Impact Response and Capacity of Precast Concrete Segmental versus Monolithic Bridge Columns

In this study, the performance of precast concrete segmental bridge columns (PCSBCs) against truck impacts was numerically investigated and compared with a corresponding conventional monolithic column (CMC). The numerical results have shown that although the impact force time histories of the two columns were quite similar under the same loading conditions, the PCSBC showed a better performance in terms of the induced bending moment and shear force by high impact force due to shear slippage and joint rocking between concrete segments. Also, the damage and failure of PCSBCs were localized at the two bottommost segments due to compression damage and/or combined flexural and shear failure of the concrete segment, whereas failure of the CMC distributed widely with flexural cracks, shear cracks, and punching shear at multiple sections. Furthermore, the base segment, which was found to absorb about 80% of the total absorbed energy of the PCSBC, played a crucial role in controlling the failure of the PCSBC. An analytical method to estimate the bending moment required to open the segment joint and the ultimate bending moment was also developed with consideration of the dynamic increase factor and the increase in axial force associated with stress wave propagation in the column induced by impact load.