【作者】 何薇；

【导师】 何川；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2013， 硕士

【摘要】 混凝土材料是地下结构工程中最主要的建筑材料之一,其性能的优劣对地下工程的质量和寿命具有决定性的影响,混凝土的抗碳化能力是衡量混凝土耐久性的重要指标之一。由于地下空间环境相对封闭,人流相对密集,混凝土碳化较为严重,因此有必要对地下工程中混凝土材料与混凝土结构的碳化问题进行研究与论证。众多学者对混凝土的碳化机理、影响混凝土碳化的因素、预测混凝土碳化深度等方面都有较深入的研究,但是这些研究大多都只停留在混凝土材料本身的层面上,而关于碳化对地下结构的影响研究甚少,在实际生活中,我们更需要的是了解混凝土碳化后对结构力学性能的影响。因此,本论文在碳化试验的基础之上进一步研究了碳化作用对地下结构的力学性能影响规律,具体研究内容如下：(1)采用室内加速碳化试验,研究碳化前后混凝土力学参数(包括弹性模量、抗压强度等)的变化,分析碳化对混凝土力学特性的变化规律；(2)利用三维数值显示仪观测碳化作用后混凝土的细观结构,找到混凝土碳化区、部分碳化区和未碳化区的分布规律；(3)以试验为依据,综合考虑地下结构碳化问题的特殊性,通过ANSYS有限元软件仿真模拟,探究不同碳化程度隧道衬砌结构的内力和位移的变化规律,揭示碳化对隧道衬砌结构力学行为的影响,利用研究成果综合评估地下结构的安全性。通过研究得出了混凝土碳化深度随时间变化的规律,碳化后混凝土抗压强度、弹性模量的变化规律；得到了碳化混凝土碳化区、部分碳化区和未碳化区的分布规律；通过数值计算分析了碳化对隧道衬砌结构力学特征的影响。更多还原

【Abstract】 Concrete is one of the important building materials applied in underground structure, its performace has a decisive influence on the quality and the life of the underground engineering. The ability on resistance to carbonation is one of the important indicators on concrete durability. Since environment of underground space is relatively closed and crowd, carbonization is more serious. Therefore it is necessary to conduct a research and demostration on concrete structure and its carbonization in underground engineering. So far many scholars have study on the carbonization mechanisim, carbonization factors and predicion of carbonization depth. But most of these studies are stayed in the perspective of concrete material itself, carbonization’s influence on structure is barely studied. In practical life, we need to learn more about the carbonization’s influence on structure. Accordingly, this paper has a further study on the mechanical behavior of the concrete carbonization based on the carbonization test. The main research contents are as follows:(1)Under the concrete carbonation test, the variation of concrete’s mechanical parameters (including modulus of elasticity and compressive strength) is studied and the effect of carbonization on mechanical behavior is analyzed.(2)By using three-dimensional numerical display, we should observe the meso-structure of carbonized concrete and find the distribution of carbonization area, partial carbonated area and non-carbonated area.(3)Based on the experiment, we explore the law of internal force and displacement of tunnel lining with varying degrees of carbonization through ANSYS and reveal the carbonation effect on the mechanical behavior of the tunnel, and evaluate the safety of the underground structure synthetically by the research results.The law of concrete carbonation depth varying with time and variation of concrete’s compressive strength and elastic modulus after carbonation is obtained through the research. The distribution of carbonization area, partial carbonated area and non-carbonated area is also obtained. This paper analyzes carbonation’s impact on the mechanical behavior of tunnel through the numerical calculation.更多还原