某铁路斜拉桥承台大体积混凝土温度控制分析研究

Temperature control of mass concrete by hydration heat in cable-stayed bridge pile caps

针对某铁路斜拉桥索塔承台大体积混凝土施工期间温度控制比较困难,采用非线性有限元软件分析了承台在不同的施工方法下承台的温度和应力,得到分层浇筑并进行管冷降温可以有效降低混凝土的水化热对于结构的影响。并针对多次浇筑成型的承台中养护温度对承台温度和应力的敏感性进行了分析研究,养护温度25℃比较适宜。最后采用不同的混凝土绝热升温函数针对该桥承台温度对比了理论值和实测值,得到复合指数式温升函数计算的理论温度与实测值相近,但承台达到最高温度的龄期相对于实测值提前。

It was difficult to the temperature control of a railway cable-stayed bridge pile caps ,because of the mass concrete hydration.It was effective by using finite element software ,which analysed the temperature and the first principal stress with the different construction methods .The mass concrete with layered casting and cooling water pipe can reduce the effective of the hydration heat. Then with the same motile,the curing temperature which was 25qC was relatively well for the temperature and the first principal stress.At last,througe the comparison and analysis for the measured value and the theoretical value, the composite index function for the adiabatic heating was real. But, the time of the mass concrete reached the highest temperature was cut short.