Blast resistance of steel jacket reinforced double-column bridge pier

Abstract

Amidst the rise of regional military conflicts and terrorist activities, explosive attacks have emerged as a significant threat to critical structures, including high-rise buildings and bridges. This study adopts four explosion loads from authoritative counter-terrorism sources and uses LS-DYNA to perform numerical simulations of explosive events. The accuracy of the numerical simulations is initially validated against field test results. The numerical analysis examines various explosion locations, typical explosive sources, and the design of steel jacket reinforcement. It analyzes the impact of explosive loading on the horizontal displacement and acceleration response of double-column piers under bridge-forming conditions and examines the effectiveness of steel jacket reinforcement in mitigating the effects of explosive loading and enhancing protection mechanisms. Additionally, a parametric study is conducted to explore the influence of steel pipe thickness and coverage rate on the explosive response. The findings reveal that as the explosion location shifts from the outer to the inner side of the double-column pier, the response and damage to the more distant columns become increasingly severe. The application of 20 mm steel pipe protection significantly reduces plastic deformation caused by explosions, as the steel pipes help absorb the explosive energy. While increasing steel pipe thickness yields only marginal improvements in blast resistance, reducing the steel pipe coverage rate significantly enhances protective performance and mitigates additional concrete damage from lateral thrust.