Safety Risk Assessment of Hydraulic Climbing Formwork Construction Based on System-Theoretic Process Analysis and Dynamic Bayesian Networks

Hydraulic climbing formwork (HCF) is an efficient and highly automated construction technology that has been widely applied in the construction of super high-rise buildings and long-span bridges. Ensuring the safety of the HCF system is crucial for preventing construction accidents. However, the dynamic and interdependent nature of risks during the construction process poses significant challenges to traditional risk assessment methods, which are typically limited to static analysis. To address this limitation, this study develops a framework that integrates System-theoretic process analysis (STPA) with dynamic Bayesian network (DBN), offering a dual perspective that combines system-level qualitative hazard identification with dynamic quantitative risk modeling. Unlike traditional approaches, this integrated framework enables the analysis of multistage risk propagation paths and their temporal evolution, thus providing a more comprehensive understanding of the safety performance of HCF construction. The results indicate that accident risks during the construction process exhibit stage-specific prominence, with falls from height being the most common type of accident. Risk structures are characterized by human factor–dominated, compound features. The findings of this study provide practical recommendations for improving safety management in HCF construction projects.