热带高温地区碾压混凝土重力坝温控措施

为了研究在高温环境下浇筑大坝混凝土时,控制浇筑温度和通冷却水等常用温控措施的效果、探索适用于高温施工环境的温控措施,利用有限元法对某一位于热带高温地区的碾压混凝土重力坝进行了施工期和运行期的全过程温度场和温度应力场仿真计算,对比分析了不同冷却水水温和浇筑温度下的坝体温度场和温度应力场.计算结果表明,坝体温度应力受浇筑温度和冷却水水温影响较大,将坝体基础约束区的浇筑温度从25℃降低到23℃、冷却水水温从20℃降低到15℃时,坝体最高温度从36.9℃降低到了34.6℃、最大温度应力从1.64MPa降低到了1.40MPa,此结果满足该大坝温控防裂要求.由此可见,在高温地区建混凝土坝时,在相对较高的浇筑温度和冷却水水温的施工条件下,坝体的温度和温度应力可得到有效控制.研究成果对简化温控措施、缩短工期、减少投资有重要参考意义.

Temperature control of RCC gravity dam in tropical high-temperature area

In order to study the effect of temperature control measures when pouring concrete dams at high temperature and find suitable temperature control measures for high-temperature construction environments,combined with the actual project,using finite element method,the temperature stress during the construction and operation phases of a RCC gravity dam was simulated,and the temperature and stress fields of the dam at different cooling water temperatures and pouring temperatures were made comparative analysis.Results show that the dam temperature stress is greatly influenced by pouring temperature and cooling water temperature.In basic restraint areas,while the pouring temperature reduces from 25℃to 23℃and the coo-ling water temperature reduces from 20℃to 15℃,the highest temperature in dam body reduces from 36.9℃to 34.6℃and the maximum temperature stress reduces from 1.64 MPa to 1.40 MPa.The result meets the requirement of temperature control and crack prevention of the dam.It can be seen that when concrete dams are built in high-temperature areas,the temperature and temperature stress of the dam can be effectively controlled at relatively high pouring temperature and cooling water temperature.The present result is of important value in simplifying temperature control measures,shortening the construction period and reducing the investment.