Analysis Of Steel Frame With A Key Column Destroyed

With the rapid development of economic,the refinement of calculation methods and the appearance of the new structure,more attentions are drawn to the security of structural buildings.Since the progressive collapse was resulted from the gas explosion in Ronan Point apartment building in 1968,in order to prevent progressive collapse,European and American researchers had done much research in the performance and design methods of the structure on this issue in the past 40 years and made considerable achievements.However,codes in China have not yet provided details on the resistance of progressive collapse . They are still relatively insufficient and have a lot to do.In this paper,the performance of the steel frame with different parameters in the progressive collapse situation is analyzed by using the software SAP2000.The main contents of this paper are as followed:(1) The current research status and the contents of main foreign design codes about the progressive collapse prevention are introduced.The software SAP2000 is adapted to analyze the behavior of steel frame losing key columns,whose results are validated by comparing with experimental results.(2) The deformation and internal force of steel frame after the removal of columns at different positions are studied by instantaneously applying load method.The influence of loading time on internal force and deformation is studied.The development process of the internal force and deformation of the adjacent nodes and adjacent beams,and the distribution of plastic hinges are studied after the removal of key column.The most unfavorable location of the node is found by comparing the performance of the destroyed structure.(3)The effect of connection stiffness on the internal forces,deformation and the capacity to resist progressive collapse is discussed.The reasonable connection stiffness is proposed by comparing the internal forces and deformation of the damaged structure with the hope of providing basic reference to the progressive collapse design.The research suggests that the capacity to resist progressive collapse is related to the position of removal column.The failure column near to the side span and the upper story,the ability of the structure to resist collapse can be improved.When the column fails immediately, the maximum response of the structure is reached.Higher connection stiffness provides higher capacity to resist progressive collapse.