Experimental investigation into stressing state characteristics of large-curvature continuous steel box-girder bridge model

This paper conducts the experimental investigation into the whole working process of a large-curvature continuous steel box-girder bridge model to reveal its behavior characteristics and unseen failure mechanism, based on the structural stressing state theory. Firstly, the structural stressing state and corresponding characteristic parameters are expressed by the generalized strain energy density (GSED) derived from the experimental strain data. Then, the Mann-Kendall (M-K) criterion is introduced to distinguish the structural stressing state leaps of the bridge model, leading to the updated definition of the structural failure load and the revelation of structural progressive failure. Furthermore, this paper proposes stressing state submodes and evaluates their roles in the structural “failure”. Finally, the coordinative working performance of the divided sub parts is modeled through the ratios between the GSED sums of individual sub parts and the ensemble.