Research on Optimal Arch Rib Inclination of Large Span Highway CFST through Arch Bridge

To investigate the reasonable range of inclination angle arch ribs, a spatial finite element method was employed based on concrete-filled steel tube (CFST) basket-handle through an bridge with span 360 m. A model established using Midas/Civil software, which verified actual data. The effects different rib angles were investigated under static loads. structural natural frequencies, linear elastic stability coefficients, internal forces, and displacements comprehensively considered to determine angle. results show that when ranges between 8° 10°, first, third, sixth frequencies structure are increased. It effectively improves lateral torsional stiffness ribs while ensuring optimal out-of-plane ribs. Compared parallel arch, is improved by 20.2%. variation displacement force not significant. Considering all indicators, for 300-m-level highway CFST bridges suggested be 8~10°.