Damage characterization and resilience optimization of reinforced concrete bridge piers under vehicle impact

Abstract

Vehicle impact creates a dynamic loading condition at high strain rate exhibiting a unique interaction with the resisting structural members’ material properties. This interaction results in an increase in the material’s strength properties, a behavior captured in analysis via the computation of a strength factor known as the dynamic increase factor (DIF). In reinforced concrete (RC) bridge piers, the concrete cover receives the initial impact from the vehicle, causing damage to this exterior surface. This makes the DIF related to the concrete material (i.e., the compressive DIF) particularly important in this initial phase of the crash scenario; thus, requiring an in-depth analysis into its effect on the performance of the pier during and after the impact event. This study initiates an investigation into the influence of the compressive DIF on the performance of RC piers under impact from vehicles classes. Of particular interest is estimating a post impact residual capacity for the pier, while also determining concrete strength parameters (compressive strength) that offers a good tradeoff between the shear capacity which primarily resists the impact loads, and the axial capacity which controls the principal serviceability of the pier. The resulting analyses, using a representative test pier, show that an optimal compressive strength of concrete will minimize loss in the residual capacity of the pier. The effect of the compressive DIF on other important design parameters, i.e., bond strength and development length is also scrutinized. This study will aid forensic structural engineers in scrutinizing the post impact concrete behavior and serviceability.

<i>Retracted: </i>Performance of Grouted Coupler Embedded in Reinforced Concrete ABC Bridge Pier at Vehicle Impact

“…Prototyped ABC pier with lower concrete strength has been utilized [7] to estimate damage of the coupler-rebar region incurred by impact. The impact of the pier specimen is subjected to the concrete strength parameters due to its high vulnerability to vehicle impact due to its exposed surface area quantifying a good composition between the shear capacity to primarily resist the impact load, and the flexural capacity predominately control the serviceability of the pier [5]. However, this present study intends to quantify the coupler high velocity post vehicle impact behavior at high strain rate load incurred by semi-trailer on the representative prototyped half sized ABC pier.…”

“…Dynamic Impact Factor (DIF) can be evaluated from Equation 5 by using ξ computed from Equation 4 [37,38]. 𝐷𝐼𝐹 = ( έ 10 −4 ) 𝜉 (5) where: DIF is the Dynamic Impact Factor, ξ is dynamic parameter, and έ is the Quasi-static strain rate of steel re-bar. Equation 5 yields the analytical DIF result as 1.053.…”

“…Quasi-static to dynamic strain rates of steel reinforcement connected to the couplers is also evaluated and published in [4]. Characterizing damage incurred by impact is subjected to the concrete strength parameters quantifying a good tradeoff between the shear capacity to primarily resist the impact load, and the flexural capacity controlling principal serviceability of the pier [5]. However, this present study intends to quantify the coupler post impact behavior at high strain rate load incurred by semi-trailer on the representative prototyped ABC pier utilizing grouted coupler.…”

Sustainability and Resiliency Investigation of Grouted Coupler Embedded in RC ABC Bridge Pier at Vehicle Impact

“…A study of the structural reliability of RC piers subjected to sequential loading exerted by blast and vehicular impact were also studied. The study showed that the structural performance of the piers are particularly sensitive to its dimensions [31,39]. This implies that an increase in the stiffness of the pier could possibly help it withstand the external forces caused by vehicular impact.…”