Fire Resistance Performance of Cables for In-service Cable-stayed Bridges in Vehicle-induced Fire Accidents
;The cable is susceptible to corrosion,vehicular-induced fire,and other detrimental effects during bridge services.The current studies on the structural safety assessment methods of in-service cable-stayed bridges under complex environmental conditions are not complete.Therefore,this study focuses on the cables of a cable-stayed bridge with a service life exceeding 25 years and conducts tensile tests at elevated temperatures to obtain corresponding degradation patterns and computational models.After defining the degradation rule of in-service cable at high temperatures,a fire source model caused by a 300 MW tank car was created using the Fire Dynamics Simulator.The heat transfer analysis model and the structural model of the in-service cable-stayed bridge were established using ANSYS,and structural thermodynamic coupling analysis was conducted.The results indicate that under the most unfavorable conditions,the fire from the 300 MW oil tanker leads to the failure and rupture of three groups(six)of cables near 1/4 of the span of the bridge,and the failure times of the groups are 551 s,592 s,and 1 064 s,respectively.Owing to the effects of the bridge dead weight,the maximum deflection of the main girder decreases by 0.08 m,the deflection span ratio is 1/1250,and the maximum deflection rate is 9.6 mm·min-1.All the outcomes are within the limits of the JTG/T D65-01-2007 standard.The 300 MW tanker truck fire cannot cause a complete collapse of the entire bridge structure but results in severe and irreversible damage to the cable.The study's findings provide a reference for structural safety analysis and evaluation of in-service bridges in complex environments.
bridge engineeringin-service cablefire testfire resistancecorrosion and fire effects
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