## 4 Case Study
### Characteristics Analysis of the Dam Deformation Zoning  
The 32 groups of deformation measuring points of the ultra-high arch dam were input according to the panel data format and the dam displacement zoning under three water level stages was calculated according to the process of the above dam deformation clustering zoning model. Three standardized distances were weighted by the CRITIC method. Based on the CSP index classification idea, after iterative calculation, the clustering threshold \(k=6\) was determined. The deformed partition model outputs the average value of \(CSP_{i}\) zone number \(k\) from 2 to 32. The results are shown in Figure 6. When k is equal to 6, its value is the largest. Currently, the inter-class distance and intraclass distance reach optimal harmony. To compare and analyze the dam deformation state under different water levels during operation, the clustering threshold is locked in the whole process. Figure 4: Distribution of deformation measurement points of the arch dam. Figure 3: Process diagram of upstream reservoir water level. (2) Deformation characteristics analysis of the second phase  
In the second phase, from July 2013 to June 2014, the reservoir water level rose to the design water level and fell back. The zoning results of dam deformation measurement points are shown in Table 2 and Figure 8. Compared with the first phase, the boundary of each deformation zone is smoother after the dam body coordinates and adapts to the water pressure for a certain time. Due to the continuous rise of water level, zones I, II, III, and IV expand upward in varying degrees, in which area I changes significantly and its area expands rapidly. The change and extension of area V to the left and right bank is obvious. At this phase, the dam deformation is mainly reflected in the direct feedback to the water pressure. (3) Deformation characteristics analysis of the third phase  
In the third phase, from July 2014 to June 2015, the reservoir water level is in normal operation for a cycle year. The zoning results of dam deformation measurement points are shown in Table 3, and the zoning of dam deformation is shown in Figure 9. Compared with the second phase, with the loading of continuous high-water pressure, the area of zone I is further expanded, and the dam deformation gradually extends from the middle-lower part to the middle-upper part. The change in Zone IV is obvious, which is mainly caused by \begin{table}
\begin{tabular}{c c} \hline \hline
**Category** & **Measuring Point** \\ \hline I & PL11-4, PL11-5, PL13-4, PL13-5, PL16-4, PL16-5 \\ II & PL11-3, PL13-3 \\ III & PL11-5, PL13-3 \\ IV & PL11-3, PL13-2, PL16-3 \\ V & PL9-2, PL9-3, PL11-1, PL11-2, PL13-1, PL16-1, PL16-2 \\ VI & PLS-1, PLS-2, PL5-3, PL5-4, PL9-1, PL9-4, PL9-5, IP11-1, IP13-2, IP16-1, PL19-1, PL19-1, PL19-1, \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Zoning results of deformation measuring points of the ultra-high arch dam during the second phase. \begin{table}
\begin{tabular}{c c} \hline \hline
**Category** & **Measuring Point** \\ \hline I & PL11-4, PL11-5, PL13-4, PL13-5, PL16-4, PL16-5 \\ II & PL11-3, PL13-3 \\ III & PL16-3 \\ IV & PL11-2, PL13-2 \\ V & PL9-1, PL9-2, PL9-3, PL19-4, PL11-1, PL13-1, PL16-1, PL16-2, PL19-3, PL19-4 \\ VI & PLS-1 PLS-2, PL5-3, PL5-4, PL9-5 IP11-1, IP13-2, IP16-1, PL19-1, PL19-2, PL19-5 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Zoning results of deformation measuring points of the ultra-high arch dam during the first phase. Figure 7: Deformation partition diagram of the ultra-high arch dam during the first phase. It can be seen from Figure 8 that in the early stage of the operation when the water level of the dam changes greatly, the measuring points sensitive to the water level is concentrated in the middle of the dam body, and the zoning at the edge of the dam body changes little, among which the measuring points distributed in zones I, II, and III change the most.