Dynamic response of piles embedded in granular soil to lateral impacts.

Soil-embedded vehicle barriers, such as W-beam guardrail systems, play a pivotal role in transportation safety, mitigating the risks associated with vehicular collisions with roadside hazards. The efficacy of these barriers greatly depends on the pile-soil system's kinetic energy dissipation capability during vehicular impacts. However, a comprehensive understanding of how soil strength, embedment depth, and impact velocity collectively govern the dynamic behavior of the pile-soil system remains a gap in current research. This study explores the dynamics of lateral impacts on piles embedded in various granular soils. The process of dynamic lateral impact and interaction between the pile and the soil was modeled using the Updated Lagrangian Finite Element Method (UL-FEM). A damage-based element erosion algorithm was incorporated into the model to accommodate severe mesh distortions and element entanglements of the soil material brought by the pile impact. Validation against well-documented large-scale physical impact tests ascertained the model's fidelity. Our findings elucidate the significant differences in resistive forces between piles in strong versus weak granular soils – notably, the former exhibited resistive forces roughly double their weaker counterparts under equivalent embedment depths and varied impact velocities. Intriguingly, a stiff pile in weak soil necessitates nearly double the embedment depth to match the energy dissipation of its strong-soil counterpart. Furthermore, the study discerned consistent depth of rotation point ranges for piles embedded in distinct soil strengths, regardless of embedment depth and impact velocity. • An investigation was conducted on the dynamics of lateral impacts on piles embedded in granular soils. • The Updated Lagrangian Finite Element Method (UL-FEM) enhanced with a damage-based element erosion algorithm was employed to effectively capture dynamic pile-soil interactions under impact loading. • The computational model, validated against large-scale physical impact tests, showcased remarkable fidelity and accuracy. • The study revealed that stiff piles in weak soil require roughly double the embedment depth to attain energy dissipation, similar to their counterparts in stronger soil. • Evaluated resistive forces and the total energy absorbed, emphasizing the roles of soil type, impact velocity, and embedment depth. [ABSTRACT FROM AUTHOR]