Structural performance degradation of cable-stayed bridges subjected to cable damage: model test and theoretical prediction

The performance of concrete cable-stayed bridge deteriorates under the influences of adverse environments and loads. This paper performs a segment model test on cable-stayed bridge with various cable damage conditions. The stiffness similarity-based method is developed and verified for the dimension design of the composite material. A test device is also designed to simulate the failure of stay cables. The effect of cable damage on the cable force, main girder stress, and deflection of the model were discussed and quantified. The experimental results indicate that cable failure changes the boundary support conditions of main girder, causing a significant change in the distribution of cable force, main girder stress, and deflection. The safety factor of the cables located in the mid-span of main girder is recommended to increase in practical engineering. Following that, a theoretical investigation model is proposed to represent the mechanical behaviour of structure, which offers a contribution in the form of analytical solution. The proposed method is verified by comparing the theoretical predictions with the numerical calculations of a cable-stayed bridge. This study can provide a reference for the structural performance assessment and maintenance decision for existing concrete cable-stayed bridges.