Evaluating the saturation of model ground by P-wave velocity and modelling of models for a liquefaction study

A substantial amount of experimental and analytical research has been carried out on the liquefaction mechanism, prediction of liquefaction, and soil improvement for liquefaction. In model tests on liquefaction phenomena, several techniques have been proposed for preparing saturated sandy ground. The vacuum method and CO₂ gas have been used for saturation by many researchers. There have been few investigations that have studied the effective of this and alternative methods to achieve saturation of the sand in centrifuge model tests. In the present study, model sandy ground was prepared by three techniques and their degrees of saturation were estimated by measuring the P-wave velocity propagating through the ground. The degree of saturation of model ground was greatly influenced by the preparation technique. Further, the reliability and repeatability of centrifuge model test must be carefully examined to conduct successful tests, because the measurements are influenced even by slight differences in preparation of model ground. In the present study, a modelling of models test using three different scaled models (1110, 1/25, and 1/50) was performed to investigate the reliability of our centrifuge model test for liquefaction phenomena. The results confirmed good agreement of the measurements in all test cases.