Study On Safety Risk Management Of Subway Shield Tunneling Construction

With the rapid development of the economical society and increasing acceleration of urbanization process, the construction scale of subway project is continuously enlarging. Shield method has been widely used in subway tunneling construction with the advantages of mechanization and stratum adaptability. However, due to the complexities of construction conditions, there are a large number of risk factors existing in the process of construction. Especially in recent years, safety accidents in subway construction happened frequently, the problem of safety risk management has received more and more attention. Therefore, it is necessary to study on the safety risk management of subway shield tunneling construction.Firstly, according to the 40 typical safety accident statisitics of shield tunneling construction and accident-causing theory, a model of safety risk formation mechanism based on risk surroundings, risk factors, elements at risk and control measure is established. Then, this paper analyzed the occurrence cause and evolution process of risk events.Secondly, based on the construction technique features of shield method and safety risk formation mechanism, by using risk identification method, this paper identified 98 safety risk factors of subway shield tunneling construction. On this basis, 40 key risk factors are extracted by using principal component analysis, according to the subordination and hierarchical structure of risk factors, an evaluation index system of safety risk is established. Then, this paper constructed a model of safety risk evaluation based on factor analysis and fuzzy comprehensive evaluation, introducing the main process and methods of this model, provide a reference for case study. In order to cope with the key risk which have higher risk grade, this paper put forward a series of management measures, organization measures and economic measures. Meanwhile, on the aspect of technical measures, according to the safety risk formation mechanism, those key risk factors are classified into 3 groups, including risk surroundings, risk factors and elements at risk, putting forward with prevention and avoiding measures, controlling and adjustment measures, protection and strengthening measures.Lastly, a case study is used to demonstrate the applicability of the safety risk bill and evaluation model, in regard to 8 key risk factors, this paper came up with specific technical measures, which provides a reference for similar project in China.