Risk assessment model for city gas system

Gas system is an important part of the city lifeline system; it mainly includes gas pipelines and regulator stations. The risk of regulator station is also an important component of the gas system risks, in the previous risk assessment of the pipelines, it is only considered in the factors of third-party damage as ancillary facilities to the ground. In this paper, through a large number of accident investigation, and based on the analysis of risk and harmful factors for the gas regulator stations and pipelines, we exploit probability importance degree and structure importance degree in fault tree to amend assessment indicators, we use fuzzy comprehensive evaluation method to establish an overall risk assessment model which is suitable for the city gas lifeline system. © 2009 ASCE.