【作者】 杜旭斌；

【导师】 陈尧隆；

【作者基本信息】 西安理工大学 ， 水工结构工程， 2010， 硕士

【摘要】 在大体积混凝土工程中,温度应力对建筑物的安全和使用等功能具有重要的影响。大体积混凝土的温度应力问题与温度控制要求在碾压混凝土坝中同样存在。随着碾压混凝土建坝技术的迅猛的发展,对温度应力要求也越来越高。对于筑坝材料,尤其是骨料,一般都是采取就近原则,但是如果本地的岩石线膨胀系数较大,那么所配制的混凝土在温升相同的情况下,温度应力就必然较大,因此,对于大体积混凝土而言,如何合理的选择骨料,所选择的骨料是否满足温控要求,对此应该有一个清楚的认识。论文根据热传导理论、三维有限元理论,推导了三维温度场有限元计算公式；根据热应力基本理论,三维有限元理论和混凝土徐变理论,推导了三维温度徐变应力场的有限元计算公式。在研究方法上采用国际大型通用有限元软件ANSYS建模来实现混凝土骨料线膨胀对碾压混凝土温度应力的仿真计算。论文通过某典型算例对碾压混凝土坝温度徐变应力场进行了仿真计算分析。分析了坝体所用混凝土骨料线膨胀系数不同时对坝踵、上游面、坝体中心部位、坝趾、下游面的温度应力的影响情况。总结出规律,得出一些具有应用价值的结论,为实践工程中对混凝土不同线膨胀系数骨料的选取和进一步的理论研究提供了一定的理论依据。更多还原

【Abstract】 In the mass concrete construction the thermal stress have great influence on safety and function of construction n. The problem of thermal stress and a need for temperature control in the mass concrete construction also occur in the roller compacted concrete dams(RCCD).With the fast developing of roller compacted concrete technique in building dam, the demands of thermal stress become more and more. The approaching principles are often taken for thematersal of dam building, especially aggregate. If the linear expansion coefficient of the local rock is too large,the thermal stress will become larger with the higher temperature of the compounded concrete. Therefore,it should be clear about how to select aggregate and whether the selected aggregate meet the demands of the temperature control for the mass concrete.Based on the heat conduction theory and the three-dimensional finite element(3-D FEM) theory,the3-D FEM theory formulas of temperature field are deduced; based on the heat stress theory and the 3-D FEM theory and creep theory of concrete,the3-D FEM theory formulas of thermal creep stress field are deduced in this paper. Study method is to adopt ANSYS-international large-scale general-purpose finite element software to realize the simulation calculation of the RCC thermal stress for Aggregate linear expansion. In this paper the thermal creep stress field, in roller compacted concrete gravity dam during construction and operation, are simulated by a type example. Changes of thermal stress of dam heel, upstream face, dam center, dam toe, downstream face for the difference of linear expansion coefficient aggregate used in the dam. The rule is summarized and the practical conclusion is drawn. The paper provides a certain theoretical research for the selection of different linear expansion coefficient of concrete aggregate in practice engineering and further theoretical research.更多还原