ABSTRACT
The cable is one of the most important components of the cable-stayed bridge. Its reliability and durability are of great importance to the safety and service performance of bridge. Owing to the possible fire accidents in the bridge, the yield strength of critical steel components of the bridge can seriously deteriorate during the service life. In this paper, the static performance of a three-pylon cable-stayed bridge under different fire scenarios was investigated. Firstly, several fire scenarios with different areas and locations of the fire accidents were assumed. Secondly, the temperature field of the stayed-cable under fire scenarios was analyzed. The damage of stayed-cable was studied by taking into account the reduced yield strength. Finally, the static performance of the whole bridge was obtained. The results showed that: (1) the vertical deflection of the bridge increases with the level of the fire disaster; (2) the maximum vertical deflection is 43.3 cm in the case where three stayed-cables ruptured in the middle span; (3) the stayed-cable fracture caused by fire near the back-stays has a great influence on the vertical deflection of the adjacent main span.
