Effects of Sample Preparation on Sand Liquefaction

The results of undrained stress controlled cyclic triaxial tests indicated that the dynamic strength of saturated sands, remolded to the same density by different compaction procedures, was significantly different. Variations in the dynamic strength of Monterey No.0 sand were found to be in the order of —100%; however, tests on other sands indicated that the magnitude of the effect of the method of preparation used may be a function of the type of sand. Fabric studies and electrical conductivity measurements indicated that the orientation and arrangement of the contacts between sand grains were probably the primary reasons for the observed differences in the dynamic strength of Monterey No.0 sand. Comparisons indicated that specimens prepared by moist tamping or moist vibratory compaction would exhibit dynamic strengths most similar to those of undisturbed samples; however, in most cases, the strength of undisturbed samples ranged from 0% to 45% higher than that of samples prepared by moist tamping.