粉煤灰对特高拱坝封拱后坝体温度升高的影响

Influence of fly ash on the temperature rise of super high arch dam after arch sealing

以某特高拱坝为例,分析其分布式光纤温度监测数据,采用封拱完成后坝体内部混凝中粉煤灰水化放热的计算方法;借助最小二乘法来拟合温度升高过程,同时以温度监测数据为基础,分析计算粉煤灰对坝体温度提高所造成的影响。结果表示,完成拱坝封拱后,粉煤灰累计放热量随时间增长的变化曲线基本和混凝土的放热曲线保持一致,这表明封拱完成后坝体内部温度增高的主要因素来自粉煤灰水化放热,要想削弱封拱完成后温度提高对坝体造成的负面影响,主要手段是调整粉煤灰在混凝土中的占比。

In order to analyze the influence of fly ash on the temperature change of super high arch dam after arch sealing,this study takes a super high arch dam as an example,analyzes its distributed optical fiber temperature monitoring data,and gives a method to calculate the hydration heat release of fly ash in the concrete inside the dam after arch sealing.The least square method is used to fit the process of temperature rise.At the same time,based on the temperature monitoring data,the influence of fly ash on the temperature rise of the dam body is analyzed and calculated.The results show that after the arch dam is sealed,the change curve of the cumulative heat release of fly ash with time is basically consistent with the heat release curve of concrete,which indicates that the main factor for the increase of the internal temperature of the dam body after the arch dam is from the hydration heat release of fly ash.In order to weaken the negative impact of the temperature increase on the dam body after the completion of arch sealing,the main means is to adjust the proportion of fly ash in the concrete.