Analysis of Liquefaction Potential of Coastal Sands Using Laminar Box System

Abstract

Liquefaction is considered as one of the geotechnical risks caused during an earthquake in a saturated sand deposit. Due to their loose, saturated, and cohesionless nature, the sands in the coastal area are susceptible to liquefaction when subjected to cyclic loading. This effect leads to an alteration of soil structure from a stable to an unstable liquid form. The study of liquefaction in Kerala, which is in earthquake zone III, has not been done much earlier and that would be beneficial because of increasing infrastructural development in these areas. This study presents the development of a laminar soil container for shaking table tests in Kerala, and the response of the excess pore water pressure at various locations of the contained sand. The laboratory investigation is intended to understand the effect of gradation of soil and amplitude of base shaking on the generation of excess pore water pressure at varying relative density of soil (30%, 40% and 50%) but at a constant frequency of shaking (1 Hz). The test results have indicated that soil liquefaction resistance decreases as the amplitude of base shaking increases and the relative density of soil decreases. Also, sand with a lower percentage of finer sand content and larger mean grain size showed higher resistance to liquefaction.