Experimental Study of the Temperature Profile of the Main Cables and Slings in Suspension Bridge Fires

Abstract

Fire raises key issues in the safety assessment and thermal protection of a suspension bridge, where the temperature profile of the main cables and slings (cable) is an important parameter that has not been quantified in previous studies. The present research investigated its evolution in fire scenarios on the emergency lane and inside lane. A suspension bridge fire experiment platform was built, and 30 sets of pool fire tests simulating vehicle fire were conducted considering the wind velocity, pool size, and pool location. The focus was on the mass burning rate of gasoline and the temperature profile of cables during fires in different lanes. The results showed that the mass burning rate increased with pool size and cross-wind. A new characterization of the gasoline burning rate was introduced. A vehicle fire in the emergency lane posed a greater thermal threat to cables than an inside-lane fire. An exponential model representing the temperature profile of cables was derived. A uniform prediction model for the maximum temperature of cables exposed to different lane fires on a suspension bridge was proposed for the first time. The predicted values of proposed model were compared with measured maximum temperature, and reliable results were obtained.

Keywords: Suspension bridge fire, Maximum temperature of cable, Large-scale gasoline pool fire, Fire protection of bridge cable, Cross wind