Assessment of Substandard Concrete Barriers as Protective Structures to Bridge Piers against Vehicular Collision Force

Abstract

Concrete barriers are used for different purposes in the highway inventory. Different test levels have been specified to help design these barriers to function as expected for their intended purpose of use. Reinforced concrete (RC) Jersey barriers are commonly used to act as intervening structures protecting bridge piers from colliding vehicles during crash events. Thus, they are subjected to vehicular collision force (VCF). According AASHTO, RC barriers used to protect bridge piers should have a minimum height of 1,067 mm and survive test level 5 (TL-5). Many existing barriers that are currently used in roadways do not meet this requirement, hereby, they are referred to as “substandard” barriers. While these barriers are found to be inadequate to solely protect bridge piers against VCF, recent research proved that their presence to intervene in vehicle–pier collisions will contribute to reducing the severity of the crash effects and, consequently, reduce the VCF demand on bridge piers. Therefore, it is important to have a comprehensive understanding about the behavior of substandard barriers during high-level crash events. This will help in proposing methodologies to upgrade these barriers in an efficient and affordable way. In this study, the behavior of a representative substandard barrier, subjected to TL-4 and TL-5 collision events, was investigated through a matrix of dynamic finite-element simulations using the general-purpose finite-element analysis (FEA) program LS-DYNA, version R10.0. The study considered various boundary conditions of the barrier. The investigated quantities were the energy dissipation, velocity reduction, contact force absorption, and lateral displacement. The results showed that the maximum energy dissipation and velocity reduction were about 45% and 30%, respectively. In addition, the highest contact force demand and maximum lateral displacement were 580 kN and 800 mm, respectively. Specific reduction values are addressed in detail in the paper.