基于MIDAS仿真大体积混凝土的温控设计

Design of Mass Concrete Temperature Control Based on the MIDAS Simulation

结合洞庭湖大桥主塔承台现场模型试验模拟现场施工环境、混凝土浇筑方式及养护条件,实测其温度场随时间的变化;采用MIDAS有限元分析软件仿真分析模型试验大体积混凝土温度场,对比实测结果反演关键参数,修正了现场主塔承台大体积混凝土的散热系数和绝热温升;利用修正后的参数应用于主塔承台大体积混凝土的温控设计,提出温控标准,现场布设测温元件,实时监测承台的温度变化,从监测结果和拆模情况来看,实测温度和仿真结果吻合,承台混凝土表面未出现温度裂缝,温控效果良好。

Measuring the temperature field changes over time of the model test combined with the environment of construction site and the way of concrete pouring and curing conditions in pile cap of Dongting Lake Bridge,using finite element analysis software MIDAS simulating massive concrete temperature field of the model,and compared with the measured results to inversion the key parameters,through which we have modified radiation coefficient and adiabatic temperature rise of pile cap mass concrete; the modified parameters was applied to the design of temperature control of pile cap. The temperature sensors are embedded in concrete to monitor the temperature of concrete in time and the results show that the real temperature inner concrete are correlative to the simulated,and there is no thermal cracks after taking off the forms. The effect of temperature control is satisfactory.