Effect of Silt Content on Liquefaction Susceptibility of Fine Saturated River Bed Sands

Abstract

The effect of silt intrusion on the liquefaction susceptibility of fine saturated sand has been studied here using a series of strain-controlled cyclic triaxial tests on isotropically consolidated soil specimens. The fine sands used in this study were collected from the Ganga and Sone river bed. The samples were prepared with 100% non-plastic silt, 100% sand and different percentage (5%, 10%, 20%, and 30%) of non-plastic silt mixed with fine sand to study the effect of intruded silt on liquefaction susceptibility of sand. It has been found that at the same relative density range (10–25%) and the same percentage of intruded non-plastic silt, the Ganga sand is having higher liquefaction susceptibility than the Sone sand. The outcome of the study also showed that the rate of generation of excess pore water pressure (EPWP) for all three soil specimens was more or less same at higher strain levels (0.66–1.31%). However, the liquefaction potential continues to increase with the increase in silt content at a lower strain rate of 0.13%. A graphical relationship has been proposed for the EPWP development model parameter as a function of non-plastic silt content. This modification in the EPWP model parameter is one of the novel aspects presented here, which can be used for site-specific nonlinear ground response analysis.