Out-plane creep stability of concrete filled steel tubular arches

To investigate the influences of concrete creep on the out-plane stability of concrete-filled steel tubular (CFST) arches, a numerical method was presented for the out-plane creep stability analysis. The method combined the age-adjusted effective modulus method (AEMM) for the creep analysis and the finite element method for the structural analysis. The time-dependent initial geometric imperfection was introduced to express the creep deformation of CFST arches at any time. Then the out-plane creep stable bearing capacity could be obtained via the finite element analysis. Based on the method, an existed experimental CFST arch model was taken as a basic researching object, and the influences of the loading levels, slenderness ratios, rise-to-span ratios, lateral loads, steel ratios and loading ages on the out-plane creep stable bearing capacity were discussed. The results show that the method is of good efficiency and applicability; the slenderness ratios, steel ratios and loading ages have great influences on the creep stability, while the rise-to-span ratios and lateral loads have little influence; the creep-induced decreased degree of out-plane creep stable bearing capacity could rise to 13.8% which should be concerned in design.