Study On The Risk Assessment Method Of Railway Tunnel Complex System Based On Bayes And Complex Network

At present,China has become the largest,most numerous and most difficult country in the world.Along with our country the construction of the railway transportation network,high temperature,cold and strong wind,extreme conditions such as high altitude,and karst conditions such as high stress and strong regional railway tunnel construction is becoming more and more,especially railway tunnel under complicated geological conditions)in the process of its long-term operation,face many threats,once fatal diseases or structural failure,tunnel light,led traffic disruption,or lead to major accidents such as elderly,this will seriously affect people's lives and property.Therefore,it is imperative to study the operation risk assessment and control of railway tunnel under complex geological conditions.However,at present,there are some problems in the safety risk of railway tunnel system during the operation period,such as insufficient understanding of the interaction of risk factors,insufficient quantitative level of assessment methods,and unscientific assessment results,etc.Therefore,this paper studies the risk assessment methods during the operation period of railway tunnel.The main work is as follows:(1)Through literature research and case investigation of railway tunnel accidents,this paper analyzes the risk assessment factors in the operation period of railway tunnel,puts forward the risk assessment method of the complex system of railway tunnel in the operation period with six factors comprehensive assessment,and reveals the action mode of multi-risk factors in most tunnel operating accidents.(2)The index system of railway tunnel operation risk assessment is established,and the structure diagram of bayesian network for five major accidents in the operation period is constructed.Aiming at the difficulty of obtaining the prior probability,the method of obtaining the prior probability from the historical data is adopted.The method of combining Noisy-Max/Min algorithm with expert investigation method is used to determine the conditional probability table.Using Netica software,the bidirectional probability of bayesian network is calculated.(3)To build the railway tunnel complex system operating accident cause of network,the connectivity and risk of density,heterogeneous average shortest path,heterogeneous nodes center node and accident center degrees five characterization parameters,by comparing the old and the new parameters to build network density values,to verify the new parameters for railway tunnel operational risk analysis of feasibility,and on the basis of the calculation formula deduction quantifiable risk consequences.(4)Taking guan jiao tunnel as an example,the risk assessment model is comprehensively verified.Based on the quantifiable assessment results,the quantifiable risk control measures are put forward,which verifies the rationality and advancement of the risk assessment model.