Finite Element Simulation Of A Composite Steel-Concrete Bridge Exposed To Fires

In recent decades, because of the rapid development of urban ground transportation systemsas well as increasing transportation of hazardous materials (flammable materials, spontaneouslycombustible materials, poisonous materials, etc.), bridge fires have become a concern in thepublic. Bridge fires are low-probability but high-consequence incidents. It is not unusual thatbridge structures are damaged or even collapsed in the high temperature caused by fire. Thisseriously threatens people’s security and influences the normal traffic. In regard to the individualbridge fires, the bridge structures response to the fire was studied by domestic and internationalacademics. Although the problem of bridge fire is serious, there are not clearly ways to preventfires and better ways of designing against failure during fire exposures. Post-fire inspection,evaluation, and fire resistant design are not enough. The need for further research in the area ofbridge fire is expressed.Composite steel-concrete bridges are widely used in the highway construction at home andabroad, but because the steel resistant, this bridge is prone to collapse in the fire. Base on oil tankfire accident occurred in the MacArthur Maze freeway in United States on April29,2007, thebehavior of composite steel-concrete bridges exposed to fires are researched in this thesis.Through ABAQUS finite element software thermal-structural analysis of the bridge approachused here gets fire resistant time. The mainly tasks in this thesis are as follows.1.The relevant literature of bridge fire is collected. The progress of the preventing fire studyin composite steel-concrete beams, fruits about properties of steel and concrete at elevatedtemperatures, the progress of oil tanker fire are summarized in this thesis.2.ABAQUS finite element software is applied to simulated transient state temperature fieldof MacArthur Maze I-580freeway that is on the effect of the oil tank fire. For increasing theprecision and convergence of simulation, the model is reasonably simple by changing3D to2Dtemperature field, and the Eurocode hydrocarbon fire is used on the full length of bridge.3.ABAQUS finite element software is applied to simulated thermal-structural analysis ofthe composite steel-concrete bridge. The vertical displacement time histories and eveydisplacement-time curves are obtained under the temperature field and pressure load, andcomprised by actually fire occurred.4. According to elevate fire resistant time, fire resistant and weathering construction steelsand fire resistant coatings two measures are used. ABAQUS finite element software is applied tosimulated thermal-structural analysis by two situations, and fire resistant times are delayed.Composite steel-concrete bridges exposed to oil tanker fires are mainly researched bynumerical modeling. The fire prevention carrying capacity of the whole process analysis methodof the restrain combination beam fire resistance is established, and the practical calculationmethod of the fire prevention design for the restrain combination beam is put forward to providethe fire prevention engineer.