Numerical Analysis of Liquefaction and Settlement in Layered Soils

Abstract

Liquefaction is the phenomena when there is a loss of strength in saturated and cohesionless soil because of increased pore water pressures and hence effective stress is reduced due to the dynamic loading. Liquefaction may cause failure of foundations, resulting in the collapse of the structure. Liquefaction depends on the characteristics of subsurface soil. Study area considered was Amaravati, de facto capital city of the Indian state of Andhra Pradesh. It is essential to evaluate the liquefaction potential and settlement analysis of the soil as the constructions are on the rise in the new capital area. Based on the borehole data collected from the study area, it is seen that the soil profile consists of the sandy layers sandwiched between two silty clay layers in many of the boreholes up to 15 m depth. In the present study, Idriss and Boulanger method (new criteria for distinguishing between silts and clays that are susceptible to liquefaction versus cyclic failure. 2005, [1]) was used and the analysis carried out by using LiqIT software. It was found from the present study that the range for the factor of safety against liquefaction is varying from 1.5 to 5.0 in few boreholes. Based on the results, the soils are not susceptible to liquefaction, and the settlements are within the permissible limits.