高速铁路预制箱梁水化热温度场及其效应研究
发布时间：2018-08-25 13:33
【摘要】：随着经济技术的不断发展,混凝土箱梁的跨度和吨位越来越大,高性能混凝土开始广泛运用于桥梁的施工之中,然而由于箱梁截面尺寸的不断增加,加之高性能混凝土的应用,导致混凝土水化热温度升高、混凝土收缩加大、应力增长大,梁体表面出现裂缝,因此使得混凝土结构的耐久性受到很大影响,并且对结构的质量和正常使用产生不利影响。大吨位预制混凝土箱梁由于水泥水化作用而产生的温度场是导致混凝土产生裂缝的重要原因,然而国内和国外的专家对其产生机理和原因进行的专项研究相对较少,对箱梁水化热温度场及其效应的研究还不够充分。综上所述,可知对于大跨度预制箱梁的水化热温度场及其影响因素的分析研究,具有相当可观的经济价值和社会效益。由于箱梁混凝土温度场的影响因素及其参数的复杂多变,所以本文将结合实际工程进行研究,并给出了控制混凝土水化热的切实可行的措施,为预制混凝土箱梁施工服务。本文以哈大高速铁路预应力混凝土箱梁的预制工程为背景,首先详尽论述箱梁预制的施工全过程,确保不会因为施工问题而影响箱梁混凝土水化热温度场的分布。然后进行混凝土温度场的理论分析,并以此为基础利用ANSYS有限元分析软件,基于三维非稳态温度场理论对跨度32m预制箱梁水化热温度场进行有限元模拟,将分析所得数据与现场实测数据进行对比研究,并对影响温度场分布的因素进行研究。研究结果表明采用数值分析的方法可以较为真实模拟混凝土水化热温度场,根据分析结果本文提出了控制温度裂缝的具体措施,并给出了对混凝土箱梁水化热温度场分布具有重要作用的影响因素。全文以实际工程项目为背景,运用有关温度场理论知识和ANSYS有限元分析软件,根据现场工程实际状况,得到了可应用于工程实践的预制箱梁的水化热温度场及其效应。本文的研究成果对于大型混凝土箱梁预制过程水化热的温度监控,预防产生温度裂缝都提供了较为可靠的依据,具有一定的理论价值和较高的实用价值。
[Abstract]:With the development of economy and technology, the span and tonnage of concrete box girder become larger and larger. High performance concrete is widely used in bridge construction. However, due to the continuous increase of box girder section size, and the application of high performance concrete, As a result, the hydration heat temperature of concrete increases, the shrinkage of concrete increases, the stress increases greatly, and cracks appear on the surface of the beam body. Therefore, the durability of concrete structure is greatly affected, and the quality and normal use of the structure are adversely affected. The temperature field of large-tonnage precast concrete box girder caused by cement hydration is an important reason for the cracks in concrete. The research on the temperature field of box girder hydration heat and its effect is not enough. To sum up, it is concluded that the analysis and study of hydration heat temperature field and its influencing factors of long span prefabricated box girder have considerable economic and social benefits. Because the influence factors and parameters of box girder concrete temperature field are complex and changeable, this paper will study the concrete hydration heat in combination with the actual engineering, and give some practical measures to control the hydration heat of concrete, which will serve the construction of precast concrete box girder. Based on the prefabricated project of prestressed concrete box girder in Harbin and Dalian high speed railway, the whole construction process of box girder prefabrication is discussed in detail, so as to ensure that the distribution of hydration heat temperature field of box girder concrete will not be affected by the construction problem. Then the theoretical analysis of concrete temperature field is carried out, and based on the ANSYS finite element analysis software, the hydration heat temperature field of 32m prefabricated box girder is simulated by using three-dimensional unsteady temperature field theory. The analysis data are compared with the field measured data, and the factors influencing the temperature field distribution are studied. The results show that the numerical analysis method can be used to simulate the hydration heat temperature field of concrete. According to the analysis results, the concrete measures to control the temperature crack are put forward in this paper. The factors that influence the distribution of hydration temperature field of concrete box girder are given. Based on the actual engineering project, using the theoretical knowledge of temperature field and ANSYS finite element analysis software, according to the actual situation of field engineering, the hydration heat temperature field and its effect of precast box girder which can be used in engineering practice are obtained. The research results in this paper provide a reliable basis for the temperature monitoring of hydration heat and the prevention of temperature cracks during prefabrication of large concrete box girder. It has certain theoretical value and high practical value.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.471;U448.13
本文编号：2203025
[Abstract]:With the development of economy and technology, the span and tonnage of concrete box girder become larger and larger. High performance concrete is widely used in bridge construction. However, due to the continuous increase of box girder section size, and the application of high performance concrete, As a result, the hydration heat temperature of concrete increases, the shrinkage of concrete increases, the stress increases greatly, and cracks appear on the surface of the beam body. Therefore, the durability of concrete structure is greatly affected, and the quality and normal use of the structure are adversely affected. The temperature field of large-tonnage precast concrete box girder caused by cement hydration is an important reason for the cracks in concrete. The research on the temperature field of box girder hydration heat and its effect is not enough. To sum up, it is concluded that the analysis and study of hydration heat temperature field and its influencing factors of long span prefabricated box girder have considerable economic and social benefits. Because the influence factors and parameters of box girder concrete temperature field are complex and changeable, this paper will study the concrete hydration heat in combination with the actual engineering, and give some practical measures to control the hydration heat of concrete, which will serve the construction of precast concrete box girder. Based on the prefabricated project of prestressed concrete box girder in Harbin and Dalian high speed railway, the whole construction process of box girder prefabrication is discussed in detail, so as to ensure that the distribution of hydration heat temperature field of box girder concrete will not be affected by the construction problem. Then the theoretical analysis of concrete temperature field is carried out, and based on the ANSYS finite element analysis software, the hydration heat temperature field of 32m prefabricated box girder is simulated by using three-dimensional unsteady temperature field theory. The analysis data are compared with the field measured data, and the factors influencing the temperature field distribution are studied. The results show that the numerical analysis method can be used to simulate the hydration heat temperature field of concrete. According to the analysis results, the concrete measures to control the temperature crack are put forward in this paper. The factors that influence the distribution of hydration temperature field of concrete box girder are given. Based on the actual engineering project, using the theoretical knowledge of temperature field and ANSYS finite element analysis software, according to the actual situation of field engineering, the hydration heat temperature field and its effect of precast box girder which can be used in engineering practice are obtained. The research results in this paper provide a reliable basis for the temperature monitoring of hydration heat and the prevention of temperature cracks during prefabrication of large concrete box girder. It has certain theoretical value and high practical value.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.471;U448.13
【参考文献】
相关期刊论文 前2条
1 阮静,叶见曙,谢发祥,王键;高强度混凝土水化热的研究[J];东南大学学报(自然科学版);2001年03期
2 杨青云;;京津城际客运专线32m双线整孔箱梁现场预制施工技术[J];铁道标准设计;2006年11期
，本文编号：2203025
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