## 5 Data and Analysis
### Changes in Structural Stiffness after Reinforcement  
According to the actual situation of the site, the vibration of the bridge slab was monitored under normal traffic conditions. During monitoring, data were collected every 5 min. The data collected from 12 measurement points were randomly selected for analysis, and the maximum amplitude of the structure before and after reinforcement was obtained. The values and minimum and average values are shown in Table 2.  
Figure 13 shows that the maximum amplitude of the bridge deck before reinforcement was greater than 2 mm, and the maximum amplitude of the bridge deck reached more than 3 mm. Among the 12 randomly selected monitoring points, the maximum amplitude of each point was different. The graph below shows obvious ups and downs, indicating that before the bridge deck was reinforced, the bridge deck had significant deflection under normal traffic conditions. \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Measuring** & \multicolumn{2}{c}{**Maximum Amplitude**} & \multicolumn{2}{c}{**Minimum Amplitude**} & \multicolumn{2}{c}{**Average Amplitude**} \\
**Point** & & & & & & \\ \hline  & **Before Rein-** & **After Rein-** & **Before Rein-** & **After Rein-** & **Before Rein-** & **After Rein-** & **After Rein-** \\
2 & 2.822 & 1.123 & \(-\)2.830 & \(-\)1.241 & \(-\)0.140 & \(-\)0.154 \\
2 & 2.301 & 0.807 & \(-\)1.978 & \(-\)1.274 & \(-\)0.632 & \(-\)0.468 \\
4 & 3.183 & 0.854 & \(-\)2.977 & \(-\)1.291 & \(-\)0.641 & \(-\)0.414 \\
5 & 2.067 & 1.107 & \(-\)2.746 & \(-\)1.344 & \(-\)0.729 & \(-\)0.309 \\
6 & 2.822 & 1.186 & \(-\)2.830 & \(-\)1.382 & \(-\)0.140 & \(-\)0.229 \\
7 & 2.197 & 1.334 & \(-\)1.978 & \(-\)1.624 & \(-\)0.634 & \(-\)0.265 \\
8 & 2.822 & 1.290 & \(-\)2.830 & \(-\)1.152 & \(-\)0.140 & \(-\)0.016 \\
9 & 3.099 & 1.220 & \(-\)2.667 & \(-\)1.246 & \(-\)0.145 & \(-\)0.036 \\
10 & 2.282 & 1.068 & \(-\)2.830 & \(-\)1.288 & \(-\)0.304 & \(-\)0.216 \\
11 & 2.822 & 1.049 & \(-\)2.830 & \(-\)1.397 & \(-\)0.259 & \(-\)0.216 \\
12 & 3.073 & 1.101 & \(-\)2.630 & \(-\)1.037 & \(-\)0.124 & \(-\)0.051 \\ \hline \end{tabular}
\end{table} 
Table 2: Maximum amplitude of deck before and after reinforcement (unit: mm). Figure 13: Maximum amplitude of bridge deck before and after reinforcement (unit: mm). After the bridge deck was reinforced, the maximum values of the 12 selected monitoring points under normal traffic conditions were relatively small. It can be clearly seen from the graphs that the maximum values after reinforcement do not exceed 1.5 mm. The curve undulates smoothly, and there is no obvious undulation, which indicates that after the bridge deck was reinforced, the maximum amplitude of the bridge deck decreased compared to that before the reinforcement, and the UHPC reinforcement had a significant effect. Figure 14 shows that the minimum amplitude of the bridge deck before the reinforcement reached \(-4.5\) mm and stayed below \(-2\) mm. Among the 12 randomly selected monitoring points, the minimum amplitude of each point was different. The associated curve has obvious ups and downs, indicating that before the bridge deck was reinforced, under normal traffic conditions, the bridge deck had significant deflection after being compressed. Similarly, after the bridge deck was reinforced, the minimum values of the 12 selected monitoring points under normal traffic conditions were relatively small. Except for point 8, the minimum values after reinforcement did not exceed \(-1.7\). The undulation of the curve is gentler than that before the reinforcement, which also indicates that the minimum amplitude of the bridge deck after the reinforcement decreased compared to that before the reinforcement, and the use of UHPC had a significant effect on the reinforcement. Figure 15 shows the comparison of the results of the average amplitude before and after the reinforcement of the bridge deck.