Progressive Collapse Analysis Of Reinforced Concrete Frame Structures

Structure safety is very important in structural design. But great deals of engineering failure are related with the accidentally loading effects which are not considered in design of structures. In recent years the knowledge about accidental loading mainly came from earthquake and terrorist attack, apart from which fire, hurricane, construction defect, human mistakes and gas explosion resulted in the structure failure. Since the progressive collapse damage was resulted from the gas explosion in Ronan Point apartment building in 1968, a widespread attention to the collapse-resistant performance of structures and its design methods has been paid. North America and Europe have conducted more than 30 years of research of the progressive collapse and developed relevant design codes and design guides. However codes in China have not yet provided details on the resistance of progressive collapse, it still have a lot to do in this issue.In this paper, corresponding design specifications for the progressive collapse prevention in the main foreign design codes are summarized, and the capacity to resist progressive collapse of a reinforced concrete frame structures due to the loss of a column is analyzed. The structures which collapse will come into plastic stage or even catenary stage and will have relatively big deflections, so the material nonlinear behavior and the geometric nonlinear behavior need to be considered in progressive collapse analysis.Now commonly used finite element analysis program Ansys , SAP2000 and so on have some limitations in this paper, and using these programs to analysis the examples in this paper are very time-consuming and resouce-consuming, and some problems in meshing and model may result in inaccurate results.In order to find a simple, applicable and convenience method to do this, a program using FORTRAN language has been developed and it can run in Windows environment. The program used Finite Element Method, in this program, the matrix considered material nonlinear and geometric nonlinear resulted by relatively big deflection. The program can be used to analyse the capacity to resist progressive collapse of plane reinforced concrete frame structures. in this paper, the program is used to calculate a 4-bay and 4-story plane reinforced concrete model frame structure in a progressive collapse experiment, the results indicate that the program are effective. Then the program is used to calculate some examples in order to study the difference of the capacity to resist progressive collapse of the reinforced concrete frame structures due to the column failure occurred in different part.