Liquefaction assessment of non-woven geotextile-reinforced sand under high-frequency torsional excitation using resonant column tests

Abstract

The current research examines the liquefaction potential of non-woven geotextile-reinforced fully saturated loose sand by imposing high frequencies (14-60 Hz) torsional excitations with the usage of resonant column (RC) undrained tests. Tests have been conducted for different but rather low values of cyclic stress ratio ( CSR ) in a range of 0.01-0.05; where, CSR = average shear stress induced isotropic effective consolidating pressure . The results clearly indicate that the buildup of excess pore water pressure ( u e ) occurs on account of an increase in effective cumulative number ( N e C ) of vibration cycles during undrained loading. The magnitude of u e for a given N e C reduces with (i) an increase in the number ( N g t s ) of geotextile sheets in the specimen, and (ii) a decrease in CSR . Liquefaction resistance curves, providing the variation of N e L C with CSR , for geotextile-reinforced sand were drawn and compared with the data reported in literature; where N e L C refers to the effective cumulative number of vibration cycles required for an onset of liquefaction. For a given specimen, the magnitude of N e L C invariably decreases continuously with an increase in CSR . The results clearly reveal that an induction of geotextile reinforcements increase the value of N e L C for a given CSR .