In-Plane Strength and Design of Fixed Concrete-Filled Steel Tubular Parabolic Arches

Abstract

Concrete-filled steel tubular (CFST) arch bridges have the advantages of high compressive strength, light self-weight, and convenience in construction, and thus have been widely used in recent years. The current codes or specifications use the equivalent beam–column method to predict the in-plane strength of CFST arches. In this method, the CFST arches are considered under central or eccentric axial compression and are treated similarly to CFST columns. However, different from the CFST columns, the in-plane strength of CFST arches is affected by not only the slenderness ratio but also the rise–span ratio. Especially for the arches with small rise–span ratios, the prebuckling deformation becomes quite nonlinear, leading to a remarkable decrease in in-plane strength. Therefore, it is doubtful if the current method for in-plane strength design of CFST arches can provide correct predictions. In this paper, the elastic buckling and elastic–plastic buckling behaviors of fixed CFST parabolic arches that are subjected to uniform axial compression are investigated. The effect of the rise–span ratio on both the elastic buckling load and the in-plane strength are studied. A new method for the prediction of the in-plane strength of fixed CFST parabolic arches that are subjected to uniform axial compression is developed by considering both the slenderness ratio and the rise–span ratio.