Analysis of Piles in Liquefied and Non-liquefied Sands Due to Earthquake Vibrations Using Opensees

During intense earthquakes, numerous structures crumble due to the severe damage inflicted upon their substructures when the soil loses lateral support owing to liquefaction induced by the seismic activity. This study delves into the nonlinear characteristics of individual piles in sandy terrain caused by liquefaction triggered by earthquakes, employing 3D nonlinear FEM models via Opensees. Various thicknesses of single piles are examined with ground slightly inclined. The ground motion input consists of sinusoidal acceleration at a frequency of 2 Hz and amplitudes varying from 0.2 g. The data collected from sensors for both individual piles and pile groups are scrutinized for displacement, bending moment (BM), and excess PWP. Through this sequence of experiments, it’s noted that majority of the highest lateral loads on the piles occur during initial phases of lateral deformation, as excess PWP progress towards liquefaction. Subsequently, lateral loads appear to diminish for the liquefied stratum. It’s observed that the BM of piles in liquefiable areas considerably rises compared to non-liquefiable areas due to the loss of lateral support from the liquefied soil. Moreover, it is discovered that displacement at the pile base in saturated terrain is relatively minimal.