Abstract: In order to explore the influence of the cooling pipe system on the temperature field of the mass concrete sidewall at an early age and reduce the cracking risk of the early-age sidewall, a heat flow coupling model considering the change of concrete behavior and the effect of cooling pipe was constructed. On this basis, Comsol Multiphysics software was used for the secondary development of the proposed model to solve the temperature field of the early-age sidewall under the action of the cooling pipe, and the early-age temperature monitoring of the sidewall was used to verify the reliability of the proposed model. Finally, the effects of cooling pipe parameters such as water temperature, flow rate, pipe spacing, and thermal conductivity on the temperature field of the early-age sidewall were analyzed. The research results show that the difference between the calculation results of the heat flow coupling model and the measured values is small, and the calculation results are reliable. The cooling water temperature gradually increases along with the direction of water flow, and the cooling pipe should change the direction of water flow regularly to improve cooling efficiency. The temperature difference in the area near the cooling pipe exhibits a trend of first increasing and then decreasing with the increase of age, reaching its maximum at the peak temperature age. Reducing the water temperature and increasing the flow rate and thermal conductivity can reduce temperature peak and cooling rate of the early-age sidewall, while it will increase the temperature difference in the area near the cooling pipe. When the flow rate exceeds 0.6 m3/h, increasing the flow rate has no significant effect on the temperature field. Reducing the pipe spacing can reduce the temperature peak, cooling rate, and temperature difference of the early-age sidewall. In practical engineering, the water temperature of the cooling pipes should be strictly controlled, with the spacing between cooling pipes kept below 100 cm and the cooling water flow rate ensured to be no less than 0.6 m3/h. Meanwhile, it is recommended to use PVC pipes, as cooling pipes, which can not only reduce the temperature peak of the sidewalls and the temperature gradient around the cooling pipes, but also lower the cost of the cooling pipes.

Key words: geotechnical engineering; early-age; mass concrete; sidewall; cooling pipes; temperature field

摘要： 为了探究冷却管系统对大体积混凝土侧墙早龄期温度场的影响，降低早龄期侧墙的开裂风险，构建了考虑混凝土性态变化与冷却管作用的热流耦合模型。在此基础上，利用Comsol Multiphysics软件进行模型二次开发，求解冷却管作用下早龄期侧墙的温度场，并借助侧墙早龄期温度监测验证模型的可靠性，最后分析了水温、流量、管距、导热系数等冷却管参数对早龄期侧墙温度场的影响。研究结果表明：热流耦合模型的计算结果与实测值相差较小，计算结果是可靠的；冷却水温度沿水流方向逐渐升高，冷却管应定时转换水流方向以提高降温效率；冷却管附近区域的温差随龄期的增大呈先增大后减小的变化趋势，并在温峰龄期达到最大值；降低水温、增大流量与导热系数均能降低早龄期侧墙的温度峰值与降温速率，但是会增大冷却管附近区域的温差，当流量大于0.6 m3/h时，增大流量对温度场无显著影响，减小管距能降低早龄期侧墙的温度峰值、降温速率与温差。在实际工程中，应严格控制冷却管的水温，将冷却管的间距控制在100 cm以下，保证冷却水流量不低于0.6 m3/h，并建议采用PVC管作为冷却管，这不仅可以降低侧墙的温度峰值与冷却管周围的温度梯度，还能降低冷却管的成本。

关键词: 岩土工程；早龄期；大体积混凝土；侧墙；冷却管；温度场