【作者】 李智；

【导师】 彭立敏； 施成华；

【作者基本信息】 中南大学 ， 土木工程， 2013， 硕士

【摘要】 盾构隧道管片常处于地下腐蚀环境中,受到各种离子的侵蚀作用,其中氯离子是引起管片中钢筋锈蚀破坏的主要因素。本文依托国家重点基础研究发展计划项目(973：2011CB013802)课题,针对侵蚀环境下盾构隧道管片氯离子扩散模型这一科学问题,采用室内人工模拟试验与理论分析相结合的方法进行了系统的研究,以期为我国城市轨道交通建设的合理设计和科学维护提供理论参考。其主要研究内容如下：(1)设计了人工环境模拟试验,考虑在不同氯盐浓度侵蚀环境下,氯离子扩散受到多种因素的影响,得到了多种因素耦合作用下管片结构不同位置、不同深度处氯离子浓度。分析了溶液浓度、荷载水平、侵蚀时间对氯离子浓度及扩散系数的影响,得到了相应的影响函数。(2)在深入探讨各因素对氯离子扩散影响机理的基础上,分析了既有氯离子扩散方程的不足,基于Fick第二定律,在考虑扩散系数随深度的变化的情况下,推导了多因素耦合作用下盾构隧道管片氯离子扩散方程。(3)根据氯离子扩散方程与热传导方程的相似性,利用ANSYS有限元软件的热分析模块,对理论模型的正确性进行了验证,并研究了钢筋间距、直径及保护层厚度对氯离子扩散的影响。图62幅,表34个,参考文献97篇更多还原

【Abstract】 Segment of shield tunnel has often been in underground corrosive environment and eroded by various ions in which chloride ions are the main factors to cause the corrosion damage of the reinforcement. In order to provide theoretical references for the rational design and scientific maintenance of China’s urban rail transit construction, the paper relying on the issues of the National Key Basic Research and Development Program(973:2011CB013802) has had a systematic study on the scientific issues that is chloride diffusion model of segment of shield tunnel on erosion environment, through the method of combining indoor artificial simulation test with theoretical analysis.The main contents have been included as follows:(1) The paper has designed the artificial environment simulation test, and considered that in the different chlorine salt erosion environment the chloride ion diffusion is affected by a variety of factors, also obtained the segment structure’s chloride ion concentration of the different positions and depths under the coupling effect of various factors. This thesis has analyzed the influence on the chloride ion concentration and diffusion coefficient made by solution concentration, load level and erosion time, also gained corresponding influence function.(2) Based on the impact of various factors made on the chloride ion diffusion mechanism,this paper has analyzed the shortcomings of the existing diffusion equation, and considering the diffusion coefficient together with the depth change, a multi-factor coupled chloride ion diffusion equation of segment of shield tunnel has been derived on the basis of the Fick’s second law.(3) According to the similarity of the chloride diffusion equation and the heat conduction equation, this paper has verified the correctness of the theoretical model and has done research on the influence of reinforcement spacing, diameter and thickness of the protective layer made on chloride ion diffusion by using thermal analysis module of ANSYS finite element software.更多还原