Evaluation of Cyclic Resistance and Postliquefaction Volumetric Strains of Intermediate Soils

Postshaking soil volumetric strains of liquefiable soils are of technical interest because they cause a relevant part of the total settlements experienced by the site of interest. In the case of liquefiable intermediate soils, such as sandy silts or silty sands, reconsolidation volumetric strains are affected by the amount of fines. The technical note reports the results of laboratory cyclic undrained tests carried out to study liquefaction resistance and postliquefaction volumetric behavior of sand-silt mixtures reconstituted with increasing amount of nonplastic fines [0 < fines content ðFCÞ < 20%]. The test outcomes indicate that the equivalent granular void ratio (e ) can be successfully adopted to quantify the volume reduction of sand-silt mixtures as long as the soil matrix is ruled by the grains of sand. An analytical relationship between e and the volumetric strain is finally proposed to be of technical help in predicting the effects of reconsolidation in intermediate soils.