Resistance mechanism and reliability analysis of reinforced concrete columns subjected to lateral impact

Abstract

In the present study, reliability analysis is carried out to evaluate the structural safety of prototype reinforced concrete (RC) columns under lateral impact loading. Since RC columns are prone to suffer shear failure due to the large shear force forming in a short interval of time, the resistance mechanism in the local response stage is numerically investigated using finite element (FE) models verified against experimental results from the literature. Based on the simulation results, a novel methodology is proposed and validated to predict the inertial force distribution of RC columns at the peak impact force, and empirical formulas for predicting the impact actions in the local response stage are derived. Moreover, a simplified analytical model on the basis of the shear failure mechanism is proposed to determine the dynamic shear demand of the column. Incorporating the uncertainties associated with the structural and impact loading properties, shear failure probabilities of RC columns are evaluated with Monte Carlo simulation method to derive fragility curves dedicated to risk analysis. The limit state function is set up based on the dynamic shear capacity for the damage assessment. From the analysis results, it is found that the structural reliability of RC columns under impact loadings is sensitive to impact mass, impact velocity, section area and concrete strength. In addition, the proposed method is convenient to implement and could be a powerful tool for the anti-impact design of RC components.