关键词: 特高拱坝, 混凝土冷却, 温降曲线, 混凝土应力

Abstract: As the intelligent temperature control technology improves, the temperature control model of three phases and nine stages for casting super-high arch dam concrete will be simplified, so that it can further improve the internal stresses of concrete. With consideration of the construction monitoring data, this paper suggests and examines two new simplified temperature control models: one phase and three stages and two phases and six stages; and presents an analysis, through numerical simulations using these models, of the strengths and weaknesses of different time variations in the internal stress of the arch dam under cooling control at each stage. The results show that of the three models, one phase and three stages has the weakest stress impact when the concrete is cooled down from the highest to arch sealing temperature in the shortest time; its maximum stress is much lower than those of the other two models. All the three stress curves are well below the safety threshold curve when arch sealing temperature is reached at 120, 150 and 180 days, and they only extend the duration of water circulation and have little effect on dam stress. For the three phases and nine stages model, the key to reducing stress in the dam body is to reasonably adjust the cooling rate and the ratio of cooling time to temperature control time.

Key words: super-high arch dam, dam cooling, temperature drop curve, dam stress