火灾下城市隧道、轨道交通、综合管廊共用结构安全性研究

Study on the Safety of Common Structure of Urban Highway Tunnel,Rail Transit and Urban Utility Tunnel in Fire Scenario

为了探明火灾下城市隧道、轨道交通、综合管廊共用结构的抗火性能,文章以义乌市商城大道隧道工程合建段为工程依托,通过理论分析与试验方法对隧道工程共用结构在最不利火灾场景下进行分析研究,得到了火灾情况下隧道结构的局部损伤情况。研究结果表明,在火灾局部高温作用下,由于混凝土的热惰性,隧道结构径向高温区范围较小。在短期火灾作用下,防火涂料可使隧道结构的损伤范围、深度及其力学性能所受的火灾高温影响较小。同时由于结构内力重分布会对其共用结构造成一定影响,其结构共墙、共板处为火灾时的薄弱位置,在抗火设计中应予以加强。该研究对类似隧道工程合建段共用结构设计具有一定参考意义。

In order to explore the fire-resistance of common structure of urban highway tunnel,rail transit and urban utility tunnel in fire scenario,based on the combined structure of Shangcheng Avenue tunnel project in Yiwu,the tunnel common structure is studied through theoretical analysis and experimental method under the most unfavorable fire scenario,and the local damage condition of the structure is obtained.The research results show that due to the thermal inertia of concrete,the range of radial high temperature of the structure is relatively small under the action of local elevated temperature.Under the effect of short-term fire,the fire-retardant coatings can reduce the influence of the elevated temperature on the damage range,depth and mechanical properties of the tunnel structure.At the same time,it will have a certain influence on the common structure because of the redistribution of internal forces.The common wall and common plate of the structure are weak positions in fire and should be strengthened in fire-resistant design.This study has certain reference significance for the design of common structures in similar tunnel engineering.