Performance of steel cable-stayed bridges in ship fires, Part II: Influencing factors and mechanisms

Abstract

In the context of frequent maritime shipment of combustibles and increasing intentional attacks, evaluating the performance of steel cable-stayed bridges subjected to underneath fires is becoming more critical. However, the current understanding does not cover what factors can affect fire damage to steel cable-stayed bridges and in what mechanisms they introduce the impact. This paper focuses on the influential factors in the performance of steel cable-stayed bridges exposed to ship fires. Nineteen fire scenarios with different longitudinal fire positions, fire intensities, fire-floor distances, and wind speeds were simulated using the fire-thermomechanical coupling method proposed in Part I. Results show that the focus of designing steel cable-stayed bridges against ship fires should be determining longitudinal fire positions and environmental wind speeds. Fire intensities and distances from fire surfaces to the girder bottom significantly affect the thermal response of the girder floor, but the caused entire structural response of the bridge is trivial because the holistic averaged stresses of exposed girders in these cases are close.