Numerical investigation of Liquefaction Induced Lateral Displacement using SPT Data of Bahraich District

Liquefaction-induced lateral displacement (LLD) is a significant geotechnical concern during the earthquake, particularly in loose saturated soil. In earlier earthquakes, lateral spreading-a frequent ground deformation brought on by soil liquefaction has severely damaged buildings and lifelines. Currently, a number of empirical techniques have been to evaluate lateral displacement. In this paper the lateral displacement is investigated using 3D finite element OpenseesPL, open-source software based on the Standard Penetration Test (SPT) data, a widely employed in-situ soil investigation technique. First of all, the Finite Element lateral displacement analysis results have been verified with benchmark case study results. After that a detailed 3-Dimensional Finite Element analysis of lateral displacement was performed considering the gently sloping terrain. Numerical simulations are carried out using the open-source platform OpenseesPL, incorporating the PressureDependMultiYield02 constitutive model to capture nonlinear soil behaviour and excess pore water pressure generation. The liquefaction susceptibility of the subsurface soil is first evaluated using the Liquefaction Potential Index (LPI), which integrates the depth-dependent factor of safety against liquefaction with a depth-weighting function. The computed LPI value indicates moderate to high liquefaction severity, with major contributions from shallow loose sand layers up to a depth of approximately 10.0 m under a shallow groundwater table. Site-specific analyses reveal significant variation in lateral surface displacement across the study area, The maximum lateral surface response of bhopatpur site is 1.867 m and minimum lateral surface response Harana Anaura site, Jarwal Block is 0.266 m. The excess pore pressure time histories indicate that pore pressure increases with time and exhibits progressively higher magnitudes at greater depths. The suggested method can be used to Obtain first approximations of the size of lateral displacements connected to a lateral spreading caused by liquefaction.