Factors that Affect the Performance of Bridge Foundations Undergoing Liquefaction-Induced Lateral Spreading

Liquefaction-induced lateral spreading has caused major damage to bridge structures in past earthquakes. Lateral spreading may cause large lateral deformations at the abutments, which may induce large forces in the foundation, superstructure, and connections, leading to severe damage or even the collapse of bridge structures. The post-earthquake condition of a bridge structure is strongly related to the level of residual lateral displacement of the pile caps and abutments in the longitudinal direction, and several factors may affect this level of residual deformation. In this paper, the relative importance of several key factors is evaluated through the use of a realistic design example. Results suggest that the most influential parameters in this problem are the characteristics of the ground motion in terms of its spectral acceleration at the degraded period of the potential sliding mass, followed by the post-liquefaction residual undrained shear strength of the potentially liquefiable material, and the error term in the estimation of the residual lateral displacements induced by lateral spreading.