Drainage Performance Degradation of Stone Columns Caused by Fine-Particle Migration during Shaking in Centrifuge Model Test

Abstract

Stone columns are widely used in mitigating liquefaction hazards by accelerating the dissipation of excess pore pressure. However, studies on shaking-induced fine-particle migration and clogging in stone columns remain scarce. In this study, a dynamic centrifuge model test on liquefiable ground with stone columns was conducted to investigate the impact and extent of fine-particle migration and clogging. Employing the transparent soil technique and a back-analysis methodology based on seepage-consolidation theory enabled the observation of clogging and direct estimation of drainage performance in stone columns. The conclusions are presented as follows. (a) Cyclic loading exacerbates fine-particle migration, causing severe clogging and degradation of drainage performance even in stone columns designed by traditional filter design methodologies. (b) The resulting degradation of drainage performance is caused by fine-particle migration and soil densification, with particle migration being the primary factor. (c) This migration and clogging exhibit a clear depth dependency. This study indicates that traditional filter design becomes less effective under cyclic loading, potentially resulting in severe clogging, which should be carefully considered in long-term engineering projects.