混凝土绝热温升组合指数式参数计算方法的改进及应用

Improvement calculation method of combined exponential formula parameters for concrete adiabatic temperature rise calculation and application

在大体积混凝土施工温控方案研究中,绝热温升计算公式的选取是开展温度场及温度应力场计算的重要基础。目前工程界常用的混凝土绝热温升双曲线式及双指数式在后续水管冷却计算中较为复杂,而朱伯芳院士提出的组合指数式可极大的简化后续计算。以双曲线式为基础,利用数学回归分析对组合指数式中三个参数的计算方法进行改进,提出了确定组合指数式参数的幂函数计算式。通过对比分析表明采用改进的算法时,组合指数式与双曲线式计算结果吻合度更高,用于混凝土绝热温升计算及水管冷却计算更为合理。将该算法应用于望丰水库大坝施工期温控方案研究,采用有限元软件ANSYS计算不同温控方案下大坝温度场分布特征,研究成果及施工期监测数据表明该算法可有效运用于大坝混凝土温控计算,可为类似大体积混凝土工程温控防裂方案设计提供参考。

Selection of adiabatic temperature rise calculation formula is an important basis for temperature field thermal stress field calculation when researching temperature control schemes for mass concrete construction.While the commonly used hyperbolic formula and double exponential formula for the calculation of concrete insulation temperature rise in the engineering community are complex in subsequent water pipe cooling calculations,the combined exponential formula proposed by Academician Zhu Bofang can greatly simplify subsequent calculations.Based on the hyperbolic equation,mathematical regression analysis was used to improve the calculation method of the three parameters in the combined exponential equation,then,3 power functions were proposed to calculate the parameters of cambined exponential equation.Through comparative analysis,it is shown that when using the improved algorithm,the calculation result of combined exponential formula and hyperbolic formula are more consistent,making it more reasonable for calculating the insulation temperature rise of concrete and water pipe cooling.Using this algorithm,temperature control schemes of Wangfeng Reservoir Dam during construction period were studied,and the finite element software ANSYS was used to calculate the distribution characteristics of the dam temperature field under different temperature control schemes.The research result and monitoring data during the construction period indicate that this algorithm can be effectively applied to the temperature control calculation of dam concrete,and can provide reference for the design of temperature control and crack prevention schemes for similar large volume concrete projects.