Research On Safety Risk Assessment Of Subway Operation Based On Extension Theory

With the rapid development of China’s social economy,spiritual and material civilization and the continuous improvement of urban modernization,the development of subway is increasingly rapid,which can greatly improve urban traffic congestion and other problems.However,subway lines are usually built underground,with closed environment,large passenger flow and high train speed.Once an accident occurs in the process of subway operation,serious consequences will be caused.Therefore,it is particularly important to establish a scientific and efficient safety risk control system for subway operation,realize closed-loop management of risk identification,analysis,evaluation and control of the whole process of subway operation,and improve the overall safety risk control level of subway operation.If the safety risks in the subway operation can be identified,analyzed and evaluated in a timely and effective manner through scientific methods and means,the necessary technical support and theoretical basis can be provided for the subway operation managers.Taking a subway as an example,this study identified,analyzed and evaluated the safety risk status in its operation process according to the relevant national laws and regulations as well as the requirements of industrial regulations and norms,in order to realize the hierarchical and standardized safety risk management in the whole operation process of this subway.(1)Identification of safety risk factors in subway operation process based on ISM.This study classifies and analyzes typical accidents in subway operation from the aspects of accident types,spatial distribution and influencing factors.The mechanism of all kinds of accidents was analyzed with the method of explanatory structure model(ISM),and the ISM model of influencing factors of subway operating accidents on the fourth floor was established.The following conclusions were drawn: the vehicles and environmental factors on the top floor were the direct causes of subway operating accidents.The second floor power supply,line,access number,civil engineering and mechanical and electrical factors are indirect reasons;The third layer of human factors is an important reason;The management factors at the fourth level are the underlying causes.This provides technical support for the establishment of risk evaluation index system.(2)Establish a subway operation safety risk evaluation index system based on the comprehensive weighting method of relative entropy.Based on the operation practice of a subway,according to the relevant principles of the safety risk evaluation index system and the ISM model of influencing factors of subway operating accidents,the evaluation index set was selected,including 4 first-level indexes,7 second-level indexes and 32 third-level indexes.The relative entropy synthetic weighting method(G1 method)combined with entropy weighting method was used to optimize the weight of the three-layer index factors,so as to establish the safety risk evaluation index system of subway operation.(3)Establishment and application of extension risk assessment model for subway operation safety.Combined with the established safety risk evaluation index system for subway operation,a safety risk evaluation model for subway operation was established based on the extension matter-element theory.The model was applied to a subway,and the result was that the safety risk level was the second level and the operation safety level was the safer.Finally,through the analysis of the evaluation results,specific preventive and improvement measures are put forward for each operation link with a higher risk level.