This paper experimentally investigates the working behavior characteristics of an integral abutment curved box-girder (IACBG) bridge model based on the structural stressing state theory. First, the stressing state of the bridge model is represented by generalized strain energy density (GSED) values at each load Fj and characterized by the normalized GSED sum Ej,norm. Then, the Mann-Kendall (M-K) criterion is adopted to detect the stressing state mutations of the bridge model from Ej,norm-Fj curve in order to achieve the new definition of structural failure load. Correspondingly, the stressing state modes for the bridge model's sections and internal forces are reached in order to investigate their variation characteristics and the coordinated working behavior around the updated failure load. The unseen knowledge is revealed by studying working behavior characteristics of the bridge model. Therefore, the analytical results could provide a new structural analysis method, which updates the definition of the existing structural failure load and provides a reference for future design of the bridges.
Keywords: integral abutment curved box-girder bridge; mutation; stressing state; stressing state mode; updated failure load.