A saturated sand deposit placed below a structure is subjected to nonuniform vertical stresses as shown in Fig. 4. It is known that there is an interesting experimental fact that a saturated sand deposit near a structure on the same horizontal plane liquefies more quickly than it below a structure. In order to clarify the liquefaction characteristics and the amount of liquefaction-induced settlement of a saturated sand deposit under nonuniform vertical stresses, a series of shaking table tests were performed on a simplified model (1), prepared in three Kjellman’s type shear boxes. This model consisted of three saturated sand layers for which the effective vertical stresses σvo′ were 10.4 kPa, 30.0 kPa and 49.6 kPa respectively. Similar tests were also carried out on four models (models (2) to (5)) consisting of two sand layers having different RVS values (=(σvo′)l/(σvo′)h) in which (σvo′)l, (σvo′)h represent lower and higher vertical stresses for the two respective sand layers.
