铁路盾构隧道双层衬砌结构耐火性能的数值模拟分析  

Numerical Simulation Analysis on the Fireproof Performance of Double-Layered Lining Structure in Railway Shield Tunnel

作　　者：邱月[1,2] 封坤[1,2] 张玉春[1,2] 何川[1,2] 薛光桥[3] 张政[1,2] 

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,四川成都610031 [2]西南交通大学土木工程学院,四川成都610031 [3]中铁第四勘察设计院集团有限公司,湖北武汉430063

出　　处：《中国铁道科学》2015年第1期83-89,共7页China Railway Science

基　　金：国家自然科学基金资助项目(51208432);国家科技支撑计划项目(2012BAG05B03);教育部高等学校博士学科点专项科研基金新教师类课题(20120184120030)

摘　　要：以某铁路盾构隧道为背景,选用RABT和RWS共2种火源曲线,通过数值模拟方法,分析在不均匀温度场作用下,铁路盾构隧道管片及二衬的应力和变形、管片混凝土的劣化深度、裂缝的产生及发展,并与单层管片衬砌结构进行对比,研究铁路盾构隧道双层衬砌结构的耐火性能。结果表明：在2种火源曲线下,无论是否使用防火涂料,铁路盾构隧道单层衬砌结构都无法达到耐火设计标准,而双层衬砌管片的温度远低于250℃的耐火极限;与单层衬砌相比,施作二衬后,管片温度与应力的变化幅度受火源曲线的影响减小,管片的最大主拉应力和主压应力均减小,衬砌结构的整体刚度增加、整体变形减小;衬砌的劣化深度对隧道半径和埋深不敏感,劣化深度为125-150mm;双层衬砌盾构隧道的防火效果较好,但建议二衬的混凝土设计标号不小于C30,设计厚度不小于150mm。Based on a railway shield tunnel, RABT and RWS fire source curves were chosen to analyze the stress and deformation of segment and secondary lining of railway shield tunnel, the deterioration depth of segment concrete, the crack initiation and growth under uneven temperature field by numerical simulation. Comparisons were made with single-layered lining structure to study the fireproof performance of doublelayered lining structure. Results show that in the two fire source curves, no matter whether fire retardant coating is used or not, the single-layered lining cannot reach the fire resistance design standard. Nevertheless, the temperature of double-layered lining is far below 250 ℃ which is the fire resistance limit. Compared with single-layered lining, after the construction of secondary lining, the extents of variation in temperature and stress were influenced more slightly by fire source curves. Both of the maximum principal compressive stress and tensile stress are reduced. The global stiffness of lining structure is increased while the global deformation is decreased. The deterioration depth of lining ranging from 125 to 150 mm is not sensitive to tunnel radius and buried depth. The research indicates that the double-layered lining structure in shield tunnel has better fireproof effect. However, it is suggested that the concrete strength grade and thickness for secondary lining should be no less than C30 and 150 mm respectively.

关 键 词：铁路盾构隧道 衬砌结构 管片 二衬 耐火性能 

分 类 号：U451.4[建筑科学—桥梁与隧道工程]