Dynamic Behavior of Rocking Concrete Bridge Piers Subjected to Vehicle Collisions

Abstract

The nonlinear dynamic behavior of rocking bridge piers with different configurations was numerically investigated in this study when subjected to vehicle collisions using finite-element (FE) simulations in LS-DYNA software. The impact performances of the rocking monolithic and segmental piers were evaluated and compared to a monolithic pier considering the variations of the impact velocity (Vimp) and the axial load ratio (ALR). The FE simulations revealed that the rocking monolithic and segmental piers experienced lower peak impact forces, mitigated flexural damage, and dissipated more energy compared to the monolithic pier owing to the slippage mechanism at the joint interfaces. In addition, although an increase in the number of segments led to more severe localized concrete spalling damage, it enhanced the energy dissipation in the rocking piers. Furthermore, compared to the total collapses of the monolithic and rocking segmental piers under a high rate of vehicle impact at Vimp=140 km/h, the rocking monolithic pier demonstrated superior impact performance by withstanding total collapse owing to the higher structural integrity of the pier and lower stress concentration. Also, an absolute positive effect of the ALR on the impact resistance of the monolithic and rocking piers was obtained when the piers were subjected to medium-velocity impacts leading to relatively low deformations in the piers. However, an ALR of 0.15 was recognized as a sensitivity level of the piers’ impact resistance under a high-velocity vehicle impact with Vimp=140 km/h.