Comprehensive Evaluation And Analysis Of Risk Factors For Subway Safety Construction

At present,as China’s urban subway construction is gradually entering a steady,orderly and rapid development stage,most of the subway works are buik in the urban environment,and the surrounding environment is very complex,whose underground pipelines,gcological and bydrological conditions are comples and diverse,and there are various methods of construction and construction.Therefore,accidents of varlous types of gubway construction often occur frequently.There are a lot of unforescen risk factors in the process of construction,which aggravate the hiddcn danger of construction.Inthis context,this paper tried to apply entropy weight method and LEC evaluation methed to safety evaluation of subway construction,which comprebensively analyzes the influcnce of uncertain and unknown factors in constroction system on construction risk,and establishes a comprehensive evaluation model based on entropy weight method and LEC evalustion method,so as to improve the accuracy and rationalsy of suway construction risk factors evaluation.The main conclusions obtaired after analysis,cakulation and research are:(1)Statistics and analysis of major safety accidents in China’s subway for 2001-2016 years.On the basis of judgement and analysis of dangerous sources and dangerous factors in subway construction,from the main aspects of the risk of destruction to surrounding environment,risk of retaining structure,risk of foundation pit slide collapse,risk of basement uplift,risk of supporting instability,unsafe behavlor of construction personnel,ursafe behavior of other personnel,etc,the risk evaluation Index system is constructed.(2)The concept of combined weight is discussod in detail,which combines the LEC method and entropy weight method to calculate the weight of the evaluation index,and constructs a subjective and objective weight evalustion method.Then,the Introduction of the concept of unkpown rationala number to the LECevalustion method is expounded,which has made two improvements to the value of E and the value of D Finally,the combined weighting method combining the two improved LEC method and entropy weight method is used to determine the weight of each evaluation index to estiruate the risk factors of subway construction.(3)The combinedweights established Inthis paper are applied to the safety evalution of the constraction risk of Weidou Road Station in Xi’an Mctro Line 6,and the resuls show that the weight of(R3)foundation pit sliding is the largest in the whole environmental risk,whose weight is 0.1891.Among them,in the risk thinning layer,the untimely dismantling and discontinuity of the(R36)support erection is the largest risk weight in(R3),and the weight is 0.5251.Therefore,we should pay more attention to the above risks in the construction process.Compared with other engincering projects,the sections of the urban subway are mostly denscly populated and well developed sections,which determines that the risk of subway construction safcty has its obvious particularity.Through dctailed analysis and research,the subjective and objective factors that affect their safety construction risks are gererated,this paper makes more scientific improvements to the risk figures in the comprehensive evaluation.Combined with specific project cases,this paper made dctailed calculation,rigorous,scieraitic and accurate,which has certain reference significance for safety evaluation of subway construction.