Fire Response Analysis Of Large Span Steel Structures

With the development of Chinese economic and comprehensive national, Large-span steel structures have been widely used in China by its virtue of magnificent shape and enormous interious space etc. Large-span building is widely used within public buildings.Large-span structures are often used for such buildings as theatre, gymnasium or exhibition hall where the dense of people is high. The fire safety of large-span building structure must be researched by structural engineer. However,the steel material is weak in fire resisting,and the aesthetic demand always leads to numerous cost. Moreover,large-span steel structure could not adopt the fire-resistance design method for common steel structures.Nevertheless the study of large-span structures centralized on their static and dynamic behavior, design method and construction method, there are few studies of fire-resistance behavior and the method of calculation,and they are very few involved in the specification.To insure the fire-resistance of large-span structures when fire occurs, the analysis of fire-resistance is very important.The article introduces that the method of analysis of large-span structures such as grid structures and latticed shell structures.It will give the suggestions for fire resistant design of the project proposal. The article completed the following tasks:(1) By the whole process of analysis of the gird structure, It gets the refractory time and the critical temperature of gird structure.It also gets the conclusion that the poles have the stage of unstable failure.If it cann't control the poles of the first failure, it will cause a "chain reaction" resulting in more poles failure in a large area.(2) It find that the latticed shell structures' unstable failure are brittle failure by two types of analysis of fire resistance.It is said that the structure will be difficult to resist loads once the occurrence of certain important poles damage.