Research On Risk Evaluation And Control Of High Altitude Railway Tunnel Construction

In recent years,the country has deeply implemented the “Belt and Road” strategy and comprehensively strengthened the construction of high-altitude railways.Affected by the rolling mountains,a large number of tunnel projects have to be built.However,most tunnel projects have more complicated typical geological conditions,unfavorable climatic conditions,large construction investment cost,and long construction period,which makes the construction of high-altitude railway tunnels more risky than traditional general tunnel construction.Therefore,it is necessary to carry out high-altitude railway tunnel construction risk assessment and control research.First of all,the 125 typical tunnel construction accidents from 2005 to 2019 are counted to form a tunnel construction accident statistics table.Based on the data statistics,the four aspects of location distribution characteristics,regional distribution characteristics,accident levels and type characteristics are adopted.The analysis summarizes the types of accidents,the direction of risk sources,the causes of accidents,and the laws of accidents,etc,to provide a reference for the identification of construction risks of high-altitude railway tunnels.Secondly,in accordance with the relevant laws and regulations of tunnel construction,the brainstorming method is used to identify and construct 7 aspects of natural conditions,typical geology,construction safety management,tunnel characteristics and structural design,construction equipment,construction technology and construction personnel.The risk assessment index system for high altitude railway tunnel construction is introduced.Then,combined with the relevant risk assessment and management specifications of tunnel construction,literature research conclusions,visit investigation conclusions and high-altitude railway tunnel construction characteristics,etc,the levels of each index in the high-altitude railway tunnel construction risk evaluation index system are divided and given high Risk level classification standard adopted in the risk assessment of the construction of the altitude railway tunnel.According to the established risk acceptance criteria,different pre-control measures are taken for different risk levels.Finally,by referring to a large number of domestic and foreign literature on risk assessment methods,combined with the construction characteristics of high-altitude railway tunnels,a fuzzy network analysis and evaluation method was used to construct a high-altitude railway tunnel construction risk assessment model.Through an empirical study on the construction of a tunnel,the results show that the construction risk level of a tunnel is Class I,which is consistent with the field investigation and proposes control measures for higher risk sources.Provide a reference for the construction of tunnels in the same type of high altitude cold area.