Flexural response of piles under liquefied soil conditions

The paper pertains to the development of a generalized procedure to analyze and predict the flexural behavior of axially and laterally loaded pile foundations under liquefied soil conditions. Pseudo-static analysis has been carried out taking into consideration the combined effect of axial load and lateral load. Based on the available literature effect of degradation on the modulus of subgrade reaction due to soil liquefaction has been incorporated in the analysis. The developed program was calibrated and validated by comparing the predicted behavior of the pile with theoretical and experimental results reported in literature. The predicted behavior has been found to be in excellent to very good agreement with the theoretical and observed values in the field, respectively. The present study highlights the importance of considering the axial load from the superstructure along with the inertia forces from the superstructure and the kinematic forces from the liquefied soil in the design of pile foundations in liquefiable areas. The significance of densification of the soil in the liquefiable areas and presence of an adequate top non-liquefied soil cover causing appreciable reduction in deflection and bending moment experienced by the piles has been highlighted.