Lateral Performance of Bridge Pile Foundations in Seasonally Frozen Soils Considering Ground Scour Effect

Abstract

This study presents experimental results from scale model tests on laterally loaded bridge pile foundations in soils subjected to seasonal freezing. A refined finite-element model (FEM) was established and calibrated based on data obtained from the experiments. Furthermore, the model was utilized to investigate the impact of soil scouring depth on the lateral behavior of bridge pile foundations embedded in seasonally frozen soils. The findings indicate that soil freezing significantly enhances the lateral bearing capacity of the pile–soil interaction (PSI) system while reducing lateral deflection of the pile foundation. However, soil freezing results in increased damage to the pile foundation and upward movement of the plastic zone toward the ground surface. Under unfrozen conditions, significant plastic deformations occur on the ground surface and even inside the piles due to the extrusion effect. Additionally, increasing soil scouring depth significantly reduces the lateral bearing capacity of the PSI system while also increasing lateral deflection of the pile foundation for a given load level. Notably, when the scouring depth exceeds 2 m in unfrozen soils, the entire pile experiences obvious deformation and inclination, exhibiting a short-pile behavior that negatively affects the lateral stability of the pile under lateral loads.