混凝土箱梁层水化热场时程分析与评价模型

Time-dependent analysis and evaluation model of hydration heat temperature fields for concrete box girder layer casting

针对混凝土箱梁墩顶块在施工浇筑过程中的早期开裂现象,基于最小目标原理,建立了混凝土箱梁水化热评价模型;在水化绝热温升模型的基础上,采用大型通用软件ANSYS,对正常浇筑模式下和3层浇筑模式下混凝土箱梁墩顶块水化热温度场进行三维数值仿真,得到水化热场温度峰值和温差峰值时程曲线,并将3层浇筑与正常浇筑模式进行了对比分析以及优化评价。研究结果表明:3层浇筑方式能够改善混凝土水化热温度峰值,但对缩小温差峰值不明显;热场评价模型能够准确地反映浇筑方式的合理性,评判其温度峰值与温差值的差异性。

Aimed at temperature fields distribution problem of concrete box girders on high piers,based on the minium goal principal,the hydration evaluation model was built,the ANSYS software was adopted to analyze the hydration heat temperature field of concrete pier on mass under the mormal casting and three layers casting conditions,the time-dependent curve of the temperature peak value and the temperature difference peak value were obtained,the comparison was made to the two casting ways,and their optimization performance was evaluated.The results show that the three layers casting way can effectively improve the temperature peak value,but has no obvious influence on temperature difference peak value,the evaluation model can correctly reflect the rationality of casting way,and can give a good judgment for the difference of the temperature peak value and the temperature difference peak value.3 tabs,6 figs,7 refs.