Lateral brace arrangement for large-span half-through concrete filled steel tube arch bridge

The reasonable space of Mi-brace and X-brace commonly used in the large-span half-through concrete filled steel tube(CFST) arch bridge was researched.Considering that both the solution of the structure natural vibration frequency and mode as well as its elastic stability coefficient can transform into eigenvalue problem of the structure dynamic equilibrium equation,taking the fundamental frequency and the elastic stability coefficient of the structure as the evaluation criteria,the possible arrangements of Mi-brace and X-brace for half-through CFST arch bridge with 360 m span were comparatively analyzed,and the advices for the reasonable space of the Mi-brace and the X-brace were advanced.Keeping the same bracing region and the similar material consumption,four arrangement schemes of the lateral brace system were presented and their ultimate loading capacity were calculated.It was concluded that the method to determine the structural parameters by summing up the results of the modal analysis and the elastic stability analysis is practicable.For the case studied in this paper the X-brace can satisfy the stiffness requirement and provide a simple and light visual effect.