LNG储罐大体积混凝土裂缝控制

发布时间：2018-02-06 06:45

本文关键词： 大体积混凝土温度场应力场裂缝控制有限元模拟　出处：《中国石油大学（华东）》2013年硕士论文　论文类型：学位论文

【摘要】：随着我国各项建设事业的蓬勃发展，在LNG储罐领域，储罐建设也向大型化发展。储罐底板属于大体积混凝土范畴。本文将理论分析与实际工程相结合进行研究，控制施工温度裂缝并利用有限元软件模拟，旨在解决储罐施工和生产运行期间的裂缝问题。首先介绍了大体积混凝土及其裂缝的概念、裂缝控制标准、等级，总结了大体积混凝土裂缝种类、成因、影响因素以及具体控制裂缝的方法。分析了大体积混凝土的热学性能，包括水泥水化热、混凝土绝热温升、温差、表面保温层计算等；力学性能，包括混凝土的弹性模量、抗拉强度、极限拉伸值；混凝土的徐变、碳化、预应力对裂缝的影响，为大体积混凝土裂缝控制提供了有力依据。其次介绍了大体积混凝土温度场和应力场，分析了混凝土的热传导原理、温度变化及应力变化过程、温度应力计算方法。介绍了使用的有限元软件。最后结合实际施工过程，对大体积混凝土施工区段各阶段温度变化、温度场、应力场进行数值模拟。比较了不同环境条件下，不同施工顺序对混凝土温度场的影响，得出的结论对施工现场质量控制、避免后期使用时裂缝的出现具有一定的指导意义，同时提出了合理的预防和防治措施。
[Abstract]:With the vigorous development of various construction undertakings in China, it is in the field of LNG storage tanks. The tank floor belongs to the category of mass concrete. This paper combines theoretical analysis with practical engineering to control the construction temperature crack and use finite element software to simulate. The purpose of this paper is to solve the problem of cracks during the construction and operation of storage tanks. This paper first introduces the concept of mass concrete and its cracks, crack control standards and grades, summarizes the types, causes, influencing factors and concrete methods of crack control in mass concrete. The thermal properties of mass concrete are analyzed, including hydration heat of cement, adiabatic temperature rise of concrete, temperature difference, calculation of surface insulation layer, etc. Mechanical properties, including elastic modulus, tensile strength and ultimate tensile value of concrete; The influence of creep, carbonization and prestress on cracks provides a strong basis for crack control of mass concrete. Secondly, the temperature field and stress field of mass concrete are introduced, the principle of heat conduction, the process of temperature change and stress change, the calculation method of temperature stress are analyzed, and the finite element software is introduced. Finally, combined with the actual construction process, the temperature change, temperature field and stress field in each stage of mass concrete construction section are numerically simulated. The effect of different construction sequence on the temperature field of concrete is of certain guiding significance to the quality control of construction site and avoiding the occurrence of cracks in later use. At the same time, the reasonable prevention and control measures are put forward.
【学位授予单位】：中国石油大学（华东）
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU755.7

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