大体积混凝土浇筑过程热应力分析和参数化模板开发

发布时间：2019-02-15 05:35

【摘要】：随着建筑行业的快速发展,混凝土结构规模日趋复杂化、大型化,大体积混凝土在早期浇筑过程中水泥水化热引起的温度应力对结构的影响日益得到重视。这种温度应力可导致混凝土内部和表面裂缝的产生,严重影响结构的强度,造成安全隐患。因此研究大体积混凝土早期的温度应力场有重要工程意义。大体积混凝土水泥水化热所引起的温度场及温度应力场的热力学参数非常复杂,其中许多的模型都是基于经验公式,如水泥水化热模型,早期混凝土的弹性模量变化模型等。针对这些问题,本文对大体积混凝土早期温度场和应力场进行了研究,并用有限元软件MSC.Marc对“莱钢银山型钢3#3200m3高炉工程高炉基础”进行仿真分析。本文首先进行大体积混凝土温度场有限元分析。建立了混凝土浇筑过程的有限元模型,进行了材料徐变的描述和确定、水化热率的描述以及其它散热和约束边界条件的确定,计算了其施工期和之后70天的温度场分布,对混凝土高炉基础的施工过程进行了动态模拟,并且通过对得到的测温点仿真温度和现场实测温度的比较,逐步完善模型和边界条件,对结果进行分析。基于所得到温度场的结果,本文进行了模型应力场有限元分析。本文利用分阶段法热力耦合仿真方法,研究了混凝土浇筑过程中弹性模量随时间变化这一普遍存在于实际工程中的难题,通过所得到的温度仿真结果与实际测量数据的比较,验证了方法的正确性；结合仿真得到的应力场的有限元结果,阐述了混凝土高炉基础结构的温度裂缝产生原因与控制方法。基于Marc与Viusal Basic的接口,本文还对典型混凝土基础浇筑仿真过程进行了参数化建模,生成了面向用户的可执行程序,提供了一种快速进行有限元仿真建模的方法,为工程实践带来了便利。
[Abstract]:With the rapid development of the construction industry, the scale of concrete structure is becoming more and more complicated and large-scale. The influence of thermal stress caused by cement hydration heat on the structure has been paid more and more attention to in the early pouring process of mass concrete. This kind of thermal stress can lead to concrete internal and surface cracks, seriously affect the strength of the structure, resulting in hidden safety problems. Therefore, it is of great engineering significance to study the early temperature stress field of mass concrete. The thermodynamic parameters of temperature field and thermal stress field caused by hydration heat of mass concrete are very complicated. Many of the models are based on empirical formulas, such as cement hydration heat model, early concrete elastic modulus variation model, etc. In order to solve these problems, the temperature field and stress field of mass concrete in the early stage are studied in this paper, and the "foundation of blast furnace in Yinshan 3#3200m3 blast furnace engineering of Laigang" is simulated and analyzed by finite element software MSC.Marc. In this paper, the temperature field of mass concrete is analyzed by finite element method. The finite element model of the concrete pouring process is established, the creep of the material is described and determined, the heat rate of hydration and other heat dissipation and constraint boundary conditions are determined, and the temperature field distribution during the construction period and 70 days after the construction is calculated. The construction process of concrete blast furnace foundation is simulated dynamically, and the model and boundary conditions are improved step by comparing the simulated temperature of the measured temperature points with the measured temperature on the spot, and the results are analyzed. Based on the results of the temperature field, the stress field of the model is analyzed by finite element method. In this paper, the time-dependent elastic modulus in concrete pouring process is studied by means of the thermo-mechanical coupling simulation method, and the temperature simulation results obtained are compared with the actual measurement data through the comparison of the obtained temperature simulation results and the actual measurement data. The correctness of the method is verified. Combined with the finite element results of stress field obtained by simulation, the causes and control methods of temperature cracks in concrete blast furnace foundation structure are expounded. Based on the interface between Marc and Viusal Basic, the parameterized modeling of typical concrete foundation pouring simulation process is also carried out in this paper. A user-oriented executable program is generated, and a fast finite element simulation modeling method is provided. It brings convenience to engineering practice.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU755

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