特高拱坝运行期温度场仿真反馈及其与设计温度差异研究

Simulation Feedback of Temperature Field of Super-high Arch Dam during Operation and Its Difference with Design Temperature

温度荷载是特高拱坝的主要荷载之一。以中国西南某特高拱坝为例,基于大坝温度监测资料,分析了坝体温度的时空演化规律。在此基础上,采用有限元仿真分析方法,对大坝上游表面温度边界条件以及混凝土热学参数进行反演,仿真分析了拱坝长期运行的温度演化过程。对比分析了设计库水温与实际库水温的分布特征,研究了设计条件和实际条件下拱坝蓄水运行期温度场的差异。研究结果表明,大坝运行期温度时空演化规律符合常规认知,仿真反馈计算值与监测值吻合较好,可以反映坝体实际温度场分布情况;设计条件下,坝体温度在封拱灌浆后缓慢地升高,逐渐趋近于稳定温度,实际条件下,坝体温度在封拱灌浆后升高了7.1~9.2℃,封拱后8~12年达到最高温度,40~80年回落至稳定温度。

Temperature is one of the main loads of super-high arch dams.Background:a super-high arch dam in southwest China was taken as an example in this paper and the temporalspatial evolution law of dam temperature was analyzed based on the monitoring data.Methods:the finite element simulation analysis method was adopted to invert the boundary conditions of temperature on the upstream surface and the thermal parameters of the concrete,and the temperature evolution process of the arch dam in long-term operation was simulated and analyzed.After the distribution characteristics of the designed reservoir water temperature and the actual reservoir water temperature were compared,and the difference of the temperature field of the arch dam during the impoundment and operation under the designed and actual conditions was studied.Results:the temporal-spatial evolution law of the temperature in the dam operation period accords with the conventional knowledge,and the calculated value through simulation feedback is in good agreement with the monitoring value,which can reflect the actual temperature field distribution of the dam.Conclusions:under the design condition,the dam temperature rose slowly after closure grouting,and then tended to be stable.Under the actual condition,the temperature rose by 7.1~9.2℃after closure grouting,reached the highest temperature in about 8~12years,and fell back to a stable temperature in 40~80 years.