## 4 Results and Discussions  
### Accuracy of Prediction Formula  
On the basis of Equation (1) and Equation (2), Equation (3) can be formed for predictive purposes.  
\[\rm T_{P}=T_{c}+\Delta T_{c}+\Delta T_{w1}+\Delta T_{w2}, \tag{3}\]  
where \(\rm T_{p}\) is the predicted value of the concrete temperature at the end of the time period \(\Delta t\) (\({}^{\circ}\)C); \(\rm T_{c}\) is temperature of concrete at the beginning of the time period \(\Delta t\) (\({}^{\circ}\)C); \(\Delta T_{c}\) is the temperature rise caused  
Figure 6: Comparisons of fitted and measured temperature variations for Wudongde dam: (**a-j**) the fitted and measured results of the ten selected concrete blocks, respectively.  
by hydration during the time period \(\Delta\)t (\({}^{\circ}\)C); and \(\Delta\)Tw1 and \(\Delta\)Tw2 are the temperature fallings caused by the upper and lower cooling pipes, respectively, during the time period \(\Delta\)t (\({}^{\circ}\)C).  
In light of the in situ monitoring data collected from main pipe (1) and G1, as shown in Figure 4, after the start of water supply, the time for each thermometer in G1 affected by the cooling pipe decreased as distance increased, and the response time of the cooling effect of the thermometers located in the middle of the two cooling pipes with a vertical space of 1.5 m was about 3 h. Therefore, the temperature at 3 h after the current time could be calculated using the cooling water data within the last 3 h. To verify the accuracy of the prediction model, the actual cooling water data were regarded as known variables. Using the data of the remaining four concrete blocks from the two dams, temperatures at 3 and 12 h were calculated and compared with the measured values, as depicted in Figures 7 and 8. Equation (2) takes into account the influence of concrete temperature, therefore, the method of superimposing the calculation according to the time period was used to reduce the error caused by excessive change in the temperature of the concrete during the calculation period. The temperature was predicted after 12 h by splitting 12 h into four 3 h parts, that is, the procedure to predict the temperature was repeated four times every 3 hours, with the results of the previous prediction used in the next calculation.  
Figure 7: Comparisons of predicted and measured temperatures for Baihetan dam: (**a–d**) the predicted and measured values of the four old concrete blocks, respectively.  
As seen from Figures 7 and 8, the accuracy of this method was desirable to some extent, and the predicted values were generally in good agreement with the actual values. The overall precision of predicting the temperature every 3 h was higher than using a single 12 h block. Usually, at the beginning, when the pouring was not or had just been completed, large discrepancies appeared under the influence of various factors. Meanwhile, because the water flow from one main pipe allocated to each branch may not be similar and only data from the main pipes were obtained, error occurred. The prediction algorithm also relies on real-time, updated data, so data interruptions or lagging had the potential to increase the prediction error.  
The calculation processes ran in the system constantly. Owing to the time intervals of the data used for the fitting generally being 3 h, if the temperature after a longer period of time was forecasted using this model, larger deviations could have appeared owing to failure to obtain accurate data from the cooling water or the accumulation of prediction errors over long periods. In this case, the time interval of the original data could be adjusted to achieve the corresponding purpose.