# Research on the Correlation of Safety Risk of Railway Bridge Construction Based on Meta-Analysis
## 4 Results
### Frequency-Based Risk Grouping
#### 4.1.1 Environment Risks  
The secondary security risk factors related to the environment encompass not only the natural environment but also the working environment and the cultural soft environment of both the enterprise and society. During the clustering process, similar risk factors such as \"Climate environment\" and \"Climate change\" were merged, while more specific risk factors like \"Kast\", \"Landslide and debris flow\", \"Strong earthquake\", and \"Avalanche\" were classified accordingly. This resulted in the identification of six secondary security risk factors: climatic conditions, hydrogeology, natural disasters, working environment, landforms, and the social soft environment of enterprises, as depicted in Table 2. The numbers in the table indicate the frequency of recognition for each category. Various natural risk factors significantly influence the operational environment, while risks associated with the cultural soft environment of enterprises and the political environment exhibit a certain level of consistency.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Primary** & & & & \\
**Safety Risk** & **Secondary Safety Risk Factors** & **Code** & **Description** & **Frequency** \\ \hline \multirow{5}{*}{Environment Risks} & Climatic conditions & E1 & Strong winds, heavy rain, etc. & 13 \\  & Hydrogeology & E2 & Ground water, stress, etc. & 9 \\  & Natural disaster & E3 & Earthquake, landslide, etc. & 6 \\  & Operating environment & E4 & Room temperature, etc. & 5 \\  & Topography & E5 & Mountain, plain, etc. & 3 \\  & Corporate social soft environment & E6 & Corporate HSE culture, etc. & 2 \\ \hline \multirow{5}{*}{Materials and Equipment Risks} & Material mass & ME1 & Incoming inspection; material characteristics, etc. & 8 \\  & Maintenance & ME2 & Level of maintenance, timeliness, etc. & 7 \\  & Safety protection & ME3 & Personal protective measures, early warning & 6 \\  & The use of materials & ME4 & Material transportation, material storage, etc. & 6 \\  & Equipment quality & ME5 & Equipment specification, quality inspection & 3 \\  & & level, etc. & & \\  & Personnel experience level & ME6 & Operation compliance, equipment & 2 \\  & Invasion limit & ME7 &
\begin{tabular}{c} adaptability, etc. \\ Invasion of falling objects, remnants, etc. \\ \end{tabular} & 2 \\ \hline \multirow{5}{*}{Technology Risks} & Scheme design & T1 & Special construction scheme design, safety & 7 \\  & Technological maturity & T2 & New technology, new process maturity, etc. & 5 \\  & Technical applicability & T3 & 4 \\  & Construction organization design & T4 & Rationality, applicability, etc. & 3 \\  & Personnel experience level & T5 & Personnel operations, personnel awareness, etc. & 3 \\  & Material and equipment & T6 & Project compatibility, limit violation, etc. & 3 \\  & Construction difficulty & T7 & The length and span of a bridge & 2 \\  & Technical disclosure integrity & T8 & 2 \\ \hline \multirow{5}{*}{Management Risks} & Monitoring & M1 & & 7 \\  & Institutional soundness & M2 & & 6 \\  & Construction organization design & M3 & Rationality, applicability, etc. & 6 \\  & Responsibility for implementing & M4 & Job Arrangement, division of labor, etc. & 5 \\  & Communication and cooperation & M5 & Information feedback, trouble shooting, etc. & 5 \\  & Site layout & M6 & & 4 \\  & Personnel experience Level & M7 & & 3 \\  & Design & M8 & Special construction scheme design, safety & 3 \\  & Work safety education & M9 & Training, assessment, etc. & 3 \\  & Technical disclosure integrity & M10 & & 2 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Classification of safety risk factors for railway bridge construction.