Research On Construction Safety Risk Assessment Of Subway Project

With the rapid development of the city,the pressure on the ground transportation is getting bigger and bigger,and the construction of urban rail transit is put on the agenda.When underground transportation facilities facilitate people's travel and improves people's quality of life,subway construction projects frequently have accidents of different security levels,resulting in huge economic losses and casualties.Due to the technical difficulty,high concealment and many risk factors,subway construction will have serious consequences in the event of an accident.The study finds that in the existing subway manual risk assessment system,the identification of risk factors is not comprehensive,and the determination of index weights has strong subjectivity.Therefore,in order to objectively and reasonably evaluate the risk level of subway construction safety,this paper constructs a set of scientific and feasible subway construction safety risk assessment system with reasonable aim of determining risk indicators and optimizing combination weights.Through analysis and research,this paper mainly obtains two research results:one research result is based on the uniqueness of subway construction safety risk factors to identify risks: Firstly,the literature research method is used to analyze the index system constructed by most scholars,and the risk indicators of the criterion level are summarized;Secondly,it analyzes the accident mechanism of the four classic accident causal theories,and summarizes the advantages and disadvantages of various causal theories,to summarize the accident causation mechanism and risk factors of subway construction projects;Then,through the accident statistics,the law of accidents occurred in 2008-2018 is analyzed,and three types of accidents occur frequently.The causal maps are analyzed to determine the specific risk factors.Finally,according to different construction methods,the process analyzes the risk sources of each construction method.Therefore,a preliminary list of risk factors is obtained.Combined with the three-round Delphi method,the risk indicators are screened and optimized,and the risk evaluation index system is determined.The reliability and validity test determines that the constructed index system has certain credibility andeffectiveness.Another research result is to construct a construction safety risk assessment model for subway projects.In order to weaken the subjectivity of index weighting,the subjective weight is determined by network analysis method according to the mutual influence relationship between indicators.The objective weight is determined by entropy weight method,and the optimal combination weight is obtained by alliance game method.In order to preserve the integrity and accuracy of the expert evaluation information,a binary semantic model is used to comprehensively evaluate the safety risk level of the subway project construction,then the risk level is determined.Finally,taking the construction of Anzi East Station of Qingdao Metro Line 11 as an example,the risk level is evaluated,then analyzes the main risk factors and proposes countermeasures.It is found through calculation that the risk level obtained by the evaluation system is consistent with the actual risk level of the project,thus verifying the feasibility and scientificity of the model.