锦屏一级高拱坝温控特点与对策

Features analysis and countermeasures for concrete temperature control in Jinping-Ⅰ high arch dam

本文从体型结构、材料参数、施工技术等方面阐述了锦屏一级高拱坝的温控特点,指出锦屏一级高拱坝底宽长、混凝土后期温度回升大、施工中通水冷却温降速度快、垫座约束复杂等因素都会对混凝土温控产生不利影响。基于仿真分析结果,本文提出了相应的对策,对于垫座和大坝基础约束区要严格控制最高温度,对于大坝非约束区要做好温降过程中空间梯度和时间梯度的控制。

The arch dam of Jinping-Ⅰ project is the highest arch dam in the world,in which the concrete temperature control is one of the main hard problems.In this article,the features of concrete temperature control of Jinping-Ⅰ arch dam are analyzed from three respects： the structure type,material parameters and construction technology.Some unfavorable factors for concrete temperature control are pointed out,such as big bottom width,excessive concrete temperature rise after first stage cooling,rapid rate of concrete temperature drop and strong restraint for concrete in bedding layers,etc.Based on the results of simulation analysis,a few corresponding countermeasures are proposed.For concrete in bedding layers and constraint region the highest temperature must be strictly controlled according to the design requirement,and for concrete in non-constraint regions the temperature gradients in time and in space during temperature dropping must be carefully controlled.