for comparison, with unreinforced soil samples or reinforced with modelled vertical drains in loose soil state. The results show that host soil characteristics are the key factor of the excess pore pressure dissipation of all models.
