油罐车火灾下双层悬索桥抗火性能研究

Study on Fire Resistance of Double Deck Suspension Bridge Under Fire of Oil Tank Truck

为了研究大跨径悬索桥高温力学性能,利用火灾动力学软件FDS及有限元软件ABAQUS建立悬索桥主桥的热-结构耦合模型,研究火灾下大跨径悬索桥高温力学性能退化规律。结果表明:火源附近上层纵横梁、桥面板和组合式横梁等成为受火高温区,相应应力较大;上层桥面板应力在528 s达到材料高温屈服强度,此时发生受火强度破坏。研究成果可为桥梁火灾韧性评价体系研究提供参考。

To study the mechanical properties of long-span suspension bridges under fire,the thermal structural coupling model of the main bridge of suspension bridges is established by using the fire dynamics software FDS and the finite element software ABAQUS,and the degradation law of mechanical properties of long-span suspension bridges under fire is studied.The results show that the upper longitudinal and transverse beams,bridge decks and combined beams near the fire source become the high-temperature area,and the corresponding stress is large.The stress of the upper deck plate reaches the high temperature yield strength of the material in 528 seconds,and the fire strength failure occurs at this time.The research results can provide reference for the study of bridge fire toughness evaluation system.