LIQUEFACTION MITIGATION OF GROUND TREATED WITH GRANULAR PILES: DENSIFICATION EFFECT

Ground treatment by rammed granular piles can offer effective solution amongst various other improvement methods. Densification of the surrounding ground by rammed granular piles modifies the soil properties. In this paper liquefaction mitigation of the ground treated by granular piles (GPs) is assessed considering the pore pressure generation and dissipation accounting for both the densification and drainage effects of GPs. Seed and Booker’s approach for pore water pressure generation and dissipation is applied with modifications for evaluating the densification effect of GPs. Specifically the modifications in coefficients of volume change and permeability of the soil surrounding the granular drains due to the densification effect are incorporated in the analysis under earthquake conditions and their effects quantified.