# Safety Risk Assessment of Highway Bridge Construction Based on Cloud Entropy Power Method
## 4 Project Example Analysis
### Risk Weight Calculation Based on Cloud Entropy Weight Method  
Based on the entropy weight method and the need for the accuracy and validity of cloud model generation [35], 10 experts were invited to score the risk indicators based on two principles: risk probability magnitude and risk loss magnitude. The scoring results are shown in Table 2.  
After processing the expert scoring results in the above table through the cloud model inverse generator, the expected score \(Ex_{j}\), the discrete degree \(En_{j}\), and the random degree \(He_{j}\) of each risk factor are obtained according to Equations (9)-(11). Then, according to Equation (12), weight \(\beta_{j}\) can be calculated by the traditional weight calculation method, and the improved weight \(\omega_{j}\) obtained by using the improved entropy weight Equation (13). The results are shown in Table 3. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Risk Indicator** & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** \\ \hline C1 Personnel quality & 78 & 80 & 65 & 55 & 85 & 43 & 68 & 78 & 72 & 72 \\ C2 Organizational completeness & 67 & 70 & 42 & 80 & 52 & 23 & 60 & 48 & 30 & 86 \\ C3 Construction management strength & 70 & 90 & 65 & 89 & 75 & 60 & 86 & 40 & 60 & 79 \\ C4 Temporary structure safety & 86 & 84 & 56 & 94 & 72 & 67 & 58 & 88 & 72 & 65 \\ C5 Construction material error & 65 & 85 & 50 & 95 & 96 & 73 & 70 & 92 & 90 & 74 \\ C6 Material equipment stacking & 63 & 75 & 40 & 79 & 60 & 55 & 63 & 86 & 84 & 78 \\ C7 Mechanical failure & 30 & 72 & 32 & 80 & 70 & 26 & 56 & 70 & 45 & 75 \\ C8 Geological conditions & 85 & 70 & 78 & 95 & 94 & 68 & 65 & 60 & 58 & 80 \\ C9 Climatic environmental conditions & 75 & 85 & 90 & 97 & 96 & 80 & 80 & 90 & 100 & 81 \\ C10 Natural disasters & 76 & 59 & 35 & 59 & 75 & 56 & 81 & 30 & 82 & 79 \\ C11 Rationality of the design & 75 & 92 & 88 & 65 & 70 & 60 & 65 & 70 & 90 & 95 \\ C12 Process maturity & 60 & 75 & 90 & 80 & 55 & 60 & 52 & 68 & 75 & 95 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Risk indicator scoring results. The analysis of Table 3 shows that the expected value of each risk index has a good distribution, and the interval difference is more obvious; the entropy value and the super-entropy value represent the dispersion degree of the expert opinions. The risk weight value obtained by the weight calculation method is generally 6% to 9%, and the weight value distribution is relatively even. Such a result is not conducive to the distinction of primary and secondary weights, and is not conducive to the judgment of factor importance. The improved weights of each risk index are sorted from small to large, as shown in Figure 5.  
As can be seen from the above figure:  
1. The ranking of the importance of indicators has not changed much after the improvement, and basically maintains the trend of the original expected value ranking, which fully reflects the opinions of experts. 2. The weight distribution is readjusted by the difference in the scoring results, which shows that the improved model makes fuller use of the scoring data results and more effectively reflects the objective scoring situation. Figure 5: Risk indicator weighting chart.