Influence of Specimen-Reconstituting Method on the Undrained Response of Sand

An experimental study aimed at a direct comparison of the undrained behavior of sand using specimens reconstituted by different techniques is presented. It is shown that at identical initial void ratio and effective stress state, the moist-tamped sand is potentially liquefiable, but in the water-deposited state may even be dilative. Water-deposited specimens are shown to be very uniform in contrast to the large nonuniformities that usually occur on moist tamping, rendering their results questionable from the standpoint of laboratory element tests. A direct comparison of the behavior of truly undisturbed sand specimens retrieved by in-situ ground freezing and their corresponding reconstituted counterparts after consolidating to identical initial states is also presented in support of the contention that the fabric that ensues on water pluviation closely simulates that of the natural alluvial and hydraulic fill sands, enabling the use of reconstituted specimens as substitutes for the expensive undisturbed frozen specimens for material characterization.