海洋环境特大型桥梁基础大体积承台温控技术研究

发布时间：2018-10-19 10:39

【摘要】：近年来，随着桥梁建设规模的扩大，承台大体积混凝土的温度裂缝问题日渐突出。对于整体浇筑的大体积混凝土，由于水泥水化热作用，会产生较大的温度变化，受到内部或外部约束时，产生较大的温度应力，若超过混凝土的抗拉强度，就会造成混凝土的开裂，影响其正常使用。因此，有必要对大体积混凝土温度场及应力场进行研究，避免混凝土温度裂缝的产生。本文依托福建琅岐闽江大桥，通过混凝土配合比的选择、冷却水管布设、温控数值仿真及现场温度监测，，对承台大体积混凝土温控开展了系统研究。主要研究成果如下：（1）基于国内外研究成果，综述了大体积混凝土产生裂缝的原因及采取的温控措施；结合福建琅岐闽江特大桥工程实际，阐释了4#主墩、5#辅墩承台技术标准和施工方案及工艺流程；介绍了混凝土水化热有限元分析的理论基础。（2）依托福建琅岐闽江特大桥4#墩、5#墩承台工程实际，综合考虑冷却水管的布设、水流及边界条件、施工工序等因素，对承台大体积混凝土进行了温控数值仿真，从中选取了可行的优化方案。（3）通过对承台大体积混凝土温度的现场监测，增加了温控施工的信息化，为承台的保温防裂养护提供了科学依据；并将所得结果与数值模拟结果进行对比分析，得出数值模拟与现场实测结果相互验证，以及相关温度变化规律，为温度裂缝控制提供了理论依据，具有重要的工程应用价值。
[Abstract]:In recent years, with the expansion of bridge construction scale, the temperature crack problem of pile cap mass concrete is becoming more and more serious. For the mass concrete cast as a whole, due to the heat of hydration of cement, the temperature will change greatly, and when the concrete is restrained internally or externally, it will produce larger temperature stress, if it exceeds the tensile strength of the concrete, Will cause concrete crack, affect its normal use. Therefore, it is necessary to study the temperature field and stress field of mass concrete to avoid the occurrence of temperature cracks. Based on the Luangqi Minjiang River Bridge in Fujian Province, through the selection of concrete mix ratio, the arrangement of cooling water pipes, the numerical simulation of temperature control and the field temperature monitoring, the temperature control of large volume concrete in the cap is studied systematically in this paper. The main research results are as follows: (1) based on the domestic and foreign research results, the causes of the cracks in mass concrete and the temperature control measures taken are summarized, and the actual situation of the Minjiang River Bridge Project in Luangqi, Fujian Province, is also discussed. This paper explains the technical standard, construction scheme and technological process of bearing cap of main pier and auxiliary pier, introduces the theoretical basis of finite element analysis of concrete hydration heat. (2) depending on the pier of Minjiang River Bridge in Luangqi, Fujian Province, the engineering practice of bearing cap of pier is introduced. Considering the layout of cooling water pipe, water flow and boundary condition, construction procedure and other factors, the temperature control numerical simulation of the cap mass concrete is carried out. The feasible optimization scheme is selected. (3) through the field monitoring of the mass concrete temperature of the cap, the informatization of the temperature control construction is added, which provides the scientific basis for the thermal insulation and crack prevention maintenance of the cap; The results obtained are compared with the results of numerical simulation, and the mutual verification between the numerical simulation and the field measurement results, as well as the related temperature variation rules, are obtained, which provides a theoretical basis for the control of temperature cracks and has important engineering application value.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.57

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