Research On Dynamic Risk Assessment Of Gas Pipeline Failure In Urban Comprehensive Pipe Gallery

As an urban infrastructure that accommodates urban electricity,drainage,gas and other municipal pipelines,the safe and stable operation of urban comprehensive pipe corridors is of great significance to the sustainable development of the city.The national "14th Five-Year Plan" proposes to promote the construction of underground comprehensive pipe corridors,and the urban comprehensive pipe corridors will be further developed in the future,and the safe and stable operation of pipe corridors has become the focus of attention.With the operation of various pipelines after the completion of the urban comprehensive pipe gallery,the potential risks and hidden dangers increase.Although the gas pipeline is located in an independent cabin,the flammable and explosive nature of the gas,once a gas leakage and explosion accident occur,it will not only damage the gas chamber,but also cause damage to the entire comprehensive pipe gallery,affect the entire urban lifeline system,and threaten the safety and stability of the city.Therefore,the risk assessment of urban comprehensive pipe gallery gas pipelines is of great significance to ensure the safe operation of cities.This paper conducts research on the dynamic risk assessment of gas pipeline failure in urban comprehensive pipe gallery,and the main contents are as follows:(1)Analysis of risk factors of gas pipeline failure in comprehensive pipe gallery.Through literature inquiry,field research,expert interviews,accident case analysis and other methods,the main reasons for the failure of the gas pipeline in the comprehensive pipe gallery were determined.Taking pipeline failure events as the top event,the accident tree model was established,and the main risk factors leading to the failure of gas pipelines in the comprehensive pipe gallery were systematically identified,and the failures of ordinary buried gas pipelines were compared and analyzed.(2)Study on the probability of failure of gas pipeline in underground comprehensive pipe gallery.The composite pipe gallery gas pipeline failure risk bow model is transformed into a dynamic Bayesian network(DBN)model by mapping transformation algorithm,and the calculation model of the probability of failure accidents of comprehensive pipe gallery gas pipeline failure is established,and the conditional probability table is improved by the Leaky Noisy-or Gate model,and the temporal changes of pipeline failure probability and different accident consequence probabilities are inferred.(3)Research on the consequences of gas pipeline failure accidents in the comprehensive pipe gallery.The calculation framework of the failure consequences of the gas pipeline in the comprehensive pipe gallery was established,the types of failure accident consequences were analyzed,and the accident consequences model and the injuries caused by various accident consequences were established.According to the actual parameters,the consequences of typical gas pipeline failure accidents such as jet fire and vapor cloud explosion were quantitatively calculated and analyzed.(4)Research on the quantitative assessment method of dynamic risk of gas pipeline in comprehensive pipe gallery.Based on the calculation model of individual risk and social risk of comprehensive pipe gallery gas pipeline,the quantitative risk calculation framework of comprehensive pipe gallery gas pipeline is established.The allowable risk standard of comprehensive pipe gallery gas pipeline is proposed,and the rationality of the established dynamic risk quantitative assessment method of comprehensive pipe gallery gas pipeline is verified through case analysis.