Dynamic Response of Elevated Rc Pile Subjected to Blast Load

Recent terrorist attacks, such as the World Trade Center in 1993 and the Alfred P. Murrah Federal Building in the United States in 1995, have highlighted concerns about structural safety against blast events. The overall structural safety is heavily reliant on the foundation's ability to behave safely during such blast events. Before any type of restoration or rehabilitation of a blast-damaged structure, it is critical to assess the effects of blast-induced shock waves on its foundation. In this paper, a blast response of an elevated RC pile foundation was analyzed using the commercially available 3D finite element software Abaqus/Explicit. Various constitutive models are employed to capture the different material behaviors, like the Concrete Damage Plasticity Model (CDP) for reinforced concrete pile, the Johnson-cook (J-C) model for reinforcement bars and the Drucker-Prager (D-P) Model for the surrounding soil. A 50 Kg TNT explosive was modelled using ConWep method, located at the distance of 3 m from the pile and 0.5 m above the ground. A comprehensive parametric sensitivity analysis was performed for various stand-off distance, unsupported length, axial load, reinforcement ratio, and concrete grades. The response of RC pile was measured in terms of its lateral deflection. The results show that the pile’s lateral displacement decrease with the decrease of unsupported length and increase of stand-off distance. Furthermore, variations in axial load, reinforcement ratio, and concrete grade have a significant influence on the pile head's lateral displacement.