Abstract: After the fire hazard in highway tunnel ,lining structures would change in physical and mechanical properties, such as reduction in thickness and elastic modulus. Firstly, damage mechanisms, mechanical properties and refractory characteristics of the concrete component after fire are analyzed; what's more, according to fire loss grades of the concrete, further research is done on the influences of the thickness and elastic modulus on the lining structure system. Using the loading??structurem ethod, the mechanical behavior of the high??order highway tunnel structure after fire hazard is analyzed; its residual capacity and regularity of the internal force and deformation is explored; and destruction points and failure mechanism are found out

Key words: highway tunnel, fire hazard, secondary lining, loading??structure method

摘要： 公路隧道发生火灾后,衬砌结构将发生物理与力学性能的改变,如厚度变薄和弹模降低等。首先分析混凝土 构件在火灾后的损伤机理、力学特性和耐火性能,然后根据混凝土火损等级,进一步研究衬砌结构厚度与弹性模量 的变化对衬砌结构体系的影响。采用荷载-结构法分析超高次公路隧道结构体系在火损后的力学行为,探寻其残 余承载能力及内力与变形规律,找出特征破坏点与破坏机制。

关键词: 公路隧道, 火灾, 二次衬砌, 荷载-结构法