Lateral displacement and pile instability due to soil liquefaction using numerical model

Pile instability due to liquefaction of loose sand is considered one of the most important causes of bridge failures during earthquakes. In this study, the 3D finite element program DIANA 9.3 is implemented to study the seismic behavior of piles penetrated into liquefiable sandy soil. This model is supported by a special Line–Solid Connection element to model the interface between pile and surrounding soil.Extensive studies were performed to investigate the effects of soil submergence, pile diameter, earthquake magnitude and duration on pile lateral deformation and developed bending moment along pile shaft. Study results show that earthquake magnitude and time duration have a particular effect on the pore water pressure generation and hence pile lateral deformation and bending moments. They also show the benefits of using relatively large piles to control the lateral displacement. Recommendations are presented for designers to perform comprehensive analysis and avoid buckling and plastic hinge failures.