The construction industry continues to face high accident rates due to complex work environments and fragmented safety-management practices. Conventional risk assessment remains heavily dependent on the subjective judgment of assessors, while availabl...
The construction industry continues to face high accident rates due to complex work environments and fragmented safety-management practices. Conventional risk assessment remains heavily dependent on the subjective judgment of assessors, while available accident databases are largely categorical and lack the contextual detail necessary for precise analysis. Furthermore, the absence of systematic linkage between risk assessment and safety regulations contributes to documentation-oriented “paper safety,” limiting the practical effectiveness of hazard prevention.
To address these limitations, this dissertation proposes an intelligent, regulation-aware, multi-level risk assessment framework that integrates three core components: (1) a machine learning (ML)–based site-level risk prediction model; (2) a task-level accident scenario inference framework using Large Language Models (LLMs) and Graph Neural Networks (GNNs); and (3) a regulation-integration mechanism that links quantitative risk results to construction safety laws.
First, a site-level risk assessment framework is developed using 13,047 accident cases from the CSI database. Three ML sub-models—predicting accident objects, accident types, and death–injury outcomes—are trained using RF, XGBoost, CatBoost, and LightGBM. After resolving class imbalance with SMOTE, XGBoost shows the best performance, with weighted F1-scores of 0.839 (object), 0.749 (type), and 0.977 (severity). A web-based prototype is implemented to operationalize these predictions for on-site decision support.
Second, to address the lack of contextual detail in structured records, the framework applies LLM-based extraction to obtain fine-grained entities—such as work tasks, equipment, and materials—from unstructured accident narratives. These entities form an accident-correlation network modeled with GNNs. Simple-HGN delivers the highest performance, achieving a 93.6% mAP for accident-object prediction and strong accuracy for accident causes and types. Scenario outputs show close alignment with real accident distributions (JSD < 0.3) and well-calibrated probabilities (ECE < 0.05). For severity prediction, a Lognormal–SVR model yields a MAE of 0.212.
Finally, a Safety Legal Map is developed to link risk predictions with regulatory requirements from OSHA, CTPA, and SAPA, enabling automatic retrieval of relevant legal provisions and documentation obligations alongside inferred accident scenarios.
Collectively, this research provides a unified methodology that advances both academic and practical domains. Academically, it demonstrates how ML, LLMs, and GNNs can be combined to overcome the contextual limitations of accident data and model complex relational patterns. Practically, it establishes the foundation for transforming construction safety management from subjective, post-incident responses to an objective, data-driven, and regulation-aligned system that supports proactive accident prevention.