大体积混凝土施工期冷却水管埋设形式的优化

采用冷却水管通水冷却是大体积混凝土坝施工期主要温控措施,而冷却水管埋设布置形式对混凝土内部温度和应力的影响较为显著.利用有限元热流耦合精细算法,考虑了冷却水管中水流与混凝土之间的相互对流热交换机制,真实反映冷却水管附近温度梯度,对冷却水管在仓面上采用不同的布置方式时混凝土内部的温度和应力分布进行详细计算分析.结果表明:相比传统的水管埋设布置方式,采用冷却水管双循环的布置方式更能充分发挥水管冷却作用,且能有效改善混凝土内部的温度和应力分布,降低混凝土内部的温度梯度,对大体积混凝土温控防裂有较为积极的意义.

Optimization of Cooling Pipe Layout in Mass Concrete During Construction Period

Pipe cooling is the main measure to control the temperature of mass concrete in the construction period, and the layout of cooling pipe has obvious influence on the internal temperature and stress of mass concrete. In this paper,a heat-fluid coupling finite element method is presented to simulate the pipe cooling of mass concrete. The method takes the heat exchange mechanism between cooling water and concrete into consideration which can accu-rately reflect the temperature gradient around the cooling pipe. The calculation results show that compared with con-ventional pipe layout,the layout of double circulating can make more sufficient use of the cooling pipe,effectively improve the distribution of internal temperature and stress,and obviously decrease the internal temperature gradient in mass concrete.