Evaluating the Performance of Concrete Barriers in Protecting Bridge Piers under Vehicular Impact in Space-Constrained Settings

Unprotected bridge piers are exposed to vehicular impact loads that can significantly exceed the code-specified design load, posing a significant risk of structural damage. Although protective barriers offer an efficient means of mitigating these risks, the effectiveness of these barriers for bridge piers is strongly influenced by space constraints between the piers and barriers. Barriers placed adjacent to piers may directly transfer impact forces and cause severe damage, while those placed with inadequate offsets can experience intrusion of vehicle components. This study evaluates the performance of a standard 1,372 mm (54 in.) pier protection barrier in adjacent and minimally spaced configurations using high-fidelity finite-element analysis. A sensitivity analysis is conducted to determine the effect of barrier height and offset distances on impact force transfer between tractor-trailers and piers in constrained spaces. Results indicate that increasing the spacing from 25 mm (1 in.) to 75 mm (3 in.) reduces the rear trailer impact force on the bridge pier by 75% for the studied cases. Additionally, increasing the height of the 1,372 mm (54 in.) tall barrier by 25 mm (1 in.) can completely mitigate the impact force due to the rear of the trailer. However, the front trailer impact force is less sensitive to changes in both height and spacing, requiring a barrier height of at least 1,422 mm (56 in.) with 50 mm (2 in.) to 75 mm (3 in.) spacing. Additionally, increasing barrier height is the most effective strategy in preventing load transfer, even in space-constrained settings.