Safety Risk Assessment Of Hydraulic Tunnel Construction In Northwestern Alpine Region

Due to the imbalance in the temporal and spatial distribution of water resources in my country,vigorously building long-distance inter-basin water transfer projects is an important measure to solve the contradiction of water resources.The special geographical location and climatic conditions in the northwest alpine region have greatly affected the safety construction of long-distance water transfer projects.As one of the most important buildings in the water transfer project,the safety of hydraulic tunnels during construction It directly affects the safety construction of the entire water transfer project.Therefore,this article combines the engineering construction in the northwestern alpine region in recent years,and on the basis of theoretical analysis,the safety risk factors in the construction phase of hydraulic tunnels are analyzed separately from the horizontal work task breakdown structure and the vertical risk breakdown structure,and then obtains the safety risk factors of hydraulic tunnel construction through coupling analysis.In order to establish a safety risk assessment index system for hydraulic tunnel construction in the northwest alpine region.On the basis of reference to relevant codes and related data,the safety risk level of hydraulic tunnel construction in the northwest alpine region is divided,and the safety risk assessment model for hydraulic tunnel construction in the northwest alpine region is established under the guidance of variable fuzzy set theory.Combining engineering examples,using the established evaluation model to calculate the safety risk level of each tunnel section in its construction,analyze the important and difficult problems in the construction,and propose corresponding risk control measures.The thesis focuses on the safety risk assessment of hydraulic tunnel construction in the northwest high-cold area.The content mainly includes the identification and analysis of the safety risk factors in hydraulic tunnel construction,the establishment of the safety risk evaluation index system in hydraulic tunnel construction,the division of the safety risk level in hydraulic tunnel construction,the grading standard of the risk evaluation index,and the safety risk evaluation model of hydraulic tunnel construction.The main research results of this paper are as follows:(1)A safety risk evaluation index system for hydraulic tunnel construction in the northwestern alpine region has been established.Combined with the occurrence mechanism of safety risk factors in tunnel construction in northwest alpine region,this paper establishes the work task breakdown structure from the tunnel construction preparation stage,process stage,and final stage analysis,and establishes the risk breakdown structure from the consideration of internal risks and external risks,and combine the two to establish a coupled risk matrix,detailed analysis of safety risk factors in tunnel construction,and constructed a safety risk evaluation index system for hydraulic tunnel construction in northwestern alpine region,including 24 evaluation indexes.(2)The safety risk level of hydraulic tunnel construction in the northwest alpine region is divided.Combining relevant standards and regulations,the construction safety risk level of hydraulic tunnels in the northwest alpine region is divided into four levels: low risk(Ⅰ),medium risk(Ⅱ),high risk(Ⅲ),and very high risk(Ⅳ).Combined with the data,the classification standard of each evaluation index is determined.According to the risk acceptance ALARP principle,the acceptability of the risk is judged in order to better propose risk control measures.(3)A safety risk assessment model for hydraulic tunnel construction in the northwest alpine region is constructed.Combining the characteristics of construction safety risk factors in the northwestern alpine region,the improved G2 method is used to calculate the subjective weight of the evaluation index,the improved CRITIC method is used to calculate the objective weight of the evaluation index,and Optimize the weights through the game theory combination weighting method to obtain a more reasonable comprehensive weight of the evaluation index.Considering that the risk problem is a multi-index multi-level evaluation problem,this paper combines the variable fuzzy evaluation method to construct a safety risk evaluation model for hydraulic tunnel construction in the northwest alpine region.(4)Application of safety risk assessment model for hydraulic tunnel construction in northwestern alpine region.Taking the 7# tunnel project of the second phase of Yindajihuang Beigan Project as an engineering example,the major and difficult points in the construction of the project are analyzed,and the construction safety risk assessment model of hydraulic tunnel construction in the northwest alpine region is used to obtain the 7# tunnel construction safety risk.Level,which verified the rationality of the evaluation model,combined with the risk evaluation level of each tunnel section,and proposed targeted tunnel construction safety risk response measures.