用遗传算法确定考虑温度历程的混凝土水化放热模型参数及试验验证

摘要

目前，考虑温度历程绝热温升模型存在参数较难确定和尚未有现场非绝热温升试验验证其精度2个问题.为了解决这2个问题，该文提供了一种合适的遗传算法实现方法，设计了2个温度历程不同的混凝土非绝热温升试验，并将一个混凝土块的试验数据及该方法反演获得的参数应用到模拟另一个混凝土块温度场中.试验结果表明，即使温度历程差异较大，遗传算法也能获取准确的参数.应用遗传算法解决考虑温度历程混凝土水化放热模型具有可行性；且较未考虑温度历程模型，考虑温度历程的混凝土水化放热模型精度有明显提高.未考虑温度历程模型的平均误差为1.1℃而考虑温度历程模型平均误差仅为0.4℃.%Although there are some studies on parameters inversion for hydration exothermic model without considering concrete temperature duration, there is few study on parameters inversion for hydration exothermic model considering concrete temperature duration. The adiabatic exothermic model considering temperature duration has better precision than those without consideration, but it will need more parameters in the model and make inversion harder when using finite element back analytical algorithm to determinate parameters, because back analysis of finite element method is easy to premature and difficult to solve the model with too many parameters. When using genetic algorithm to inverse parameters, the result of the parameter inversion is greatly depended on the way to complete genetic algorithm. A proper genetic algorithm method (the one with proper encode operation, proper construction of fitness function and proper crossover operation) is presented in this paper to solve this problem, and two non-adiabatic temperature rise experiments with quite different temperature duration are designed. Based on the measured data of one test block, the parameters of adiabatic temperature rise models were inversed by proposed genetic algorithm method, and then those parameters were verified with the data of another test block. The results show that the parameter inversed by one block can be well used in the other block even when temperature duration is quite different. That means it is feasible to use the proposed method for back inversion of parameters of adiabatic temperature rise models considering temperature duration. In this paper it is shown that adiabatic temperature rise is highly depended on the concrete temperature duration, the hydration exothermic will be different with the changing of temperature duration. So when without considering temperature duration, hydration model can not be expressed by one expression. By comparing the results of the parameter inversion for hydration exothermic models with and without considering concrete temperature duration, it is showed that the adiabatic exothermic model considering temperature has better precision than the one without consideration.