考虑非保向力效应的单点或半跨加载钢管混凝土拱稳定性能研究

For through concrete-filled steel tubular (CFST) arch bridges, the tilting loads can increase their load-carrying capacity significantly, which should be considered in research. Hence, a finite element (FE) model for central-loaded and half-span-loaded CFST parabolic hingeless arches considering tilting loads was established using ABAQUS, and the model was validated to investigate the failure process of the arches. The results show that for the two arches, five and four plastic-hinge regions form at the peak load, respectively, and finally fail in strength failure. A parametric analysis was conducted to study the influences of rise-to-span ratio, slenderness ratio, steel ratio, steel strength, and concrete strength on the buckling capacity of the arches. The results show that the buckling capacity of the arches decreases significantly with the increase in slenderness ratio, but increases almost linearly with the increase in rise-to-span ratio and steel ratio. Based on the parametric analysis results, design formulae for the central-loaded and half-span-loaded CFST arches considering tilting loads were proposed by modifying the nonuniform distribution coefficient of the moment in the existing equation for CFST parabolic hingeless arches. The results obtained by the proposed design formulae are in good agreement with the simulation results, with a correlation coefficient of 0. 988.