Peformance And Reliability Study On Progressive Collapse Of RC Frame Structures Based On Pushdown Analysis

The progressive collapse of structures is regarded as a serious structure disaster.Resisting progressive collapse capability and reliability of reinforced concrete frame structure are analysed by the way of pushdown analysis method based on alternate load path. There are the specific research contents:SECTION I : By the means of analytical method, the progressive collapse resistance of frame structure with and without floor are analysed and calculated.Meanwhile, the finite element model is built by ANSYS to analyze and calculate the progressive collapse resistance of structures through pushdown analysis method based on alternate load path. The results of analytical method and finite element analysis are compared, and the analytical method is proved to be reasonable. What’s more, the effect of the bottom reinforcement and plate thickness on resisting progressive collapse capability of frame structures are analysed.SECTION II : With regard to reinforced frame structure whose top reinforcements of beams are cutthrough and not cutthrough, using the analytical method to analyze and calculate the progressive collapse resistance of beam mechanism and catenary mechanism. The definition of resisting progressive collapse ductility factor is put forward on base of ducility damand. When the top reinforcements of beams are cutthrough, it is in favour of enhancing the resisting progressive collapse capability and ductility.SECTION III : With Opensees and Matlab as the analysis platform, the procedure of the reliability of damaged structure adopting random pushdown analysis method is introduced. Aiming at the uncertainty of material performance,the resisting progressive collapse reliability of damaged structure is researched,whose column is removed according to the GSA advice. The reliability index can be used to estimate the structure resisting progressive collapse capability.