Essential working characteristics of concrete-filled steel tubular arch supports discovered by modeling experimental strains

Abstract This study reveals the general working law of concrete-filled steel tubular (CFST) arch supports by exploring the experimental strain data based on structural stressing state theory. Firstly, the tested strains are transformed into the generalized strain energy density (GSED) values to model the stressing state mode and the characteristic parameters of CFST arch supports. Then, the Mann-Kendall criterion detects the mutation points in the evolving curves of characteristic parameters to the increasing load. Accordingly, it is verified that the stressing state modes also present the corresponding mutation features. The stressing state mutations reveal the failure starting point and the elastic–plastic branch (EPB) point of the CFST arch support’s working process, complying with the natural law from quantitative change to qualitative change of a system. Finally, the existing failure load and design load are redefined according to the revealed mutation features, which could update the working behavior analysis of CFST arch supports and promote the more rational design.