Research on Dynamic Mechanical Response of Rectangular Reinforced Concrete Pier with High-Performance Concrete Protection under Explosion

The dynamic mechanical responses and damage mechanism of high-performance concrete (HPC) protected rectangular reinforced concrete piers under explosive loads are investigated. An existing embankment-crossing continuous rigid-frame bridge having such type of piers was used for a case study. Based on the K&-C and C&-S dynamic material constitutive models, finite element models of the rectangular reinforced concrete pier before and after the addition of HPC protection layer were built up in ANSYS/LS-DYNA to analyze the dynamic mechanical responses of the pier to explosive loads. And the influences of HPC protection layer (with thicknesses of 20, 30, and 40 cm, respectively), TNT equivalent(of values of 275, 300, 325 and 350 kg, respectively), and explosion distance(of 10. 9 m and 8. 5 m, respectively)on the explosion resistance of the pier were compared. The results demonstrate that adding HPC protection layer can improve the explosion resistance of the rectangular reinforced concrete pier. With a 40 cm-thick HPC protection layer, the pier did not reveal large areas of damage. TNT equivalent is closely associated with the structural damage characteristics of the pier, when the TNT equivalent reaches 350 kg, the deformation of the pier as well as the stresses in the stirrups and main reinforcement are significantly intensified. Under the same level of protection, the pier damage area is inversely related to TNT explosion distance. In the explosion protection design of a pier, the TNT equivalent and TNT explosion distance must be considered so as to set a rational protection target. © 2023 Wuhan Bridge Research Institute. All rights reserved.