Abstract
In the train operation department, humans are the most important and dynamic element, and their safe behavior is directly related to the safety of railway transportation. How to accurately assess the safety behavior risk of on-site workers is an urgent problem to be solved. In risk practice, some scholars directly use the accident potential data to calculate the risk parameters, and the accuracy of the risk magnitude is greatly affected by the data quality. Second, the traditional two-dimensional matrix only considers two external factors, probability and severity, without an in-depth analysis of the inherent vulnerability of risk, resulting in low accuracy of risk assessment. With a focus on the hazard factor, this study proposes a three-dimensional risk assessment approach based on grid management to carry out a personalized risk assessment of grid events. Through the grid division, the method can accurately identify the risk events of employees in any cell grid at a certain moment in the “grids-events-time” three-dimensional coordinate system, providing modeling support for personalized risk assessment. Then, a “probability-severity-vulnerability” three-dimensional risk assessment model is constructed. In this model, the probability is obtained by the induced intensity assignment function of the hazard factor, the vulnerability is obtained by the coupling strength assignment function of the hazard factor, and the severity of a single risk event is given a constant value. On this basis, the risk magnitude is determined by the “sum” algorithm of the three risk parameters. This methodology solves the problems of incomplete consideration of risk parameters and insufficient accuracy of quantitative analysis of risk magnitude in the previous risk assessment process and realizes the personalized and dynamic assessment of risk events of the train operation department. Finally, the methodology is applied to the risk event assessment of “the assistant watchman does not appear as required” at Huangyangcheng station of the Shenshuo Railway, and the evaluation results show that the risk magnitude of different elements in the same cell grid has an obvious individual difference, which fully embodies the advantages of grid risk assessment.