ABSTRACT
Risk assessment of bridge fire safety usually receives less consideration than that of building or tunnel structures in civil engineering. This paper sets up a complete bridge fire risk assessment process and integrates the advantages of traditional quantitative evaluation method and qualitative evaluation method by innovatively introducing fuzzy mathematics into the analytic hierarchy process. First, a multilayer risk evaluation index system of bridge fire safety is proposed based on risk identification process. The evaluation indexes are established based on the statistic data on the causes for fire accidents of bridges and a scenario analysis is used to find the typical fire scenarios. Second, the AHP-FCE method is presented for evaluating the risk probability and risk loss of the bridge fire safety problems. The weighting coefficients of the indexes are calculated through the Analytic Hierarchy Process (AHP) and fuzzy consistent judgment matrix is introduced to avoid the consistency verification. The Fuzzy Comprehensive Evaluation (FCE) is used to realize the multilayer comprehensive evaluation and the Zadeh operator is used to consider the influence of those important factors to the risk probability and risk loss. Third, the risk level of bridge fire safety is obtained by the integration of the risk probability and risk loss values through the 2-dimension evaluation model with the basic risk control principles. As a case study of engineering application, the risk level of the bridge fire safety is assessed by the proposal AHP-FCE method according to the practical conditions of the Academician Road Bridge.
