Ductility Requirement And Mechanism For Progressive Collapse Resistance Of Reinforced Concrete Frame Structures

The collapse cases, due to terrorist attack, fire, construction defect and gas explosion, are more and more. Structural progressive collapse caused serious loss of life and property increasingly, it has become a serious threat to public safety problem. Many practicing engineers and academic researchers have been engaged in the prevention of progressive collapse since the gas explosion accident of the Ronan Point apartment building in1968, and design guides for preventing progressive collapse have been put forward, such as the Tie Force and Alternate Load Path methods. However, research in the realm of progressive collapse in China is still not in sufficient. Although the codes criteria about the resistance of progressive collapse had been provided, it not perfect to design and still have a lot to do in this issue.In this paper, a review of the current state for the progressive collapse prevention are provided, and the object of study is the typical reinforce concrete frame structure. Using analytic method analyzes the whole process of the vertical continuous collapse,the corresponding Anti-Progressive collapse mechanism,the resistance capacity of the progressive collapse and calculate the resistance of various mechanisms. This method is also applicable to space reinforced concrete frame structure, the result compared the experiment of the structure progressive for space frame structure.Point out the view that the ductility requirement between the resistance of the structure progressive collapse and the structure of seismic are different. Given the definition and method of calculation for the ductility coefficient βR.Discuss these parameters influent the capacity of structural progressive collapse and the ductility,which is the ratio of span to height,the lever coefficient,the form and number of reinforcement. The current finite element analysis software ANSYS is used to calculate the result of a typical plane reinforce concrete frame structure model in progressive collapse,the results of it is coincide to the theoretical analysis.Then calculate the result of the experiment for space reinforce concrete frame structure,the results indicate that the analysis of theoretical and the experiment is similar.Based on the research of that, the measures and suggestions for design, the requirement of ductility for the resistance of the progressive collapse are put forward as the frame structure for the seismic design.