【作者】 郭信君；

【导师】 徐志胜；

【作者基本信息】 中南大学 ， 土木工程， 2013， 博士

【摘要】 火灾会对隧道产生严重的损坏,结构的抗火性能是盾构隧道火灾安全工程的一个重要组成部分。本文采用试验研究与数值模拟相结合的方法,从材料、构件、结构三个层次研究了盾构隧道混凝土管片构件的抗火性能,取得了研究成果如下：(1)对盾构隧道管片混凝土进行了抗火性能的试验研究,得到了高温下(后)混凝土和钢筋力学性能变化规律,获得了掺加聚丙烯纤维后抗渗性能随温度变化的规律。(2)对盾构隧道混凝土管片构件在荷载和温度耦合作用下的抗火性能进行了试验研究,研究了高温下构件的力学行为,获得了内部温度场分布情况和挠度变化,进行了损伤构件的静载试验,得到了不同受火温度后构件剩余承载力的规律。(3)建立管片构件有限元模型,对其进行与试验工况相同温度的热力耦合数值模拟。将数值模拟结果与试验结果进行对比,验证数值模拟结果的准确性,为进一步理论研究构件高温后承载力提供基础数据。(4)基于盾构管片构件试验结果和理论分析,对盾构隧道管片结构在火灾下(后)温度及力学行为的行为进行了数值模拟研究,得到了温度、荷载水平对衬砌管片的内力影响规律,分析了管片衬砌温度场变化规律及变形特征,建立了管片衬砌结构火灾损伤分析模型,得到了不同工况下截面的极限承载力。(5)在试验研究、理论分析和数值模拟的基础上,提出了南京长江盾构隧道的防火措施,运用于实际工程设计及施工,取得了良好的效益。取得的试验研究盾构隧道管片混凝土防火性能关键技术参数,模拟分析火灾在隧道内的高温分布、灾变行为特征等研究成果,为制定我国盾构隧道管片混凝土抗火设计关键技术参数,提供科学验依据,对国内类似水下隧道工程的实际应用也有很大的实际价值和指导意义。更多还原

【Abstract】 Fire would cause serious damage to the tunnel lining structure, for fire resistance performance of tunnel structure, it is an important concern to protect tunnel structure from fire in tunnel fire safety engineering. Experimental research and numerical simulation analysis are applied to study the fire resistance performance of concrete segment component of shield tunnel at three levels i.e. material, structural element and structural system. The main researches are as following:(1) Though the experimental research on fire resistance performance of concrete block, laws of mechanical characteristics of concrete during and after high temperature are analysised, effect of temperature on impermeability of concrete before and after high temperature is obtained.(2) Though the experimental research on fire resistance performance of concrete segment component of shield tunnel under coupling of load and temperature, the mechanical behavior under fire is studied and the laws of temperature field distribution and deflection change are summarized. Through the static loading test, the failure mode and residual bearing capacity of damaged member are studied.(3) Analysis on coupled thermal-mechanical simulation of concrete segment component of shield tunnel by established finite element model. Verify the accuracy of simulation results by compare the simulation results and test results, provide the basic data for the further theoretical studies of residual bearing capacity of concrete segment component structures after fire.(4) On the basis of test research and theoretical analysis of concrete segment component, by using finite element analysis, temperature field distribution and mechanical characteristics of shield tunnel structure during and after fire are carried out, the temperature field distribution and deformation features after fire are obtained, ultimate bearing capacity of different fire scenarios are analysised.(5) On the basis of test research, theoretical analysis and numerical simulation, fire protection measures in segment structure of Nanjing Yangtze River Tunnel are proposed.The obtained key characteristics of fire resistance, temperature distribution and mechanical characteristics can provide not only direct guidance for the fire resistant design of concrete segment component of shield tunnel structures, but also important practical and guilding significance for similar engineering.更多还原