Centrifuge testing to investigate effects of partial saturation on the response of shallow foundation in liquefiable ground under strong sequential ground motions

Abstract

Induced partial saturation is one of the novel techniques to increase the liquefaction resistance of saturated sandy ground. Nonetheless, a limited number of experimental studies are available on the delineation of this method. Moreover, the performance of induced partial saturation under sequential ground motions is poorly understood. Dynamic centrifuge experiments are carried out to investigate the effects of partial saturation on the response of shallow foundation resting on liquefiable ground under sequential ground motions. Centrifuge models consist of two distinct shallow foundations and associated superstructures resting on a liquefiable uniform sand layer. The drainage-recharge method is used to induce partial saturation in the model ground. Compressibility change of pore fluid and alteration of ground permeability because of induced air voids, affect the deformation mechanism of the ground-foundation system. Assessment of maximum potential volumetric compressibility of pore fluid because of induced air voids is essential to understand the effectiveness of induced partial saturation. Centrifuge test results signify that the induced partial saturation reduces the overall deformation of the foundation-structure system. However, slightly amplified kinematic seismic demand is observed at superstructures in case of partially saturated ground in comparison with fully saturated ground.