Research On Construction Risk Assessment Of Through-Type Concrete Filled Steel Tubular Arch Bridge Based On Bayesian Network

Concrete filled steel tubular(CFST)arch bridges are increasingly being constructed in road transportation networks due to their high bearing capacity,elegant appearance,and strong adaptability.The through-type CFST arch bridge,which has the advantages of large clearance under the bridge,low deck elevation,and significantly reducing the amount of bridge approach work,has also been well used.However,in the process of bridge construction,due to the existence of many uncertain risk factors,construction accidents are still common,seriously affecting the safety of the country and society,and bringing extremely serious economic losses.To ensure the safe and smooth completion of engineering construction projects,it is necessary to carry out construction risk assessment work.This article focuses on the construction risks of the supported steel tube concrete arch bridge and conducts research on bridge construction risk assessment.The main research content is as follows:(1)Drawing on the current research results of bridge construction risk assessment,based on the theory of construction risk analysis,this paper proposes the identification basis of construction risk source,analyzes the construction risk factors with the decomposition of construction operation procedures as the main line,and establishes a list of risk source for risk assessment in combination with expert opinions,on-site survey and other risk identification methods.(2)A combination of quantitative and qualitative methods is used to establish the classification criteria for risk probability and risk loss level.A method for determining risk probability and risk loss level is proposed based on fuzzy theory,and an improved risk level evaluation matrix is established using the ALARP criterion.The risk matrix method is used for risk level assessment.(3)According to the characteristics of mutual influence and transmission between risk source,a dynamic assessment of construction risks is proposed.First,Decisionmaking Trial and Evaluation Laboratory(DETAMTEL)is introduced to identify the risk source with transfer effect,then the transfer network of risk source is constructed based on the transfer theory of risk source.Finally,the dynamic assessment model of construction risk is established by combining Bayesian network,and the Bayesian network reasoning function is used to conduct the dynamic assessment of construction risk according to the assessment model.(4)Based on a certain bridge as a supporting project and combined with its structural characteristics,the construction risk source was identified,and the corresponding risk level assessment of risk source was completed.The construction risk dynamic assessment model was established.With the help of Bayesian analysis software Ge NIe,the reasoning analysis was completed,and the major risk source and major risk source transmission paths were identified.On this basis,the risk control measures were proposed for major risk source.