Computing System In The Temperature Distribution And Reliability Analysis Of Concrete Girder Bridges Under Standard Fire

After the1990s,With the speeds up of China’s urbanization trend, highwayconstruction has made great achievement. Which is associated with all kinds ofbuildings andBridges fire accident, and cause huge economic losses to the so-ciety. Fire on the structure of the bridge itself may lead to serious safety threa-t and even bridge collapse risk. So it is necessary for us to have analysis andresearch the fire resistance of the bridge structure system, It also has great res-earch value. to evaluate the safety, applicability and durability of fire damage-dreinforced concrete of the bridge structure.In this paper,a systematic summary of the heat conduction coefficient, spec-ific heat,mass density,and thermal expansion coefficient thermal parameter calc-ulation resultsof concrete and steel; Contrast summary both domestic and inter-national about the degradation regularity of mechanical properties of the concr-ete and steel after high temperature, such as elastic modulus, with easy langua-ge program compiled "concrete, reinforced thermal parameter calculation systemv1.0"," calculation system v1.0for concrete after high temperature mechanicsperformance index" and " calculation system v1.0for steel after high temperat-ure mechanics performance index ",After that, the resultsof scholars are turned into area chart;To screening out the suitable mechanical parameters that are re-quired on concrete structure thermal structure analysis.Using the standard heating up curve for fire heating curves,Transienting m-ethodsthat are on three sides by the fire without flange platethe of fire temp-erature field innonlinear analysis for box girder cross section and T beam cro-ss sectionand get thetemperature field distribution of fire.Introducing the solution called hierarchical to research the reduced coeffici-ent ofof the post-fire concrete structure，The papers also take the loss of bon-ding power reduction factor between steel and concrete caused by the fires andhigh temperature intoaccount for calculating the resistance structure after fire.On the basis of the structuralreliability about resistance calculation,Taking the concrete strength reduction and the reinforced adhesive power losses reduction factor into account, I get the correction for mula of reliability calculation of rei-nforced concrete beam structure after the fire. According to the correction form-ula,I also have a calculation and analysis about the resistance of structural reli-ability before and after the fire,and compared the structure reliability indicators,This calculation method is simple and practical.