Condition assessment of stay cables using normalized sequence of vehicle-induced cable force peaks of stay cables on same side

Abstract

The condition of stay cables greatly affects the safety of bridges. Cable force is an important health indicator of cables, but it is difficult to directly assess the condition of a stay cable by the cable force because the cable force is affected by the operating environment including temperature and vehicles. In this paper, the condition of the stay cable is assessed by constructing a normalized sequence of the vehicle-induced cable force peaks (VICFPs) of the stay cables on the same side. The normalized sequence of the VICFPs of the same side cables is only related to the structure itself, and the damage to the cable can cause an abnormal reduction in the sequence. First, the normalized sequence of the VICFPs of the same side cables is derived and defined, and the change in the normalized sequence of the VICFPs with damage is qualitatively analyzed by a simplified mechanical model. An indicator of the change in the normalized sequences is constructed, and the condition assessment of the stay cables is realized by building the control chart of the indicator. Second, via a finite element model of a cable-stayed bridge, the sequences of different vehicle weights, different lanes, and different damage degrees are verified and analyzed. Last, the proposed method is applied to an actual bridge, and the results indicate that the proposed method has sufficient feasibility and accuracy.