RELATIONS BETWEEN LIQUEFACTION RESISTANCE AND SHEAR WAVE VELOCITY AS AFFECTED BY AGING OF SAND DEPOSITS

Since shear wave velocity is determined by non-destructive experiments in the narrow range of small strain, some researchers have reservations in employing it in the assessment of medium-to-large phenomenon, i.e. liquefaction. However, some others confirm that the shear wave velocity is more likely to suit for distinguishing the liquefaction and non-liquefaction susceptibility of sand deposits by means of the chart correlating liquefaction resistance to shear wave velocity, similar to the other types of indices, i.e. SPT and CPT, despite of its few limitations. Such liquefaction charts have commonly been proposed based on the liquefaction resistance of young Holocene deposits, without taking “age” into account. In an attempt to bridge the gap between those ideas, relations between liquefaction resistance and shear wave velocity of sand deposits are proposed under aging effect using a new-introduced index property, i.e. “cyclic reference strain” or “cyclic yield strain”, to differentiate between new and old sand deposits. The smaller the cyclic yield strain, the less ductile response of soil and vice versa. It may be concluded, therefore, that this parameter can be employed as a criterion for taking into account the cementation or the effect of age in sandy soils.