Liquefaction of sub-soil is a phenomenon in which partially saturated or saturated loose cohesionless sub-soil, especially loose fine sand, significantly lose their strength and stiffness in response to applied stresses. It occurs generally during earthquake shakings because of the generation of surplus pore water pressure, causing it to lose its effective stress and act like a liquid. Essentially, prediction of the liquefaction severity accurately is very important for liquefaction-prone sites for different seismic conditions. All the structures that are constructed on sub-soil are susceptible to liquefaction and can get damaged as a result of earthquake ground motion. Since earthquakes are one of the most disastrous events, analysis for sub-soil needs to be conducted to understand the soil behavior and its stability against liquefaction at different sites. There are several simplified techniques to assess liquefaction potential on the basis of standard penetration test (SPT), cone penetration test (CPT), and shear wave velocity (Vs) test. In this paper, simplified liquefaction analysis has been carried out based on SPT data for 10 sites in Bahraich District situated in Uttar Pradesh. Liquefaction potential index (LPI) has been calculated and the level of liquefaction severity is classified. It was observed that out of 10 site that have been evaluated 5 had moderate to high severity; while, the remaining 5 sites had high to very high severity. The classification helped in preliminary comprehension of the liquefaction susceptibility of the sites selected for construction.
