Seismic Performance Evaluation of Steel Circular Hollow Section Bridge Piers with Corroded Ends

Abstract

Steel circular hollow section (CHS) bridge piers have been widely used in the engineering practices. However, end corrosion is one of the most common damages to steel bridge piers, leading to degradation of seismic performance and changing of failure modes. This paper investigates the seismic performance of the corroded steel CHS bridge piers and proposes a method to predict its lateral ultimate strength under the transverse cyclic loads. Firstly, the multi-scale finite element (FE) models of the CHS steel bridge pier are developed considering both the local buckling and the end corrosion, which are calibrated against the previous test results. Subsequently, the effects of the characteristic parameters (i.e., the corrosion conditions and the column parameters) on the failure modes and the horizontal ultimate strengths of the corroded steel CHS bridge piers are investigated, and then the sensitivity of the parameters is quantified using the Sobol method. Finally, a method is presented for estimating the ultimate strength of the end corroded steel CHS bridge piers under the horizontal cyclic loads. Results show that the end corroded bridge piers exhibit more significant stress concentration when comparing with the uncorroded bridge piers. The buckling half-wavelength is influenced by corrosion parameters, and the buckling position changes. The ultimate strengths of end corroded bridge piers are reduced, which is more sensitive to the corrosion rate. The proposed theoretical method to predict the ultimate strengths of corroded steel CHS bridge piers is accurate enough with errors less than 10%.