Residual Deformation-Based Performance Evaluation Method for CFST Piers Subjected to Vehicle Collision

Abstract

Concrete-filled steel tubular (CFST) piers have been applied in bridge structures due to their high bearing capacity, good ductility, and light weight. During their service life, CFST piers may suffer vehicle collision. Nevertheless, there is still a lack of a performance evaluation method for CFST piers subjected to vehicle impact. Therefore, this paper presents a residual deformation-based method to evaluate the performance of CFST piers under truck impact. Before that, a numerical model was developed to simulate responses of CFST piers under truck collision and validated by reported impact tests. Then, the performance levels of 6- and 12-m high CFST piers under 20 and 40 ton and 60, 100, and 140 km/h truck collisions were numerically investigated. Afterwards, a residual deformation-based performance evaluation method was proposed based on the numerical investigations. In this method, the ratio of the residual lateral deflection at the mid-height to half of the pier height was first selected as the evaluation index. Then, threshold values of the evaluation index at different performance levels were determined. Finally, an analytical model for the evaluation index was developed. Comparisons indicate that the analytical performance levels are in good agreement with the numerical results. The proposed residual deformation-based performance evaluation method can be used for design and accident analysis of CFST piers subjected to truck collision.