Risk Analysis Method For Confined Space Operation Of Metro Tunnel

Subway tunnel project is a high-risk project with complex operation environment,prominent safety hazards and easy to induce accidents.At present,subway construction risk management has problems such as ineffective resource allocation and difficulty in risk identification.Although modern construction technology has greatly improved the safety level of subways,the deepening of subway projects fineness puts forward higher requirements for subway construction risk management,in addition,researches on subway construction risk in china mostly starts with the accident itself,and rarely considers the risk from the perspective of confined space.Therefore,this paper aims to study the risk of confined space operation in subway tunnels for the purpose of controlling and reducing subway accidents.It has great significance on assisting the subway project to conduct risk control more effectively.Confined space operation system of subway tunnel itself has complicated structure and many operation procedures.This paper divides it into three subsystems: lifting and transporting operations,assembly and disassembly operations,and shield tunneling operations by the system analysis of subway shield construction.Based on the theoretical characteristics and application conditions,the system dynamics is applied to the risk analysis of metro tunnels in confined space operations.In order to realize the risk prediction and scientific control of the subway tunnel confined space operation,the SD model is constructed to simulate the risk evolution trend of the operation system.The main work of this paper is as follows:Firstly,according to the relevant specifications of confined space operation and the operational characteristics of subway tunnel construction,subway tunnel confined space operation is defined.In addition,according to the accident precursor theory and the safe iceberg theory,the accident mechanism of confined space operation is analyzed from the perspective of human-machine-environment-management.Secondly,according to the relevant confined space and tunnel construction operation specifications,the risk of metro shield operation in confined space is identified by theimproved JSA-SHEL risk identification method,and the risk system of metro tunnel operation in confined space is constructed,and the weight of risk factors is determined by employing DEMATEL method.Thirdly,employing the system dynamics theory and method to analyze the internal structure relationship of the subway tunnel confined space operation risk system,introduce the variables such as flow position and flow rate,and complete the construction of the system SD model.Lastly,according to the empirical research on the SD model,the evolution trend of system risk is predicted,and the risk management strategy is proposed from the simulation control of risk investment and risk variables.