Numerical simulation of mitigation of liquefaction seismic risk by preloading and its effects on the performance of structures

The present paper deals with the influence of soil non-linearity, introduced by soil liquefaction, on the soil-foundation–structure interaction phenomena. Numerical simulations are carried out so as to study an improvement method to reduce the liquefaction potential in a sandy soil profile subjected to a shaking. The efficiency of the preloading in both the mitigation of a liquefiable soil and the reduction of induced structure relative settlements is showed. However, the intervention at the foundation soil modifies the dynamic characteristics of soil–structure system and it seems to increase the induced seismic forces during earthquake. In addition, a numerical parametric analysis is performed so as to quantify the impact of the uncertainties associated with the input signal on both the ground motion and the apparition of liquefaction phenomena.

► The foundation soil mitigation modifies the characteristics of soil–structure system.
► Preloading produces significant reduction of structural settlement.
► Preloading could increase the structural seismic demand.
► Mitigation method decreases the liquefaction probability for a given seismic hazard.