海底环境下盾构隧道混凝土结构耐久性研究

发布时间：2018-03-12 21:46

本文选题：碳化　切入点：氯离子渗透　出处：《北京交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：混凝土由于碳化作用和氯离子渗透作用导致钢筋发生锈蚀,是海洋工程中钢筋混凝土破坏的主要形式。对于海底大直径盾构隧道管片,在已经有初始裂缝并且长期受到周围土体围压作用和海水的持续性浸泡、侵蚀作用下,要实现高性能海工混凝土材料的优化配制,是现阶段增强海洋工程管片混凝土耐久性的研究热点。本文结合广东汕头市苏埃通道盾构隧道工程项目,进行了海底环境条件下盾构隧道混凝土结构耐久性的研究。本论文的研究工作主要体现在以下几个方面： (1)根据工程所在地的地理作用环境、水域或土中的主要腐蚀性化学成分(如Cl-、SO42-、Mg2+侵蚀C02含量和pH值等)以及运营阶段的隧道环境条件,通过查阅相关混凝土耐久性规范,对混凝土所处的环境类别进行划分并提出了保证盾构隧道混凝土结构耐久性的基本要求。 (2)根据已确定的保证混凝土结构耐久性的基本要求,并基于国内外相关配合比计算方法,进行海底环境下管片混凝土的配合比优化设计和试验项目选择。 (3)通过分别改变混凝土的水胶比和矿物掺合料掺量,进行混凝土的力学性能、变形性能和耐久性能试验,确定满足混凝土耐久性要求的最优混凝土配合比,提高海底环境下管片混凝土的耐久性。 (4)查阅相关规范和工程实例,并参考苏埃通道的环境条件,确定提高海底环境下管片混凝土结构耐久性的附加防腐蚀措施。
[Abstract]:Due to concrete carbonation and chloride penetration caused by steel corrosion, is the main form of failure of the reinforced concrete in marine engineering. For large diameter shield tunnel segment, have long been the initial crack and surrounding soil confining pressure and duration of seawater immersion, erosion, optimizing preparation to achieve high performance marine concrete, is the research focus of ocean engineering durability of reinforced concrete segment.
According to Guangdong Shantou su'ai channel shield tunnel project of shield tunnel concrete structure durability of the undersea environment conditions. The research work of this paper is mainly reflected in the following aspects:
(1) according to the geographical location of the environment engineering, the main chemical composition of water or corrosive soils (such as Cl-, SO42-, Mg2+, C02 content and pH value of erosion etc.) and operation phase of the tunnel environmental conditions, by referring to the relevant concrete durability specification, the concrete environment and put forward the category division the basic requirements of shield tunnel to ensure the durability of concrete structures.
(2) according to the basic requirements for determining the durability of concrete structures, and based on the relevant calculation methods at home and abroad, the optimization design and selection of test items for segment concrete under seabed environment are carried out.
(3) by changing the water binder ratio and mineral admixture amount of concrete respectively, the mechanical properties, deformation properties and durability tests of concrete are carried out, and the optimal concrete mix proportion to meet the durability requirements of concrete is determined, so as to improve the durability of segment concrete under seabed environment.
(4) refer to the relevant specifications and engineering examples, and the reference channel conditions, identify additional corrosion protection measures of segment of improving the durability of RC structure underwater environment.

【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.43;U459.5

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