Out‐of‐plane stability of CFST parabolic arches

Abstract Owing to their superior composite performance, concrete‐filled steel tubular (CFST) arches have been increasingly employed in bridge construction, with parabolic arches accounting for nearly half of such applications. The excellent mechanical properties of CFST arches often lead to slender designs, making their out‐of‐plane stability a critical concern. However, existing research and design standards primarily focus on circular arches, with limited studies addressing the out‐of‐plane stability of parabolic arches. This study investigates the out‐of‐plane buckling behavior of CFST parabolic arches subjected to vertically distributed loads along the span. In this paper, a theoretical framework for analyzing out‐of‐plane buckling is adopted using energy principles and a generalized Ritz method. The theoretical solutions were subsequently compared with numerical solutions obtained with finite elements models. The comparison shows agreement in internal force distributions and buckling loads.