A method for investigating the responses of cable-stayed bridge exposed to distinctive tank truck fires

Abstract

This paper designs novel tank truck fires on deck and establishes a fire-structural calculation method for cable-stayed bridges. The designed fires include tank fire, spill fire, and their combined fire, the features of fire sources are configured based on surface conditions of deck and thickness of fuel. The established calculation method is traced in three stages, reproducing tank truck fires on deck by fire dynamics model, simulating thermal conduction in finished cables via heat transfer model, and analyzing thermal-mechanical performances of entire bridge through multi-scale finite element model. The calculation process of fire-exposed cables is experimentally validated and utilized for capturing fire responses of a cable-stayed bridge under the three fire scenarios. The main findings indicate that, tank fire causes a more significant reduction in force on several cables before their fracture than spill fire; spill fire eventually induces the fracture of more cables than tank fire; their combined fire contains the differences in fire behaviors of tank fire and spill fire; and a steeper deflection or rotation increment eventually occurs under spill fire or combined fire. The designed tank truck fires and the proposed calculation method provide an accessible approach for evaluating fire responses of cable-stayed bridges.