ABSTRACT
Cable-stayed bridges are infrastructure facilities with a highly public nature. Therefore, it is essential to ensure operational safety and prompt response in the event of a collapse or damage caused by natural and social disasters. Among social disasters, impact accidents can occur in bridges when a vehicle collides with a pier or when crashes occur owing to aircraft defects. In the case of offshore bridges, ship collisions may occur at the bottom of the pylon. In this research, impact analyses were performed by setting a virtual scenario in which a light aircraft impacts one of the cables on a cable-stayed bridge, and impact analysis techniques and procedures were proposed. The suggested procedure includes 1) setting up suitable aircraft impact hazard scenarios, 2) introduction of a missile–target interaction impact analysis method using the three-dimensional light aircraft model, 3) modeling the bridge structure based on considerations of the complex behavior mechanisms of cable-stayed bridges, and 4) assessment of the impact resistance performance of the cable-stayed bridge using numerical impact simulations. It was observed that in some scenarios, the stress of the cables that the aircraft impacted exceeded the maximum allowable stress of the cables (0.5 fu = 882.5 MPa) specified by PTI, and the maximum stress observed was approximately 96 % of the cable’s yield stress (fy = 1,570 MPa). Additionally, upward displacement of ~100 mm occurred in the deck at the location of the impacted cable. However, it is concluded that the probability of failure or considerable damage of the bridge is very low based on considerations of the span length of the bridge (center span: 470 m, side span: 200 m), the tensile strength of the cables (fu = 1,765 MPa), and the strain-rate effect of the material. If impact analyses are performed in the future based on additional scenarios, the critical location and critical level of impact could be identified.
