Structural behaviour evolution of composite steel-concrete curved structure with uncertain creep and shrinkage effects

This paper presents a new computational scheme to robustly determine the structural behaviour (both serviceability and strength) of composite concrete-filled steel tubular (CFST) arch with consideration of uncertain creep and shrinkage effects. The focused uncertainties in this study originate from the intrinsic viscoelastic effects of concrete, which inevitably affect the structural performance of CFST arch through its service life. Due to the diverse variations and intricate nature of creep and shrinkage observed in engineering practices, it is advisable that the two mercurial parameters are modelled as uncertain-but-bounded variables. The effects of uncertain creep and shrinkage on the long-term structural behaviour are investigated such that the worst and best scenarios of structural responses at each specific loading time can be precisely calculated. The proposed computational method competently determines the bounded structural responses at any specific loading time such that, evolutions of structural behaviours of CFST arch can be quantitatively constructed for the purpose of safety assessment. Numbers of often encountered engineering examples are investigated to illustrate the capability, credibility and efficiency of the proposed approach.