Study On Safety Risk Management Of Subway Tunnel Construction By Mining Method

With the rapid development of Chinese economy, the process of urbanization is accelerating and urban population is increasing, which cause great pressure on city traffic.The city subway get a rapid development because it is effective to alleviate traffic problems. Mining method is widely used in the construction of subway, because it is suitable for the city intensive areas, especially suitable for the construction of the rock stratum.However, most of the city subway is located in the city center, the construction environment is complex and changeable, which leads to the frequent occurrence of subway construction accidents.Therefore,strengthening the management, taking the risk control measures can not only contribute to the subway construction in the construction stage, but also avoid property loss of state and society.Firstly, this paper expounds mechanism of safety risk occurrence in subway construction,analyzes the reasons of risk occurrence and mainly study on four types of risk source, including reconnaissance design, geological environment, construction technology and construction management. The combination between work breakdown structure and fishbone diagram adopted to identify risk.Mining method can be divided into shaft construction, primary support, tunnel excavation, secondary lining and auxiliary construction, etc.Then, analyzing risk through fishbone diagrams from four types of risk sources for each stage. This paper finally determines about83 safety risk factors that may occur in the construction of the subway tunnel by mining method.Secondly, according to safety risk factors for the subway construction by the mining method,the risk matrix method based on the fuzzy theory is used to establish the risk assessment model,which consider risk probability and risk loss at the same time.Through the investigation by experts,estimating the probability of occurrence of risk and the loss of the risk faintly and determining the risk rating through the risk matrix method.Taking different control measures to treat risks according to the risk acceptance criteria for 5 level.Finally, based on practical engineering, this risk identification and assessment models has be applied to verify its validity and applicability. Specific measures are taken to deal with heavy risks. The research can provide reference for other subway construction like this.