Dynamic Response of GESCs‐Supported Embankments in Sand Under Sinusoidal Loading: A Fluid‐Solid Coupling Method

ABSTRACT The geosynthetic‐encased stone columns (GESCs) are extensively used for improving weak foundations. Three‐dimensional numerical models with a fluid‐solid coupling method are established to delve into the dynamic response of GESCs‐supported embankment in sand under sinusoidal loading. Further, loading frequency ( f ), loading amplitude ( a m ), embankment loads ( σ e ), space‐to‐diameter ratio ( s / D ), column length‐to‐foundation thickness ratio ( L / H ), and Young's modulus of soil ( E s ), are selected to conduct the parametric study. Numerical results indicate that encasement guarantees the anti‐liquefaction of GESCs compared to OSCs and untreated foundations. However, the soil outside of the GESCs reinforcement region results in the absolute value of the excess pore water pressure ratio ( R u ) larger than 1.0. The sand foundations develop slip surfaces under embankment and sinusoidal loads based on maximum lateral displacement and their positions. GESCs are more sensitive to lower f and higher a m . It is recommended to consider the σ e in the dynamic analysis process. A larger L / H or E s / E c ( E c = Young's modulus of column) or smaller s / D is conducive to the dynamic resistance of GESCs.