A Review on Soil Liquefaction Mitigation Techniques and Its Preliminary Selection

Soil liquefaction is a phenomenon where a saturated cohesion-less soil substantially losses its strength as a result of reduction in effective stress and/or increase in the pore water pressure due to sudden change in stress condition, causing soil to behave like a liquid. Liquefaction may cause detrimental effects on infrastructures, loss of life and lifeline systems, which was historically observed in numerous earthquakes with major manifestations in 1964 Niigata, Japan, 1964 Alaska and recently in 2001 Bhuj, India, earthquake. In order to mitigate liquefaction effectively, knowledge about prevailing site conditions, subsurface stratification, project constraints, ground water table fluctuation, details of past seismic events, etc., and thorough technical knowledge of various liquefaction mitigation techniques is required. This article provides a concise summarization of various soil liquefaction mitigation techniques in current state of practice. Based on the mechanism of soil improvement, methods were categorized as (a) hydraulic modification, (b) soil structure densification and (c) reinforcement of soil. Finally, each of the listed methods was evaluated by generating a feasibility index through rated score analysis. These ratings were established on the basis of available literature while considering equal weightages to technology selection parameters. It is intended that the calculated feasibility index will serve geotechnical professionals by eliminating least feasible methods for given site conditions during initial stage of project.