Study On Risk Evolution Mechanism And Control Measures Of Expressway During Nighttime Maintenance Construction

The safety problem of expressway nighttime maintenance construction is an important frontier research and practical problem in the field of expressway construction.Previous research mainly focused on the identification and evaluation of risk factors in expressway daytime maintenance construction operations or construction operations of new construction,renovation and expansion.There is still a lack of systematic research on the quantitative analysis of expressway nighttime maintenance construction operation risk.This article aims to use Structural Equation Model(SEM)and Bayesian Networks(BN)to carry out the risk analysis of expressway nighttime maintenance construction operation.Qualitative and quantitative analysis,explored the risk evolution mechanism of operation risk in the workzone,and proposed targeted risk control measures.The main research contents of the full text are as follows:(1)Through the actual expressway nighttime maintenance construction,the construction work content,workzone definition and length division are determined.The traffic characteristics of the workplace are analyzed from five aspects: driver,vehicle,road,workzone and environment.It expounds the advantages and disadvantages of nighttime maintenance construction from five aspects: transportation,construction,human,economy and environment.(2)Literature reviews,accident data analysis,questionnaire surveys et al.were used to extract 5 first-level indicators and 36 second-level indicators that affect nighttime maintenance and construction operations.Conduct questionnaire surveys around relevant indicators,and use Exploratory Factor Analysis and Confirmatory Factor Analysis to cross-validate the data.The constructed SEM has a good fit,except that the regression coefficient of the environmental dimension to the vehicle dimension is not significant,and the other dimensions have significant effects between each pair.Identify the 10 most noteworthy Second-level indicators,the degree of impact of the five first-level indicators on operational risks is in order of driver,workzone,vehicle,road and environment.(3)Perform BN analysis on the acquired data based on the research of SEM model evaluation.It is concluded that the driver,workzone and vehicle are the top three factors with the highest risk of occurrence under the background of the establishment of the evidence hypothesis.The sensitivity of the environment,roads,workzone,vehicles,and drivers to the risk of traffic accidents decreases in the process of sensitivity analysis.In the process of intensity analysis,the driver is the parent node with the greatest impact on the risk of traffic accidents.(4)Based on Dynamic Bayesian Networks(DBN),a risk evolution model for expressway nighttime maintenance construction operations was constructed,and the evolution mechanism of the “L type” curve of expressway nighttime maintenance construction operations risk was obtained,and the operation risk evolution reasoning was carried out by setting evidence nodes.(5)According to the characteristics of the expressway nighttime maintenance construction operation process and risk transmission,the risk interruption method of the risk transmission interrupter is proposed,and the classification and mechanism of the interrupter are briefly introduced,and the four-level interruption defense strategy is carried out based on examples.Application analysis,examples of risk management and control measures corresponding to interrupters in each operation stage are illustrated.