A Simplified Procedure for Evaluating Post-Seismic Settlements in Liquefiable Soils

The importance of predicting ground deformation in loose, saturated granular soils has been widely recognized for a reliable evaluation of liquefaction damage. A procedure is proposed in this paper for the evaluation of post-cyclic consolidation settlements, as a result of volumetric strains induced by the dissipation of excess pore pressure. A stress-based model is first adopted for generating the excess pore water pressure in 1D free-field conditions, allowing for an effective stress analysis according to a loosely coupled approach. Then, the post-cyclic settlement is simply calculated integrating the vertical strains. To this aim, by considering a well-documented case history in which an extremely small settlement was observed upon seismic excitation, soil stiffness is estimated on the basis of either CPT data or shear stiffness decay curve, to show the effect of modelling hypothesis on the results. Both approaches result into a value of the settlement close to the observed one and much lower than that calculated using a well-established empirical procedure.