Effects of Stress History on the Liquefaction Resistance of Saturated Sand

It is a well known fact that stress history is one of the most important factors determining the liquefaction characteristics of sand. Consequently the liquefaction potential of a sand layer in the filed can not be determined satisfactorily by laboratory cyclic shear tests on sand samples prepared at the same void ratio as in the field. The purpose of this study is to obtain fundamental information on the effects of stress history on the liquefaction characteristics of saturated sand subjected to cyclic stresses. For this purpose, a series of liquefaction tests with constant amplitude cyclic stresses were performed on sand samples which had been previously subjected to simple stresses. Through this study, it has been recognized that the effects of stress history on the liquefaction characteristics of saturated sand are brought about by fabric changes during preshearing, an that the character of these effects of stress history can be explained by the observations obtained during stress reversal tests on dry sand