Study On Construction Safety Risk Assessment Method And Application Of Highway Tunnel Engineering

With the rapid development of highway transportation industry in China,the construction scale of highway tunnels is increasing.The construction process of highway tunnels is dynamic and changeable with high concealment,difficult construction,long construction period and large investment.There will be many uncertain factors and increasing construction safety risk issues in the tunnel construction process.Therefore,it is of great practical significance to carry out research on risk assessment of road tunnel construction.In this paper,we carry out the research on the safety risk assessment of highway tunnel construction with methods of literature research,field investigation,expert survey,theoretical analysis and simulation.Based on the Jinzhupa Tunnel of YA19 project department of Puyan expressway,carrying out the safety risk assessment and application of highway tunnel construction.The research studied on the direction of refinement,quantification or semiquantification.The main work and results are as follows:(1)Collecting and sorting out the domestic tunnel construction risk accidents and according to guidelines and specifications related to the tunnel safety risk,various risk factors affecting the safety of tunnel construction were analyzed.The overall risk assessment system of construction safety is established with geological conditions,construction scale,climate and terrain conditions,construction conditions and data integrity as main indicators.AHP is used to construct the pairwise judgment matrix of overall risk assessment and calculate the subjective and objective weight of each assessment index.Using AEW to solve the objective weight of index.Based on the idea of maximum deviation for combination assignment,getting a more reasonable combination weight.(2)Normalizing the piecewise linear part of the traditional attribute measure interval function,proposing a method of calculating single index attribute measure using piecewise normal distribution function and introducing the homogenization coefficient to transform the measure interval into real value.In order to get the overall risk level of tunnel construction safety,using the method of index combination and single index measurement calculation to get multi-attribute measurement and analyzing attribute recognition based on confidence criterion.(3)A coupling matrix of WBS and RBS is established for refined risk identification of highway tunnel construction.By analyzing the risk factors of tunnel accidents,selecting the independent risk factors as fault tree bottom event,and constructing the T-S fuzzy fault tree structure of collapse accident to form a special risk assessment model for tunnel construction safety.(4)A Bayesian network model is built based on T-S fault tree to quantitatively analyze and diagnostic reasoning on risk events and derive the probability of occurrence of risk events.Aiming at the importance of the risk source to the accident,the sensitivity analysis of the root node is conducted to provide a basis for risk event assessment and identification of significant risk sources.