An Integrated Pythagorean Fuzzy TOPSIS Framework for Occupational Safety Risk Prioritization in Bridge Construction Projects

With the continuous expansion of government investment in transportation infrastructure, transportation investment has increased, and bridge engineering has flourished. However, safety accidents frequently occur during the construction stage, so the safety situation of bridge construction units remains unfavorable. Bridge construction is a high-risk occupational activity because operations are performed under complex site conditions, variable geological and hydrological environments, long construction periods, and frequent interaction among workers, machinery, materials, technologies, and surrounding environments. Existing bridge construction safety assessment methods have improved hazard identification and risk prioritization; however, many still have difficulty representing uncertainty, hesitation, and subjective judgment in expert-based occupational safety evaluation. To address this problem, this study proposes an integrated Pythagorean fuzzy TOPSIS decision-support framework for occupational safety risk prioritization in bridge construction projects. A safety risk indicator system is established from five dimensions: human, management, material, technical, and environmental factors. Expert judgments are expressed using linguistic variables and converted into Pythagorean fuzzy numbers. The Pythagorean fuzzy weighted average operator is used to aggregate multi-expert evaluation information, and criterion importance is determined from expert-based Pythagorean fuzzy assessments. The model is applied to a bridge reconstruction project, followed by sensitivity analysis and comparison with several existing methods. The results indicate that low work quality, non-standard construction, construction site environment, lack of safety awareness, and insufficient construction technology are the most critical occupational safety risk indicators. The proposed method provides a practical decision-support tool for identifying priority safety risks under fuzzy and uncertain evaluation conditions.