Scoured failure wedge model for analysis of scoured pile-soil interaction in sand

Abstract

Comprehensive assessment of scour effects is an important consideration in the design of pile foundations in water bodies because they can have a significant impact on the performance and bearing capacity of piles and the integrity of the supported structure. This study presents a scoured failure wedge (SFW) model to simulate the interaction between the laterally loaded pile and sand with local scouring. The developed model is incorporated into an efficient theoretical method to analyze the nonlinear behavior of laterally loaded piles under scour conditions accounting for the scour-hole dimensions and soil stress history. The developed SFW model is validated by comparing its predictions with experimental observations from relevant literature. Subsequently, the validated solutions are utilized to investigate the lateral performance characteristics of the pile under scour conditions. The findings reveal several important insights: (1) the impact of scour on soil properties is primarily confined to the shallow zone, approximately four times the scour depth (4 Hs) below the mudline after scouring; (2) the scour hole dimension has a more pronounced influence on the behavior of laterally loaded piles compared to the soil stress history; and (3) the pile response under lateral loading is positively related to the depth and width of the scour hole and negatively related to the slope angle of the scour hole.