基于热流管单元的大体积混凝土一期冷却效果精细模拟

Refined simulation of first stage artificial cooling effect in mass concrete based on heat-fluid pipe element

结合大岗山拱坝工程实例,基于ANSYS平台建立混凝土浇筑块及冷却水管精细仿真计算模型.通过数值仿真计算,分析冷却水管周围混凝土温度场及应力场随时间的变化规律,混凝土特征点的温度及应力与其距离冷却水管的距离之间的关系,以及水管周围混凝土温度梯度、应力梯度随时间的变化关系.在不同冷却水温度情况下对通水冷却过程进行数值仿真模拟,对比分析不同条件下仿真计算结果,确定一期冷却水温的合理范围;同时对开始通水时间进行仿真模拟计算,分析开始通水时间对混凝土温度及应力的影响.最后,综合分析各仿真计算结果,为工程实践中如何防止冷却水管周围混凝土温度裂缝的产生,提出几条合理的控制措施.

Combining with Dagangshan project example,the finite element simulation model of the concrete grouting blocks and cooling water pipe is established based on the platform of ANSYS.Through numerical simulation,the first is to analyze the change rule of temperature field and stress field of concrete around cooling water pipe with time.The second is to find out the relationship between the temperature and stress of feature points with the distance from the water-pipe;and the concrete temperature gradient and stress gradient transform relationship over time.With different cooling water temperatures the water cooling process is simulated;comparative analysis of calculated results and confirms the reasonable water temperature of water cooling;moreover,to numerical simulate water cooling start time,and analyze how various water cooling start time affect the temperature and stress of the concrete.At last,comprehensive analysis of the numerical simulation results,the paper puts forward several reasonable control measures to prevent concretc cracking.