A Comprehensive Spatio-Temporal Network-Based Model for Dynamic Risk Analysis on Struck-by-Equipment Hazard

There has been a need for a systematic risk analysis method for struck-by-equipment hazard that considers interactions and interrelationships among entities (equipment and workers-on-foot) on a job site and also analyzes safety risk at multiple levels. This paper presents a comprehensive spatio-temporal network-based model, developed for dynamic risk analysis pertinent to struck-by-equipment hazard. In the developed model, the dynamic interactions and interrelationships among entities presented on a job site are quantified and conceptualized in a weighted network. The network-based model is capable of conducting safety risk analysis at both entity and network levels in a real-time and proactive manner. Three safety leading indicators, including relative risk score (based on algebraic connectivity), degree centrality, and eigenvector centrality, are adopted to identify different aspects of the dynamic risk of individual entities and job sites. Three simulated job sites were used to illustrate the network-based model for risk analysis. The results show that while the risk level of each job site can be identified, the entities bearing different aspects of risk can also be detected. The over-time risk evolution at both entity and network levels were tracked to gain a full understanding of the dynamic risk on job sites.