A comparative study of seismic performance evaluation of stone column, micro-pile, and geosynthetic-encased stone column for liquefaction flowslide mitigation

Abstract Soil liquefaction is the phenomenon associated with strong earthquake and has caused severe damage to structures. Liquefaction is a critical concern for geotechnical engineers because, during seismic excitation, the shear strength of loose, saturated sands decreases drastically due to the generation of excess pore pressure, leading to the breakdown of grain-to-grain contacts. This study systematically examines the effectiveness of various ground improvement techniques in mitigating liquefaction in mildly sloping ground conditions, to accurately predict the liquefaction triggering and permanent deformation of liquefied soil under different earthquake conditions. In practice, liquefaction mitigation measures, such as installing vertical drains to dissipate excess pore pressures, are often unsustainable due to their high cost, energy demands, and resource-intensive nature. This study evaluates the effectiveness of sustainable alternatives for mitigating liquefaction hazards in soils, focusing on the stone column (SC), micro-pile (MP), and geosynthetic-encased stone column (ESC) techniques. A three-dimensional finite-element simulation through OpenSeesPL has been demonstrated that the soil constitutive and the employed computational framework could reasonably predict the response of mildly-sloping liquefiable ground under seismic loading. The results show that the SC and ESC techniques are found to significantly reduce excess pore pressure generation, contributing to lower liquefaction susceptibility. While, the MP and ESC would appear to provide more resistance to the lateral deformation in mild sloping ground. It is also observed that the permeability, spacing, and diameter of the techniques also play an important role in achieving an effective design of the liquefiable ground during earthquake.