Study On The Influence Of Bearing Capacity Of Fire On Steel Arch Bridge And Fire Alarm System

Steel Arch Bridge is a not so old type of bridge, which rose from the IndustrialRevolution and got a rapid development in the following centuries. Its beautifulshapes and strong impressions made it a popular type of arch bridge. So it was widelyconstructed in China. As an important component of modern transportation system,Bridge was getting more and more attention. Once a bridge was on fire, it will causeserious economic loss and abominable social influence. So it was very important tostudy Steel Arch Bridge’s after-fire mechanical properties and automatic fire alarmsystem.This paper aims to study the overall mechanical properties and alignment changeof Steel Arch Bridge. Finite element analysis software ANSYS is applied to buildmodel and do the thermo-structure analysis of Steel Deck Arch Bridge when somecolumn was on fire. This paper also put forward a feasible automatic fire alarmsystem. The following researches have been carried out in the dissertation:①Summarized the rules of the material properties and mechanical propertiesunder fire condition, and the model of stress-strain relationships for high strengthensteels under high temperature；②Based on foreign literature’s experiment results, an ANSYS thermal andstructure finite model was established to get calculated results. The calculated resultsare identical with the experiment results③Studied the variation law of deformation of arch rib and bridge deck,.Evaluated influence scope when some column was on fire.④Studied the variation law of internal force of column and arch rib.⑤Studied yield time and critical temperature of chords on three differentpositions of arch rib.⑥Put forward a feasible automatic fire alarm system for bridge.